Fifty years later: Soyuz-1 revisited (part 2)The investigationOn April 27, 1967, Ustinov met with the leading space industry representatives and established a special governmental commission under his direction to determine the causes of the accident. The commission included seven sub-commissions. One of them, to investigate the landing itself, was headed by the recently-appointed director of the M. M. Gromov Flight-Research Institute (LII), Viktor Utkin, a respected aeronautical engineer. The commission included two representatives from TsKBEM, Mishin and Bushuev. Soyuz mission backup cosmonauts Gagarin and Bykovskii also served as members.29
The Utkin sub-commission finished its work, which included some experimental analyses, by June 20, and emerged with the probable cause of the accident: a release failure in the container block of the primary parachute. The primary parachute (which had a surface area of 1,000 square meters) was packed into an elliptical container at great pressure. When descending through the Earth’s atmosphere, a special pressure sensor in the Descent Module typically issues a command to jettison the lid of the container. At this point, the internal pressure of the container drops abruptly to the value corresponding to an altitude of 9.5 kilometers. The internal pressure of the Descent Module, basically one atmosphere (or sea level), acts on the body of the container. Due to this pressure differential, a compressive force acts over the entire surface of the container. This pressure then helps to eject out a “braking” or drogue parachute, which, over a period of 17 seconds, slows down the vehicle to a manageable 40 meters per second. At that point, the drogue pulls out the main parachute that, after being full of air, releases the braking parachute.30 In the case of a failure of the primary parachute, detected by a sensor measuring descent velocity, then a command is issued to jettison the lid of the backup parachute system, with a surface area of 570 square meters, which has a similar profile to the primary in terms of its operation. The investigation commission produced its report in the autumn of 1968, over a year after the accident. On Soyuz-1, according to the commission, the primary parachute failed to deploy, most likely because the pull force that the drogue parachute imposed on the parachute container was insufficient to pull out the main parachute. The commission concluded that the pull force was insufficient because the primary parachute’s cylindrical container had become deformed due to the sudden pressure differential between the low pressure (at altitude) from the now-opened container and the sea-level pressure from the main cabin of the Soyuz that enclosed the container. There was an elastic movement that squeezed the outer container inwards, jamming the main parachute. In this situation, the amount of force needed to pull the parachute out of the container was much larger than that applied by the drogue parachute.31 At this point, after the failure of the primary parachute to open, the backup parachute should have been deployed. But, the drogue chute for the main parachute had still not been jettisoned and remained deployed above the rapidly descending space capsule. Once the backup parachute began to unfurl, it began to extend under the still-attached drag parachute from the primary system and thus got tangled. Hindered by the flailing drag chute, the backup parachute never filled with air. Without any means of braking, the ship plummeted and hit the ground at a velocity of 144 kilometers per hour (40 meters per second).32 An autopsy of Komarov confirmed that he died on impact with the ground and that the effects of the fire were secondary. Despite rumors to the contrary, Komarov did not cry or scream before the impact, although during the last seconds he was surely aware that he had little chance to live.33 Due to the rapid velocity of descent, the frontal heatshield was never discarded at an altitude of three kilometers, and the soft-landing engines never fired prior to touchdown. The latter, in fact, detonated after landing, burning with the 30 kilograms of concentrated hydrogen peroxide from the capsule’s attitude control engines. From launch to impact, Komarov’s ill-fated flight had lasted 1 day, 2 hours, 47 minutes, and 52 seconds. This effect of the pressure differential on the deployment of the primary parachute—essentially a design defect—had not been detected on the three precursor missions because one was blown up before reentry, one never got off the ground, and the third had a hole in its bottom, thus equalizing the pressure with the outside and negating the possibility of the pressure differential that caused the parachute to jam. Yet, the same system had in fact been tested on at least four drop tests prior to Soyuz-1 without detecting the problem, a result that investigators attributed to “probability,” i.e., statistical anomalies.34 Given this rather striking conclusion, some, including Chief Designer Mishin, had also suggested that the parachute had been packed improperly, something he believed for many years, although some doubt was cast on this theory during post-accident observations of the packing procedure, which supposedly repeated what had been done before Soyuz-1.35
