Part II Post #4: Making Raketoplans
Part II Post #4: Making Raketoplans
Like many in the United States, the leaders of the Soviet Union were not entirely clear what missions Dynasoar would be used for. They knew that the original brief had been for an intercontinental range skip-glide reconnaissance platform and bomber, but by 1963 ICBMs and spy satellites appeared to be making these missions obsolete. Despite this, the Americans were continuing to spend huge sums of money developing their spaceplane. The official line, that Dynasoar was intended to advance techniques for the peaceful manned exploration of space, seemed inadequate in the face of the costs.
To the minds responsible for guiding and protecting the home of the World Socialist Revolution, the absence of an obvious visible mission could only mean that there was a secret, hidden purpose to Dynasoar. If Soviet experts were unable to deduce that mission, the conclusion must be that the US were taking extreme measures to keep it secret, in turn proving that it must be a vital, even game-changing advancement of the Cold War. So came the final conclusion: The USSR must develop an equivalent capability! Even if they could not currently see the value in it, they needed to be able to match the Americans on the day their secret purpose was finally revealed!
It was this chain of reasoning, as well as his personal contacts with a sceptical Khrushchev, that enabled Chelomei to maintain support for his Raketoplan spaceplane development even in the face of massive cuts to the Soviet military forces. Following the September 1959 decree formally authorising the project, OKB-1 quickly began drawing up plans and conducting experiments to make Chelomei’s vision of a family of responsive military spacecraft a reality. The common service module that would support the various specialised Raketoplan payloads was considered to be relatively straightforward to develop, but the protective aeroshell and in particular the manned spaceplane presented more challenging problems.
Working closely with TsAGI (Tsentralniy Aerogidrodinamicheskiy Institut, “Central Aerohydrodynamic Institute”), LII (Lotno-issledovatel'skiy institut, “Flight Research Institute) and VIAM (Vsesoyuznyy nauchno- issledovatel'skiy institut aviatsionnykh materialov, “All-Union Scientific Research Institute of Aviation Materials”), a number of sub-scale test vehicles were developed starting in 1960 for both the spaceplane and aeroshell. These were used in a series of wind tunnel and suborbital ballistic tests through to the first half of 1962, the results of which validated Chelomei’s approach of using a standard, discardable aerodynamic heat-shield for re-entry. However, the tests also uncovered serious problems with his preferred deployable swing-wing aircraft design.
Based on his earlier work with Naval cruise missiles, Chelomei had proposed to duplicate their pop-out wings on a larger scale in order to fit his spaceplane behind the aeroshell. However, there were severe challenges involved in scaling up this mechanism for a manned spacecraft whilst making it both reliable enough and, critically, light enough to be worth the trouble. As on almost all space projects, weight growth was a serious issue for Raketoplan, and the wing deployment mechanism soon came to dominate the system’s mass budget discussions.
Reluctantly, Chelomei was forced to change tack and accept TsAGI’s recommendation for a fixed delta-wing spaceplane. However, this approach raised new issues, as the tips of the wings would now project outside of the aeroshell. Whilst this would provide an opportunity to improve stability and control on re-entry, it also exposed the thin wing edges to greater temperatures. In response, the shape of the aeroshell was adjusted to minimise the exposure of wings to the plasma flow, and a tough, tungsten-based alloy with a protective sheath of graphite was developed by VIAM for the wing leading edges.
A full-scale aerodynamic model of this version of the spaceplane, code-named “Orel” (“Eagle”), took its first flight in May 1963 from Kapustin Yar. Flying without a Service Module, the Orel test article and its aeroshell, weighing a combined 5 tonnes, were installed on the nose of a modified R-6 first stage for a suborbital test. The test was largely successful, with the aeroshell demonstrating excellent hypersonic manoeuvrability and a clean separation from the spaceplane. Orel also performed moderately well at first, gliding downrange as intended, but five minutes after separation it suddenly veered sharply to the left and entered a steep dive. The recovery parachute deployed, but the aircraft hit the ground nose-first, causing considerable damage.
Film footage from one of the Sukhoi Su-9 chase aircraft showed that a section of the leading edge of the left wing had detached, partially ripping away the skin of the wing as it departed. Later analysis proved this had been caused by a failure of the thermal protection along the leading edge, leading to a redesign of the system to include ablative “Sabot” shields built into the aeroshell along the wing edge, which would be jettisoned along with the shell after re-entry.
