Ammonia

For those of you who might have missed it, or more importantly, for those of you who only heard about it in the mainstream media, there was an emergency declared this morning on the International Space Station. The “tl;dr” version is that everyone followed the procedures that they’ve practiced hundreds of times, everyone’s safe, the emergency turned out to be a faulty sensor, and everything’s getting back to normal.

Not that you would know it from looking at the stupid clickbait headlines in a vast number of online “news” sites. I don’t know which worries me more, the fact that so many of our traditionally reliable and trustworthy news sources are turning into happy-talk, sensationalist, fear mongering, nonsense sites, or that so many of the general populace doesn’t know and/or doesn’t care that it’s happening and believe every word without question.

Anyway…

Up on ISS, there are three BIG problems that are top of the list in potential crises. First, depressurization, perhaps if they’re hit by a piece of debris or a micrometeorite. Secondly, fire and smoke, which can get out of control, behave in an unusual way, and get very deadly very fast. Third, an ammonia leak from the cooling system, which can get into the cabin air and become extremely toxic and poisonous.

All of the equipment running on ISS creates a lot of heat, which has to be dissipated. There’s a water cooling loop inside – but it can’t go outside because the water would freeze and/or boil in the temperatures, breaking the system. So outside there is a coolant loop of ammonia, which is very good for the job but also very poisonous in high concentrations and being pumped around under pressure. In between the two systems are a series of heat exchanging radiators.

That’s where the problem could come in. If something cracks in one of those radiators and fails despite the safeguards, ammonia could get into the cooling water, and from there into the air.

What controllers on the ground at NASA saw about twenty-one hours ago was a rise in pressure in the water cooling system. This is a potential sign that ammonia is possibly leaking into the system. Then they saw a rise in the cabin air pressure, which would be a second sign of possible ammonia contamination.

As planned in such a situation, the astronauts in the American side of the station (where the ammonia/water cooling loops are) put on gas masks, retreated to the Russian side of the station (where there is no ammonia system), and closed the hatches. (Each segment of the station has a hatch at every entrance that can be closed, sealed, and locked quickly, just like in a submarine. In an emergency, it limits the potential damage.)

From there they tested the air in the Russian segment (it was fine) and the controllers on the ground started shutting down systems on the American side to save power and minimize the load on the cooling system. From there, the crew could stay for a considerable time (weeks if necessary) using just the Russian food, oxygen, and toilet. It would be crowded and inconvenient, but it would be safe.

Once in a safe mode, ground controllers began testing the cooling system and double checking the monitoring sensors and computers. At no point was there every any evidence that an ammonia leak had actually occurred. All that was seen were the two pressure readings that might possibly be early warning signs of a leak.

After several hours, the controllers on the ground were convinced that it was in fact a false alarm, caused by a problem with one of the interface cards that connects the computers to the sensors. The go-ahead was given to start procedures to re-enter the American side of ISS.

With the three Russian cosmonauts and one Italian astronaut all going into the two Soyuz vehicles (which in an incredibly extreme scenario could be detached from ISS and bring the occupants back down to Earth), the two American astronauts donned protective gear (gas masks and so on) and cracked the hatch between the American and Russian sides. The air tested fine. They went through the hatch and then shut it behind them, then went slowly through the entire American side. The air all tested fine.

The “all clear” was given and everyone was given the go-ahead to put away the safety gear and start restoring everything to normal operations. The ground controllers do a lot of this, bringing systems back online slowly and in a controlled fashion so that nothing gets overloaded, much like how the power grid is brought back up after a large blackout.

Tonight the two American and one Italian astronauts all slept in their normal quarters in the American segment. No damage was reported to any of the science experiments running and no science data was lost, just some time. They’ll have to juggle schedules and might miss a few hours of their nominal off-duty time on the weekend to get caught up, but that shouldn’t be a big deal.

So, a couple of things to remember:

First, as always, if you run into anyone who says that NASA doesn’t exist anymore and we don’t have anyone in space, either straighten them out yourself or sent them to me for some references and factual information. Don’t be mean to them — they’ve probably just been getting their information from that “mainstream media” and don’t know any better. We can fix that, one person at a time if necessary.

Secondly, don’t ever forget just how dangerous it can be to be off-planet. We’ll always do our best to keep everyone safe, but it is an extremely harsh, hostile, and dangerous environment. It can kill you in a heartbeat if you’re not constantly vigilant and prepared.

The fact that it’s dangerous doesn’t mean that we can’t go there, or that we shouldn’t go there. There are environments just as hostile and dangerous here on Earth that we have tens of thousand of people living in every day. Think about life on a nuclear sub, for example. Very similar — isolated, crowded, cramped, a hole in the hull will kill you, a fire onboard can kill you, and a contaminated atmosphere in an small, enclosed space can kill you. Yet we still have hundreds of submarines with tens of thousands of sailors aboard.

We can survive in those environments, in particular by doing our best to think through in advance what emergencies might arise and how we’ll deal with them. Today everyone did what they were supposed to, and the system worked like it should have. Even if it had been a major ammonia leak, there are procedures beyond what was done today to seal it, clean or vent the contaminated atmosphere, and restore the contaminated areas to normal use.

Just don’t panic if you see a sensational headline on a normal news source or website. (That goes for everything else such as plane crashes or terrorist attacks or local traffic accidents.) Double check your facts and never believe everything you read or see on the internet.

(Except for here, of course! NOT!)

2 Comments

Filed under Computers, Disasters, Space

2 responses to “Ammonia

  1. Jemima Pett

    Mmm, emergency procedures, love them! Must get my spacemen to practice them….

    Liked by 1 person

    • Same thing with flying or anything else that could “ruin your day”. Always hated it when my instructor would cut the engine to idle at some random moment or yell “Go around!” in the middle of some random touchdown. But when it happens in real life, it’s a good thing to react quickly & correctly thanks to all that training.

      Liked by 1 person

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