ISS Learns from Mir’s Flame-Up
The notorious fire on claptrap Mir is a good lesson in zero-gravity fire response.
1. A cooling line ruptures, leaking ammonia into the atmosphere.
2. A micrometeorite rips through the hull, creating a rapid depressurization.
3. An electrical fire erupts in an equipment rack.
THE SITUATION 10:35 p.m. Moscow time, February 23, 1997. After a dinner of jellied piked perch and borscht, cosmonaut Sasha Lazutkin activates a backup oxygen canister to accommodate the overlapping six-man crew. Soon after, the master alarm erupts. American astronaut Jerry Linenger’s eyes widen at the sight of a 4-foot flame shooting across the Kvant 1 research module.
Warm air doesn’t rise in a weightless environment, so fires can’t spread with earthly speed. But this one has a built-in oxygen supply. The blowtorch-like flame renders the station’s water-based extinguishers useless and blocks access to one of the two Soyuz vehicles. That means only three of the six men can evacuate if the call comes.
THE RESPONSE Unable to suppress the fire directly, commander Valeri Korzun aims the extinguisher at the far wall to keep it from melting. The extinguisher acts like a thruster in zero G, so Linenger has to keep the cosmonaut steady, then ferry in new extinguishers when the old ones run out. The rest of the crew shuts down equipment and powers up the accessible Soyuz. Fourteen minutes later, the canister burns out. “Russian officials reported it was like a cigarette burning for a few seconds,” Linenger says, “but it was a 14-minute, raging blowtorch. I’ve never seen smoke spread like it did on Mir.”
LESSONS LEARNED On the International Space Station, oxygen canisters include a containment shield and are subject to stricter quality control–an unidentified internal flaw caused the Mir fire. Cable cutters are now standard too, as jury-rigged power and data lines between modules prevented the crew from sealing hatches.
WHAT WOULD HAPPEN ON THE ISS?
The International Space Station has yet to experience a major incident, but it’s something astronauts train for. ISS Environmental Engineer Steven Blaha gave us a crash course on surviving mission-critical tech failures in orbit.
Problem #1: A cooling line ruptures, leaking ammonia into the atmosphere.
WHAT TO DO:
1. Hit the toxic spill alarm to shut down the ventilation system.
2. Close hatches to seal contaminated area.
3. Don personal protective equipment.
4. Activate the air-scrubbing system.
5. If all else fails, depressurize the affected modules and vent the ammonia into space.
Problem #2: A micrometeorite rips through the hull, creating a rapid depressurization.
WHAT TO DO:
1. Shut down the ventilation system to stabilize pressure.
2. If airflow and pressure sensors don’t pinpoint leak, use handheld ultrasonic detectors.
3. Still can’t find it? Retreat to Soyuz escape pod, closing hatches as you go. If the pressure stabilizes on your side, leak is on other.
Problem #3: An electrical fire erupts in an equipment rack.
WHAT TO DO:
1. Locate the fire–most racks have their own smoke detectors, but handheld combustion-product monitors will also work.
2. Shut off power to the rack.
3. Shut down the ventilation system.
4. If the fire doesn’t smother itself, use a portable fire extinguisher to finish the job.