Prior to the completion of the International Space Station over a decade later, the Mir space station was clearly the most advanced, not to mention majestic structure in orbit.

But with great complexity comes great blunders in navigation and visiting vehicles to the station over its history. One event you’ll likely know, which came very close to a loss of the entire station and its crew.

Progress M-7: March 21, 1991

The Progress is an unmanned Soyuz-shaped cargo and fuel carrier. Progress was a single unit, however, as opposed to the multiple modules of Soyuz. Its forward section held cargo, and tanks for replenishing and refueling station liquid consumables filled the rest of the pressurized section.

Progress-M spacecraft
The Progress M-series, the current version in use with the ISS. Earlier versions were very similar.

Used even today with the ISS, the Progress spacecraft also kept the Mir fueled and stocked over some 63 flights.

These cargo ships (and manned Soyuz spacecraft) used the Kurs automated docking system.

Three attempts were made in docking M-7 with the young space station. The first attempt was waived off at 1,600 feet (500 m) distance. A second attempt was stopped while the vehicle was 160 ft (50 m) away…but not before the M-7 spacecraft drifted to a dangerously close 16 ft (5 m) distance from the station before it reached its holding attitude.

After Soyuz TM-11 was undocked from the forward port of the Core Module and moved elsewhere, M-7 managed to dock with that forward port.

Soyuz TM-17: January 14, 1994

With the arrival of a fresh crew, cosmonauts Vasili Tsibliyev and Alexander Serebrov boarded Soyuz TM-17 and undocked for the ride home.

Standard procedure involved a fly-around inspection of the Soyuz before departure. In addition, the crew were tasked to take photos of the APAS-89 docking system, which would be used by the first U.S. Space Shuttle to dock with the station in less than a year.

They were working on getting a closer shot of the port when TM-17 drifted too close to the station. The commander moved the translating hand controller in the Descent Module to correct the probe–and nothing happened.

A side of the forward Orbiting Module smacked Mir’s Kristall module, twice. Some smart flying after regaining control avoided further collisions with the station’s more sensitive elements.

Thankfully, no damage occurred to either Mir or the departing Soyuz. The cause of the accident? A switch that determined which hand controller was active in either Descent or Orbital Module was flipped to the wrong direction.

While the crew landed safely later, inspection of the Descent Module revealed that the crew had brought back various souvenirs from their visit. This, in itself, isn’t unusual since spaceflight began. Apollo crews made flying ceremonial swag such a habit that eventually one crew got in a bit of trouble for allegedly commercializing such things.

But this swag could’ve resulted in serious problems. The souvenirs made the TM-17 module overweight enough that not only the crew’s landing could’ve been jeopardized (landing rockets that fire just before touchdown may not have compensated for the extra weight, leading to module impact damage and crew injury), but the mass of the souvenirs may have contributed to attitude control of the spacecraft prior to or after collision.

Progress M-24, August 27, 1994

Six months later, Mir had another close encounter.

The Kurs automated docking system failed on approach for M-24. Perhaps also there were communications issues with ground control.

The Progress struck Mir’s docking system at least a couple of times and drifted away.

Later, the crew managed to regain control of the Progress and used a backup manual docking system, TORU, to safely dock the cargo ship. Mir was not damaged.

But the worst was yet to come, from similar circumstances.

Progress M-33: March 4, 1997

Vasili Tsibliyev, Commander of Soyuz TM-17 when it collided with Mir three years before, was back on board.

Mir had grown substantially since his last tour. It just been upgraded two years before with a new module: Spektr. Originally a military applications lab that was grounded due to lack of funding, some help from NASA as part of the US-Russia cooperative space ventures got the module off the ground and docked to Mir as a science lab. Spektr also became the living module for the American astronauts that spent time on Mir as part of the Shuttle-Mir program. On board for his tour on Mir was NASA astronaut Michael Foale.

Things became more complicated with Mir’s administrative operation. With the breakup of the Soviet Union, the Kurs automation became the property of the nation of Ukraine. Over the years the country ultimately raised the cost for the use of the Kurs system to such prohibitive expense that the Russian Federation planned to discontinue the use of Kurs in favor of TORU, the backup manual control system for Progress remote control.

TORU didn’t have a great reputation. Only one ship had been successfully docked using TORU before, after a fashion: Progress M-24, after it had collided with Mir, three years earlier, due to a Kurs malfunction.

Russian Federation Mission Control, or TsUP, had directed crews to manage all docking operations using TORU as an attempt to begin weaning from Kurs.

TsUP had directed Tsibliyev to make one earlier test of TORU on the Progress M-33 cargo carrier on March 4, 1997.

TORU looked much like a flight simulator computer game, comprised of a center screen with a forward camera view from the Progress, overlaid with readouts, with two hand controllers.

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The current ISS TORU system, used in the Russian segment of the ISS. (NASA)

At the time, TORU’s reliability was problematic. This March test began with TsUP moving the cargo craft about seven kilometers away from the station, with Tsibliyev using TORU to re-dock.

 

But the display failed. Tsibliyev found himself flying blind with only telemetry to guide. Progress M-33’s re-docking attempt was aborted. The spacecraft floated away, never to dock again, missing the station by a mere 655 ft (200 m).

Loss of Spektr: Progress M-34, June 25, 1997

No, we’re not talking about a victory by James Bond against an evil overlord’s operation.