This improved version took its first flight in January 1964, and proved far more successful. The plane made a smooth landing on the frozen Kazakh steppe, its rugged skids cushioning the landing, and was recovered by Army helicopter for shipment back to Moscow. The Orel was found to be in good shape, and was later re-flown on the fourth suborbital flight test in July. Meanwhile, starting in May 1964, a series of piloted test flights were performed out of the State Red Banner GK Scientific Research Institute VVS at Khodynka, outside Moscow. These test flights involved using Orel’s small jet engine to fly to altitude and then perform a series of varying approaches to the airstrip. Later tests added a small rocket stage to the rear of the plane, boosting it to the supersonic speeds and high altitudes it would experience upon aeroshell separation, then manoeuvring unpowered until its airspeed dropped low enough for the jet to cut in. Pilots reported that the aircraft handled well at high speed, but became less stable as the speed reduced, with a stall speed of around 190 knots (350 kph). It was flyable, but would require special training to ensure safety.
Atmospheric flight testing of the Orel Raketoplan spaceplane.
As work progressed steadily on Raketoplan, the development of its UR-500 launcher was also underway. Chelomei had sold the UR-500 in 1959 as a “Super ICBM”, capable of delivering a new generation of “Tsar Bomba” superbombs anywhere in the US. But as with Orel, changing circumstances were undermining its justification. As nuclear weapons became lighter and their delivery systems more accurate (thanks in part to Chelomei’s advances in hypersonic re-entry), the extra costs of the UR-500 no longer matched its usefulness. In particular, the huge silos that would be needed to protect the UR-500 from a disabling first strike would be prohibitively expensive, to the point where it would be cheaper to use three of Yangel’s R-36 missiles against a target rather than a single UR-500.
In addition to these economic problems, the UR-500 was also running into technical issues. Glushko had hoped to develop a common set of engines for the UR-500 and Yangel’s R-200, but diverging requirements and scaling problems made this increasingly difficult. In response, Glushko had chosen to focus first on the R-200’s RD-201 engines, then use these as a basis for the larger RD-221 later. Partly this was down to a rational engineering assessment by Glushko, but he was also influenced by a simple preference for working with Yangel over the assertive, arrogant Chelomei. This would not be the last time that Chelomei’s focus on charming the bosses whilst ignoring his peers would come back to bite him.
The two people that saved the UR-500 from outright cancellation were Khrushchev and von Braun. Von Braun was important because it was his Minerva rocket that convinced enough of the Soviets’ top generals that the USSR needed an equivalent. As with Dynasoar and Raketoplan, Minerva and the UR-500 were linked as move and counter-move in the chess game of the Cold War. Khrushchev was of course vital because of the personal support he lent Chelomei at the top of the Soviet government. Chelomei had plans to use the UR-500 not only for his Orel spaceplane, but also for his planned “Almaz” military space station and his capsule-based “Safir” Raketoplan variant for circumlunar flights. Whilst the military showed some interest in Almaz, it was only Chelomei’s hard lobbying of Khrushchev, and the latter’s desire for further space spectaculars, that won him support for development of Safir.
As Chelomei’s UR-500 struggled towards realisation and Yangel’s R-200 moved smoothly through development, a third rocket was being created by Mishin. Authorised in the 1959 decree to develop a five-tonne class launcher using kerosene and liquid oxygen propellants, Mishin had quickly managed to expand the scope of his M-1 vehicle by assuming that “Five tonnes” referred to the payload of one of his Molniya military communications satellites. These were planned to use a highly eccentric (and so highly energetic) elliptical path that would keep them over the northern hemisphere for the majority of their orbit. To support this capability, the M-1 would have to be considerably larger than Chelomei had intended when he agreed to the draft decree for the Central Committee. In fact the M-1 in its final configuration would match the R-200’s 10 tonnes to low Earth orbit, double the original specification.
Building on the experimental work Mishin had been overseeing since the mid-’50s, the M-1 design came together quickly, and the first prototype launcher had reached the pad at Kapustin Yar in April 1962. With a first stage powered by six of OKB-385’s in-house VM-12 engines, the two-stage rocket lifted from the pad, but then quickly veered off course due to a failure in the guidance system. The M-1 was destroyed as a safety measure, but even in the face of this apparent failure Mishin was able to point to the fact that no cloud of poison gas had been created during the accident.
