A broken cooling line on the $100 billion International Space Station which is presently orbiting the earth about 400 kilometers from where you will read this, has forced NASA to postpone a cargo mission and schedule a series of spacewalks to repair the problem.

NASA

Mastracchio and Hopkins to be sent outside the space station

American astronauts Rick Mastracchio and Mike Hopkins will be sent outside the space station on three separate spacewalks, beginning on Saturday and ending on Christmas Day, the US space agency said on Tuesday.

The ISS uses two external cooling loops to circulate ammonia on the outside of the platform in order to keep both internal and external equipment cool. A broken valve on one of these loops will be replaced over the three spacewalks; the valve began failing on December 11th.

NASA turns off nonessential equipment

While NASA says that the six-man crew is not in any danger, it did force them to turn off all nonessential equipment and halt a number of science experiments.

This is not the first time that the ISS has had issues with the cooling system. In 2010, astronauts over three separate spacewalks were forced to replace a nearly 800-pound pump. While the valve will be considerably lighter and less bulky, Mastracchio and Hopkins will need to first visit an external storage site to gain access to the replacement valve.

“The next week will be busy with spacewalks so not much tweeting from here,” Mastracchio Tweeted from space soon after the decision to launch the spacewalks was announced.

“Have not looked out the window in 4 days,” he said in another tweet. “Too busy building space suits. Where did I put my gloves?”

Orbital Sciences’ cargo run delayed

As a result of the needed repairs, Orbital Sciences Corp (NYSE:ORB) will have to wait to make its first cargo run to the International Space Station which was scheduled to launch from Wallops Island, Virginia today.

Orbital Sciences Corp (NYSE:ORB) is one of two companies hired by NASA to fly supplies to the outpost after the abandonment of the Space Shuttle program that ran for thirty years.

The flight, the first of eight under a $1.9bn NASA contract, will be rescheduled for no earlier than the second week of January, said NASA spokesman Josh Byerly, at the Johnson Space Center in Houston.

The spacewalk on Saturday will be the first by NASA crew members since July, when Italian astronaut Luca Parmitano almost drowned after his helmet filled with water causing a “redesign” of the helmet that would make TV’s MacGyver proud. The astronauts used a snorkel and absorbent towels last weekend to Jerry-rig a solution.

The space station also hosts one Japanese and three Russian crew members at present.

In an unrelated space walk, Russian Commander Oleg Kotov and Flight Engineer Sergey Ryazanskiy are scheduled to make their own walk on December 27, to install cameras and other gear on the platform outside the Russian segment of the ISS.