NASA Made the Hubble Telescope to Be Remade

When NASA decided in the 1970s that the Hubble Space Telescope should be serviceable in space, the engineering challenges must have seemed nearly insurmountable. How could a machine that complex and delicate be repaired by astronauts wearing 130-kilogram suits with thick gloves?

In the end, spacewalkers not only fixed the telescope, they regularly remade it.

That was possible because engineers designed Hubble to be toroidal, its major systems laid out in wedge-shaped equipment bays that astronauts could open from the outside. A series of maintenance workstations on the telescope's outer surface ensured astronauts could have ready access to crucial telescope parts.

On five space-shuttle servicing missions between 1993 and 2009, 16 spacewalkers replaced every major component except the telescope's mirrors and outer skin. They increased its electric supply by 20 percent. And they tripled its ability to concentrate and sense light, job one of any telescope.

The now legendary orbital observatory was built to last 15 years in space. But with updates, it has operated for more than 30-a history of invention and re-invention to make any engineering team proud. Twice the lifetime," says astronaut Kathryn Sullivan, who flew on Hubble's 1990 launch mission. Just try finding something else that has improved with age in space. I dare you."