On Saturday astronauts completed the third and riskiest spacewalk in their mission to upgrade and fix the Hubble Space Telescope. The Washington Post calls intergalactic repairmen John Grunsfeld's and Andrew Feustel's work "a wild success" after removing "a refrigerator-sized, mirror-packed instrument." The most harrowing of the repairs required Grunsfeld to remove 32 screws from Hubble's Advanced Camera for Surveying unit, which was not designed to be opened or fixed -- much less opened and fixed in outerspace. The procedure was considered risky because Grunsfeld had to reach into the unit, where sharp edges could have poked a life-endangering hole in his space suit, and physically remove an electric circuit card. With Feustel standing behind him and assisting, Grunsfeld shook and pulled for some time at the card with needle-nosed pliers, then panted via radio: "I think we'll get it." The spacewalk's plan required six and a half hours; Grunsfeld and Feustel took an extra six minutes to complete the task, considered a great success after other spacewalks met hitches earlier in the week.