NASA retirees save the Hubble space telescope

Hubble space telescope

NASA had to turn to former employees for help because a 30-plus-year-old computer on the Hubble telescope suddenly failed. Why couldn’t you solve the problem without the retired specialists?

It is a story worthy of Hollywood. For 31 years, the Hubble telescope has been circling the Earth at an altitude of about 550 kilometers, providing us with fascinating photos of distant stars and galaxies. The mission was originally supposed to last only 15 years, but our distant galaxy telescope is still in orbit and has sent nearly 1.5 million images to Earth so far.

However, on June 13, 2021, Hubble’s payload computer, which controls and coordinates the science instruments aboard the telescope, suddenly failed. When the main computer stopped receiving the signal from the payload computer, it automatically puts all of Hubble’s science instruments into sleep mode. But all attempts by the team to restart the crashed computer through the main computer failed.

NASA Hubble Telescope

There is a backup computer, but how does it work?

This is no cause for alarm, as important Hubble components were installed in duplicate after all, just in case. There is also a backup computer, just never used since the telescope was launched in 1990. But a computer like that cannot be started by simply pressing the power switch.

How is it possible that NASA, highly technical, no longer know how these devices worked before? Imagine that you find a box with memories of your childhood in the basement: a music cassette with your old favorite songs and a floppy disk with photos. As your grandson asks you what these strange gadgets are, you wonder who could still have a cassette and floppy disk player to play the recordings.

These are banal examples, but ancient technology and knowledge are easily lost, and any mistake in NASA’s rescue operation could have spelled the irreparable end of the Hubble mission.

Retirees support the new team

To be sure, Nzinga Tull, head of the Hubble emergency team, rounded up some former employees. Repairing a telescope built in the 1980s required the knowledge of employees throughout Hubble’s history, NASA writes in an open statement following the success of the mission.

More than 50 people participated in the rescue operation, which lasted two weeks. Together, the new and old team members initially worked on the list of possible weaknesses and tried to isolate the problem.

Analog knowledge in mind and on paper

Former employees who had already participated in the construction of the telescope were still familiar with the old command and data processing unit of the payload computer. Other NASA retirees found the decisive clues to the correct procedure in original Hubble documents that were between 30 and 40 years old.

“That is one of the advantages of having a program that has been running for more than 30 years: the incredible amount of experience and knowledge,” said Nzinga Tull. “It has been humbling and inspiring to work with both the current team and those who have moved on to other projects. They all showed a lot of dedication to their colleagues at Hubble, to the observatory and to the science for which the telescope is famous.”

The merger of galaxies as a reward

The computer startup was calculated step by step in a simulator in the control center. Thanks to a joint effort, the standby computer was successfully commissioned on July 15, after a forced hiatus of five weeks.

Two days later, the instruments returned to provide fascinating photos of distant galaxies. First, Hubble photographed two newly merging galaxies in Capricorn with three spiral arms. Thus, the space telescope is back in full operation thanks to the help of NASA retirees.