Category Soviet Robots in the Solar System

The competition between the United States and the Soviet Union in the Cold War produced one of the greatest adventures of exploration in the history of humankind. As a by-product of military competition between the two countries in weapon delivery systems and laying claim to the propaganda ‘high ground’, both countries applied themselves to the conquest of space by attaching civil payloads to their rockets in order to conduct both human missions in Earth orbit (and to the Moon in the case of the US Apollo program) and robotic missions beyond Earth orbit to the Moon and planets.

This book describes the 20th Century history of the Soviet adventure in robotic exploration of the Moon and planets. Our chronicle includes just those missions launched by the Soviets into deep space whose objective was to explore the Moon or planets. It does not include missions sent into deep space to study the Sun or Earth – Moon space environment. Test missions launched beyond low Earth orbit with operating lunar or planetary spacecraft, such as the Zond series, are included. Launch tests carrying non-operating model spacecraft are not included. We have endeavored to provide a comprehensive and accurate account of all relevant missions conducted between the year 1958, the date of the first Soviet spacecraft launch attempt to the Moon, and 1996. the date of the last Russian deep space mission to be launched in the 20th Century. All missions that were assembled on the launch pad with intent to fly are included. Some launch attempts suffered explosions on the pad, or shortly after booster ignition, or at some point during the flight of the launch vehicle. The Russians were particularly beset by launch vehicle failures, most often involving the upper stages.

There are inconsistencies in the data reported both in Western and Russian sources on Soviet lunar and planetary missions. We have attempted to provide the best possible information based on the published data and on interviews conducted with Russian participants in the former Soviet space program. In some cases w’e have made judgments to select what appears be the most accurate.

Wesley T. Huntress. Jr.

Mikhail Marov January 31, 2011

Acknowledgments

Wesley Huntress sincerely thanks the Geophysical Laboratory of the Carnegie Institution of Washington for his emeritus position, and also the Jet Propulsion Laboratory of the California Institute of Technology, Director Charles Elachi and Chief Scientist Moustafa Chahinc, for their support. Much of this book was written during the time spent at JPL as a Distinguished Visiting Scientist. I would also like to thank several friends who provided assistance, including Viktor Kcrzhanovich. Sasha Zakharov and particularly my co-author Mikhail Marov. Most importantly. I acknow ledge the patience and understanding of my wife Roseann while I w orked on this manuscript.

Mikhail Marov expresses his thanks to the M. V. Keldysh Institute of Applied Mathematics where he has worked for nearly 50 years as an Institute staff member involved essentially in all major endeavors of the Soviet robotic and human space program, and where he served as Scientific Secretary of the distinguished Space Research Council of the Soviet Academy of Sciences (MNTS Kl) that w as hosted by the Keldysh Institute while Mstislav Keldysh, its Director, and President of the Academy of Sciences, was Chairman of the Council. 1 would like to thank all my colleagues in the organizations of industry and Academy of Sciences, in particular in the S. P. Korolev Rocket-Space Corporation Energiya and Scientific-Industrial (NPO) Lavochkin Enterprise with whom 1 worked on space activities resolving numerous problems. I also thank my Russian friends who helped to find out and/or clarify historical data for this book, including Victor Legostaev, Vladimir Efanov. Igor Shevalev. Yury Logachev. Arnold Selivanov and Sasha Zakharov. Special thanks to Olga Devina who assisted me in data compilation and cross-examination. Finally, 1 appreciate Wesley Huntress’s kind invitation to participate in this project and co-author the book, as well as friendly cooperation and mutual understanding while working on the manuscript.

The illustrations in this book are mainly from governmental sources in the US. including NASA, and in Russia including Energiya. NPO-Lavochkin, the Institute for Space Science and the Institute of Geochemistry and Analytical Chemistry. We found the books ‘S. P. Korolev Rocket-Space Corporation Energiya. 1946-1996’ Volume 1, published by Menonsovpoligraph (1996), S. P. Korolev Rocket-Space

Corporation Energiya at the Boundary of Two Centuries. 1996-200Г Volume 2 (ed. Yu. P. Semenov). OOO Regent Print (2001), and ‘Automatic Space Vehicles for Fundamental and Applied Studies’ published by NPO-Lavochkin, MAI PRINT Moscow (2010) particularly useful. We appreciate the kind permission of V. P. Legostaev, the First Deputy of the President and General Designer of Energiya. and also of V. V. Khartov, the General Designer of NPO-Lavochkin, to reproduce photographs, diagrams and drawings from their organizations either published in their publications or placed on internet sites.

For non-governmental sources every effort has be made to trace the original copyright holders and seek formal permission for all figures that have appeared in previously published works. Л number of these images are from older and out-of­print books, and due to mergers and acquisitions in the publishing industry it has not been possible to track down all potential original copyright holders. We offer our apologies to any that we may have inadvertently overlooked. In all such cases we have cited the publication, author, or artist if known. We have used several unattributed drawings from the 1981 "Space Travel Encyclopedia (in Hungarian) by I. Almas and A. Horvath, others from the 1972 "Robot Explorers’ by Kenneth Gatland with art by John Wood and others, several by Ralph F. Gibbons from the "Soviet Year in Space’ series published by the American Astronautical Society, some drawings by Peter Gorin in Asif Siddiqi s ‘Challenge to Apollo and by an unattributed artist in the NASA "Pioneering Venus’ publication. Many thanks to Asif Siddiqi and Don Mitchell for permission to use material from their print and web publications. Special thanks to James Gary for pennission to use his art work and to Ted Stryk for images from the Soviet program that he has reprocessed with modern methods. Unfortunately, many of the older diagrams and images from the Soviet program are not the best quality for modern publication, but are illustrative of the times. Finally, thanks to David M. Harland for his diligent job of editing and his many improvements to the manuscript.

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On March 8, 1957 Korolev’s OKB-1 founded a new department to develop manned satellites and spacecraft for lunar exploration. It was headed by Tikhonravov, and in April he submitted the first plans. These required that the basic 8K71 R-7 rocket be fitted with a third stage, and by the summer of 1957 technical plans were completed. The third stage would be mounted on top of the sustainer using an open truss so that its engine could be started before the sustainer was shut down – a measure designed to prevent the cavitation in the propellant tanks that would occur in zero-G if ignition were to be delayed until after the core stage had shut down.

Work began on two different vacuum-performance engines for the third stage, one by Glushko s design bureau, OKB-456, and the other by OKB-1 itself, working with Semyon A. Kosberg’s OKB-154 in Voronezh. The decision to build two versions of the third stage originated in a clash between Korolev and Glushko concerning the development of Glushko’s engine, resulting in a bitter rivalry that persisted through the development of the ill-fated N-l Moon rocket and contributed to the ultimate failure of the Soviet manned lunar program. Glushko wanted to develop a powerful 10-ton thrust engine using new hvpergolic fuels, unsymmetrical dimethlyhydrazine (UDMH) and nitric acid, instead of the standard kerosene fuel used by Korolev and Kosberg’s 5-ton thrust engine. However, Korolev was wedded to the LOX-kerosene combination and disliked Glushko’s toxic fuel, calling it “the devil s own venom”. He doubted that such a new engine could be developed in time for his schedule, which called for the first test of the three-stage rocket in June or July 1958, the launch of a lunar impact probe in August or September, and a flyby mission to photograph the far side of the Moon in October or November. He ordered the development of a 5-ton thrust engine at OKB-1 based on the R-7’s verniers. He was aware of developments at Kosberg’s aviation design bureau, w’hieh was working on a restartable LOX-kerosene engine using a new turbopump based on jet engine designs. To speed his ow7n development at OKB-1, Korolev engaged К os berg. As a neophyte in the rocket engine business, К os berg initially demurred, but Korolev persuaded him to collaborate on an engine that could operate in vacuum. For his part, Glushko was not happy with this parallel work, especially since OKB-154 was outside the circle of space developers. Glushko felt that he was due deference from Korolev, and he considered Korolev*s overtures to Kosberg an insult. But Korolev’s instincts proved correct. Glushko was struggling with problems when Kosberg’s engine became available for use in August 1958. It used a higher density kerosene to yield the needed thrust levels. The development of a third stage based on Glushko s engine was finally canceled in 1959.

Korolev’s ambitious schedule had to take second priority to developmental tests required to make the basic R-7 an operational ICBM. During the first half of 1958. his lunar plans were constantly threatened by difficulties with numerous changes to the engines and failures in development flight tests. A prototype of the lunar rocket with a dummy third stage equipped with avionics and telemetry, but no propulsion, was launched on July 10. 1958, powered by an improved set of booster and sustainer engines but these failed a few seconds into the flight, bringing down both the rocket and the timetable. Korolev shot for the Moon at the earliest opportunity on the very first flight of the new third stage on September 23, 1958. This and a second attempt on October 12 failed when the boosters fell apart and all flights had to be suspended until the problem was analyzed and fixed. Frustratingly, the cause turned out to be longitudinal vibrations in the strap-on boosters caused by the addition of the third stage. With this problem fixed, a third attempt failed on December 4, 1958, when the second stage engine shut down prematurely. On January 2, 1959. the rocket worked properly and although Luna 1 did not impact the Moon, the 6.000 km flyby was a sufficiently impressive achievement for the Soviets to declare that this had been the objective.