More tests followed, starting at Kapustin Yar and then moving to Tyuratam as Barmin completed the necessary facilities in late-1962. These tests culminated in March 1963 with the successful orbiting of an experimental communications satellite.
With the Zarya-3 tragedy coming just three months later, Mishin received authorisation to push ahead with the modifications needed to launch manned Zarya capsules on the M-1. These modifications were tested in November 1963, with the unmanned launch of a Zarya-B spacecraft. Enclose within a new fairing design that sported a launch escape tower on its nose, the rocket successfully delivered the capsule to a 300 km circular orbit. Supplied by its enlarged service module, the Zarya-B (given the cover name “Kosmos-27”) remained on-orbit for six days before performing a re-entry burn. Separation from the service module was clean, and the return vehicle made a perfect landing back in Russia. When a second unmanned test showed similarly textbook mission profile in January 1964, Mishin gave the go-ahead for a manned flight, which if successful would be the USSR’s first manned mission for over a year.
On 10th March 1964, cosmonauts Aleksei Leonov and Pavel Belyayev were strapped into their capsule at Tyuratam for the Zarya-3 mission (Kuznetsova’s failed mission of the same name having been deleted from the official history books). Unlike the earlier missions, this time there was no ejection seat. If anything went wrong with the M-1, the two cosmonauts would have to rely on the Escape Tower to pull them clear of the explosion. Whether the tower worked as planned or not though, Leonov and Belyayev knew that the M-1’s non-toxic propellant mixture meant that they would at least be spared the fate of poor Tanya.
At 10:15 am local time, the VM-12 engines roared into life and Zarya-3 left the launchpad. Despite their fears, the first stage burn went completely according to plan, with forces on the two test pilots climbing to over 6 gee at first stage burnout. The first stage was jettisoned, along with the unneeded escape tower, and the single VM-22 second stage engine ignited to complete the insertion of Zarya into its planned 220 km by 330 km orbit. Both cosmonauts reported a smooth ride and no problems as they separated from the second stage and deployed the PA module’s small solar panels.
Zarya-3 stayed in orbit for over a full day, smashing the 7 hour duration record set by Mercury-5 the previous December. In terms of man-hours on orbit, Zarya-3’s record was an even more impressive, topping 51 hours for a single mission. Although conditions were cramped for Leonov and Belyayev, the removal of ejection seats meant that they had enough space to remove the outer layers of their spacesuits, and both men were able to sleep for short periods during the mission.
The only significant problem encountered during the mission occurred during the return to Earth. Following the separation of the PA, the SA re-entry capsule experienced a sudden depressurisation. Fortunately both cosmonauts had been wearing their spacesuits for the critical return journey, and both were able to seal their faceplates before suffering any worse than a bloody nose and a minor fright. However, the air-cooled electronics in the SA module soon began to overheat in the near-vacuum of the cabin, and the cosmonauts were forced to quickly shut down all unnecessary systems in an effort to keep essential systems functioning. Fortunately the aerodynamic design of the Zarya capsule meant that the re-entry was able to continue unguided to a successful ballistic landing in Russia a few hundred kilometres from the target zone, with recovery forces arriving on the scene around two hours after touchdown. The cause of the depressurisation was later traced to a faulty valve in the SA - a case of poor quality control. This event solidified the Soviet practice of cosmonauts always wearing full spacesuits for critical mission events.
The Zarya-3 mission was a badly needed propaganda boost for the Soviet Union. Whilst the USAF could just about manage to send one man into space for a few hours, the USSR was launching multi-man, multi-day flights. For Khrushchev the mission gave him a genuine triumph to point to at a time when the Soviet economy was slowing and Soviet influence abroad was waning.
Mishin too was buoyed by the success. He was directing real missions with real achievements, whilst arch-rival Chelomei played with his toy spaceplanes. With his next flight, Mishin aimed to top Zarya-3’s achievements with something even more spectacular - something that would finally give him enough prestige to overcome Khrushchev’s patronage and supplant Chelomei as the undisputed leader of the USSR’s space programme.