Scientists in Geneva took some antiprotons out for a spin—a very delicate one—in a truck, in a never-tried-before test drive that has been deemed a success.

If this so-called antimatter had come into contact with actual matter, even for a fraction of an instant, it would have been annihilated in a quick flash of energy. So experts at the European Organization for Nuclear Research, known as CERN, had to be extra careful when they took 92 antiprotons on the road for a short ride on Tuesday.

The antiprotons were suspended in a vacuum inside a specially designed box and held in place by supercooled magnets.