This R-7E. which tvas an 8K71 with a Block E third stage, was designated 8K72 and informally known as the ‘Luna’ launcher. It could put 6 tons into low Earth orbit and send 1.5 tons into deep space. It was used exclusively for the first generation of Luna probes in 1958 1960 including the successful Luna 1, 2 and 3. It came to an ignominious end with an explosive failure less than one second into the flight of the final such probe on April 19. 1960. The booster and core stages w’ere upgraded and the third stage improved, including upgrading its engine, to produce the 8K72K three-stage heavy lift orbital version of the R-7. This was used to launch the manned Vostok orbital spacecraft and the first Soviet photoreconnaissance satellites, known as the Zenit 2 series.

TIMELINE: AUG 1958-SEP 196ft

The space age began on October 4, 1957, with the launch of Sputnik during a test flight of Korolev’s new R-7 launcher. The ignition of the rocket’s engines on the pad in Baikonur on that day was the explosion that opened the floodgates of space exploration. A little over ten months later, on August 17, 1958, the first attempt was made to send a spacecraft to the Moon, a tiny orbiter, and this time launched by the US, but the rocket exploded. On September 23, the USSR attempted to send a lunar impactor to the Moon using a new variant of the R-7 augmented with a small third stage to reach escape velocity. The booster failed and was destroyed. The race to the Moon and planets was on.

In the three years 1958-1960, the US attempted nine times to send a small Pioneer class spacecraft to the Moon. All failed in one way or another. In the two years 1958-1959, the USSR also attempted nine times to send a spacecraft to the Moon. Of these, six were lost to launch vehicle failures, the Luna 1 impactor missed the Moon by 6,000 km, Luna 2 succeeded in impacting the Moon, and Luna 3 traveled beyond the Moon and sent back grainy pictures of its hitherto mysterious far side.

THE YE-1 LUNAR IMPACTOR SERIES: 1958-1959

Campaign objectives:

After the launch of Sputnik, Korolev took advantage of the world’s reaction to push the Soviet government into approving plans for non-military applications of his R-7 rocket, including lunar exploration. An earlier attempt in 1955 had been of no avail, but now’ the time was ripe. He established three new design groups at OK. B-1, one for

W. T. Huntress and M. Y. Marov, Soviet Robots in the Solar System: Mission Technologies and Discoveries, Springer Praxis Hooks 1, DOl 10.1007/978-1-4419-7898-1 6,

© Springer Science+Business Media, LLC 2011

communications satellites, one for manned space flight, and the third for robotic lunar spacecraft. Mikhail Tikhonravov and Gleb Maksimov were in charge of the latter. Mstislav Keldysh provided specific scientific goals. After a few months work, Korolev and Tikhonravov sent a letter to Moscow on January 28, 1958, proposing a lunar impactor and a lunar flyby mission to photograph the far side. Korolev and Keldysh jointly convinced the government, and on March 20 approval was granted. In fact, lunar spacecraft designs were underway and in February Korolev had begun to develop the third stage required for his R-7 launcher. He was very aware of well – publicized plans in the US for a lunar orbiter to be launched in the summer of 1958, and he wanted to be first.

While preparing for the launch of the first spacecraft to the Moon in the summer, Korolev and Tikhonravov expanded the scope of their plan for the conquest of space by the Soviet Union. This plan was finished in early July 1958, but was held secret outside of a few people in the closed Soviet space circle. It called for upgrading the R-7 to three stages to launch robotic lunar landers and photographic flyby missions, then upgrading the R-7 again to four stages to launch spacecraft to Mars and Venus, and developing orbital rendezvous and other techniques and technologies to enable men to fly around and land on the Moon, as a precursor to creating a colony on the Moon and visiting Mars and Venus.

Maksimov and Tikhonravov also prepared detailed designs for five types of lunar spacecraft in the spring of 1958:

Ye-1 Lunar impact spacecraft, 170 kg

Ye-2 Lunar Гаг-sidc photographic flyby, 280 kg

Ye-3 Same as Ye-2 with improved photographic equipment

Ye-4 Lunar impact spacecraft with explosives, possibly nuclear, 400 kg

Ye-5 Lunar or biter

The Soviets were concerned about proving that their spacecraft had hit the Moon, not recognizing at first that they could be tracked by any other country with the right equipment. Telemetry cessation was not definitive and so the notion was considered of exploding a device on the Moon for all to see, hence the Ye-4 with sufficient payload capacity to carry a nuclear or a large conventional explosive. Korolev was reluctant to use a nuclear explosive, and after consultation with recognized nuclear physicist Yakov Zeldovich and several other physicists this idea was dropped. The Ye-4 itself was eventually abandoned as the technical and political problems became clear, and tracking was recognized as the solution. Even so, the Ye-1 third stage was outfitted with a device to release a sodium cloud for optical tracking and for general observation around the world. The Ye-5 lunar orbiter project was canceled when the new7 8K73 rocket which w7as to launch it suffered engine development problems and was itself canceled.

As the summer of 1958 arrived, Korolev rushed to launch his first lunar impactor before the date set by the Americans for their tiny orbiter. Although he was having technical problems with his first three-stage vehicle, he decided to take the risk and readied his R-7 on the same day as the Americans, but stood down w’hen he learned that the IJS rocket had exploded. But the extra time w as of no avail, and one month later his launch vehicle also exploded after a short flight. Ко matter, the space race was on and its public characteristics were now’ well defined.

In the Soviet program, planning and launch information were held secret and only successful launches reported. Spacecraft that were launched successfully but failed in their objectives had their missions redefined in the Soviet press to make all appear successful. By contrast American plans were announced well in advance, and open to press and public scrutiny. It made for a dramatic contest on each side; one well aware of the other’s plans and proceeding to blind-side its competitor, and the other mostly unaware of the other’s plans and groping almost blindly to seize and retain a leading position.

Six Ye-1/1A spacecraft were launched in the 12-month period between September 1958 and 1959. Only two. Luna 1 and 2. escaped launch vehicle mishaps. Luna 1 and its flight past the Moon wras a sensation to match that of Sputnik almost a year earlier. The Soviet press referred to the w’hole system, launcher and all. as the "First Cosmic Rocket’, and when it passed the Moon the spacecraft was renamed ‘Mechta’ (Dream). Years later, it was retroactively named Luna 1. It w as intended to hit the Moon but on January 4, 1959, it missed its target by about 6,000 km. Nonetheless, it was the first spacecraft to attain Earth escape velocity. On September 14, 1959. the second spacecraft to be launched successfully, Luna 2, became the first spacecraft to impact the Moon, thereby fulfilling Korolev’s program goals for this series.

Ye-1 No 1 Lunar Impact or USSR OKB-1 Luna

September 23. 1958 at 09:03:23 UT (Baikonur) Booster failure.

Ye-1 Ко.2 Lunar Impaetor USSR OKB-1 Luna

October 11. 1958 at 23:41:58 UT (Baikonur) Booster failure.

Ye-1 No.3 Lunar Impaetor USSR OKB-1 Luna

December 4, 1958 at 18:18:44 UT (Baikonur) Second stage failure.

Luna 1 (Ye-1 No.4)

Lunar Impaetor USSR OKB-1 Luna

January 2. 1959 at 16:41:21 UT (Baikonur) January 4. 1959

Missed the Moon, entered solar orbit.

Ye-1 A No.5 Lunar Impaetor USSR OKB-1 Luna

June 18, 1959 at 08:08:00 UT (Baikonur) Second stage failure.

Luna 2 (Ye-1 A No.7)

Lunar Impaetor USSR OKB-1 Luna

September 12. 1959 at 06:39:42 UT (Baikonur) September 14, 1959 at 23:02:23 UT Success, impacted Moon.

The scientific goals of these first interplanetary spacecraft were to study cosmic radiation, ioni/cd plasma, magnetic fields and the micromcteoroid flux in the region between the Earth and Moon known as cislunar space. In addition to assisting with
optical tracking, the sodium release experiment would also allow for visualization of the magnetosphere and diffusion in the upper atmosphere of the Earth in transit.

