NASA’s John Grunsfeld at an Earth Day event in Washington, D.C., in 2015

NASA’s John Grunsfeld at an Earth Day event in Washington, D.C., in 2015

NASA/Aubrey Gemignani

‘Hubble repairman’ to retire from NASA’s top science spot

NASA Associate Administrator John Grunsfeld, an astrophysicist and astronaut who worked on three repair missions to the Hubble Space Telescope, will retire from his position as head of the science mission directorate on 30 April, the agency announced today.

Grunsfeld served for many years as an astronaut within NASA’s human spaceflight division, and flew on five shuttle missions. Since 2012, he led NASA’s science division, where he became an advocate for marrying the agency’s human and robotic exploration divisions.

It was not his first time at headquarters. In 2004, he was chief scientist—an advisory role to the administrator—and he was put in the difficult position of having to defend a decision to cancel Hubble’s final servicing mission (which ended up going ahead in 2009). After a stint at the Space Telescope Science Institute in Baltimore, Maryland, Grunsfeld was called back to headquarters in Washington, D.C., in 2012, following the departure of Associate Administrator Ed Weiler.

Like Weiler, Grunsfeld oversaw a bevy of planetary missions. He arrived just in time to see the successful landing of the Curiosity rover in 2012 (a mission that Weiler delayed because of problems with the rover’s motors). This year, Grunsfeld made a similar decision to postpone but not cancel the InSight mission to Mars because of problems with an instrument designed to measure tremors. Grunsfeld also got to see the Pluto flyby, led by former science chief Alan Stern, although work for that mission began a quarter-century before.

The most important thing Grunsfeld did while sitting atop the science division may have been to keep the $8.7 billion James Webb Space Telescope on budget and on track for launch in 2018. In an interview with Science in 2012, Grunsfeld said that keeping “Hubble 2.0” on track was his top priority. “Hubble 2.0” would be “amazing,” he said. “But we have to deliver it.”

In the end, most will remember Grunsfeld for his joyful work as the starry-eyed repairman to the Hubble telescope, a mission that he loved so much that he was willing to risk his life for it. NASA said that following Grunsfeld’s retirement, deputy Geoff Yoder would serve as acting associate administrator until a permanent replacement is named.