Atlantis launched from Kennedy Space Center on May 4, 1989 at 2:46 PM EDT and landed at Edwards Air Force Base on May 8 at 12:43 PM PDT. The shuttle orbited 65 times at an altitude of 184 nautical miles at an inclination of 28.8 degrees and travelled 1.7 million miles. The mission lasted 4 days, 0 hours, 56 minutes, and 27 seconds.
The primary mission was the launch of the Magellan probe that would travel to and study the planet Venus, adding vastly to our store of knowledge about our nearest neighbor towards the Sun.
Magellan/Venus radar mapper spacecraft and attached Inertial Upper Stage (IUS), was deployed six hours, 14 minutes into flight. The IUS first and second stage fired as planned, boosting the Magellan spacecraft on a proper trajectory for a 15-month journey to Venus.
The launch scheduled for April 28 was scrubbed at T-31 seconds due to a problem with the liquid hydrogen recirculation pump on the number one main engine and a vapor leak in a four-inch liquid hydrogen recirculation line between the orbiter and the external tank. The repairs were made and launch was reset for May 4. Liftoff was delayed until the last five minutes of a 64 minute window opening at 1:48 a.m. EDT due to cloud cover and high winds at KSC shuttle runway, violating return-to-launch-site limits.
Secondary payloads were: Mesoscale Lightning Experiment (MLE), microgravity research with Fluids Experiment Apparatus (FEA), and Air Force Maui Optical Site (AMOS) experiment.
One of five General Purpose Computers (GPC) failed and had to be replaced with a sixth onboard hardware spare. This is the first time a GPC was switched on orbit.
Atlantis was crewed by Commander David M. Walker, Pilot Ronald J. Grabe, Mission Specialists Norman E. Thagard, Mary L. Cleave, and Mark C. Lee.