Two astronauts are taking one of the most complicated spacewalks in NASA history today (Nov. 15) to revive an ailing $2 billion experiment on the International Space Station and you can watch it live online.
European Space Agency astronaut Luca Parmitano, the station's Expedition 61 commander, and NASA astronaut Andrew Morgan are expected to spend. 6.5 hours working outside the orbiting lab on the Alpha Magnetic Spectrometer, a sophisticated cosmic ray detector designed to seek out antimatter and dark matter. It's the first of at least four spacewalks planned to repair the instrument, which has a coolant leak and needs a new cooling system.
"These will be very complex...it was never intended for repair in space!" Morgan said in a Twitter post Thursday (Nov. 13).
You can watch the spacewalk live on Space.com, courtesy of NASA TV. Parmitano and Morgan began their work at 6:39 a.m. EST (1139 GMT) as the station sailed 259 miles above the Indian Ocean.
Related: Astronauts to Take 4 Most Challenging Repair Spacewalks Ever
More: How the Alpha Magnetic Spectrometer Works in Space (Infographic)
The Alpha Magnetic Spectrometer (AMS) has been part of the space station's exterior since its installation in May 2011. It was designed to last for at least 3 years, relying on a set of four cooling pumps to keep its systems cool. Two of those pumps failed in 2014, raising concerns for the instrument's life.
"We knew we had to do something about it, especially since AMS was getting such compelling science," Ken Bollweg, the AMS program manager, said in a news conference Tuesday (Nov. 12). "We knew we wanted to extend its life."
Over the course of four spacewalks, Parmitano and Morgan will fix a coolant leak and install an entirely new cooling system with tools and techniques never used in space. They are the most complex since NASA's final Hubble Space Telescope repair in 2009, the agency said.
"The AMS originally was designed for a three-year mission and, unlike Hubble, was not designed to be serviced once in space," NASA officials said in a statement. "More than 20 unique tools were designed for the intricate repair work, which will include the cutting and splicing of eight cooling tubes to be connected to the new system, and reconnection of a myriad of power and data cables."
That includes cutting cooling fluid lines, something completely new for spacewalking astronauts.
"Astronauts have never cut and reconnected fluid lines during a spacewalk," NASA officials said.
Editor's note: You can follow today's AMS repair spacewalk live on Space.com.
- In Pictures: The Most Memorable Spacewalks in History
- Antimatter-Hunting AMS Experiment in Space (Photos)
- A Space Magnet, Hunting Dark Matter, Turns Up Juicy Secrets of Cosmic Rays
Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik. Follow us @Spacedotcom and Facebook.