Gazing at his spectrometer, almost ready for space at last, Dr. Ting shrugged off the question of what he had up his sleeve next.

“You must think I am really stupid,” he said. “You see how much trouble this was.”

The experiment was born in the early 1990s when, despite his prestige, Dr. Ting failed to land a role on the largest physics machines ever contemplated, the Superconducting Supercollider (canceled before completion in 1993 by Congress) or the Large Hadron Collider (now operating at CERN, as the European Organization for Nuclear Research is known).

So he turned his eyes to the heavens. According to the laws of physics, equal amounts of matter and its science-fiction-sounding evil twin, antimatter, which annihilates ordinary matter in a flash of energy upon contact, should have been created during the Big Bang. It is one of the abiding mysteries of science why the universe is now all matter. Or is it?

The discovery of a single atomic nucleus heavier than anti-helium could mean there was an anti-star or maybe a whole anti-galaxy somewhere.

“If you don’t do the measurement, you will never know,” Dr. Ting said.

In 1994 Dr. Ting told Dan Goldin, then NASA’s administrator, that he could make that measurement with a space-based cosmic ray detector. Mr. Goldin was instantly smitten and agreed to put the spectrometer on the International Space Station, which was desperately lacking scientific credibility, bypassing the agency’s normal peer-review procedures and setting off resentment among other cosmic-ray physicists that still lingers.

Part of the lure was that the space agency would not have to pay for it. The bulk would be paid for by Dr. Ting’s army of collaborators abroad, which grew to 600 scientists from 16 countries, including Italy, Germany, Russia, China and Taiwan.

In 1998, a prototype of the spectrometer was built and flown successfully on the space shuttle for 10 days on a trip to the Mir space station, although not without some Tingian drama. Behind in the construction schedule, Dr. Ting announced one day that he was canceling the Christmas break. “Perhaps on Christmas Day we will take a few minutes to reflect,” Peter Fisher, an M.I.T. physicist who was there, recalled Dr. Ting saying.