Kosmos-140: Paving the way to... disaster
Undeterred by two ill-fated launch attempts in November and December 1966, developers of the Soyuz 7K-OK spacecraft pressed ahead with yet another test mission. They hoped it would finally deliver a clean performance of the new vehicle and thus open the door for the resumption of the politically important manned space flight in the USSR after a two-year hiatus. The third unmanned Soyuz flew in February 1967 and could be considered a resounding success for the new-generation spacecraft... if not for a nasty surprise at the very end of the mission...
In the course of the Kosmos-140 mission in February 1967, the unmanned Soyuz 7K-OK spacecraft conducted successful orbital maneuvering.
Soyuz 7K-OK No. 3 (Kosmos-140) mission at a glance:
In 1967, the USSR prepared to mark a major political milestone -- the 50th anniversary of the Bolshevik Revolution in October 1917, which gave rise to the Soviet state. Naturally, leaders in the Kremlin hoped to mark the occasion with new impressive firsts in the Soviet space program, which itself was about to turn a decade-old after the launch of first Sputnik in 1957.
In the high-profile field of human space flight, two projects came to the forefront. The first was the new-generation Soyuz 7K-OK, which, so far, had made one less-than-spectacular test flight and one disastrous launch attempt, fortunately both times without crew. Just slightly behind 7K-OK, the Soyuz-derived L1 project was approaching the launch pad with the goal of carrying Soviet cosmonauts around the far side of the Moon.
With two programs in full swing, the head of OKB-1 Vasily Mishin and other top managers of the manned program were increasingly splitting their time between the OK and L1 variants of the Soyuz 7K. On December 10, 1966, before the second attempt to launch 7K-OK, a meeting of the chief designers reviewed preparations for a joint flight of Vehicles 7K-OK No. 3 and No. 4 with crews onboard. The same meeting also reviewed various aspects of the 7K-L1 project, as well as details of the upcoming government decree for the development of the 7K-LK lunar lander, which was still on the drawing board at the time.
However after the disastrous loss of the Soyuz vehicle No. 1 on Dec. 14, 1966, Mishin had no choice, but to turn his full attention back to the 7K-OK and prepare a yet another unmanned test flight before missions with crew could proceed. Almost immediately after the accident, a decision was made to use Vehicle 7K-OK No. 3 (with a passive docking port) for a solo test mission without crew. In parallel, Vehicles No. 4 and No. 5 would now be prepared for the first joint manned flight, in the hope that their unmanned predecessor would successfully complete its mission.
On Dec 15, 1966, Mishin had already drafted a plan to convert Vehicle No. 3 into an unmanned spacecraft, by removing some components, including the Igla rendezvous system, pilot seat, the life-support system and all other hardware to support the crew. Also, Mishin apparently planned to postpone the delivery of the next spacecraft (Vehicle No. 4) to Tyuratam and complete all its necessary upgrades at the manufacturing plant in Podlipki near Moscow instead.
Problems on the ground
Another serious problem facing the Soyuz project was the devastation of the launch pad at Site 31 in Tyuratam in the aftermath of the December 14 launch attempt. It was now urgent to complete previously planned upgrades at the launch pad at Site 1, so that Soyuz launches could move there. However, the pre-launch operations with the Soyuz spacecraft would have to be either urgently organized at Site 2, (which normally supported launches from Site 1) or the processing would continue at Site 31, requiring an unusual operation of transporting the fueled Soyuz spacecraft around 30 kilometers to Site 2, where it would be integrated with its rocket, before its rollout to Site 1. (It was not possible to transport the fully assembled rocket from Site 31 to Site 1 over the conventional rail lines.)
Immediately after the accident, Mishin apparently gravitated toward the first option. In order to process the Soyuz spacecraft at Site 2, he ordered the move of the 11N6110 diagnostics equipment complex for Soyuz from Site 31 to Site 2. (774) However the plan was apparently dropped and Vehicle No. 3 was prepared and fueled for launch at Site 31, before its subsequent transfer to Site 2 for integration with the launch vehicle. (804)
On Dec. 17, 1966, Mishin already expected to receive a construction schedule and a list of needed equipment to complete renovations at Site 1. As had happened previously with Site 31, Mishin hoped to urgently obtain badly needed hardware for Site 1 from the Ministry of Defense, which operated the similar four-pad Facility No. 317 for R-7 ballistic missiles in Plesetsk. On the same day, Mishin met Marshall Nikolai Krylov, the Commander of the Soviet ballistic missile forces, to discuss the issue. Fortunately, by that time the R-7 ICBM was already considered obsolete and there was a plan to convert three of four pads in Plesetsk for launches of Zenit, Meteor and Molniya satellites, while Pad No. 2 could be cannibalized for parts.
