Launch is one of the more dangerous phases of any crewed space mission. Sitting on top of a high-performance rocket filled with hundreds of metric tons of volatile propellants, a malfunction of even a small component during ascent can result in a catastrophic failure. For this reason, crewed spacecraft have usually included abort options during all phases of the ascent into orbit in case of a problem – the notable exceptions were the Soviet Voskhod (see “The Mission of Voskhod 1”) and the American Space Shuttle which had no survivable abort options available up to a couple of minutes after liftoff. The Soyuz, like the earlier American Mercury and Apollo spacecraft, has an LES (Launch Escape System) that uses a solid rocket motor on top of the spacecraft to pull the capsule carrying the crew safely from the launch vehicle in case of a malfunction during the earliest phases of the ascent. The only time an LES was employed operationally on a crewed flight was on September 26, 1983 for a mission that was originally to have been called “Soyuz T-10”.

Long Duration Missions to Salyut 7

After climbing a rather steep learning curve during the 1970s as they developed the means to support crews on extended stays in orbit on board the Salyut series of space stations, Soviet crewed spaceflight operations began to hit their stride with Salyut 6 launched in September of 1977. Built with docking ports fore and aft, the new generation of Salyut space stations could support a pair of docked spacecraft at a time. This allowed a long duration crew to receive much needed supplies from unmanned Progress freighters as well as host short-duration stays from visiting crews. Frequently, the visiting crew would leave their fresh Soyuz spacecraft behind for the long duration crew’s use and return in the older Soyuz well before the spacecraft had reached the end of its recommended time in orbit.

The Salyut 7 space station, launched on April 19, 1982, built on the experience gained from the long-duration expeditions to Salyut 6 from 1977 to 1981 lasting up to six months in order to support still longer missions in orbit. The crew for the first Salyut 7 long duration mission, EO-1 (the Russian acronym for “Principle Expedition-1”), was launched aboard Soyuz T-5 in May of 1982 and spent a record 211 days in orbit before returning in the Soyuz T-7 spacecraft left by their second visiting crew in August. Soyuz T-8, carrying cosmonauts Vladimir Titov, Gennady Strekalov and Alexander Serebrov, was launched on April 20, 1983 for the second long-duration expedition to Salyut 7. Unfortunately, a radar failure in the automated docking system of the Soyuz 7K-ST spacecraft (the first such failure in six years) led to a manual docking attempt in darkness which was aborted after consuming too much propellant. Soyuz T-8 was forced to return early after only two days in orbit.

The EO-2 expedition, consisting of Vladimir Lyakhov and Aleksandr Aleksandrov, finally arrived at Salyut 7 on board Soyuz T-9 on June 28, 1983 for what was planned to be a four-month stay on the space station. Because Salyut 7 had been boosted into a higher orbit since the launch of Soyuz T-8, the Soyuz 7K-ST with the Soyuz-U rocket could only carry two cosmonauts instead of three like on the earlier flights when station was in a lower orbit. In the meantime, Titov and Strekalov from the Soyuz T-8 mission were quickly recycled to the top of the flight roster to take advantage of their training for the next mission to Salyut 7 in late September. The crew of was to be called “Soyuz T-10” were supposed to spend a month onboard the space station with Lyakhov and Aleksandrov performing EVAs to upgrade Salyut’s solar panels and other systems. The EO-2 crew would then return to Earth in late October leaving Titov and Strekalov to finish their three-month stay on Salyut 7 as the EO-3 crew.

The mission commander, 36 year old Vladimir Titov, was a pilot instructor supporting cosmonaut training before being selected as a cosmonaut in 1976. The unsuccessful Soyuz T-8 mission was his first spaceflight. Gennady Strekalov, who served as the mission’s flight engineer, was 43 years old at the time and had been working at as an engineer at TsKBEM (Central Design Bureau of Experimental Machine Building – the forerunner of today’s RKK Energia which still builds Russian crewed spacecraft) before he started training as a cosmonaut in January 1974. His first spaceflight was as the research engineer on Soyuz T-3 mission launched on November 27, 1980 for a two-week visit to Salyut 6.

The Launch Abort

For this flight, Soyuz 7K-ST serial number 16L was to be launched into orbit from the launch pad at Area 1 by the Soyuz-U 11A511U launch vehicle serial number Yu15000-363. Titov and Strekalov boarded their spacecraft at around 21:00 Moscow Time on September 26 for a nighttime launch scheduled for 23:38 Moscow Time. All was going well with the countdown until about 90 seconds prior to launch. A malfunctioning valve allowed pressurized nitrogen to enter the kerosene fuel turbopump of the RD-117 engine of the launch vehicle’s Blok B booster causing it to spin up. With no fuel in the pump, the turbine was quickly spun up beyond its design limits and failed causing a fuel leak at the base of the rocket.