Campaign objectives:

OKB-1 started development work on the Ye-7 lunar orbiter at the same time as the Yc-6 soft lander, but it progressed more slowly. After NPO-Lavochkin took over the robotic program the Soviets became anxious to upstage the American orbiter, which was scheduled for its first launch in mid-1966. They also needed to acquire close up imagery of potential landing sites and information on the environment in lunar orbit for the manned lunar program. An incentive presented itself in early 1966 when the long duration manned Voskhod 3 flight that was to have coincided with the opening of the 23rd Congress of the Communist Party in April (the first for new Communist Party leader Leonid Brezhnev) was canceled and there was a requirement for a new’ space spectacular. The Ye-7 was not ready, but Babakin offered to produce a lunar satellite by replacing the lander of the Ye-6 with a pressurized module carrying a payload of readily available instruments. The first orbiter, the Ye-6S, was cobbled together in less than a month. It is possible that the orbiter module was adapted from an Earth satellite of the Cosmos series.

After a launch failure on March 1, 1966, a backup spacecraft was prepared and successfully dispatched to the Moon on March 31, fortunately for Babakin just in time to satisfy the political objective. By becoming the first lunar orbiter, Luna 10 marked another milestone for the Soviet space program. In a moment of theater, it played a recording of the uInternationale’ to the Party Congress.

The US sent its first orbiter to the Moon a little over 4 months later. This project was successful on the first try, and Lunar Orbiter 1 sent back the first pictures from lunar orbit. With landers and or biters returning high quality data, the US was finally catching up.

Having achieved lunar orbit ahead of the US and provided the required space spectacular for Moscow, Babakin resumed work on the Ye-7 orbiter whose task was lunar photography. When it was decided to use the Ye-6 cruise stage to make the midcoursc and orbit insertion maneuvers, the orbiter spacecraft became the Yc- 6LF.

Luna 10 had significantly deviated from its predicted path in lunar orbit, and radio tracking had shown the Moon to have an irregular gravity field. As a manned lunar lander would require a precise orbit if it were to land at a preselected point, in

addition to lunar photography the Ye-6LF was given the task of accurately mapping the lunar gravity field.

Two of these spacecraft flew as Luna 11 and 12, and although both achieved lunar orbit an attitude stabilization problem prevented Luna 11 from providing any useful imagery. Even with new tracking data, the navigators could not predict their orbits with the desired accuracy. A second modification to the orbiter module produced the Ye-6LS that was to acquire more precise lunar gravity field data and also test deep space communications for the manned lunar program. After a test mission in Earth orbit and a lunar attempt that was lost to a launch vehicle failure, the third Ye-6LS was successful as Luna 14.

Spacecraft:

These orbiters all used the Ye-6 cruise stage with the lander replaced by an orbiter module. An interesting feature of the orbiters is that they carried no solar panels for recharging batteries, with the result that their operating time was defined by battery life. Lunar orbit insertion was a much smaller burn than the braking maneuver for a landing mission. In the case of the Ye-6S Luna 10, the orbiter module was released on its own in a spin stabilized condition. For the Ye-6LF and Ye-6LS, however, the orbiter modules of Luna 11, 12 and 14 were retained so that they could be stabilized to perform photography. The Ye-6S orbiter module was 1.5 meters long, 0.75 meters in diameter and massed 248.5 kg. It carried two radios transmitting at 18.1 and 922 MHz. Including the cruise stage and a large conical equipment module the Ye-6LF orbiters were 2.7 meters long and 1.5 meters in diameter. The Ye-6LS was similar to the Ye – 6LF but with an improved navigation system to more precisely measure the orbit and apparatus to test a communication system intended for the manned lunar program.

Luna 10 launch mass: Luna 11 launch mass: Luna 12 launch mass: Luna 14 launch mass:

Payload:

Ye-6S Luna 10:

1. Boom-mounted triaxial fluxgate magnetometer

2. Low energy x-ray spectrometer

3. Gamma-ray spectrometer

4. Gas discharge counters

5. Ion trap solar plasma detectors

6. SL-1 radiometer

7. Micrometeoroid detector

8. Infrared radiometer

9. Gravitational field mapping experiment (using spacecraft tracking)

The Yc-6S flown as Luna 10 had seven instruments developed for the Ye-7, but not the camera. The magnetometer was on a 1.5 meter long boom. Low energy x-ray and gamma-ray spectrometers were to measure the composition of the lunar surface; piezoelectric sensors were to measure micrometeoroid fluxes; an infrared radiometer was to measure thermal radiation from and the temperature of the lunar surface; gas discharge counters were to measure solar and cosmic rays in the lunar environment and soft electrons in a lunar ionosphere; ion traps were to measure electrons and ions in the solar wind and search for a lunar ionosphere; and the SL-1 radiometer was to measure the lunar radiation environment. Another key investigation was to measure the lunar gravity field by radio tracking of the spacecraft. There was no imaging on this first hastily prepared orbiter.

Ye-6LF Luna 11 and 12:

1. Facsimile imaging system

2. Low energy x-ray spectrometer

3. Gamma-ray spectrometer

4. SL-1 radiometer

5. Micrometeoroid detectors

6. Ultraviolet spectrometer

7. Long-wave radio astronomy experiment

8. Gravitational field mapping experiment (using spacecraft tracking)

9. Lunar rover wheel drive technology experiments

The imaging system was similar to the facsimile film camera used by Zond 3 the previous year. At the altitude at which the pictures were to be shot, an image would encompass an area of 25 square kilometers and the 1,100 scan lines would provide a maximum surface resolution of 15 to 20 meters. Two cameras were carried on each mission. The ultraviolet reflectance spectrometer was to measure the structure of the surface. Ко data was ever published on the composition of the lunar surface or of the magnetic field, radiation and micrometeoroids in the lunar environment. Nor was the analysis of the irregular gravity field published. In addition to scientific instruments, the spacecraft carried technology tests of lubricants for operating gears and bearings in vacuum to qualify them for use on lunar rovers.

Ye-6LS Luna 14:

1. Lunar communications system test

2. Cosmic ray detector

3. Solar wind plasma sensors

4. Radiation dosimeter

5. Gravitational field mapping experiment (using spacecraft tracking)

6. Lunar rover wheel drive technology experiment

The main goal of Luna 14 was to test the spaceborne and ground segments of the new communication system for the manned lunar program. Other objectives were to continue to investigate the lunar radiation and plasma environment and to use a new: navigation system to more precisely map the lunar gravity field and librations. The spacecraft also carried more engineering tests of lunar rover motors including gears, ball bearings and lubricants Гог vacuum operation.

Mission description:

On March L 1966, the first spacecraft, Yc-6S No.204. was stranded in parking orbit when the fourth stage lost roll control during the unpowered coast and was unable to lire its engine for the escape burn. It was designated Cosmos 111 and re-entered the atmosphere 2 days later.

Four weeks later on March 31,1966. Ye-6S No.206 was successfully dispatched as Luna 10. It made a mideourse correction the following day and then at 18:44 IJT on April 3 it became the first spacecraft to enter orbit around another celestial body, achieving a 350 x 1,017 km orbit inclined at 72 degrees to the lunar equator with a period of 2 hours 58 minutes. The cruise stage then released the or biter module. On April 4 the ‘Internationale was played to the 23rd Congress of the Communist Party of the Soviet Union. In Tact w hat the Congress heard was a rehearsal playback from the previous evening, because at a second rehearsal on the morning of the meeting it w as observed that one of the notes had gone missing. Luna 10 operated for 56 days. 460 lunar orbits and 219 radio transmissions before the battery drained and contact was lost on May 30, 1966.

Spacecraft Ye-6LF No. 101 was launched on August 24, 1966, as Luna 11, and at 21:49 UT on August 28 it entered a 160 x 1,193 km lunar orbit that was inclined at 27 degrees with a period of 3 hours. Coming 2 weeks after the first US or biter, there was every expectation in the West that the Soviet mission would send back images. The transmissions had been recoded to prevent interception by the likes of Jodrell Bank, but no pictures w’ere forthcoming. An attitude control thruster had failed and prevented aiming either the camera or the ultraviolet instrument at the lunar surface. It was suspected that something had become lodged in the nozzle of the thruster. By sheer bad luck, the x-ray and gamma-ray spectrometers also failed. The spacecraft w as placed into a spin stabilized mode and the other experiments apparently worked satisfactorily. After 38 days, 277 orbits and 137 radio transmissions the batteries ran out on October 1, 1966, and the Soviets, without mentioning imaging, reported that the mission was complete.

