The space agency’s finest scientific instrument escaped a death sentence last Tuesday when Michael Griffin, the NASA administrator, approved a shuttle mission to service and upgrade the Hubble Space Telescope.

For a decade and a half, the Hubble has made discoveries that have helped revolutionise our understanding of the universe. Its role is to pick up a hint from ground-based telescopes and then use its vantage to probe deeply into some puzzling phenomenon.

The Hubble has peered farther into space and farther back in time than any other instrument. It has discovered more than 500 proto-galaxies that emitted light when the universe was in its formative stages, confirmed the discovery that the expansion of the universe is accelerating, and helped establish the rate of expansion and the age of the universe.

The threat to the Hubble’s future came unexpectedly from NASA itself in early 2004. In a myopic decision, Sean O’Keefe, the administrator at the time, unexpectedly cancelled the next

servicing mission, ostensibly because of safety concerns after the Columbia disaster. Now Griffin has concluded that the mission can be conducted safely.

A Hubble mission may be marginally more risky than a flight to the space station, but that risk is surely worth taking for the scientific payoff.