NASA's storied space telescope could operate for another five or six years without maintenance, according to experts.
Over 25-years ago on April 24, 1990, the Hubble Space Telescope was launched into space. NASA, which jointly runs the telescope with the European Space Agency, has marked the anniversary with a display of fireworks—the latest spectacular image from the veteran observatory to be released.
Hubble’s silver anniversary image is of a star cluster called Westerlund 2—a giant grouping of around 3,000 stars, 20,000 light-years away in the southern hemisphere constellation of Carina, the ship’s keel.
The whole region around the cluster is a giant stellar nursery where new stars are being born. Those in the cluster are young at around two million years old, and are particularly hot and massive. It obtains a mix of ultraviolet light and hurricane-force winds from the largest stars creates the features in the surrounding cloud of hydrogen gas.
Although the image was taken primarily as a “pretty picture” for the purpose of public outreach, Hubble is still working hard as the most important scientific tool available to astronomers. Over 13,000 scientific papers using Hubble data have been published since its launch, and the telescope is still going strong.
It is more than five years since the last time the space telescope was serviced, in 2009, and the retirement of the Space Shuttle means that is a less simple—in fact impossible—operation to carry out again in the foreseeable future.
Just like any piece of technical equipment, Hubble is bound to deteriorate without servicing, in the inhospitable void of space. As well as suffering extremes of temperature as its orbit carries it in and out of sunlight, its bodywork is being peppered by meteoroids. And one of the six gyros that keep it oriented properly has failed.
The good news is that the end is not near. Hubble’s main equipment and instruments are all working well and seem to have at least another five years left in them. The bad news is that its orbit, 560 km (350 miles) above the Earth, will gradually decay with time, due to drag from the tenuous upper fringes of the atmosphere, bringing it lower.
Latest projections suggest that that is unlikely to cause Hubble to re-enter until about 2037, due to the reduced effects of solar activity on the atmosphere—earlier forecasts had predicted it could happen as soon as 2024.
