AMS-02 Roma Group
An artist's conception shows the Alpha Magnetic Spectrometer on the left, installed on one of the International Space Station's truss sections. The device is to be brought up on the shuttle Endeavour.
Big particle-physics experiments have caused their share of unwarranted nightmares over the past few years, including the worries about globe-gobbling black holes and strangelets that might be created by Europe's Large Hadron Collider. The Alpha Magnetic Spectrometer, a $2 billion particle detector due to go into orbit on the shuttle Endeavour, just might actually detect strangelets, or the traces of mysterious dark matter, or bits of antimatter that couldn't possibly be created on Earth.
But Samuel Ting, the Nobel-winning MIT physicist who has guided the spectrometer through a troubled 17-year-long development effort, will actually be sleeping a lot easier once the AMS is launched.
"Our only nightmare for AMS during the 17 years was to be removed from the manifest," Ting, the experiment's principal investigator, told me today.
A few years ago, it looked as if NASA would be leaving the van-sized apparatus on the ground just because it couldn't spare a shuttle mission to fly it up to the International Space Station. Ting said he was surprised by that decision, particularly because scientists from 16 countries had contributed so much to the experiment. "I would say 'surprised' is the most polite word I can think of," he said.
Fortunately, Congress set aside the money for a flight to send up the AMS. And when NASA decided to extend operations on the space station to at least 2020, Ting and his team retrofitted the 7-ton, cryogenically cooled detector to make it last as long as the station, even if it stays in orbit until 2030.
Ting reiterated the main goals of the AMS experiment during a news briefing today:
- Look for heavy antimatter particles, such as the nuclei of antihelium or anticarbon, that would otherwise be annihilated as they passed through Earth's atmosphere. The presence of such cosmic particles could shed light on what happened to all the antimatter that should have been created along with ordinary matter in the big bang. "If you expect 20 antihelium and anticarbon [particles], and you never see one, something's wrong," Ting said.
- Watch for the traces left behind by exotic particles that may theoretically account for dark matter, which is thought to account for 90 percent of the matter in the universe but can only be detected by its gravitational effect.
- Keep an eye out for anomalous combinations of particles, such as strangelets, which incorporate an unusual type of "strange" quark.
To make such detections, the AMS will rely on the most powerful magnet launched into space and a complement of seven particle-detecting instruments. An early version of the device underwent real-world testing aboard the shuttle Discovery in 1998, so Ting is confident that AMS-2 will work like a charm after its installation and a shakedown period of eight hours. Once it's installed, the astronauts on the station don't really need to do anything:The data will be beamed down to Earth for analysis — at first to a control center at NASA's Johnson Space Center, and eventually to CERN, Europe's particle physics research center. That's right, the same center that plays host to the Large Hadron Collider.
I suppose the only nightmare Ting has to worry about now is that, for some reason, the AMS doesn't work as planned. He doesn't sound all that worried ... but other physicists have questioned whether the $2 billion project will end up being worth it. In last week's issue of the journal Science, the University of Chicago's Dietrich Muller was quoted as saying that the scientific questions being addressed by the AMS could have been done much more cheaply using high-altitude balloon experiments. And the University of Michigan's Gregory Tarle contended that nuclei from antimatter galaxies would never make it to our corner of the cosmos anyway.
"The major justification for doing AMS has evaporated," Tarle said.
When a reporter brought up Tarle's criticism at the end of today's briefing, Ting dodged the criticism and instead talked about Tarle's university.
"University of Michigan is where I went to school," he observed. "Used to have a very good football team. In the last few years, the team has gone to pot. Last year, they have changed the coach.
"I have no other answer."
Professor Tarle, I think you just got Tinged.
More about the antimatter quest:
- It's official: Heaviest antimatter found
- Space mission hunts for antimatter galaxies
- Antimatter atoms captured at last
- AMS may lead to space radiation shield
Stay tuned for further updates from Kennedy Space Center, in Cosmic Log as well as in msnbc.com's space news section. You can join the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.