Upgrades to Site 1 also included dismantling of the radio-guidance hardware in the launch control bunker, apparently because this equipment was only needed for ballistic missile launches.
Also, on December 17, Kerim Kerimov, who led the State Commission responsible for Soyuz testing, presented the official return-to-flight plan. The launch of Vehicle 7K-OK No. 3 was now penciled for Jan. 20, 1967, just two days after the launch pad at Site 1 would be ready for operations. To achieve that, the integration of the launch vehicle with the spacecraft would have to be completed on January 15, followed by the rollout to the launch pad the following day.
Around the same time, Mishin apparently received the informal blessing of Yuri Gagarin and Vladimir Komarov, who led a group of cosmonauts preparing to fly Soyuz, to begin manned missions after a successful flight of test vehicle No. 3. Komarov stressed that the Descent Control System, SUS, remained the only untested component of the Soyuz, thus implying that the successful landing of Vehicle No. 3 would close that issue.
The next day (on December 18, 1966), Mishin met with the leaders of the construction team responsible for repairs at Site 31. He reviewed an extremely challenging schedule that had allocated just three months for the pad restoration:
Mishin noted the particular difficulties in removal and re-installation of fueling systems, which required to custom-fit piping hardware right at the site. In turn, this required deploying and building many new facilities at the site, such as workshops, warehouses and warm-up sites for workers. With the winter reaching its peak, Mishin had to underscore (literally) in his notes the task of getting warm clothing for the construction personnel.
The price tag for the restoration of Site 31 (reaching around 4 million rubles) turned out to be high enough for Mishin to request additional funding.
On Dec. 20, 1966, Mishin drafted the following processing schedule for the Soyuz 7K-OK No. 3:
When Mishin met with a group of cosmonauts, including Komarov, Gagarin and Leonov, on Jan. 17, 1967, he still promised liftoff of the final unmanned Soyuz flight at the end of January, followed by a manned rendezvous mission in March of the same year. (804)
Fixing escape systems
In January 1967, the work on Soyuz continued progressing on parallel tracks with the hectic pre-launch tests of the L1 lunar-flyby spacecraft, increasingly complicating the work at the OKB-1 design bureau, which itself was in the process of restructuring into what would become TsKBEM. (774) At the time, Chertok recalled the first signs that Mishin's leadership in the program was being questioned, just a year after he had replaced Sergei Korolev and his unshakable authority. At the State Commission meeting on January 17, which considered the status of 7K-OK and L1 projects, just on the eve of Mishin's birthday on Jan. 18, Mstislav Keldysh, the head of the Academy of Sciences, remarked that the guiding role of the technical leader had been lacking and the Council of Chief Designers, which used to run the entire Soviet space program, was now meeting too sporadically.
On the programmatic side, the meeting reviewed new delays in the 7K-OK and L1 projects, apparently postponing the third Soyuz launch attempt from the end of January to the beginning of February 1967. By January 19, Kamanin heard the news that the testing of the Emergency Escape System, SAS, conducted in Vladimirovka, near Kapustin Yar, and the ship's landing systems in Feodosiya, Crimea, required that testing be extended until February 15, in turn, pushing the first manned flight from March to the beginning of April 1967. (804)
To complicate things further, in January, a number of key officials, including Mishin came down with the flu, which was spreading around Moscow.
On January 21, Kerimov called Kamanin and said that some members of the State Commission would leave for the launch site in Tyuratam on January 23, but warned him that the Soyuz launch was now expected no earlier than February 2 or 3. However on January 26, Kerimov called Kamanin again and said that the launch could now take place between Jan. 29 and 31, 1967.
