Lichtenberg was the first Payload specialist. He flew on the Spacelab-1 (STS-9) mission (10 days in 1983), conducted multiple experiments in life sciences, materials sciences, Earth observations, astronomy and solar physics, upper atmosphere and plasma physics. His second flight was ATLAS-1 (STS-45) Spacelab mission (9 days in 1992); conducted 13 experiments in Atmospheric sciences and astronomy. He has flown 310 orbits, and has logged 468 hours in space.