Tag Archives: coolant leak

Astronauts will replace a pump tomorrow on their spacewalk in the hope this will fix the leak in ISS’s solar panel cooling system.

The astronauts will replace a pump tomorrow on their spacewalk in the hope this will fix the leak in ISS’s solar panel cooling system.

The spacewalk has still not been approved, though it seems likely it will happen.

Update: As of this morning the spacewalk has been approved, set to begin at 8:15 am (Eastern).

Astronauts today spotted an ammonia coolant leak in ISS’s left-side power truss.

Astronauts today spotted an ammonia coolant leak in ISS’s left-side power truss.

They are monitoring it, but have so far not made any decision about what to do about it, if anything.

This problem is a perfect illustration of why a flight to Mars is more complicated in terms of engineering than first appears. We might at this time be able to build that interplanetary spaceship (with the emphasis on the word “might”) but could its passengers maintain it millions of miles from Earth? Right now I’d say no. We need to learn how to build an easily repaired and self-sufficient spaceship. ISS is neither. It is also not a very good platform for testing this kind of engineering.

Update: The astronauts on ISS are preparing for a possible spacewalk on Saturday to deal with the problem. More details here.

A spacewalk November 1 will attempt to find and repair a coolant leak that could force a power reduction at the station.

Construction workers in space: A spacewalk November 1 will attempt to find and repair a coolant leak that could force a power reduction at the station.

A slight 1.5-pound-per-year leak in the channel 2B cooling system has been present since 2007 and during a shuttle visit last year, two spacewalking astronauts added eight pounds of ammonia to the reservoir to boost it back up to a full 55 pounds. The plan at that time was to top off the system every four years or so to “feed the leak,” replacing the lost ammonia as required.

But over the past few months, engineers saw the leak rate suddenly quadruple, either because something changed at the original leak site or, more likely, because another leak developed somewhere else in the system.

Whether the leakage was caused by space debris or a component failure of some sort is not yet known. But the result is: If the leak continues at its current rate, the coolant will drop below a 40-pound safety limit and the system will shut down by the end of the year or shortly thereafter, taking power channel 2B down with it. While the space station can operate without the full complement of power channels, the loss of channel 2B would force flight controllers to power down equipment, eliminating redundancy and reducing the amount of research the crews could carry out.