MK-700 Credit: Mark Wade. 5,747 bytes. 640 x 94 pixels.

Chelomei was the only Chief Designer to complete an Aelita draft project and present it to the Soviet government. He proposed two launches of the enormous UR-700M launch vehicle to assemble a 1400 tonne MK-700 spacecraft in earth orbit. Nuclear thermal stages allowed a net functional payload (living quarters, Mars landers, earth return capsule) of 250 tonnes.

A government expert commission reviewed the preliminary draft project for the UR-700M launch vehicle and MK-700 spacecraft in 1972. Based on the decades worth of development and tens of billions or roubles required, the state commission recommended that further work on manned Mars expeditions be deferred indefinitely.

In the post-Apollo moon landing euphoria, NASA was pressing for funding for a manned expedition to Mars. The Soviet leadership reacted in kind. Development of an advanced project for the MK-700 was authorised in Ministry of Defence decree 232 of 30 June 1969. The TTZ specification document was written by the TsNIIMASH and NIITI institutes, and the project was given the code name 'Aelita'. The TTZ called for a Mars expedition spacecraft of 1,500 tonnes mass.

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MK-700 Mars craft - MK-700 manned Mars spacecraft designed by Chelomei in 1970's Credit: Andy Salmon. 12,800 bytes. 472 x 183 pixels.

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• Variant 1: A launch vehicle with a payload of 750 to 800 tonnes payload (requiring two launches and one docking in earth orbit to assemble the 1,500 tonne MK-700 spacecraft). This was the preferred variant.
• Variant PA: Launch vehicle with 480 to 520 tonne payload, requiring three launches and two dockings to assemble the spacecraft.

Further studies by Section p/Ya A-1233 of Chelomei's TsKBM managed to reduce the mass of the spacecraft for the Mars expedition to 900 to 1,.000 tonnes. This allowed the PA variant booster to be used with just two launches and one docking.

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RD-0410 NTP Engine - RD-0410 Nuclear Thermal Engine Credit: © Dietrich Haeseler. 25,183 bytes. 159 x 327 pixels.

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A government expert commission reviewed the preliminary draft project in 1972. Two variants were presented:

• Variant 1 used 40 tonne and 3.6 tonne thrust nuclear rocket engines in the upper stages. It required delivery of 1,400 tonnes of payload to low earth orbit, requiring two UR-700M launches and one docking.
• Variant 2 used Lox/LH2 chemical propulsion in the upper stages. It would require delivery of 2,500 tonnes into earth orbit, using four UR-700M launches and three dockings.

The first variant was the preferred option. The MK-700 spacecraft design is represented by a model in the TsNIIMASH museum. This indicates that it consisted, from fore to aft:

• Launch 1: MK-700 Spacecraft. This consisted of:

  • VA re-entry capsule, a stretched version of that used in the LK-1 and LK-700 lunar spacecraft and TKS manned orbital ferry designs. Access from the capsule to the living quarters would have been through a hatch in the heat shield. Base diameter of the VA was about 5 m.
  • Living/equipment module, 15 m long and with a diameter of 10 m. This was presumably the living quarters for the crew. It was equipped with solar panels with a span of 20 m. These would have provided auxiliary power in case of failure of the nuclear power plant and/or during the return of the spacecraft from Mars. The VA and Equipment Module were covered by a payload fairing during ascent to orbit and were presumably topped with a large launch escape tower to pull the VA away in case of a launch vehicle emergency.
  • Primary module 10 m in diameter and 45 m long. This assembly would have included the Mars lander , probes, and the cruise/Mars manoeuvring nuclear stage. At the base was a flared interstage that would have docked with Launch 2 portion of the spacecraft in earth orbit. The propulsion stage would have had a mass of about 450 tonnes and the VA, Equipment module, lander, and probes about 250 tonnes.

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  Salyut and MK-700 - Salyut and MK-700 models Credit: © Mark Wade. 32,102 bytes. 635 x 442 pixels.

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• Launch 2: The second module would probably be a 700 tonne trans-Mars injection stage, 12.5 m in diameter and about 75 m long.

• The problem of crew survival for 650 days on the voyage to Mars had not been solved. 12 to 15 years of studies of the affects of space on human beings would be required aboard space stations in earth orbit before this would be possible.
• Nuclear engines for the first variant were only in the draft project stage. It would take 15 to 20 years to reach technological maturity.
• The radiation safety problem of nuclear thermal propulsion had only been solved theoretically. Negotiations with the United States would be required to achieve international permission for placing large nuclear reactors into orbit. The outcome of these negotiations was uncertain.
• Variant 2, requiring 2,500 to 3,000 tonnes of payload, was technically and legally more achievable, but the mass to be placed in orbit was unrealistic.
• Total program would cost 30 to 40 billion roubles at 1973 prices. The Soviet Union did not have the resources to pursue a project of that size.

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  Manned station - Large manned space station or interplanetary spacecraft, probably Chelomei design, with launch escape tower, TKS-type reentry capsule, large windowed pressurized module at rear. Credit: Andy Salmon. 9,953 bytes. 446 x 189 pixels.

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Some sources indicate Chelomei proposed yet again a single-launch Mars flyby expedition in 1974. This would be launched on the UR-900 or a more modest version of the UR-700M, with a low earth orbit payload of 250 tonnes. A crew of two in an MK-700 spacecraft would spend two years on a flight to Mars and then return to earth using the re-entry capsule developed for Chelomei's TKS orbital ferry.

Craft.Crew Size: 2. Design Life: 730 days. Total Length: 140.0 m. Maximum Diameter: 12.5 m. Total Mass: 1,400,000 kg. Main Engine Propellants: LH2. Main Engine Isp: 900 sec. Electrical System: Nuclear reactor.

Ministry of General Machine Building (MOM) Decree 232 'On start of work on the UR-700M rocket' was issued. The decree allowed development of an advanced project for a manned Mars expedition using the UR-700M booster and MK-700 spacecraft. The TTZ specification document was written by the TsNIIMASH and NIITI institutes, and the project was given the code name 'Aelita'.

Chelomei's preliminary draft project for the UR-700M launch vehicle and LK-700 spacecraft was reviewed by a government expert commission. Based on the decades worth of development and tens of billions or roubles required to realise the project, the state commission recommended that further work on manned Mars expeditions be deferred indefinitely.

As the only remaining contender for the Aelita design competition, Chelomei proposes a Mars flyby using an MK-700 spacecraft. A crew of two would be sent on a two year mission in a single launch of a UR-700M booster. The spacecraft would have a mass of 250 tonnes in low earth orbit and be equipped with an RD-410 nuclear engine.

• 122 - Vick, Charles, Spaceflight, "Energomash Reveals 'F-1 Class' Rocket Engine", 1994, Volume 36, page 321.
• 443 - Yeteyev, Ivan, Operezhaya vremya, Ocherki, Moscow, 1999..