October 17, 2011
When the space shuttle Endeavor took its final flight to the International Space Station in May, it took with it a remarkable payload: the world's largest space-based high energy physics experiment ever. The Alpha Magnetic Spectrometer (AMS) is the result of more than 17 years of planning and collaboration that now includes 56 scientific institutes across the world—and overseeing NASA's part was AMS Project Manager Trent Martin, who graduated UT with a BS in Aerospace Engineering in 1994.
"The way I like to describe the instrument package is if you put 500 physicists in a room and asked each of them to pick their favorite high energy physics instrument, they would end up with a list of every one that we put on the AMS," Martin said. "We have built a detector that rivals anything we have on the ground and surpasses anything we've built for space in size and complexity for the study of charged particles."
Martin said the AMS will allow scientists to search for antimatter, dark matter and other cosmic ray phenomena as it collects information through 300,000 data channels. He said in space, the AMS will be able to look at 25,000 particles every second.
"Unlike a telescope, where you're looking at light rays that don't have a charge, we see everything else," he explained. "If you have an isotope of helium or a carbon atom coming from some distant sun, we can see that."
The detector almost literally opens the door to a universe of possibilities.
"All of our knowledge of the universe to date comes from telescopes looking at light rays, whether infrared or visible light," Martin said. "AMS opens up a whole new world for us in that now we can look at charged particles."
Although the agreement to build the AMS was signed between NASA and the U.S. Department of Energy in 1994, the project has undergone several modifications since it began. After a flight on Discovery in 1998 to ensure the instruments would work in space, the delays in the space station and the shuttle schedule delays following the Columbia disaster gave scientists more time to add instruments to the AMS and improve the science significantly, Martin said.
Martin himself did not go straight from UT to NASA following graduation. After a couple of years working in the oil field, Martin found his way back to the space industry, like he'd always dreamed of as a child, and began and working for Lockheed Martin at Johnson Space Center. He started as a structural analyst on AMS on the contractor side and then, in 2004, he was asked to join NASA. In 2005, he was named the NASA AMS project manager.
Although Martin said his UT education gave him the foundation for how to build something that needs to function in space, it didn't necessarily prepare him for perhaps the most difficult part of his job: dealing with Nobel laureate physicists.
"Half of my job isn't just putting the AMS into space—that was the easy part," Martin said. "The hardest part of my job is getting 600 people from 16 different countries to try to speak the same language and communicate on how we should build this payload. I have to know the technical side, but a lot of my job is getting people to communicate."
Martin describes himself as part aerospace engineer, part department of international relations and part department of export control. All three require "a whole lot of communication.".
"I discovered that engineers often work in teams whereas scientists work as individuals," said Martin, pointing out that scientists are concerned with what they might publish next and are therefore less open with engineers and with each other. "Trying to get scientists to work in teams is a big challenge."
But the launch of the AMS, which will remain on the International Space Station through its lifetime of at least 2020 (or even 2028 if the space station lifetime is extended), is a testament to Martin and his team's success in the collaboration of so many scientists. The ability to search from space for dark matter—the elusive "something" which scientists hypothesize is causing the universe to expand—and for antimatter—in which atoms have a reverse charge with a negative charge in the nucleus which is orbited by a positron on the outside—is a huge opportunity for astrophysicists. Finding dark matter could, as Martin said, "redefine physics as we know it."
For now, the AMS will be the only physics experiment of its magnitude in space now that the shuttle program has ceased.
"The loss of the shuttle is a huge hit for very large science experiments because there is just no easy way to get large science experiments to space, particularly if you want to return them," Martin said. "We can and will continue to launch large science experiments on rockets, but there is no existing spacecraft to get an experiment of this size to the ISS without the shuttle." (The AMS is 15,251 pounds and 15 feet across.)
But because the AMS will last at least through the end of this decade, the billions of pieces of information it collects from billions of charged particles will keep scientists learning for a long time to come.
