LAUNCH CONTROL: 3, 2, 1, we have booster ignition and liftoff of Endeavour on a voyage to view the universe! JOHN GRUNSFELD: We spent about 16 days doing astronomical observations from a very high mountaintop that was moving very fast.

John Grunsfeld was a scientist and astronaut who was making his first trip to space. He and six crewmates headed for orbit aboard space shuttle Endeavour 25 years ago today.

Endeavour carried telescopes for observing everything from the Moon to distant galaxies — a mission known as Astro-2. It was a follow-up to a shorter flight five years earlier.

The crew operated three telescopes. The telescopes observed the universe in ultraviolet light, which is impossible to see from the ground. They took pictures and other observations of hundreds of targets.

Doing astronomy from the shuttle had both good points and bad points, as Grunsfeld recalled in this 2010 interview:

GRUNSFELD: From a technical perspective of trying to do high-precision astronomy, the shuttle’s not the best place. People moving around inside the system, attitude maneuvers, all conspire against you. Other than that, the space side, we offered an on-site problem solving that allowed extremely high observing efficiency for an observatory that was built around the space shuttle.

Today, most space astronomy is conducted by free-flying satellites, such as Hubble Space Telescope. But some is being done from the International Space Station, with some instruments tended by astronauts — just like Astro-2.

Script by Damond Benningfield