Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

It has been said that everything in the universe is connected to everything else and you can’t pick up one tail without picking up the entire thing.  This is usually not obvious, but there were several news stories this past week that all shared a common link; and that news was space and fire.

The first story that caught my eye was that the Apollo 1 capsule had been moved to a ‘safer’ storage area.  The 40-year-old capsule was deteriorating and it’s been moved to a more climate-controlled area.  So why are we preserving this capsule?  Because it burned and took the lives of three astronauts. It was a horrible news story.  The fire engulfed Apollo 1 at Cape Canaveral during a launch pad test.  The fire killed Lt. Col. Virgil I. Grissom, Lt. Col. Edward H. White and Lt. Cmdr. Roger B. Chaffee and it nearly derailed the Apollo program but the good news is that the fire prompted many design and procedural changes in the NASA space programs.

Edward White, Gus Grissom, Roger Chaffee Credit NASA

The astronauts were sealed in an Apollo space capsule, scheduled to be the first of its type to fly in late February 1967.  A routine test of launch procedure at Cape Kennedy, Fla., had run long with various technical and communications glitches.  “How do you expect us to get to the moon if you people can’t even hook us up with a ground station?” astronaut Gus Grissom groused at controllers. The first indicator of trouble was when Roger Chaffee shouted “There’s a fire in the cockpit!”  Controllers watched in horror as instruments showed a sudden buildup in pressure inside the cockpit.  Fourteen seconds later, the capsule ruptured and the crew fell silent.  It took technicians another five minutes to fight through the smoke to pry open the craft. The astronauts were breathing pure oxygen, which is unbelievably flammable.  Although investigators never found what caused the initial spark, it spread quickly in the pure-oxygen environment inside the capsule, which was filled with combustible items – paper, clothing, and patches of Velcro.  And worse yet, the way out consisted of two separate hatches and required removing several dozen bolts. But the fire spread so quickly that even if exit had been easy, the astronauts probably wouldn’t have made it.

The Apollo 1 capsule

Unlike a variety of other historic spacecraft, the Apollo 1 capsule has never been on public display and as kept in a secure storage container.  However, the container was deteriorating, NASA said.  The capsule, the conical command module, was moved 90 feet to a newer environmentally controlled warehouse at the center, where its very existence serves as a grim reminder of the dangers of fire in a space environment.

Apollo 1 capsule interior

Although Apollo 1 was on the ground, there have been fires in space.  The most dangerous one occurred aboard the Mir space station ten years ago in February 1997 when a fire broke out in the Kavant1 module.  Fire is terrifying in space as there is nowhere to go to escape the flames and they burn precious oxygen.  The1997 fire started in a back-up oxygen canister and it quickly filled the entire space station with smoke.

The crew of six was in the Base Block when the fire began in an adjacent room.  Two of the Russian crewmembers, Valeri Korzun and Aleksandr Kaleri fought the fire with extinguishers but they had no effect.  The crew watched in horror as two-foot long flames threatened to burn through the aluminum hull.  The fire also blocked the escape route to one of the two docked Soyuz spaceships.  Finally, after 14 endless minutes, the flames burned out.

The fire had filled the entire station with smoke and generated a huge amount of molten metal.  All the crewmembers had to wear gas masks.  The effective time limit for wearing the masks was 2.5 hours, and by the time Mir's overworked air filtration system cleared most of the smoke the time limit for the masks was almost up.  Jerry Linenger, the American on board at the time, ran tests to see if the fire had released dangerous levels of formaldehyde.  The cause of the oxygen canister's failure and the subsequent fire has never been determined.

Jerry Linenger wearing an oxygen mask after the fire aboard Mir

Notice that I said that Korzun and Kaleri fought the fire with fire extinguishers, but they had no effect.  Fire burns differently in a weightless environment.  It can form floating balls that simply scatter before a fire extinguisher.  After decades in space, we still don’t know the best way to put out fires.  And that’s what a team of five Viterbi School aerospace engineering students at the University of Southern California wants to find out.

Fire damage aboard Mir

This March, the group, which founded a new student space exploration club called USC Students for the Exploration and Development of Space (SEDS), will have a rare opportunity to find out more about how fire behaves at very low gravity, or microgravity when they conduct a flame experiment aboard NASA’s modified KC-135 aircraft, sometimes referred to as the “Vomit Comet.”  The KC-135 “weightless wonder” is the only experimental facility that can recreate specific gravities, such as lunar gravity, reduced gravity, Martian gravity, or a sustained hypergravity.

Experimenters floating in microgravity aboard KC-135. (Image courtesy of USC Viterbi School of Engineering)

The USC team will be concentrating solely on microgravity, which is similar to conditions onboard the orbiting International Space Station.  Flying aboard the KC-135 will be Daniel Calvo, a junior aerospace engineering major and captain of the USC flame experiment; Emily Hedges, a junior aerospace engineering major; Adriel Carreno, a junior mechanical engineering major; and John Duncan, a junior aerospace engineering major.  Alternates are Quinn Freyermuth, a junior mechanical engineering major, and Mikeala Blackler, a junior industrial systems engineering major.  

Calvo and his team competed against scores of undergraduate teams across the country in NASA’s Reduced Gravity Student Flight Opportunities Program.  The program gives students nationwide a unique opportunity to purpose, design, fabricate, fly and evaluate a reduced gravity experiment of their choice aboard its one-and-only flying microgravity laboratory.

Since fire burns so differently in space, the team will test three different atmospheres; a carbon dioxide (CO2) atmosphere, a helium-based (He) atmosphere and a nitrogen-based (N2) atmosphere to see how fast fire burns in each of them.

CO2 is used as a fire suppressant in terrestrial fire extinguishers but according to the team, research indicates that CO2-based atmospheres will actually cause fire extinguishers to increase the burning rate of a flame in a weightless environment.  They theorize that the inertness of helium will have the opposite effect and may actually slow the burn rate of a flame in microgravity.  Nitrogen, the third experimental atmosphere will act as a control, as well as to simulate the type of environment experienced in manned space vehicles.

Physically, the experiment consists of a test chamber and stand, and wax balls that will be ignited and studied inside the chamber.  The students will fill the chamber with each of the three gases — CO2, He and N2 — to create the three different atmospheres, then ignite and study the wax balls as they burn in each atmosphere.

The team will get two flight days aboard the Vomit Comet to conduct their experiment, which means they will have about 60 chances to ignite and measure their fireballs in weightlessness.  Four additional teams from other institutions, each with four team members, will be sharing the ride and running independent experiments simultaneously.

Calvo is particularly keen to see how the flames behave in a CO2-based atmosphere, because that would confirm his suspicion that the current CO2 fire extinguishers used by astronauts should be replaced.  “There hasn’t been a fire onboard a spacecraft in a long time, so people haven’t thought much about fire extinguishers or fire safety for a while,” Calvo said.  “This is a good time to revisit the issue.”

Words of wisdom, indeed.  And it’s good to know that there are students who are actively experimenting in space technology and in methods to keep our astronauts safe.