NASA | Hubble Memorable Moments: Powering Down

In this first video of NASA's Hubble Memorable Moments series celebrating Hubble's 25 years, the telescope must be completely powered off to replace Hubble's heart. In 1999, engineers at NASA's Goddard Space Flight Center discovered that there was a problem with Hubble's Power Control Unit. Hubble team members came up with a plan to replace the unit on Servicing Mission 3B. On March 6, 2002, the day came to put that plan into action. What could go wrong? Stay tuned throughout 2015 for more Hubble Memorable Moments.