WASHINGTON – NASA’s Hubble Space Telescope resumes observations on March 11 after a software bug put it in protective safe mode a few days earlier, but the incident is a reminder of the telescope’s death.
NASA said Hubble resumed observations at 8 p.m., East March 11, more than four-and-a-half days after a software bug left the spacecraft in safe mode and suspended the normal operation of the nearly 31-year-old space telescope. .
The software bug was detected after what the agency’s statement called an “improvement” recently uploaded to the spacecraft. The enhancement was intended to compensate for fluctuations of one of the telescope’s gyroscopes, but a bug in the software caused a broader problem with Hubble’s mainframe, causing the safe mode early on March 7th.
Administrators have fixed the issue for the time being by disabling the software enhancement, and plan to correct the bug and test the new software further before re-uploading.
However, the safe mode caused two other issues with Hubble. The opening of the telescope, a lid on top of the telescope, is designed to close automatically when the spacecraft enters safe mode to prevent stray sunlight from entering, which can damage instruments and optics. In this safe mode, however, the door did not close, a problem that Hubble had never seen before.
Engineers solving the problem found that the door closed as soon as they switched to a backup car. They have now set the car as the primary car as they continue to study the problem with the other car.
One of Hubble’s instruments, the Wide Field Camera 3, encountered an unexpected error while restoring safe mode. NASA did not elaborate on the error, but said that observations using the instrument would remain on the line while engineers studied the problem. The other instruments of the spacecraft, including a camera and two spectrographs, function.
The safe mode and related issues are a reminder of Hubble’s age. The spacecraft was launched in April 1990 and operated five times by the spacecraft, most recently in May 2009. With the shuttle that has long since retired, astronomers know that at some point Hubble will suffer an irreparable failure that will end its historic mission.
“Right now, we’re in the middle of what I think is a very good news story about Hubble,” Jennifer Wiseman, an astronomer at NASA’s Goddard Space Flight Center, said at a space telescope conference last year. She and others believe that the telescope could remain in operation for much of this decade, based on trends in the performance of key components, such as the gyroscopes and batteries.
Some have argued for a new service mission to Hubble using a robot or crew of spacecraft. John Grunsfeld, a former NASA astronaut who flew on three Hubble service missions and later served as co-administrator of the Science Agency, last year presented a draft for an Orion spacecraft crew camp and a module equipped with a robot arm and airlock. That spacecraft would take off at Hubble, with astronauts then doing repairs just like on previous missions.
“We have the technology to go back to Hubble,” he told the Space Transportation Association in June last year, saying a commercial crew vehicle, such as the Crew Dragon, could be used in place of Orion. “We can keep Hubble going for a few more decades.”
However, NASA has not shown any public interest in such a service mission, the cost of which would be hundreds of millions to billions of dollars. ‘It’s not currently in the books. Nobody really talks about it, at least in public, “Grunsfeld admitted.
Without a service mission, Hubble could last for years, or fail tomorrow, astronomers like Wiseman admit. “We do not know how long Hubble will last,” she said.