The International Space Station was outfitted Thursday with a $2 billion state-of-the-art particle detector aimed at determining what composes the universe and how it began.

The Alpha Magnetic Spectrometer (AMS) was installed at 4:56 a.m. CDT on the upper right side of the space station's truss, where it will operate for as long as the complex is in orbit.


Mission specialists Drew Feustel and Roberto Vittori used the shuttle's robotic arm to extract it from Endeavour's cargo bay. They then handed it off to the space station's Canadarm2.

Pilot Greg H. "Box" Johnson and mission specialist Greg Chamitoff used the station's robotic arm to install AMS on the starboard side of the ISS.

"AMS is now successfully installed," reported Chamitoff from inside the station's Cupola. "Huge congratulations to everyone on the AMS team."

"I am sure Professor Ting and his group have been holding their breath. You guys can all start breathing again now," said Chamitoff.

"Thank you very much for the great ride and safe delivery of AMS to the station," radioed Sam Ting, the Nobel laureate who led development of the AMS for more than 15 years. "Your support and fantastic work have taken us one step closer to realizing the science potential of AMS. With your help, for the next 20 years, AMS on the station will provide us a better understanding of the origin of the universe."

"AMS looks absolutely fantastic on the truss," replied commander Mark Kelly. "I know you guys are really excited and you are probably getting data and looking at it already."

The AMS uses a powerful magnet to alter the path of the charged cosmic particles traveling through space. Eight different instruments will provide information on those particles as they make their way through the AMS.

Armed with that data, hundreds of scientists from 16 countries are hoping for clues on the origin of dark matter and the existence of antimatter and other unusual matter. AMS could also provide information about pulsars, blazers, gamma ray bursts and any number of other cosmic phenomena.

"I think in the next 20 to 30 years, nobody will be able to do such a thing again," said Ting, addressing the station's crew. "I hope together with you we'll try to make a contribution to a better understanding of our universe."

Endeavour's crew and Expedition 27 flight engineer Ron Garan, who is matching sleep schedules with the shuttle crew, began their day at 9:56 p.m. The wake-up song "Luna," performed by Jose Serrano for his friend Chamitoff, was transmitted about 30 minutes later after a comm drop-out cleared.

"That song was made especially for our flight, STS-134," said Chamitoff.

Following the successful installation of the AMS, Endeavour's crew took part in several interviews with National Public Radio, Reuters, Associated Press and Fox News Channel.

Kelly, Johnson, Chamitoff and Fincke also answered questions that were posed through an online forum hosted by Google, YouTube and the PBS NewsHour.

Mission managers and engineers have been able to clear one, if not two, of their "areas of concern" on space shuttle Endeavour's heatshield but a third damaged tile may require the STS-134 astronauts perform "focused inspections" on Saturday.

Photos taken of Endeavour's tile-covered underbelly as it approached the International Space Station on Tuesday revealed seven areas of damage running in a rough line from the right-side main landing gear door to an aft elevon. Four of those seven dinged tiles were earlier cleared as safe for reentry.

Of the remaining three damaged sites, one was cleared on Thursday, and a second located on Endeavour's right-side inboard elevon was expected to be ruled not a concern by Friday morning.

The third, a 3.22 by 2.49 inch gouge found between the right main landing gear door and an external tank feed line port, may require better imagery before managers can decide a course of action.


"The team has not completed our assessments on this site, but the work we've done so far, we believe we may need to do a focused inspection in order to get some fidelity," said mission management team chair LeRoy Cain. The existing pictures of that area, he said, "are kind of fuzzy."

If managers do decide they need the additional images, it will be only the fifth time focused inspections have been conducted in the 21 flights that have followed the loss of space shuttle Columbia in 2003.

One of those previous inspections was conducted in 2007 for a gouge on Endeavour's belly that was similar in size and location to the one now a concern. The focused inspections conducted by the STS-118 astronauts provided engineers on the ground the information needed to clear the tile for a safe reentry.

Cain said he expected the outcome this time to be similar.

"I feel pretty confident if, in fact, we're not able to clear it by the morning, when we get focused inspection data we will be able to clear this problem and not have to do anything," he said.

"I'm not concerned about the damage that we're seeing here, it's certainly not alarming," Cain said. "My confidence is largely derived from the fact that we have a very good process for dispositioning these things, we know exactly how to go assess them. We've gotten better and better at it and we know that our models are doing nothing but improving as time goes on and we get more experience."