Ye-6LF No. 102. Luna 12. entered a 3 hour 25 minute 103 x 1,742 km lunar orbit inclined by 36.6 degrees on October 25, 1966. It did not suffer the problems of its predecessor except for the ultraviolet spectrometer, which again failed. Tile primary objectives were the lunar photography that Luna 11 had been unable to provide and to continue to chart the gravitational field. On October 29 the spacecraft transmitted its first photographs. In this regard the Soviets were 2 months behind the Amerieans. A total of 40 images were returned by each of the two cameras. Once the spacecraft had finished imaging, it was placed into a spin stabilized mode and the other tasks were sueeessfully performed, ineluding testing electric motors for a rover, hven with the new gravity maps developed by tracking Luna 1L the orbit of Luna 12 deviated surprisingly far from that predicted. Its perilune dropped by 3 to 4 km, day relative to the prediction, and the failure of one of the attitude control thrusters made it difficult to raise the perilune to compensate. Finally, on January 19, 1967. after 85 days. 602 orbits and 302 communication sessions, transmissions ceased.

The next mission to be launched was a test flight of the second modification to the orbiter. The Ye-6LS No. lll spacecraft was to be launched into a highly elliptical Earth orbit with an apogee near 250.000 km in order to perfect a means of accurately measuring and adjusting an orbital trajectory to compensate for gravity anomalies, but the fourth stage shut down prematurely leaving the spacecraft in a lower 260 x 60,710 km orbit. Despite the low apogee, it was probably put through its intended operations. Designated Cosmos 159, it re-entered on November 11, 1967. The Ye – 6LS No. l 12 spacecraft failed to achieve parking orbit when the third stage ran out of propellant early at the 524 second mark as a result of excessive fuel consumption through the turbine gas generator. The last spacecraft of this type. Yc-6LS No. l 13. was successfully dispatched as Luna 14 and at 19:25 UT on April 10. 1968. it entered a 160 x 870 km lunar orbit at 42 degrees. It marked the end of the second generation of Luna missions.

Results:

Luna 10 conducted an extensive study of the Moon from lunar orbit. Its path varied much more than the Soviets expected. This was due to a very uneven gravity field that featured localized ‘mass concentrations’ (mascons) below the surface. Luna 10 established the importance of charting the lunar gravity field, and also of providing spacecraft with robust propulsion for precise control of their orbital trajectories. The Soviets discovered this well before the Americans, who were generally given credit because their space program results were more widely published. Luna 10 found the Moon to have no detectable atmosphere, the lunar surface to have large expanses of basalt but few, if any. granitic provinces, and measured the amount of potassium, uranium, and thorium in the crust. It mapped a magnetic field whose strength was 0.001 % of Earth, and found it not likely to be intrinsic. It showed that the Moon had no trapped radiation belts like those of Earth. The micrometeoroid flux and cosmic radiation in lunar orbit was also measured.

The x-ray and gamma-ray spectrometers on Luna 11 failed and imaging was not possible, but it was able to make observations of solar radiation and also conducted a successful test of lunar rover reduction gear operation in vacuum. The first images

were obtained by Luna 12. On October 29, 1966, it transmitted images of the Sea of Rains and the crater Aristarchus with resolution of 15 to 20 meters. Owing to their low quality, only the first few images were released. Ironically, the Soviets used the more extensive and far better imagery from the Lunar Orbitcr scries to select landing sites. Furthermore, like the Americans they ultimately chose three sites, one each in the Sea of Tranquility, the Central Bay and the Ocean of Storms. The radio tracking of Luna 11 and 12 revealed the need for even better orbital tracking experiments to provide a more precise lunar gravity map. Luna 12 also detected x-ray fluorescence of the surface induced by the solar wind, and this provided a means of measuring ihe composition of the surface. Radiation fields and micrometeoroid flux were measured in lunar space and the engineering test of reduction gears was successful.

The mission of Luna 14 passed almost without comment, perhaps because to have described what it was doing would have revealed too much about the manned lunar program. It was assumed in the West at the time to be a failed photographic mission, but it is now known to have mapped the figure of the Moon and its gravity field to a high degree of precision, to have provided data on the propagation and stability of radio communications to the spacecraft at different orbital positions, measured solar wind plasma and cosmic rays in lunar orbit, measured the librational motion of the Moon, and determined the Harih-Moon mass ratio. The eommunicalions system for the manned lunar program was also successfully tested. Further engineering tests of rover motors were conducted to select the materials and lubricants that operated best in vacuum for the systems intended for roving vehicles.

Campaign objectives:

In addition to the lunar surface rover and sample return missions, the Ye-8 modular spacecraft also flew orbital missions to support the engineering requirements of the planned manned missions. The principal requirements were to photograph the lunar surface at high resolution and conduct remote surface composition measurements to assist in selecting landing sites. Л secondary objective was to acquire data on the radiation and plasma in lunar orbit in order to understand the risks to humans. Two Ye-8LS orbiters were launched successfully as Luna 19 and 22. Their tracking data continued the accurate mapping of the lunar gravity field that Luna 14 initiated.

Spacecraft:

The spacecraft was essentially the same as the lander stage for the lunar rover, but with a payload consisting of a pressurized module for the orbital instruments. This was a squat cylinder and, just like the Lunokhod, had a hinged lid that exposed solar panels on the underside.

Luna 19 launch mass: 5,700 kg

Luna 22 launch mass: 5,700 kg

Payload:

1. Imaging system

2. Gravitational field, experiment

3. Gamma-ray spectrometer for surface composition

4. Radiation sensors

5. Magnetometer

6. Micrometeoroid detector

7. Altimeter

8. Radio occultation experiment

For these arbiters, new linear-scan cameras were developed based on the Luna 9 and 13 panoramic imagers. Basically the motion of the spacecraft provided the long axis of the image and the photometer scanned only perpendicular to the direction of orbital motion. The field of view was 180 degrees centered on the nadir and gave a ‘cylindrical fish-eye’ image. At 4 lines per second from an altitude of 100 km it had a resolution of 100 meters in the direction of travel and 400 meters perpendicular to it. Luna 22 carried an additional camera and engineering tests of solid lubricants for operation in vacuum and wafer tests of surface reflection properties.

The Ye-8 lunar orbiter series: 1971-1974 265

Mission description:

Luna 19 was launched on September 28, 1971, and on October 3 it entered a 2 hour circular lunar orbit at 140 km inclined by 41 degrees. Three days later the orbit was changed to an elliptical one of 127 x 385 km. Several months later the perilune was lowered to 77 km to undertake closer photography. After more than 4,000 orbits the spacecraft ceased operations on October 3, 1972.

Luna 22 was launched on May 29, 1974, and entered a 219 x 221 km lunar orbit at an inclination of 19.6 degrees on June 2. It made many orbit adjustments over its 18 month lifetime to optimize experiment operation, at times lowering its perilune to 25 km to improve photography. Sporadic contact was maintained after the supply of attitude control gas ran out on September 2, and the mission was concluded in early November 1974.

Results:

Luna 19 and 22 both returned images of the lunar surface from orbit, with Luna 19 apparently returning about 5 panoramas and Luna 22 ten panoramas. Both spacecraft extended the systematic study to locate mass concentrations (mascons) begun by the earlier Luna orbiters. They also remotely sensed the composition of the surface and directly measured the properties of the orbital environment including the radiation, plasma, magnetic fields and micrometeoroid flux. Altimetry measure­ments of lunar topography were made, and the electromagnetic properties of the regolith examined. The results must have been substantial but few results were published, particularly from Luna 22.

The tortuous path from Phobos to Mars-96:

Turmoil reigned after the failure of the Phobos missions. The long-held tolerance in the Soviet space program for failure in the attempt of bold initiatives collapsed. One result of international exposure was to open the Soviet space program to scrutiny at high political levels, where it was punished by a severe budget cut in 1990, a year of general economic gloom in the USSR.

rnside IKI a debate ensued about whether to repeat the Phobos mission in 1992 with the backup spacecraft, or to devise a new mission to the Martian surface. There were competing priorities at IKI, at the Vernadsky Institute, and with the French who were still pursuing their balloon ideas with the Soviets albeit this time at Mars
instead of Venus. While the Phobos missions were being developed, a follow-on mission plan had been studied. Named ‘Columbus’, this called for dual or biters in 1992 and 1994 with entry vehicles to drop French balloons into the atmosphere and Soviet rovers onto the surface. By 1989 the government had not provided the money required to launch the project in 1992 so the proposal was delayed with two orbiters in 1994 carrying small landers and the French balloons, two orbiters in 1996 with the rovers, and a sample return mission in 1998. A meeting was held in Moscow’ in November 1989 to solicit international participation. The first funding for Mars-94 w7as in April 1990, and both Germany and France agreed to contribute investigations equivalent to over SI20 million. Ultimately twenty countries, including the US, were to provide science investigations.