Per Kerimov's request, Kamanin flew to Tyuratam on January 27. The next day, the State Commission reviewed the status of upgrades to Vehicle No. 3 and the readiness of the launch complex. The officials gave the green light for the fueling of the spacecraft, but its launch was now expected between February 8 and February 10, 1967.
In the midst of preparations in Tyuratam, Soviet officials received shocking news from the US about the death of three American astronauts in a fire in the cockpit of the Apollo spacecraft, during ground tests on January 27. (804) Mishin's team even felt necessary to prepare a special affidavit, assuring that a similar accident could not take place onboard the Soviet spacecraft, which used an air mixture in its atmosphere, rather than the hazardous pure oxygen life-support system aboard the Apollo.
However, Soviet engineers still had a great deal of work on their own safety problems surrounding the operation of the Emergency Escape System, SAS. Because the accidental firing of the SAS was the main culprit in the previous failure, its urgent upgrades were now driving the schedule.
Based on the latest tests, Chertok and Bushuev signed documents guaranteeing the safe manual activation of SAS from a launch control bunker. The system was calibrated to ensure the parachute deployment at an altitude of no less than 800 meters, with the subsequent touchdown of the capsule not closer than 100 or 170 meters from the launch site. (466)
Gearing up for launch
During the weekend of Jan. 29, 1967, when winter temperatures in Tyuratam plunged to minus 20 degrees C, the personnel at Site 31 began fueling Vehicle No. 3, marking the beginning of irreversible operations with the Soyuz.
On January 30, the fueled spacecraft was moved back to the processing building, where it underwent a three-day final processing, culminating with the transfer to Site 2 on February 2. Despite a speed limit of just 16 kilometers per hour and four stops along the way to check for the cargo, the train's locomotive still managed to get off rails, delaying the transfer by 12 hours, but, fortunately, causing no damage. (804)
On Feb. 2, 1967, Boris Chertok and his flight control team, known as GOGU, headed directly to Crimea, while key experts on spacecraft testing Igor Yurasov and Arkady Ostashev went to supervise the final preparations of the spacecraft in Tyuratam. The final checks were greatly simplified by the absence of the Igla rendezvous system, which was not needed in a solo mission. In the meantime, a pre-launch rehearsal at mission control in Crimea demonstrated much better coordination and orderly performance compared to chaotic scenes during the first flight. The engineering team was joined in Crimea by a group of cosmonauts who were training to fly Soyuz, including Yuri Gagarin. (466)
On the same day, the State Commission cleared Soyuz for rollout to the launch pad on February 3, at 08:00 Moscow Time. Among top members of the Commission only Kerimov and Kurushin was present, while Mishin was sick for almost two weeks in the runup to the launch, according to Kamanin. Despite minus 30-degree temperatures, the rocket was erected on the launch pad as planned.
On February 5, search and rescue planes, helicopters and their crews were declared ready for supporting the launch and landing, again despite severe winter temperatures hovering between minus 20 and minus 30 degrees C.
The liftoff of the third Soyuz was planned for February 6, at 06:00 Moscow Time, however as the countdown reached the four-hour mark, operations had to be put on hold. An over-sensitive indicator located in the firing bunker, a part of the 11N6110 diagnostic system, showed an electric discharge on the structure of the habitation module of the Soyuz. The pesky problem, which had often irritated the test personnel in the past, required a 24-hour delay. (466) However in a worst-case scenario, failure to find the source of discharge could require to remove the spacecraft from the rocket, delaying the launch by as much as two or three weeks. (804)
February 7: Third Soyuz lifts off
With the electric problem quickly resolved, the State Commission met in the wee hours of February 7 and gave the green light to the fueling of the rocket and the liftoff. Extreme winter weather still persisted in Tyuratam, with minus 22 degrees C outside and wind gusts reaching between 7 and 8 meters per second. During the final preparations, a minor problem in the heating system on the launch pad required a 20-minute delay.
The Soyuz 7K-OK No. 3 lifted off on Feb. 7, 1967, at 06:20 Moscow Time. The ascent seemed to be normal, but officials in Tyuratam did not get an immediate confirmation that the spacecraft had reached orbit. Apparently, due to a lower-than-usual ascent trajectory, the flight had left the range of the ground station in Tyuratam before orbital speed was reached. The next ground station downrange from Tyuratam was located in Sary Shagan (further east in Kazakhstan), but it took eight heart-wrenching minutes after the ship had left Tyuratam's communications range for Sary Shagan to finally confirm the successful orbital insertion. (804)
The mission was announced in the Soviet press under name Kosmos-140. As usual, the official announcement provided no information on the real nature of the launch. According to the Soviet data, the spacecraft entered the 170 by 241-kilometer orbit with an inclination of 51.7 degrees toward the Equator.
