The STS-77 Space Shuttle in-flight crew was made up of six astronauts: the Commander, Colonel John H. Casper (USAF), the Pilot, Lieutenant-Colonel Curtis L. Brown, Jr. (USAF)and the four Mission Specialists: Commander Daniel W. Bursch (USN), Mario Runco, Jr. Canada's own Marc Garneau, Ph.D., and Andrew S.W. Thomas, Ph.D
Mission objectives included deploying and retrieving Spartan-a scientific data collecting satellite-using the Canadarm. Marc Garneau was responsible for manoeuvring the Canadarm during the retrieval operations of the Spartan satellite.

Four experiments on board were Canadian: the Commercial Float Zone Furnace (CFZF), the Aquatic Research Facility (ARF), the Nanocrystal Get Away Special (NANO-GAS), and the Atlantic Canada Thin Organic Semiconductors (ACTORS). On orbit, Marc Garneau was responsible for the CFZF, a joint project between Canada and Germany.
Dr. Garneau completed his Mission Specialist training in 1994. He was responsible, along with his crewmates, for the operation of orbiter systems during spaceflight. He was also trained to operate the Canadarm and do "spacewalks" to work outside the shuttle if required. Mission Specialists do not fly the shuttle, but they must be able to make repairs in case of any failures or breakdowns.
Canada's first astronaut to fly, Marc Garneau once again made history, this time, as the first Canadian to fly twice into space.