The French balloon was a bold and exciting aspect of the 1989 plan. Its envelope was a 6 micron thick film in the shape of a cylinder 13.2 meters in diameter and 42 meters tall. It was to be inflated with 5,000 cubic meters of helium at an altitude of about 10 km during the parachute descent. After being released, it would float at an altitude of 2 to 4 km during the warm day and descend during the cold night to drag a 7 meter long instrumented tail along the surface in order to ensure that the balloon remained airborne. The tail, also known as the snake, carried 3.4 kg of instruments including a gamma-ray spectrometer, thermometer, and a subsurface radar that used the titanium segmented snake as its antenna. A 15 kg gondola suspended below the balloon and above the snake carried a camera, infrared spectrometer, magnetometer, re fleet ome ter and al time ter. and a meteorological package to measure temperature, pressure and humidity. It was expected that the balloon would last 10 to 15 diurnal cycles and travel several thousand kilometers. In another first, tests of the balloon were carried out in the American Mojave desert in 1990 by a joint team of Russian. French and American scientists and engineers.

The other exciting feature was the Mars rover. The USSR had sent two successful rovers to the Moon in the early 1970s. and now7 modified this technology for Mars. The Mars rover was smaller than its lunar predecessor, but at 200 kg was still large. It had a clever new chassis and wheel design, and with a top speed of 500 meters per hour it w7as expected to drive 500 km during the lifetime of 2 to 3 years facilitated by its R I G power supply. The rover was equipped with four cameras for panoramic coverage, a quadrupole mass spectrometer for atmospheric analysis, a laser aerosol spectrometer, a visible-infrared spectrometer for surface analysis, magnets to reveal the magnetic properties of the soil, a radio sounder to probe subsurface structure to a depth of 150 meters, a meteorology package, and a manipulator arm that would dig 10 cm into the surface to obtain samples for a pyrolytic gas chromatograph. The arm also carried a camera for close-up observation of the soil, an alpha, proton and x-ray spectrometer for elemental analysis of the soil, a Mossbauer spectrometer to analyse the iron mineralogy of the soil, and a gas analyzer to identify any trace gases.

Both the balloon and the rover would ultimately be deleted, however. In 1990 the USSR was in financial distress, and the money for developing the Mars-94 mission arrived slowly and in smaller amounts than required. By April 1991 it was clear that the money was insufficient to address all of the ambitions of the mission. It became necessary to postpone the balloons and rovers to 1996, and send a simpler mission in 1994. The Mars-94 mission would now be a single launch of an orbiter with small landers similar to that of Mars 3 (which was successfully delivered to the surface, although it had failed immediately afterwards) and new penetrators developed by the Vernadsky Institute.

On New Year’s Day 1992 the USSR was formally dissolved, Russia emerged as an independent state, and financial problems became acute. In the past money had never been an issue in developing a planetary mission but it now became the pacing item. It was not delivered when required or fell short. Parts were not delivered by contractors. Work on Mars-94 declined into a stop-go affair depending on whether there was money and parts. In desperation the project asked for financial assistance from its international partners. In order to protect their investments in the mission, Germany and France sent $10 million in late 1993. An appeal was made to the US. but after the loss of the Phobos missions the Americans were suspicious of Russian capabilities and were nervous about investing in a foreign project that was in such a visibly dismal state. Besides, in August 1993 NASA had its first ever inflight loss of a planetary spacecraft when Mars Observer fell silent while preparing for Mars orbit insertion, and the agency was struggling to salvage its own program.

Fearing that the troubled Mars-94 project was in severe danger of delivering an ill-prepared spacecraft in 1994. the new Russian Space Agency (RSA) postponed the mission until 1996. The second spacecraft with the balloon and rover was slipped to 1998. The risk in this move was that money from the new7 and financially strapped government would dry up altogether, but the RSA gave the Mars-96 mission its full support and the government declared the project to be a high priority. If it w ere not for the international obligations and the Western currency involved, the mission just might have been canceled. It continued in the face of technical and financial issues. When the camera scan platform ran into technical difficulties the Russians proposed deleting it in favor of fixed mountings in order to save money. The Genua ns. who were building the cameras, became outraged, and in the end saved the scan platform by sending their own engineers to fix the problems. The Russian government did not send all the money that it had promised. The RSA pulled funds from lower priority missions, and more money ultimately as much as SI80 million more was sent by Western partners to keep the project alive. Cancellation remained a possibility. The RSA went 80 million rubles into debt to complete the final integration and testing of the Mars-96 spacecraft in early 1996, by which time the Mars-98 mission with the balloon and rover had been canceled. Promised funding from the government just never arrived. The financial problems in the Russian space program were so bad that the ships in the tracking fleet were recalled to port and most of them sold off. One ship was made into a museum, and another was conscripted into the Ukrainian Black Sea naval fleet. The loss of these tracking vessels would eventually prove a serious problem to the project.

The situation at Baikonur in the summer of 1996 while preparing the mission for launch was atrocious. There were power shortages as utility bills went unpaid. Work was often done with heat from kerosene burners, light by candle, and labor without pay. With such a long protracted development under such adverse conditions, it took a heroic effort to get the Mars-96 spacecraft to the launch pad. Perhaps due to all the

Mars-96 (Ml No.520) Mars Orbiter/Landers USS R/NPO-Lavochkin Pro ion-K

November 16, 1996 at 20:48:53 UT (Baikonur) Launch failure, fourth stage misfired.

adversity in mounting this mission, ii failed during the launch process and ihere was little hope that the Russians would be able to attempt another planetary mission for many years to come.

FIRST ON THE MOON, FIRST ON VENUS, AND FIRST ON MARS

The latter hall’ of the 20th Century will forever be known as the time when the human race broke its Earth-bound chains and began to explore the boundless reaches of interplanetary space. The Soviet Union initiated this enterprise with its Earth orbiting satellite ‘Sputnik’, meaning ‘fellow traveler’, in 1957, and shortly thereafter Soviet scientists made the first attempts to send spacecraft to the Moon and to the planets. What followed were 38 years of triumph and tragedy in one of the most cxcitmg adventures in recent human history.

The first pioneers of space flight lived in the first half of the 20th Century. Tsiolkovsky, Tsander and Kondratyuk in Russia, Obcrth in Germany, Goddard in the US, and later Korolev and Glushko in the Soviet Union, von Braun in the US, and Esnault-Pcltcrie in France, all believed that humankind could travel to other planets in the Solar System using new developments in rocket propulsion. These early visionaries established the notion that it was in fact possible to fly to the planets, but their dreams became reality only after the intervention of World War II created the technological catalyst for accomplishing deep space propulsion. By the end of the 20th Century, humans had set foot on the Moon and had sent robotic spacecraft to most of the planets, as well as to some comets and asteroids.

Most of the history of space exploration in the 20th Century is characterized by intense competition for dominance between the USSR and USA. At the dawn of the ‘space age’ the two nations were developing TCBMs to drop nuclear warheads on each other’s cities. Europe and Japan were preoccupied with rebuilding after the devastation of World War II. The USSR launched the first artificial satellite, Sputnik on October 4, 1957, using a modified version of their first operational ICBM. The first human space flight was also Soviet; Yuri Gagarin’s orbital flight of April 12, 1961. These events shocked Americans, who had difficulty imagining how they could not have been first into space. The Americans also immediately recognized the implications of these events for their national defense. The USA mobilized a massive space development program of its own in 1958, and on May 25, 1961 President

W. T. Huntress and M. Y. Marov, Soviet Robots in the Solar System: Mission Technologies >

and Discoveries, Springer Praxis Books 1, DOl 10.1007/978-1-4419-7898-1 1,

© Springer Science 4-Business Media, LLC 2011 4 Space race

Kennedy formulated a national goal to land a man on the Moon before the decade was оul implicitly meaning that this man should be American, not Russian.

The Soviet Union was slow to respond to the challenge, but in 1964 initiated a national program to send a cosmonaut to the Moon ahead of the Americans. The Americans won the ‘race’ on July 20, 1969. with Apollo 1 Us touchdown on the Sea of Tranquility. The Soviet program stalled after a series of failures of the N-l heavy rocket, their equivalent to the American Saturn V, but the USSR produced dramatic results with robotic lunar rover and sample return missions through 1976. The Americans shut down their Apollo lunar program in 1972 after six successful flights to the lunar surface.

The space race’ was a Cold War phenomenon, but just like the international air races in the first half of the 20th Century, the space race resulted in an explosion of research and technological development. While competition in space exploration between the USSR and the USA originally focused principally on flying humans to the Moon, there w as also competition to fly robotic spacecraft to the Moon and beyond, and this yielded remarkable feats of engineering and enormous scientific progress in understanding our Solar System and technological progress for Earth applications. If it had not been for the political imperatives of the Cold War, it is highly unlikely that the national investments required for this progress would have been made. After the fall of the Soviet Union in 1991, the Russian robotic space exploration program withered aw’ay.

