English: Figure 6-3. Average changes in body weight, isokinetic leg strength, and leg volume of crewmembers on the three Skylab missions. Only the bicycle ergometer was used on Skylab 2, the MK I and MK II “Mini Gym” exercisers were added for Skylab 3, and a passive “treadmill” was flown on Skylab 4. The average work load per day on the cycle ergometer is also provided by mission for comparison.
The NASA website hosts a large number of images from the Soviet/Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.
The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use. [2]