To remedy the parachute container problem, the commission recommended redesigning the parachute container by making it conical instead of cylindrical, increasing its internal volume, and polishing the inside walls. In addition, an autonomous emergency system for separating the primary drogue chute was installed, and new procedures introduced for photographing the pre-flight assembly of the parachute packages. As far as the other problems on the spacecraft, the failed solar panel deployment was later traced to the panel getting snagged on the external vacuum-shield cover of the spacecraft. The 45K attitude control sensor had failed because its optical surface had been “fogged up.”36 Over the months after the official conclusion was issued, an “unofficial” version of the cause of the accident also circulated among engineers, one that attributed the accident to gross negligence on the part of technicians at TsKBEM’s manufacturing plant in the northeastern Moscow suburb of Podlipki. Boris Chertok describes this chain of events leading to the failure: According to the standard production process, after the thermal protective coating was applied to the [Soyuz] Descent Module, it was placed in an autoclave, where the synthetic resins that make up the thermal protection [system] were polymerized at high temperature. Deviating from the approved process, all Descent Modules up to No. 4 and No. 5 [i.e., Soyuz-1 and Soyuz-2] went into the autoclave without the parachute containers.37 What was the consequence of this lapse in quality control, apparently because the covers of the parachute compartments weren’t ready? Like the exterior of the spacecraft, the insides of the parachute containers were also polymerized “causing the [inside] surface to become grainy, bumpy, and sticky,” thus making it very difficult for a drogue parachute to pull out the tightly packed main parachute. 38 The most chilling implication of both failure scenarios—the jammed parachute from either pressure or friction—was that both Soyuz spacecraft were doomed to failure. In other words, if Komarov had not faced any troubles in orbit and Soyuz-2 with cosmonauts Bykovskii, Eliseev, and Khrunov had lifted off for their mission, all four cosmonauts would have most certainly died on return. Not everyone believed the unofficial explanation for the accident either. When Chertok first published this theory in the 1990s, some workers at the factory were particularly incensed, arguing that the parachute lids were, in fact, installed for the polymerization tests. Perhaps Mishin’s assertion that the parachutes were packed incorrectly was also true? A senior TsKBEM designer Eduard Korzhenevskii told Chertok many years later that in his opinion “the parachute was so severely jammed into the cramped, rough container that no addition adhesion was required” to prevent it from pulling out the primary parachute.39 The existence of concurrent official and unofficial versions raises at least a question of how the Soviets managed crisis resolution in their space program in the 1960s. Clearly, job security for some was a big factor in squelching the unofficial version of the events. But how did a post-accident testing program incorporate procedures that accounted for the unofficial version without explicitly acknowledging it? Was the unofficial account common knowledge among technicians and engineers? These questions still remain unanswered despite the fact that the massive official history of Mishin’s organization, published in 1996, included both the official and unofficial causes of the Soyuz-1 accident.40 The one major casualty of the post-Soyuz-1 investigation was Fedor Tkachev, who was the chief designer at the organization responsible for the design and manufacture of the parachute system, the so-called Scientific-Research and Experimental Institute of the Parachute-Landing Service (NIEI PDS). Although the unofficial version exonerated his organization of any blame, Tkachev was fired from his job in 1968, ending his role in designing the parachute systems for Vostok, Voskhod, Zenit, Soyuz, and many other Soviet spacecraft of the era. Two further parachute failures during tests following Soyuz-1 apparently sealed his fate.41 He was replaced by Nikolai Lobanov. Another senior designer at TsKBEM, Pavel Tsybin, who was responsible for ground testing of all spacecraft, was also “released” from his position as deputy chief designer under Mishin, although he had not been directly involved in preparations for Soyuz-1.42