This book provides the technical details of the Soviet Union’s robotic space exploration missions, beginning with the attempted launch of a lunar impaetor on September 23, 1958. and concluding with the final launch in the Russian national scientific space program in the 20th Century, the Mars-96 mission, on November 16. 1996. Each flight campaign is placed into the political and historical context in which the entire endeavor occurred, chronicling the boldness of the program, the daring spirit of its creators, the genius of its implementation, and the successes and in some cases the tragic failures in its execution. The book is in two parts. Part I describes the pieces that must be combined to make up a space program: the key players who make things happen; the institutions that design, build and operate the hardware; the rockets that offer access to space; and the spacecraft that carry out the enterprise. Part II is a chronological account of how the pieces are put together to undertake space flight and mission campaigns. Each chapter covers a particular period, usually several years, when specific mission campaigns were undertaken during launch windows determined by celestial mechanics. Each chapter in Part 11 gives a short overview of the flight missions that occurred during the time period and the political and historical context for the flight mission campaigns, including what the Americans were doing at the time. The bulk of each chapter is devoted to the scientific and engineering details of each flight campaign, and in each case the spacecraft and payloads are described in as much technical detail as is available at the time of writing this book, the progress of the flight is described, and a synopsis of the scientific results is given.

The Soviet robotic space program was dramatic, and was driven by a thirst for technological achievement and a desire for international recognition and respect. It achieved all these things. Soviet robotic spacecraft were first on the Moon, first on Venus, and first on Mars.

In early 1958 Korolev began planning for planetary missions. His original intention w as to use the 8K73, a version of the 8K72 with a more capable third stage. During that summer OKB-1 began w ork on spacecraft for launch to Venus in June 1959 and Mars in September 1960. However, the 8K73 project and the 1959 Venus mission were abandoned w’hen Glushko’s engines for the new’ third stage had development problems. Korolev turned to Kosberg again and decided to adapt the second stage of the new’ silo-based ICBM under development, the R-9A. also know n as the 8K75. as the third stage for his planetary launcher. Kosberg fitted the stage with larger tanks to sustain the longer engine burn times. In the meantime, the R-7 w as still in its final development phases in preparation for operational deployment.

During 1958 an improved version of the basic tw o-stage R-7. the R-7A or 8K74.

was being developed for easier operational servicing and greater performance. The 8K74 had all-inertial guidance with the original radio guidance system retained only as a backup, improved engines for reliability, redesigned verniers for simpler control and increased performance, a new ignition system, and some portions of the engines were moved nearer to service hatches. The first launch of the 8K74 on December 24. 1959, was a success. The 8K74 became the basic two-stage booster for generations of launchers to the present day. The only 8K71-based vehicles used after this 8K74 test were two 8K72 Luna launches on April 12 and 18. 1960. both of which failed.

In all this rush of rocket development in 1958 59, Keldysh*s mathematicians had determined that continuous burn of all stages was an inefficient use of energy to reach interplanetary velocities. Continuous burn also required precise timing without margin for launch delays. Instead they recommended a scheme in which the booster placed an escape stage into low Earth orbit. This would be ignited when the orbital phasing was optimum for launch towards the Moon or planetary target, and once on course it would release its payload.

Abandoning the three-stage approach for lunar and planetary launches, in early 1959 Korolev began w ork on a four-stage approach. The airframe of the 8K74 core vehicle w as strengthened to support the mass of the new upper stages, modifications w ere made to the operating pressures and burn programs to increase the thrust of the core vehicle, a stronger open truss was provided between the suStainer and third stage, and new guidance and control systems were supplied for the upper stages. The К os berg third stage was modified further with an increased propellant load and an upgraded 8D715K four-chamber engine and designated Block I. The 8K74 III two – stage core vehicle w ith the new Block I third stage and a first burn by a new fourth stage. Block L. built by OKB-1. would put the Block L and spacecraft combination in Earth orbit. The Block L was made res tart able, so that its second burn would put the spacecraft on an interplanetary trajectory. It would be capable of sending 1,600 kg to the Moon or 1,200 kg to either Venus or Mars. This four-stage 8K78 is known as the ‘Molniya* launcher. A prototype with a dummy fourth stage w7as successfully tested on January 20. 1960, with a second successful test 10 days later. The Block L completed its ground tests in the summer of 1960. and Korolev rushed preparations for three Mars launches on the first tests of this new launcher. 1 he spacecraft were also built in a great rush before the launch window7 closed in mid-October. Only two rockets made it to the launch pad on time.

The first flight test of the complete 8K78 occurred on October 10, 1960, w ith a 1M Mars spacecraft at the top of the stack. The spacecraft had to be stripped down in order to provide sufficient mass for rocket test instrumentation. The launch failed when resonant vibrations in the upper stages damaged the avionics during third stage burn and the rocket veered off course. A second attempt on October 14 also failed when the third stage engine did not ignite because a LOX leak on the pad had frozen kerosene in the fuel lines. The first test of the Block L did not come until the third flight on Kebruary 4, 1961, which attempted to launch a 1 VA Venus spacecraft. The first three stages performed perfectly, but the Block L was stranded in Earth orbit by a primary powder failure.

The Block L stage was a challenging design because it had to coast unpowered for

almost 2 hours in Earth orbit without losing volatile propellant, orient itself to the proper firing attitude at a programmed time, and ignite its engine in a zero-G state. The engine used a more efficient ‘closed-cycle’ technology which US rocket makers deemed unworkable, and used gimbals for yaw and pitch control and a pair of small verniers for roll control. The stage used, a cold gas attitude control system and solid rockets to provide ullage control before engine ignition in zero-G. The challenges of perfecting this planetary injection stage proved difficult. The Block L succeeded on its second opportunity on February 12, I960, deploying Venera 1. But it failed many times thereafter, including the final planetary mission to use the Molniya launcher on March 31, 1972, when the Block L stage failed to put another spacecraft intended for Venus on an escape trajectory.

In 1962 an extended shroud was introduced to accommodate the next generation

2MV Mars and Venus spacecraft and the sustainer engines were upgraded. In 1964 a new version of the 8K78 was introduced, with improved versions of Glushko’s RD – 107/8 engines and an improved engine in the Block L fourth stage. This vehicle was designated 8K.78M, and was known in the West variously as SL-6 and А-2-е. Tt was first used for the test launch of a 3MV Venera spacecraft on March 19, 1964, then used consistently for Venus missions until the introduction of the Proton-launched spacecraft in 1975. Mars launches used the 8K78 until switching to the Proton in 1969. The Ye-6 Luna probes used both the 8K78 and 8K78M vehicles until Luna 9 on January 31, 1966, when the SK78M came into exclusive use. A variant of this vehicle was created for the Luna soft landing missions, in which the avionics were deleted from the upper stages to save mass and the Ye-6 spacecraft controlled the functioning of the third and fourth stages. This vehicle was designated with a / Ye-6 suffix. The 8K78 vehicle was completely replaced by the 8K78M after December 1965. ‘

The 8K78M received another upgrade in 1966-67 when the core and strap-ons were replaced by those of the three-stage LSoyuz’ version used in the manned space program. In 1965, responsibility lor the Block L stage was transferred from OKB-1 to NPO-Lavochkin, which introduced improvements in 1968 including upgraded avionics and a new third stage interface and fairing design. Lavochkin produced two versions of this new Block L, one for lunar and planetary missions and the other to place ‘Molniya’ communications satellites into highly elliptical Earth orbits. Further improvements to the 8K78M were made in 1974 and again in 1980. In its various forms the Molniya launcher was the workhorse for the lunar and planetary program in the 1960s and early 1970s, successfully deploying the Luna 4 to 14 missions from 1963-1968, Mars missions from 1960-1965 including Mars 1, and Venera 1 to 8 from 1961-1972. The versatility of the ‘Semyorka’ rocket is demonstrated by its continued

use up to the present day, particularly in its three-stage Soyuz* variant. It resumed its utility for planetary launches on June 2, 2003, with the successful launch of the Mars Express spacecraft for the European Space Agency using a Soyuz fitted with the new Fregal fourth stage.

Of the six Ye-1 spacecraft launched, only two survived the process. A seventh was returned to the barn after its launcher failed to lift off. Aware from press reports that the Americans were to try for the Moon on August 17, Korolev managed with great effort to prepare a vehicle for the same day. There were a number of malfunctions during pre-launch preparations, but he knew that his flight path to the Moon was shorter than the Americans so he waited before risking a launch to see if the Florida launch succeeded. When the US rocket blew up after only 77 seconds of flight, he stood down in order to perform more careful preparations and additional testing. How ever, the launch on September 23 failed when the strap-on boosters of the first stage developed resonant longitudinal vibrations in the second minute of flight. The various stages separated at 93 seconds, fell back and exploded. Reacting to pressure to beat the US to the Moon, Korolev is said to have lost his temper and replied "Do you think only American rockets explode? ‘ Indeed not, and he could not know that the Soviet lunar program w ould be plagued w ith rocket failures for years to come.

