NASA AMS: The Alpha Magnetic Spectrometer on Shuttle STS-134

The AMS is to launch on space shuttle Endeavour in April.

The Alpha Magnetic Spectrometer (AMS) will revolutionise what we know about invisible cosmic rays, in the same way that NASA's Hubble Space Telescope rewrote what we know about the visible universe, says the intellectual force behind the instrument.

Those expectations are not lost on the team putting the finishing touches on the AMS and packing it for launch.

"This kind of has grains of Hubble, looking at the universe in a different perspective," said Boeing's Bob Hart, the payload flow manager for the AMS. "The science, the exploration potential that will come out of this makes it very exciting to be a part of."

Professor Sam Ting, a Nobel Prize winner for his 1974 discovery of a heavy elemental particle, sees the AMS as a revolutionary observatory to measure invisible cosmic rays as they traverse the universe.

The AMS is a 2-ton ring of powerful magnets and ultrasensitive detectors built to track, but not capture, cosmic rays.

The 15,251-pound instrument will be connected to the outside of the International Space Station, braced on the orbiting laboratory's right hand truss and tilted a bit so it will not interfere with any of the station's mechanisms and storage platforms.

AMS will be operated remotely from Earth and should not require any attention from astronauts in orbit. "The astronauts on the space station have many things to do," Ting said. "We wouldn't dare bother them."

By recording the traces that cosmic rays make as they pass through, the AMS might uncover a universe that is now invisible. Although Ting is hesitant to make predictions about what the instrument will find, he said the instrument was designed with dark matter and antimatter in mind. Very little is known about dark matter although it makes up an estimated 90 percent of the mass in the universe.

Although Earth-based facilities have been built to create powerful streams of subatomic particles, Ting said their limits are more than 14 million times weaker than the power produced by cosmic rays in space.

"No matter how large an accelerator you build, you're not going to compete with space," Ting told reporters recently. Ting offered the news media a close look at the AMS before it was packed for loading into Endeavour's cargo bay for launch.