Chertok recalled a very tense atmosphere after launch at the Crimean ground station, where engineers focused on testing of a complex system for the transmission of tele-commands to the spacecraft. Once that task had been successfully completed, the next step was to try the attitude control system relying on the 45K star sensor and the power supply system, which in turn, would clear the way for the test-firing of the SKDU and DKD propulsion systems. (466)
Back in Tyuratam, around 20 minutes after the successful launch, top officials gathered at the Soyuz assembly building at Site 2. With positive reports about the flight at hand, arrangements were made to fly to the nerve center of the mission in Crimea. (466) Kamanin's air force flight was scheduled to depart at 11:00 and Mishin with his entourage of civilian managers was to follow at 15:00. It would take them nearly five hours to get to the Saki airfield in Crimea.
In the meantime, the Soyuz made its first three orbits around the Earth in seemingly good health. According to Kamanin's recollections, the Soyuz performed a small orbit correction, (probably with the use of attitude control thrusters) during the fifth orbit of the mission, entering a 238 by 172-kilometer orbit, high enough to guarantee the flight only for 48 revolutions before the object would decay due to natural friction with the upper atmosphere. (804)
However, according to Chertok, there were already signs of trouble, during the fourth orbit. According to the flight program, before leaving the range of Soviet ground stations (at 17:00 Moscow Time), which would keep the spacecraft out of view until the 13th orbit, it was supposed to enter a slow spin with its solar panels pointed at the Sun, to ensure a reliable power supply to rechargeable batteries. However commands to spin the vehicle during the 5th orbit were not going through. Whether the issue was in the new DRK radio system or in the onboard flight control system, engineers had no chance to determine before the spacecraft left the communications range.
To make matters worse, the analysis showed overuse of the attitude-control propellant. Nearly 50 percent of propellant had been consumed during the star-tracking attitude control exercise. The star tracking navigation system was also apparently misbehaving. Optics experts could not confirm that the 45K tracker had locked onto the right star. As a result, the initial order at mission control quickly descended into chaos with hectic demands for information, sporadic meetings and dozens of often unsolicited proposals what to do next. The work was also constantly disrupted by the need to update Mishin, Kerimov and high officials in Moscow on the latest developments.
After heated discussions, it was decided to at least boost the ship's orbit to prevent its premature reentry. The maneuver required firing of the SKDU engine, while holding the spacecraft along the direction of the flight. As usual, the primary star orientation could be backed up by the ionic attitude control system. (466)
February 8: Soyuz rises its orbit
The engine of the Soyuz 7K-OK No. 3 finally fired for 58 seconds during the 22nd orbit of the mission. The maneuver delivered 36 meters per second in velocity, inserting the spacecraft into a 310 by 220-kilometer orbit. (804)
According to ballistic forecast experts, the orbit was high enough for the Soyuz to stay aloft for a month and they warned mission managers that returning the spacecraft back to Earth would now have to be their primary concern.
Fortunately, Irina Yablokova, who was in charge of the power-supply system, broke Chertok the news about unexpected reserves in the ship's batteries for another day of flight, despite the botched solar orientation. (466)
The second attempt to spin-stabilize the spacecraft relative to the Sun was made at the end of the second day of the flight, as the ship was approaching another extended period of flight out of range of mission control. This time, the Sun itself was apparently used as a reference. (466) However the result of the effort could not be determined until the Soyuz would re-appear over Soviet ground stations during its 29th orbit, around 1:30 a.m. on February 9.
Ironically, had the pilot been onboard, the attitude control problems could easily have been resolved with manual control -- a fact that Gagarin was quick to point out to Chertok. Chertok admitted that it would indeed be possible. Kamanin even expressed satisfaction in his notes that problems with Soyuz had yet again stressed the importance of a pilot onboard the spacecraft.