The second American attempt at the Moon was scheduled for October 11, amid a flurry of press coverage. Korolev w’as again ready that same day. The wdiole world w as aware of events in Florida, but only a few in the USSR were aw are of Korolev with his linger on the launch button at Baikonur, ready to beat the Americans to the Moon using a faster trajectory. News of the US launch was relayed to Korolev. But the third stage failed, preventing Pioneer 1 from reaching the Moon. Sitting now in the catbird seat, Korolev proceeded with his launch. Later the same day, the second Luna 8K72 launcher blew up 104 seconds into its flight due to the same vibrations wiiich had destroyed the first vehicle.

The two failures in row w’ere demoralizing. It w’as discovered from analyzing the w reckage that the additional mass of the third stage was creating resonant vibration in the basic R-7 booster wThich had not been present before. The problem was solved with minor design changes, but it would take two months and Korolev had to watch over his shoulders as America made a third attempt on November 8. but this too fell short.

The third launch on December 4 failed yet again, this time caused by a different problem. The rocket sailed through the period wdien vibrations broke up the previous two rockets, but after 4 minutes of flight the thrust of the second stage engine began to diminish and then the engine shut dow n due to a gear box failure in the hydrogen peroxide turbine pump. Frustrated, but relieved by the fourth American failure two days later on December 6, Korolev prepared for another

attempt. The fourth launch was a success and on January 2, 1959, put Ye-1 No.4 on a trajectory to the Moon. The spent third stage released a 1 kg cloud of sodium gas on January 3, some 113,000 km from Earth, producing a glowing orange trail visible over the Indian Ocean with the brightness of a sixth-magnitude star. The experiment provided data on the behavior of ionized gas in near-Earth space, and was used for tracking. Luna 1 (as the probe was later named) missed its target and passed within 5,965 km of the lunar surface on January 4 after 34 hours of flight. The miss was caused by a late second-stage shutdown command from the ground radio guidance. Nevertheless, Luna 1 holds three cosmic ‘firsts’, being the first spacecraft to achieve escape velocity, the first spacecraft to fly close by the Moon, and the first spacecraft to enter an independent heliocentric orbit. Contact was lost on January 5, after 62 hours of flight, possibly when its battery drained.

Luna 1 was a major success and feather in the cap of Soviet space exploration, but it failed to impact the Moon as planned and the program goal was not yet fulfilled. After further problems with the R-7 in the beginning of 1959, another spacecraft was readied that incorporated modifications to the magnetometer, Geiger counters and micrometeoroid detectors resulting from the successful m-flight measurements of both Luna 1 in January 1959 and the American Pioneer 4 lunar flyby in March. The modifications earned it a new Ye-IA designation. The first attempt to launch a fifth spacecraft, Yc-IA No.5, was aborted on June 16, 1959, when it was discovered that the third stage tank had been filled with the standard kerosene instead of the higher density type required for this mission. The tanks were emptied, refilled with the proper fuel, and a second launch attempt made two days later. All went awry when the launch vehicle deviated from the planned trajectory after 153 seconds. One of the gyroscopes in the inertial guidance system had failed, and the launcher was destroyed by ground command.

An aborted launch of a sixth spacecraft occurred on September 9, 1959, when the core sustainer engine failed to reach full thrust upon ignition. ‘Hie launcher remained on its mount, and all the engines were shut down after 20 seconds. The rocket was replaced by a backup. The spacecraft on the aborted rocket was probably the Ye-1A Ко.6 model. Three days later Luna 2 (Ye-IA Ко.7) was successfully launched on a lunar trajectory. On 13 September, at a distance of 156,000 km, the spent third stage released its sodium cloud. Luna 2 impacted the Moon at 23:02:23 UT September 14. after 33.5 hours of flight, near the Autolycus crater in the Marsh of Decay region at about 29. Г N 0.0 E. Some 30 minutes later, the third stage of the Luna launcher also impacted the Moon.

Luna 2 was the first spacecraft to impact another celestial body. The Soviets had announced their transmission frequencies and Jodrcll Bank in hngland tracked the spacecraft through its the final plunge to silence. There had been some claims in the West that Luna 1 was a fraud, but Sir Bernard Lovell’s tracking and radio recordings provided all the proof needed that Luna 2 had hit the Moon. Nikita Khrushchev celebrated the achievement by presenting President Eisenhower with duplicates of the Soviet emblems that had been carried to the Moon at a United Nations meeting in Kew York on September 15, 1959.

Results:

Luna 1 was the first spacecraft to reach the vicinity of the Moon. The measurements obtained provided new data on the Earth’s radiation belt, and discovered the solar wind – a thin, energetic ioni/cd plasma flowing outward from the Sun past the Earth and Moon. It established that the micrometeoroid flux between Earth and Moon was small, and placed an upper limit on the strength of any magnetic field that the Moon may possess at no more than 1/10.000th that of Earth.

Luna 2 was the first spacecraft to impact on the Moon. It verified at much closer distance that the Moon had no appreciable magnetic field, and found no evidence of radiation belts around the Moon.

Campaign objectives:

By the end of 1965 the Soviets had failed in a total of sixteen launches to Venus and Mars. Ten of these failed attempts were aimed at Venus, including the most recent Venera 2 and 3 missions that had come so close to achieving their goals. Adding to the frustration was the fact that by this time the US had succeeded with close flybys at Venus in 1962 and at Mars in 1964. Nevertheless, the Soviets were encouraged by their near successes, and were determined to push on. Realizing that the US was to attempt another Venus flyby mission in 1967. the Soviets wanted to outdo them with two missions to pierce the cloudy veil of the planet and obtain new information on its mysterious atmosphere and surface.

After Venera 2 and 3 the robotic planetary program was transferred from OKB-1 to NPO-Lavochkin. Beginning in April 1965 Babakin decided not to send any more llyby missions to Venus after the 1965 campaign and Lavochkin began to revise the 3MV spacecraft for the 1967 window for this planet, concentrating heavily on entry and landing. Working from 3MV blueprints supplied by OKB-1 and insight drawn from the Venera 2 and 3 experience. Babakin’s engineers devised improvements to the thermal control and other systems. Lavochkin did more ground testing and built two new test facilities, one a thermal vacuum chamber completed in January 1967 to test the spacecraft under simulated flight conditions and the other a centrifuge rated at 500 G to test the entry and descent system. The first test of an entry probe in this chamber at the 350-450 G load expected for high angle Venus entries near 11 krn/s destroyed its internal components. As the earlier descent capsules would certainly not have worked, the design had to be modified. This revitalized effort was rewarded immediately with the USSR’s first truly successful planetary mission in 8 years of trying, with Venera 4 yielding in-situ data on the atmosphere of Venus. It began a new and much more fruitful era in the Soviet investigation of this planet.

Spacecraft:

Carney spacecraft:

These spacecraft were the first 3MV for Venera missions built by NPO-Lavochkin which, in particular, greatly improved the thermal control system that had caused so much trouble with Venera 2 and 3. The hemispherical fluid radiators on the ends of the solar panels were deleted and a new system of heat transfer pipes located behind the parabolic antenna, which itself served as a radiator since it faced in the opposite direction to the solar panels. Liquid coolant was abandoned in favor of gas coolant. The communication system was also improved and the omnidirectional antenna was replaced by low gain spiral cone antennas mounted on booms connected to the solar panels and angled in flight to keep Earth in the radiation pattern. As previously, the spacecraft had to be turned to aim its high gain antenna at Earth, but this was only during scheduled communications sessions and operations at Venus.

Like its predecessors. Venera 4 w? as 3.5 meters tall, the solar panels had a span of 4 meters and the parabolic high gain antenna w as 2.3 meters in diameter. The panels measured 2.5 square meters but. as previously, were sparsely populated with cells. The noticeable difference between Venera 4 and its predecessors in the 3MV series were the change in the solar panels to a more rectangular shape and the absence of the hemispherical radiators.

Entry vehicle:

For the 1967 mission the entry capsule was strengthened to resist stresses as high as 350 G and given an internal damper to reduce shock effects during entry and landing. At 1 meter in diameter it was 10 cm larger than the previous probes and nearly spherical with an ablative surface and a covered opening in the rear hemisphere for deployment of the parachute and antennas. It was the first of a series of entry probes which would be progressively better suited to survive the descent down to the surface. The internal mass distribution was bottom heavy to ensure the proper pointing on entry and aerodynamic stability during the descent. It was pre­cooled to -10 C by a system in the main module prior to separation, and operated a re-circulating fan thereafter. The capsule was intended to transmit atmospheric data

and radar data on descent, survive the impact and make measurements on the surface. The 28 amp-hour battery, which was rechargeable by the spacecraft during the cruise, could sustain 100 minutes of independent operation. The capsule design pressure was 10 bar with a margin up to about 18 bar, and the maximum survivable temperature for the parachute was 400°C.

