Acton worked at the Lockheed Palo Alto Research Laboratory and specialized in solar physics. His payload-specialist assignment reflected the shuttle program's use of researchers who knew the instruments and science goals of specific payloads.

STS-51-F carried Spacelab 2, a major science mission focused on astronomy, solar physics, plasma physics, and life sciences. The mission reached orbit after an abort-to-orbit event and still completed significant research objectives.

Acton's role connected ground-based and orbital solar research. As a payload specialist, he helped operate experiments and interpret observations in real time from inside the shuttle laboratory environment.

After the mission, Acton returned to scientific work and education. His career is part of the story of laboratory scientists flying as working researchers rather than permanent NASA astronauts.