Within a minute, the spilled kerosene ignited and a fire started on the pad. By the time the launch director, Alexei Shumilin, noticed the flames through his blockhouse periscope, the fire had already burned through the ground command lines that were used to activate the Soyuz LES to pull the crew to safety. Since the Soyuz crew had no means of manually activating the LES themselves, a backup system using a radio link that relied on a simultaneous command from two different locations (an arrangement used to minimize the chances of an unintended abort command being accidentally sent) had to be used. As events quickly unfolded, Titov knew that something had gone terribly wrong and tightened his restraints in anticipation of a pad abort while recommending Strekalov do the same.

About ten seconds after the fire was first noticed, the abort command was finally sent followed 1.2 seconds later by the LES being activated. The descent module and orbital module above it were separated from the launch vehicle and the solid rocket motor generating 785 kilonewtons of thrust fired as flames engulfed the Soyuz launch vehicle. Some three or four seconds later, the Soyuz-U toppled over and exploded causing much damage to the launch pad.

In the meantime, the LES with the Soyuz orbital/descent modules encased in their launch shroud had accelerated to Mach 1 in just five seconds subjecting the crew to peak acceleration of 14 to 17 gs. Once at an altitude of 650 meters, aerodynamic brakes were deployed and the descent module was released from the launch shroud. The Soyuz descent module jettisoned its heat shield and deployed it fast-opening reserve parachute for the quick descent back to the ground. Titov and Strekalov landed softly after five minutes and 13 seconds of flight some four kilometers from the burning launch pad where they were quickly rescued by recovery crews. Their first request was for a cigarette and they were offered a shot of vodka. The remains of the Soyuz-U launch vehicle burned for another 20 hours before the damage could be assessed and repairs on this vital launch area could begin. The aborted flight of Soyuz T-10-1, as it was officially designated by the Soviets (but frequently referred to as “Soyuz T-10A” in the West), had come to a quick, but safe end.

Rumors about the launch abort reached the Western press about three days later prompting speculation about what had happened and whether the crew had even survived. It would be a month before Soviet authorities publicly revealed the first details of the launch pad abort during the IAF congress in Budapest and made it clear that Titov and Strekalov had survived the launch abort. The crew was seen publicly during the Red Square military parade on November 7 proving the point. But over the years to come, more details would come to light especially after the Space Shuttle Challenger disaster as an attempt to show how much safer the Soyuz was than the Space Shuttle.

With no replacement crew coming, Lyakhov and Aleksandrov remained on Salyut 7 to continue their work including upgrading the station’s solar arrays without additional help. When their stay exceeded the nominal 100-day in-orbit life of the Soyuz in early October, unfounded rumors began to swirl around the West of the crew being stranded in orbit. While 100 days was a conservative estimate of the lifetime of the improved Soyuz 7K-ST spacecraft, the design proved itself when the EO-2 crew successfully returned to Earth in their Soyuz T-9 on November 23, 1983 after spending almost 150 days in orbit. In the meantime, the Salyut 7 space station was left unoccupied for a couple of months as the Soyuz T-10-1 failure was investigated and corrective action taken. A replacement EO-3 crew of three cosmonauts was finally sent to Salyut 7 on Soyuz T-10 launched on February 2, 1984.

As for the crew of aborted Soyuz T-10-1 flight, Titov would eventually command the Soyuz TM-4 mission to the Mir space station in 1987. Strekalov would fly much sooner as a flight engineer on the Soyuz T-11 mission to Salyut 7 on April 11, 1984. After three attempts in less than twelve months, Strekalov would finally reach Salyut 7 to spend a week in orbit visiting the EO-3 crew. Both men would continue their space careers including participating in American Space Shuttle flights to the Russian Mir space station.

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Related Video

Here is a Russian documentary about the Soyuz T-10-1 launch abort.

Related Reading

“Soyuz 18A: The First Crewed Inflight Launch Abort”, Drew Ex Machina, April 5, 2019 [Post]

“Rendezvous in Space: The Gemini 6 Launch Abort”, Drew Ex Machina, December 12, 2015 [Post]

General References

Phillip Clark, The Soviet Manned Space Program, Orion Books, 1988

Rex D. Hall and David J. Shayler, Soyuz: A Universal Spacecraft, Springer-Praxis, 2003

Dennis Newkirk, Almanac of Soviet Manned Space Flight, Gulf Publishing, 1990

James E. Oberg, The New Race for Space, Stackpole Books, 1984