SPACE LABORATORY

In essence, the Salyut space station was a series of cylinders with small, medium, and large diameters. It had a total length of 13.6 metres, a maximum diameter of 4.15 metres and a mass of 18.6 tonnes. It comprised four sections. At the front was the transfer compartment. This was the smallest habitable section. It was 3 metres in length, just over 2 metres in diameter and had a volume of 8.1 cubic metres. It contained the life support and thermo-regulation systems. It also contained the No. 5 control panel for the Orion ultraviolet telescope. On the outside of this section were various masts and antennas, and a pair of solar panels which were identical to those on the Soyuz. The docking cone was on the axis at the front of this section. The hatch on the inward side of the docking system was one of three hatches in the compartment. There was a second axial hatch to provide access to the work compartment, and also a hatch on the outer wall with diameter of 80 cm to facilitate spacewalking, but there were no plans to go outside – indeed DOS-1 carried no EVA suits.

To enter the station, the cosmonauts had first to clear the docking system from the tunnel and then open the hatch to pass through the transfer compartment to the work compartment beyond. This was the largest component of the station and was in two sections. The smaller section (known as the first work compartment) was connected to the transfer compartment via a conical section 1.2 metres long. It was cylindrical, 2.9 metres in diameter and 3.8 metres long. It contained the central control panel, which incorporated a computer – the first on a Soviet manned spacecraft. Facing the panel were seats for two cosmonauts – the commander on the left (as viewed from the rear) and the flight engineer to his right. It was one of seven workstations for controlling Salyut’s systems and experiments. The No. 1 station was to control the life support and thermo-regulation systems, and to control the automatic orientation and navigation of the station, but it also included a periscope for manual orientation. From there, actually, the commander could control and fly the station using displays and control handles similar to those of the Soyuz. The central panel consisted of the main control panel and command and signal devices. It provided information on the station’s position over the Earth’s surface, the number of the current orbit, the times at which the station would enter and exit the Earth’s shadow and the periods during which it would be able to establish communication with the TsUP.

The system for orientation and control consisted of the following apparatus:

• ion sensors to measure the orientation of the station relative to its velocity vector;

• infrared sensors to determine the local vertical;

• Sun sensors;

• sensors for the angular speed during the rotation of the station;

• gyroscopes for measuring the angle of the station in three axes;

• an integrator for longitudinal accelerations;

• a stabilisation system;

• a control system for the orientation engines; and

• radio-location rendezvous apparatus.

While firing the manoeuvring engine, small orientation engines would hold the station stable. The system for manual control allowed the crew to align the station towards the Earth, the Moon, the Sun or the stars. While in stellar orientation, they would use a globe marked with the constellations and all stars brighter than the fifth magnitude.

The life support system controlled the gas mixture, eliminated strong smells and filtered out dust. In terms of millimetres of mercury, the pressure was maintained at 760 to 960, the oxygen concentration was 160 to 280, and carbon dioxide was never allowed to exceed 9. The air was cycled through a regenerator which contained an active chemical substance that removed carbon dioxide. Another unit topped up the oxygen. Water vapour was removed by a condensation trap. Special filters absorbed unwanted chemicals released by the materials on the station, the experiments and the crew. The equipment for the air regeneration system was to the left of the No. 1 control station.

The No. 2 station was for manual orientation and navigation. It included the control handles for the orientation of the station, a periscope and a means of stabilising the cosmonaut at his work position. Next was the No. 6 station, which included the flight engineer’s seat. To the right, on the side of the compartment, was the No. 7 control panel to operate the scientific apparatus installed externally to analyse the environment around the station.

Aft of the central panel of the No. 1 station was the table for preparing and eating meals. Each cosmonaut had four meals per day, consisting of breakfast, morning tea, the main meal (lunch) and dinner. For the main meal, each cosmonaut had one item (soup or coffee) warmed on a small heater beside the table. They could choose on a daily basis between three types of ration for each of the four meals. For example, ration No. 1 had the following products:

• The 1st breakfast (705-756 calories) о Sausages

о Borodin bread о Chocolate о Coffee with the milk

• The 2nd breakfast (600-700 calories) o Russian cheese

o Rizhskiy bread o Cookies

• Lunch (798-928 calories)

o Green shchi (a type of soup with mixed vegetables) o Chicken meat o Bread

o Plum jam with nuts o Blackcurrant juice

• Dinner (593-745 calories) o Caspian roach

o Puree o Bread o Honey cake.

The water tanks were located nearby the table and at the aft end of the working compartment. Each man was allowed 2 litres of water per day, but actually they did not use more than 1.2 litres. As on Soyuz 9, silver ions had been added to the water tank prior to launch to keep the water fresh.

Usually, the cosmonauts spent their spare time in this first working compartment, where they had a tape recorder with a selection of pre-recorded music cassettes, a small library and a sketchpad.

Externally, the larger section was 2.7 metres in length and 4.15 metres in diameter. It was joined to the smaller compartment by a short conical adapter. There was no internal distinction, however; the compartment was a single room with total length of 7.7 metres and a volume of 74 cubic metres. Including the transfer compartment, the total habitable volume of the station was 82 cubic metres. The central part of the larger working compartment was occupied by the main scientific equipment (ONA), which took the form of a large white conical unit that rose from the floor almost to the ceiling. It included the OST-1 orbital solar telescope, the RT-2 X-ray telescope, the ITS-K infrared telescope and spectrometer, the OD-4 optical viewer that had a magnification of 60, the FEK-7A photo-emulsion chamber, photographic apparatus and various other apparatus. On the walls around it were three portholes. The No. 3 station to control the scientific apparatus was adjacent to the ONA and included a viewing port. Unfortunately, the protective cover had failed to release when Salyut achieved orbit, and therefore these scientific instruments were unusable. The second control panel of this compartment was the No. 4 station, which was mounted on the adapter between the two sections of the working compartment. It was to control the main medical research equipment, and comprised scientific experiments, a viewing port and a chair.