The Venera probes were targeted to the center of the planetary disk as seen from Earth for optimum communications directly back to home. A helical antenna on top of the descending capsule was used to direct a radiation pattern to the zenith, and the telemetry was sent at 1 bit/s on 922,8 MHz using a pair of redundant transmitters. Measurements were sent back every 48 seconds. If the capsule w’ere to splash down in an ocean, which few people believed was likely, it would float and a ‘sugar seal’ would release a semaphore signal to signify this fact.

Figure 10.15 (left) show’s the entry vehicle without its upper insulation layers. The two ports arc for testing the insulation system on this engineering model. Inside the thick, porous and lightweight ablative material is ihe descent capsule itself shown in Figure 10.15 (right). Hanging out over the side are the radio altimeter antennas that spring out when the parachute deploys. In accordance with international regulations, the capsule was sterilized prior to launch.

Five levels of redundancy w’ere provided to ensure separation from the spacecraft. First by direct command from Earth, second by the on board sequencer, third by the triggering of a G switch on atmospheric entry, fourth by a sensor activated if Earth communications were interrupted by reorientation on entry and, as a last resort, the bands attaching the capsule to the spacecraft would burn through during initial entry.

Launch mass: 1,106 kg

Entry vehicle mass: 383 kg

Payload:

Carrier spacecraft:

1. Triaxial fluxgatc magnetometer

2. Solar wind charged particle detector

3. Lyman-alpha and atomic oxygen photometers

4. Cosmic ray gas discharge and solid state detectors

It had the same instruments as the Venera 2 and 3 cruise modules, except that the cosmic ray instrument included a second gas discharge counter of a different type.

Descent I landing capsule:

1. Temperature, pressure and density sensors

2. Atmospheric chemical gas analyzers

3. Radio altimeter

4. Doppler experiment

The temperature, pressure and density sensors were the same as on Venera 3. The gas analyzers used eleven cells to measure carbon dioxide, molecular nitrogen.

molecular oxygen and water vapor. The composition was identified by how the atmosphere reacted with the material in each cell, such as by the electrical conductivity of chemically absorbing surfaces; or by reactive heated filaments; or by how the internal pressure varied with specific absorptive materials. The experiment was to take a set of readings at parachute deployment and then again 347 seconds later. The instrument wras the same as flown on Venera 3 but included a hydrometer Гог water vapor measurement. A radio altimeter was carried for the first time to obtain absolute altitudes and confirm landing on the surface. The system w:as built by the Research Institute for Space Device Engineering and adapted from one used in aircraft. To conserve bandwidth, it did not issue continuous data, but only a semaphore to indicate falling through the altitude of 26 km. The Doppler experiment required no hardware on the capsule, utilizing the frequency shift of the carrier wave of the transmitter to determine the line of sight velocity of the probe as it descended through the atmosphere.

Some of the instruments carried by previous probes had to be deleted in order to release mass for the radio altimeter and the structural strengthening. The gamma-ray instrument, wave motion sensor, and photometer were sacrificed. But, as always, it carried a medallion with the coat of arms of the USSR and a bas relief of Lenin.

Mission description:

The first spacecraft was launched successfully towards Venus on June 12. 1967, and became Venera 4. The second was stranded in parking orbit on June 17, when the fourth stage did not ignite because the turbopump had not been pre-cooled. It was named Cosmos 167 by the Soviets and re-entered 8 days later. Venera 4 performed well during cruise, reorienting itself every few days to point its high gain antenna at Earth for a communication session. A midcourse correction was made on July 29 at a range of 12 million km from Earth. It arrived at Venus on October 18 and released the entry capsule at 04:34 IJT, at which time it was 44,800 km over the night side. The carrier spacecraft sent measurements on the upper atmosphere and ionosphere until it broke up in the atmosphere. The capsule entered the atmosphere at 10.7 kiu/s and slowed through a peak deceleration of 350 G. At a pressure level of 0.6 bar and a speed of 300 m s it shed the rear cover and deployed the 2.5 square meter drogue parachute. Several seconds later it deployed the 55 square meter main parachute and radio altimeter antennas. The instruments were turned on at 55 km altitude, at w hich time the rate of descent was 10 m/s. The mechanical commutator interrogated each instrument in turn and fed the data to the transmitter. It transmitted for 93 minutes on its parachute descent before falling silent. It reached the surface at 19 N 38 E, in darkness near the morning tenninator. It was 4:40 Venus solar time and the solar zenith angle was 110 degrees. Including three intended test flights, this was the first successful Soviet planetary mission after twenty attempts, and the first successful entry probe by either spacefaring nation.

Jodrell Bank reported receiving signals from the surface, not realizing that these had been sent during the descent. Thinking the capsule had reached the surface in an

operational slate, the Soviets reported that it had landed. But it slowly became clear that this could not be the case. The data from Mariner 5, which flew by Venus a day after Venera 4 arrived, indicated that the surface temperature was much higher than the final measurement reported by the entry probe. A series of meetings by Soviet and American scientists conducted over the next 2 years decided that the probe had succumbed to the increasingly hostile environment and had been disabled while still far above the ground. Nevertheless, as the first mission to transmit data from within a planetary atmosphere it achieved a major scientific milestone. The data return was significant and demonstrated just how hostile was the environment of Venus. It was evident that future probes would have to be further strengthened.

Results:

During its descent the Venera 4 entry probe returned more than 23 sets of readings by the atmospheric structure experiment. They began at an altitude of 55 km, and the atmospheric temperature was measured over the entire 93 minute descent. The initial temperature was 33nC and it increased to 262nC. The initial pressure reading was 0.75 bar, and the instrument reached its limit of 7.3 bar long before the probe ceased to transmit. Using atmospheric models constructed from the data at the time, it was concluded that the signal was lost at an altitude of 24 km. Atmospheric density
was obtained by plugging the temperature and pressure data into the hydrostatic equation and the result tested against the parachute descent characteristics. Doppler data (i. e. changes in received master oscillator frequency) provided altitude profiles of wind speed and direction, both horizontal and vertical, but the measurement errors were large.

The atmospheric composition experiment showed the atmosphere to be composed mainly of carbon dioxide:

carbon dioxide molecular nitrogen molecular oxygen water vapor

The percentage of carbon dioxide was initially disputed because the expectation was that at least 50% of the atmosphere would be molecular nitrogen, and American scientists were skeptical. But later missions would prove Venera 4 correct. The arid nature of the atmosphere was also unexpected. The model of Venus as a watery world had to be completely scrapped.

The aircraft-derived radio altimeter was designed to send a signal semaphore at an altitude of 26 km, but it had not been adequately adapted for the Venus mission and actually sent its signal at twice that altitude, 52 km. This was a principal cause of the confusion over whether Venera 4 had reached the surface or not. Atmospheric data and Doppler measurements showed that the probe had descended through about 28 km during transmission and the altimeter semaphore indicated that the top level was 26 km. The last measured temperature of 262 C and the derived pressure of 18 bar were about what was expected at the surface at the time. However, measurements of the planet’s microwave brightness made by terrestrial radio telescopes had indicated values of about 325 C. The chemical analysis by Venera 4 showing the dominance of carbon dioxide required a reanalysis of the radio-telescope microwave brightness based on atmospheric models with less carbon dioxide. A new analysis in 1967 explained some of the unusual features of the microwave spectrum of Venus as due to carbon dioxide, and resulted in surface conditions of about 427 C and 75 bar that were inconsistent with the Venera 4 probe having reached the surface. Atmospheric models based on Mariner 5 data also showed far higher temperatures and pressures at the surface. One suggestion was that Venera 4 had landed on a large mountain, but Carl Sagan pointed out that radar studies of the planet had found no such large edifice. Extrapolation of the Venera 4 atmospheric profile indicated conditions at the surface at the impact site to be 500°C and 75 bar. Eventually the data wns reconciled by Avduevskv, Marov, and Rozhdestvensky (1969) using an adiabatic model of the Venusian atmosphere which confirmed loss of signal at 18 + 2.5 bar at an altitude of about 24 km and extrapolated conditions at the surface as 442 C and 90 bar.

The signal ceased near the pressure limit of the capsule, but it is possible that the probe exhausted its battery near the 18 bar level after 93 minutes of operation. In any case the capsule would have been crushed and thereafter the parachute would have burned, leaving the capsule to free fall to the surface.

Prior to breaking up, the main spacecraft provided the first in-situ measure­
ments of the close-in magnetic field, thermosphere, ionosphere, and solar wind interaction. In 1962 Mariner 2 had flown past Venus at 34,773 km. which was too great a range to detect a magnetic field or magnetospheric signature. Venera 4 found no intrinsic planetary magnetic Held. The low fields detected were due to interaction of the solar wind with the ionosphere. No radiation belts were found, and an extended corona of atomic hydrogen was discovered reaching 10,000 km into space from the planet.