The soft-landers and orbiters

With man-on-the-moon plans in full swing, the next stage for the Soviet Union was to send unmanned probes to pave the way. These were essential for a manned landing on the moon. The successful landing of a probe intact on the lunar surface was necessary to test whether a piloted vehicle could later land on the moon at all. The nature of the surface would have a strong bearing on the design, strength and structure of the lunar landing legs. The level of dust would determine the landing method and such issues as the approach and the windows. The successful placing of probes in lunar orbit was necessary to assess potential landing sites that would be safe for touchdown and of scientific interest. Stable communications would also be essential for complex opera­tions taking place 350,000 km away. Unmanned missions would address each of these key issues, one by one.

ORIGINS

As noted in Chapter 2, the Soviet pre-landing programme can be dated to the 5th July 1958 when Mikhail Tikhonravov and Sergei Korolev wrote their historic proposal to the Soviet government and party, Most promising works in the development of outer space. Among other things, they proposed:

• The landing of small 10 kg to 20 kg research stations on the moon.

• A satellite to photograph the lunar surface.

• A lunar flyby, with the subsequent recovery of the payload to Earth.

Noting the American attempts to orbit the moon with Pioneer, Korolev made a proposal to government in February 1959 for a small probe to orbit the moon, the Ye-5. However, this required a heavier launcher than was available; and, in any case, the proposal was subordinated to the need to achieve success with the

Ye-1 to -4 series, which was proving difficult enough. The Ye-5 never got far. Korolev revised his proposals in late 1959, by which time a much more advanced upper stage was now in prospect, one able to send 1.5 tonnes to the moon, a considerable advance, but a figure identified by Tikhonravov as far back as 1954 in Report on an artificial satellite of the Earth. By now, the proposal was for:

• A new lunar rocket and upper stage, the 8K78, later to be called the Molniya.

• A lander, called the Ye-6.

• An orbiter, the Ye-7.

These were approved by government during the winter of 1959-60. OKB-1 Depart­ment #9, under Mikhail Tikhonravov, was assigned the work and he supervised teams led by Gleb Maksimov and Boris Chertok. Design and development work got under way in 1960, but it does not seem to have been a priority, the manned space programme taking precedence. The 8K78 was primarily designed around the payloads required for the first missions to Mars and Venus, rather than the moon, but they equally served for the second generation of Soviet lunar probes.