Shuttle's risky mission to repair Hubble
With custom-made tools and a rescue plan, the seven-member crew of the Atlantis aim to upgrade the iconic telescope.
For 19 years the Hubble Space Telescope has provided mankind with extraordinary views of the universe. It now awaits the launch of one of the most extraordinary space-shuttle missions in history.Skip to next paragraph
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Monday afternoon, the shuttle Atlantis and its seven-member crew are set to lift off from the Kennedy Space Center in Florida for a fifth and final house call to Hubble – an astronomical icon that has revolutionized humanity's understanding of the cosmos and served as NASA's most consistent, high-profile ambassador for space exploration.
During Atlantis's 12-day mission, astronauts are slated to repair Hubble components that failed last September, undercutting the telescope's capabilities. They will also wrestle two new instruments into place – upgrades that will keep the observatory on the cutting edge of astronomy and astrophysics for several more years – and perform maintenance tasks.
A delayed mission
For a telescope designed for servicing every three years or so, this mission is long overdue. It was canceled after the loss of the shuttle Columbia and its crew in 2003, only to be revived amid public pressure and after planners persuaded former NASA administrator Michael Griffin that the mission could be flown at an acceptable risk. The shuttle program could not afford to lose another orbiter and crew and still keep its international commitments to complete the space station.
The last flight to the orbiting observatory took place seven years ago. "Hubble needs a hug," quipped mission specialist John Grunsfeld during a recent briefing. He's making his third consecutive trip to the telescope.
What a hug. If all goes as planned, "the Hubble Space Telescope will be at the apex of its capabilities," says David Leckrone, the senior project scientist for Hubble at NASA's Goddard Space Flight Center in Greenbelt, Md. A new wide-field camera will enable astronomers to observe the 13.6-billion-year-old universe when it was a scant 500 million years old. That shaves some 200 million years off the youngest objects Hubble can spot today.
The camera will be able to observe objects near and far at wavelengths ranging from ultraviolet light through visible light to near-infrared radiation. The capability is expected to yield new insights into areas ranging from the evolution of stars to the evolution of galaxies at a broad span of distances. By mapping this matter and its make-up, astrophysicists hope to track how the chemical composition of galaxies changes with time.
In addition, astronauts are slated to install a new spectrograph that will reveal the composition of matter in visible, web-like filaments of gas, galaxies, and galaxy clusters. These gather and glow to mark the boundaries of vast voids in the cosmos, the largest-scale structures in the universe.
Custom-designed tools to make repairs
Unlike the four previous servicing missions, however, astronauts will be making detailed repairs on components not designed for on-orbit servicing. A space-station construction mission has spacewalkers wielding wrenches and connecting large cables. Some of the spacewalkers on this mission will be standing inside the telescope's bays, working in tight quarters with small fasteners and circuit-board modules.
The crew's toolkit testifies to the job's unique nature of the task. Of the 180 tools the crew is carrying, 116 were custom-designed for this house call.
There is little or no margin for error.