The experiments performed on Columbia's crew and on laboratory animals (48 rats held in 24 cages), along with data collected on the SLS-1 mission (STS-40) in June 1991, will provide the most detailed and interrelated physiological measurements acquired in the space environment since the Skylab program in 1973 and 1974.

[5] McArthur and Blaha began using the Lower Body Negative Pressure device on flight day 3 (FD 3), which is being tested as a countermeasure for the detrimental effects of microgravity.

All three flight crew members will collect urine and saliva samples and keep logs of their exercise and food and fluid intake as part of the Energy Utilization detailed supplementary objective.

The information will be useful to scientists and engineers planning future Spacelab microgravity research flights in which experiments will need a quiet, motion-free environment to produce the best possible data.

On October 28, 1993, after enjoying a half a day off, the astronauts aboard Columbia continued to collect scientific data on how humans and animals adapt to the absence of Earth's gravity.

[5] Payload commander Rhea Seddon sent down a special message to her husband, Astronaut Office Chief Robert L. Gibson when she surpassed his total of 632 hours, 56 minutes in space.

[5] Pilot Rick Searfoss took time out from snapping some infrared photography of the wildfires burning in southern California to say that the crew's thoughts are with the firefighters working to quell the flames and the residents whose homes are being threatened.

He said he hoped the fires would be brought under control soon, and added that the photographs he was taking will be among some 4,000 frames that will be returned to Earth for meteorologists, geologists, ecologists and archeologists to study after the flight.