At 1:38 a.m. EST on March 2, 1995, space shuttle Endeavour lifted off from Launch Pad 39A at NASA’s Kennedy Space Center in Florida. Secured inside its payload bay was the Astro-2 package: a trio of specialized ultraviolet telescopes mounted on a Spacelab instrument pointing system. Eight and a half minutes after launch, Endeavour reached orbit, setting the stage for what would become a record-breaking astronomical campaign.
Refinement of the Payload
The hardware inside Endeavour’s cargo bay had flown into space once before. In December 1990, the same instrument array flew on the STS-35 Astro-1 mission, but onboard equipment malfunctions limited that flight to achieving only 80 percent of its scientific objectives. According to NASA history, agency planners originally scheduled a seven-day reflight called Astro-2 aboard the orbiter Discovery. However, shifting orbiter assignments expanded the flight's parameters. Moving the flight to Columbia doubled its available observation time. Later, when Columbia entered a scheduled maintenance period, NASA transferred Astro-2 to Endeavour, expanding the mission outline to more than 15 days in Earth orbit.
Dual Shifts in Earth Orbit
To make full use of the extended timeline, NASA structured the seven-person crew to conduct continuous science operations. In August 1993, astronaut Tamara Jernigan, who had previously flown on STS-40 and STS-52, was assigned as the Astro-2 payload commander. To maintain round-the-clock observations, the crew split into two distinct shifts. The red shift comprised Commander Stephen Oswald, Pilot William Gregory, and Mission Specialists John Grunsfeld and Ronald Parise. The blue shift consisted of Mission Specialist Wendy Lawrence, payload commander Jernigan, and Payload Specialist Samuel Durrance. Once in orbit, the crew deployed the payload bay radiators, activated the Spacelab pallet, and began alternating 12-hour shifts.
Continuous Pointing and Observation
Operating without interruption, the astronauts executed 385 distinct shuttle maneuvers to point the cargo bay telescopes precisely at targeted astronomical objects. Across 23 scientific studies, the instruments observed more than 250 celestial targets. Among these investigations were joint observations of Jupiter, coordinated directly with the Hubble Space Telescope. Alongside the telescope operations, the crew conducted secondary middeck experiments, including the Middeck Active Control Experiment, which evaluated the structural control of flexible spacecraft components in microgravity.
Record Duration and Landing
Weather postponements at Kennedy Space Center added two extra days to the flight before Oswald and Gregory guided Endeavour to a touchdown at Edwards Air Force Base in California on March 18, 1995. The mission logged 262 orbits over 16 days, 15 hours, and 9 minutes, establishing a record shuttle flight duration at the time. Endeavour's 262 orbits proved that continuous, crew-managed orbital pointings could retrieve high-yield astronomical data and salvage complex scientific objectives from past hardware failures.
Cover: AI-generated editorial illustration; not a documentary photograph.
Source: 30 Years Ago: STS-67, the Astro-2 Mission
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