February 9: The ice water landing
At 1:40 a.m., Kamanin got a phone call from Yakov Tregub, breaking the news that the Soyuz had failed to maintain its solar orientation. According to Kamanin, plans to keep the Soyuz in orbit for a third day were now had to be dropped due to lack of propellant and power supply onboard.
At 2:30 a.m. top officials gathered at mission control and made a decision to conduct the reentry and landing during the 33rd orbit of the flight. Apparently during this meeting, Boris Raushenbakh warned that he could not guarantee reliable operations of the ionic attitude control system during the braking maneuver due to concerns about interference from the powerful exhaust of the main engine. This news added even more anxiety to a heated atmosphere in Crimea.
Still, engineers successfully uplinked reentry sequence instructions to the Soyuz and the spacecraft was left in the care of the ionic orientation system, which had to point the spacecraft with its engine against the direction of the flight for the braking maneuver.
Fortunately, at the right time, the spacecraft downlinked data indicating that the braking firing had been completed with an on-time engine cutoff via a primary command from the flight control sequencer. Mission control also confirmed that the three modules of the spacecraft had separated as planned and the descent module had switched to power supply from its own battery.
However, as the capsule exited the period of radio blackout, caused by friction with the atmosphere, communications with the spacecraft never resumed. (466) According to Kamanin, the UHF transmitter of the capsule did not work at all during the parachute descent, while the short wave radio signals were too poor to track the vehicle either via the Krug tracking network or from the search aircraft.
Only after the scheduled landing at 05:49 Moscow Time, did weak beeps appear in short waves at 05:52 Moscow Time. They were determined to be coming from the Aral Sea region, instead of the nominal landing site to the east.
Mission controllers first thought it was a mistake, but after a four-hour search by aircraft, the descent module was spotted at 09:50 Moscow Time, sitting on the ice of the Aral Sea, three kilometers from shore with its parachute strewn along it. (466) (According to Kamanin, the landing site was 11 kilometers off the Cape Shevchenko, or 510 kilometers short of the mission's planned destination.) (804)
It was now clear that the spacecraft had failed to conduct a controlled aerodynamic reentry, which could give it some lift and carry it to the nominal landing site. Instead, the capsule had slipped into the ballistic trajectory falling short of its destination. (52)
Between five and six hours after touchdown, still before the recovery team could get to the unexpected landing site, the capsule (apparently still hot from reentry) melted the ice and sank, leaving only its parachute on the surface. It was another shocking news for the officials, because the crew module was supposed to float. "It was so ashamed of its inaccurate landing that it drowned itself," Chertok remembers jokes from engineers with responsibilities other than the design of the descent module... (466)
February 10: Recovery operations begin
Obviously, it was now absolutely crucial for the Soyuz developers to inspect the sunken vehicle, which had ended up at a depth of 10 meters in the freezing waters of the Aral Sea.
Air Force General Kutasin, who led the recovery operations, tried to get information from OKB-1 on the mass of the capsule filled with water, which would be critical for planning air-lifting operations, as well as the status of the 10-kilogram explosive charge, APO, inside the vehicle, which could pose a treat for his personnel. However he got no answer, probably due to paranoid secrecy. Kutasin reported the situation to his boss Marshall Rudenko, who on February 10 summoned a meeting of the State Commission at his office. At the meeting, Mishin and Kerimov went on the offensive with complaints about the slow pace and poor organization of the recovery effort, which had failed to secure the spacecraft in time.
Now, officials had to urgently assemble a diverse team of specialists to salvage the precious capsule.
Major General S. F. Dolgushin led the team of Air Force search and rescue personnel, while A. A. Lobnev was in charge of the technical team from TsKBEM. Mishin also asked his senior engineer Vladimir Timchenko to join the operations. Finally, a team of frogmen led by 2nd Rank Captain Bezzhanov from the Black Sea Fleet based in Sevastopol flew in. The complex operation had to be choreographed by the minute. Despite some level of coordination with Moscow, the team on the ice had to make key operational decisions on the spot.
The capsule had no special attachments for airlifting. Instead, the Mi-6 transport helicopter had to pull the module by its parachute lines. As it turned out, the weight of the spacecraft filled with water hovered at the limit of the aircraft's lifting capabilities. After the module had finally been secured and made ready for recovery, Vladimir Timchenko and Yuri Semenov from TsKBEM stayed on the ice to monitor the process.