Through the years, there have been sporadic but unconfirmed reports of Komarov bidding his farewells in orbit, Komarov screaming to his death, and even Komarov attempting to repair his ship in space by climbing into inaccessible areas of his ship.43 All of these can be rejected as untruths or exaggerations. With regard to foreign monitoring of his mission, there was one postscript to the mission that emerged 30 years after Soyuz-1. Boris Pokrovskii, a high-ranking official in the Command-Measurement Complex, the Soviet space tracking service, wrote in his memoirs in 1996 that: I remember that several days after Komarov's death I was summoned by General A. G. Karas [the then-head of the ‘military space forces’] who told me by phone to bring a tape-recorder to his office. It turned out that the USSR Ministry of Foreign Affairs had forwarded a tape received via “diplomatic channels” from [West Germany]. Remembering that I knew a little German, Andrei Grigor’evich invited me to listen to the tape that German specialists had recorded by radio several minutes of information from on board Soyuz-1. The specialists’ commentary on the tape was naturally in German. From Komarov’s brief phrases it was possible to conclude that he was somehow distraught, and later through the radio noise it was possible to hear the word “I’m dying.” But nothing was said about the parachute system. The words were on the rising temperature inside the ship. The recording was made, apparently, on one of the last orbits, if not the final one. The German commentary was not that interesting…44 This report, like many of the more sensationalist reports, is riddled with inconsistencies and should probably be taken with a grain of salt. But there remains the question, what did Komarov say or do as his capsule plummeted to the ground, after entering the Earth’s atmosphere? Komarov’s tape recorder and logbook were destroyed in the fire, so we have no recordings he might have made. He could have communicated with others by radio but only if his primary (or reserve) parachute had opened, for the high-frequency antennas for communication during that period were installed on the parachute lines. The only other manner of communication would have been through a slot antenna on the hatch in the Descent Module operating in VHF-FM range, but there was nobody in range of the power of the transmitter to hear anything.45 Thus, the claim that Komarov was screaming in panic as he plummeted to the ground is based on absolutely zero evidence. What Komarov may have thought or said during his tragic descent, unfortunately, will never be known. ConclusionIt’s clear from all available evidence that the Soyuz spacecraft was not ready for piloted flight in the spring of 1967. The design bureau had not conducted a single fully successful automated flight before launching Komarov into orbit. This was a basic and cardinal rule of the early years of the space race, broken with great risk. If the proximate reason for Komarov’s death was a problem, either by design or in assembly, of the parachute system, the more systemic reasons were threefold. First, there was immense pressure to launch a Soyuz as early as possible, as there had been a gap of nearly two years since the last Soviet piloted mission. Second, several key anniversaries were imminent in 1967 (May Day and the 50th anniversary of the Bol’shevik Revolution) and required a major space spectacular to coincide with them. Third, and perhaps most important, the system was not designed to encourage dissenting opinions, especially when it came to making critical launch decisions. At least three individuals, Lieutenant-General Aleksandr Mrykin (a senior official at TsNIIMash, the leading R&D institution in the Soviet space program), Ivan Prudnikov (a senior designer at TskBEM), and Major-General Anatolii Kirillov (a deputy chief of the Baikonur launch site), who expressed their objection to the launch at different stages of the process were overruled by the majority vote at various meetings.46 It is worth noting, though, that even the dissenters never once considered the possibility that the parachute system would fail. Finally, we must attribute some blame on poor leadership, particularly Dmitrii Ustinov (the Party leader of the space program), Leonid Smirnov (the chairman of the Military-Industrial Commission), Sergei Afanas’ev (the minister in charge of the space program), and, of course, Vasilii Mishin (head of the design bureau). All told, the responsibility and guilt for the accident lay not on the conscience of any one man, but on a technological culture that considered high risks acceptable in the face of incessant political pressure from above. Endnotes
Home |
|