In the upper corner to one side of the ONA sleeping bags were slung from hooks, but if they preferred the cosmonauts could sleep in the Soyuz orbital module or in the transfer compartment. On the opposite side and in front of the ONA there were exercise devices, including the KTF treadmill, an exercise bike and chest expanders. The crew had special ‘penguin’ suits designed to stimulate the muscles that would otherwise decay in weightlessness. The Polynom medical apparatus was for general monitoring of the crew’s health. A small medical kit, identical to that carried on the Soyuz, provided pain relief, heart stimulation, relief of gastric problems, antiseptics, bacteriostatics and sleeping and stress relief tablets.[66] In fact, during the entire flight there were very few cases when the cosmonauts required medication.

At the aft end of the compartment, behind the ONA and separated from the rest of the working area, was the sanitary and hygienic unit. It had its own ventilators and its surface was a washable material. An airflow drew urine into a collector, where it was separated into its fluid and gaseous components. Solid waste was stored in hermetic tanks. Also at the aft of the compartment were the fridges containing food.

To assist the cosmonauts orientate themselves, the work compartment was painted in different colours – the front and rear were light grey, one wall was green, the other was light yellow and the floor was dark grey.

The cosmonauts had a collection of underwear and sports T-shirts. For cleansing their faces, hands and bodies following experiments, maintenance work or physical exercise they used wet and dry tissues and special towels made of bacteriological materials. From time to time, they were to clean the station using a vacuum cleaner.

Detachable panels on the walls and the floor covered support apparatus, electrical cabling, equipment for operating the station, monitoring the composition of the air, thermo-regulation, radio-links and the main command lines. The cosmonauts could open every panel and check the apparatus mounted on the compartment’s structural frames. Hand rails on the walls and floor allowed easy movement in weightlessness. The walls held lockers of food, equipment, documentation, packed clothes, books, hygiene supplies and miscellaneous spare parts for repairs.

The thermo-regulation system had two major elements, one to cool the station and the other to warm it, each with an internal and an external loop. The fluid was based on antifreeze. The external loop ran through radiators with a total area of 21 square metres installed on the surface of the main compartment. The system maintained the air temperature between 15°C and 25°C, the humidity between 20 and 80 per cent, and the maximum airflow at 0.8 metres per second. The temperature and the airflow could be controlled from the central control panel.

An unpressurised section extended the line of the main compartment 1.4 metres to the rear. This was the only section which was inaccessible to the crew. It housed the

An inside view of the Salyut space station showing the main control panel, the seats for commander (left) and flight engineer, and the open hatch leading to the transfer compartment.

This section of the main control panel on the commander’s side shows a globe for navigation and (bottom row, left to right) voltage, current, pressure and temperature, as well as the time, range and approach speed.

KTDU-66 propulsion system comprising a main and a backup rocket engine. It was based on that of the Soyuz, but had larger tanks containing 1,490 kg of propellant (UDMH fuel and nitric acid oxidiser) for a total burn time of 1,000 seconds. At the rear was a smaller cylinder 1.8 metres in length with a diameter of 2.17 metres that housed 32 small orientation engines and had a second pair of solar panels installed on its exterior. Each of the solar panels had an area of 7 square metres, for a total of 28 square metres. In ideal conditions, they had a total output of 2 kW. Because the panels were carried in a fixed orientation on the side of the station, it was necessary to align the station to maximise the illumination of the panels. However, 40 per cent of each orbital period was spent in the Earth’s shadow, and at such times cadmium

The flight engineer’s side of the main control panel.

accumulator batteries supplied direct (dc) and alternating (ac) electrical currents. A static voltage stabilisation system limited the variation in the voltage to 1.5 per cent. In the docked configuration, the solar panels of the Soyuz spacecraft fed electricity to the station.

In addition to two-way voice and telegraph links, the radio system fed telemetric data to the TsUP. The antennas were on the exterior of the main compartment. The cosmonauts had helmets incorporating headsets. Salyut had four TV cameras: two inside and two outside. One of the inside cameras was static and viewed the area of the central control panel of the working compartment. The other could be set up to record activities anywhere in the station. At launch, one of the outside cameras had documented the separation of the station from the third stage of its Proton rocket. The other had shown the rendezvous and docking operations. The cosmonauts also used them in orienting the station.

Specific references

1. Davidov, I. V., Triumph and Tragedies of Soviet Cosmonautics. Globus, Moscow, 2000, Chapter “Полет продожается” (Flight Continues) (in Russian).

2. Kamanin, N. P., Hidden Space, Book 4. Novosti kosmonavtiki, 2001, pp. 316­317 (in Russian).

3. Chertok, B. Y., Rockets and People – The Moon Race, Book 4. Mashinostrenie, Moscow, 2002, pp. 316-320 (in Russian).

4. Vasilev, M. P., Salyut on Orbit. Mashinostroenie, Moscow, 1973, pp. 38-42 (in Russian).

5. Clark, Phillip, The Soviet Manned Space Programme. Salamander Books, London, 1988, pp. 56-60.