Progress M-34 arrived a month after M-33, and was initially docked without issue on April 8. The crew were asked to make yet another TORU attempt with it two months later.

TsUP reviewed the problems of M-33’s display failure and believed that the Kurs antenna signal interfered with the visual link.  TsUP decided that an interim fix was to power-off the Progress’s telemetry used for TORU.

So Commander Tsibliyev was left with a reversed issue from Progress M-33. Re-docking Progress M-34 restored his display of the cargo ship this time, but now he lacked any data on the ship’s range, range rate or speed.

To compensate for the lack of spacecraft telemetry, TsUP directed astronaut Michael Foale and cosmonaut Aleksandr Lazutkin to break out a handheld laser rangefinder and a stopwatch and look outside a window to eyeball Progress’s progress.

There are times, especially for skilled pilots with malfunctioning aircraft instruments, where the Mark One Eyeball can save a mission, your aircraft, and your life. But space is different.

Tsibliyev’s visual was a simple black-and-white image of Mir, as seen from the approaching Progress ship, with some grid lines to aid in alignment. But seeing is not believing in orbital mechanics. He couldn’t really determine much data from the image, especially the rate that Progress was closing in, much less the approach angle. The lighting conditions were poor. Tsibliyev had a hard time discerning Mir’s image from the earth’s cloud cover at that point in the orbit.

And TsUP was out of communication range during the attempt, unable to provide any ground data or assert ship control to support the re-docking.

Very few cosmonauts had practiced much with TORU. Tsibliyev hadn’t run simulations in several months.

Foale and Lazutkin were holed up in the Mir Base Block and Kvant-1 modules to gauge the distances. They had a very hard time locating the cargo ship at all. Later investigation would show that the two men could not have used TsUP’s improvised rangefinding because the station’s solar panels would block their view.

The Progress didn’t respond as Tsibliyev expected. What wasn’t known was that Progress had been overloaded, so its mass caused differing reactions to Tsibliyev’s thruster control that TORU did not anticipate.

The commander was told by TsUP to keep Progress rotating relative to the station to keep it in his view. To do that, Tsibliyev directed Progress to pitch downward relative to the station’s orbit. But when you move a spacecraft lower in orbit, you increase its relative velocity. Unknown to anyone, Progress was now increasing in forward velocity, and the offset in mass from overloading made any attempts in correcting the problem impossible without the powered-off telemetry.

Then Lazutkin saw it. Progress was the wrong place, and approaching much, much too high and fast. Tsibliyev was unable to sense the vehicle’s speed. Lazutkin shouted to Foale to escape to the Soyuz for possible evacuation, fearing the worst.

Realizing the problem, Tsibliyev hit the braking rockets on Progress but way too late.

The cargo ship slammed into one of Spektr’s solar panels, heavily damaging it and a nearby radiator, before spinning back to collide with the hull of the module.

The impact caused the station to reel and tumble. The cargo ship tumbled away.

The crew’s ears popped from a change in atmospheric pressure. Spektr’s hull had been breached.

Foale and Lazutkin moved swiftly to the hatch connecting Spektr to the Base Block to clear it. The hatch was blocked open by an assortment of cabling and tiedowns of gear. Two electrical cables hadn’t quick-disconnects to remove it, and the two spacemen used knives to hack them apart.

Spektr’s hatch couldn’t be pulled closed due to the rushing air. They managed to find an external hatch cover nearby to quickly seal the module from the rest of the station.

Their troubles weren’t over. Cutting off the power from the venting Spektr reduced the station’s total power to 40%. The central computer itself shut down as the station’s slow tumble moved the solar panels away from the sun. Batteries had drained quickly as well, leaving the station’s gyroscopes also out of power needed to stabilize.

The commander was soon able to communicate with TsUP and recount the station’s condition. They received steps on powering down non-critical systems to conserve what battery power was left.

Later, Foale helped determine the roll rate of the station’s tumble, relaying that estimate to the commander, who used their Soyuz spacecraft’s reaction control to stabilize the station and return the solar panels to their proper orientation for power generation.

NASA wasn’t told of TsUP’s improvised telemetry until after the collision. It’s a pretty good chance that they weren’t pleased with Mike Foale achieving the dubious first of living through the first on-orbit uncontrolled depressurization of a spacecraft.

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The mangled solar array of the depressurized Spektr module. (NASA)

TsUP planned an interior spacewalk within the depressurized Spektr to restore its connection to station power. But the crew, especially the commander, were tired and prone to error. At one point the station began to tumble again due to their fatigue. TsUP would leave Spektr’s power restoration for a fresh crew.

Despite later repairs that restored about 70% of total station power, the leak in Spektr was never found and the module remained inhabitable for the rest of Mir’s life.

Blame for the incident was initially given to the crew, but an international commission led by NASA astronaut and Apollo-Soyuz commander Tom Stafford dismissed this; the crew did the best they could given their fatigue and insufficient training.

Attempts to keep additional funding for Mir’s operation into the new millenium failed, especially with new obligations with the growing International Space Station. The great space station was eventually de-orbited in early 2001.

Since the Spektr incident, it’s not clear whether NASA has helped out on keeping Kurs funded since the Mir collision (an advanced version is in use with current vehicles).

Kurs remains the preferred docking system with all Russian spacecraft coming to the ISS. You can be assured that cosmonauts, since M-34, now have regular TORU training, which also has had upgrades since 1997.

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