Is the Hubble Telescope Still Working? NASA's Iconic Spacecraft Down for Nearly a Month

NASA scientists are still trying to get the Hubble Space Telescope back up and running, and engineers are turning to increasingly risky fixes in order to recover the famous spacecraft.

Hubble stopped working unexpectedly on June 13 this year, when an onboard computer went into safe mode and shut down.

Engineers are still trying to work out exactly what has happened by conducting various tests of the telescope's systems. But so far the exact cause of the issue has remained elusive.

Paul Hertz, NASA's director of astrophysics, told Space.com that engineers are turning to what he called "riskier" troubleshooting methods in order to get the telescope back up and running.

At first, he said, the spacecraft's main computer was thought to be the culprit. This theory was ruled out after engineers switched to the backup and found the problem was still there.

The experts have since turned their attention to other systems that work with the computer, such as its data and power supplies. But, swapping these systems out with backups is challenging.

Hertz told Space.com: "To swap them out and swap in the redundant components on the other side would require commanding of the spacecraft, which is riskier because if you do something wrong, you'll leave the spacecraft in an undesirable condition."

He described the ongoing efforts to fix Hubble as "a bit of detective exercise," but said NASA was making sure the team had plenty of time to solve the problem, rather than rushing them.

Looking to the future, he said the telescope could go "another five, 10, 12 years before something else fails" and that the mission could even continue after that.

The Hubble Space Telescope was launched and deployed by the space shuttle Discovery in April 1990, and has operated ever since for more than 30 years.

The orbiting telescope has provided some of the most arresting images of deep space known, since it can peer into the cosmos without the Earth's atmosphere getting in the way.

One famous example is the Hubble Deep Field image, which Hubble was able to capture after scientists pointed the telescope at a tiny patch of sky and left it to collect all the light it could for 10 straight days in 1995.

It found what NASA has called a "treasure trove," a vast collection of galaxies from which light had travelled for as long as 10 billion years before it finally hit the telescope's lens.

Hubble was looking back in time into an era long before the sun even existed.

It has also been upgraded a number of times, with astronauts servicing the telescope with new parts to extend its lifetime. The last such service was 12 years ago.

Hubble telescope
The Hubble Space Telescope, photographed attached to the space shuttle Atlantis as it orbits Earth in 2009. Hubble has operated for more than 30 years. NASA / Getty