Cheli trained as a military pilot and test pilot before astronaut selection. He was selected by the European Space Agency and trained with NASA for shuttle mission specialist duties, representing the generation of European astronauts who flew on U.S. shuttle missions before the ISS became fully operational.

STS-75 launched in February 1996. The mission deployed the Tethered Satellite System Reflight experiment, but the tether broke during deployment; despite that failure, the crew gathered important data and completed a broad microgravity research program.

After his astronaut career, Cheli remained active in aviation and aerospace.