关于这张图
This is an onboard photo of the Hubble Space Telescope (HST) power control unit (PCU), the heart of the HST's power system. STS-109 payload commander John M. Grunsfeld, joined by Astronaut Richard M. Lirnehan, turned off the telescope in order to replace its PCU while participating in the third of five spacewalks dedicated to servicing and upgrading the HST. Other upgrades performed were: replacement of the solar array panels; replacement of the Faint Object Camera (FOC) with a new advanced camera for Surveys (ACS); and installation of the experimental cooling system for the Hubble's Near-Infr…