On the windless cold day, the helicopter failed at the first attempt to lift the capsule, but when it finally did, the aircraft struggled to pull the module out of the water and carry it to the shore. (52)
It took 54 hours to yank the descent module from the bottom of the Aral Sea. At 12:00 on February 11, Kamanin got a phone call from General Goreglad confirming that the operation was finally completed. (804)
During the inspection of the descent module, engineers discovered a 30 by 100 millimeter melted hole near the center of the capsule's bottom, which had led to loss of pressure early in the atmospheric descent and the subsequent sinking of the spacecraft. (52) (Kamanin claimed the hole was 250 by 350 millimeters.) (804)
The analysis of the first Soyuz landing in the previous November indicated that the loss of pressure likely resulted from a structural breach in the jettisonable heat shield, which covered the bottom of the capsule until the final moments of the flight. By design, the heat shield had a hole for the pipe of a temperature-measuring sensor, which would be normally sealed with a screw plug glued in before launch. However it was impossible to tell what had happened to that plug on Vehicle No. 3. On the surface of ice, search teams picked only random fragments of the heat shield which had shattered on impact. The main part of the shield remained missing, despite prolonged search on the surface of ice and by frogmen on the bottom. However one piece of the shield did have a portion of the screw groove with traces of burn through. (52)
If such a situation happened on a manned vehicle, the crew would be guaranteed to die without space suits and could also be killed by hot gases even when wearing spacesuits. Clearly, serious fixes were needed on Soyuz. On February 14, Mishin summarized opened issues with the 7K-OK project, which had to be discussed with his technical management in the wake of the third launch:
Mishin's also chaired the Chief Designers' Council meeting, apparently focused on flight control problems, where Pavel Agadzhanov reported on the poor quality of measurements delivered by the Saturn-MS long-range ground station. Mishin also stressed the absence of an operational system for the management of command transmission and the need to manually record the timing of the commands. He also noted the need for upgrades of the antenna feeder system and the lack of integration of the KTNA-200 radio-telescope into the flight control loop. Finally, the telemetry recording system onboard the spacecraft had exhibited problems (during the flight), Mishin noted.
Mishin proposed to continue testing the long-range communications system in interaction with the Molniya-1 communications satellite and reminded Agadzhanov that his team was yet to deliver deciphered telemetry received during the crucial 22nd orbit of the mission, when the spacecraft had performed the crucial orbit correction.
As many times before, the meeting then had to switch to other issues, such as preparation for a spacewalk from one spacecraft to another during the upcoming joint flight of Vehicles No. 4 and No. 5 and the work on the L1 project. (774)
On the afternoon of Feb. 16, 1967, the State Commission met in Podlipki (home of TsKBEM) to review the results of the investigation into the problems with vehicle No. 3 and formed several working groups to oversee corrective actions. (466) It was decided to no longer drill a hole for the temperature probe in the heat shield. Also, special inserts were introduced to reduce mechanical pressure on the shield. The analysis also revealed that some parts of the thermal protection layers on the sides of the vehicle needed extra strengthening. Therefore, it was decided to cover potentially vulnerable areas with paneling made of a material called ftorolon, which sublimates at temperature of around 600 degrees C.
Now, the top managers of the Soyuz project had to decide how to proceed with further flight tests. Despite a long string of problems, the overwhelming opinion of most officials at the meeting on February 16, was to proceed with the first manned Soyuz at the beginning of April, on the condition that all the corrective actions had been implemented on time and that the crews had completed their ongoing training. Conveniently, officials hoped to launch the first manned Soyuz mission by April 12, to mark the sixth anniversary of Gagarin's pioneering mission aboard Vostok in 1961. (804)
As with the previous unmanned Soyuz test flight, the true mission of Kosmos-140 remained secret in the USSR until the publication of the Encyclopedia of Cosmonautics in 1985, which identified Kosmos satellites flown within the Soyuz testing program, but provided no other details besides launch and landing dates for those missions. (2)
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A Soyuz 7K-OK spacecraft with a "passive" docking mechanism undergoes pre-launch processing in Tyuratam. Image courtesy Amy Collins
During the second flight of Soyuz, the spacecraft was expected to conduct a solo flight.