The Hubble Space Telescope in orbit in 1999, just after a maintenance mission by astronauts.
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NASA
The Hubble Space Telescope is suffering from the kind of aches and pains that can come with being old, and NASA officials say they are adopting a new way of pointing the telescope to get around a piece of hardware that has become intolerably defective.
Officials also announced that, for now, they had decided not to pursue the project proposed by a wealthy private astronaut who wanted to travel to Hubble aboard a SpaceX capsule, as part of a mission to extend the life of the telescope by upgrading it to a higher level. a higher orbit and perhaps even adding new technologies to improve its operations.
“Even without this stimulus, we hope to continue producing science for the remainder of this decade and into the next,” Mark Clampin, director of the astrophysics division of NASA’s Science Mission Directorate, told reporters at a teleconference on Tuesday.
Due to atmospheric drag, the bus-sized telescope slowly drifts toward Earth. If nothing is eventually done to bring it back up, it will likely plunge into the atmosphere and largely burn up by the mid-2030s.
That’s one reason NASA was so interested when Jared Isaacman, who had previously been in orbit in a SpaceX capsule, suggested mounting a mission to Hubble as part of a series of spaceflights technology demonstration he planned.
NASA and SpaceX jointly worked on a feasibility study to see what might be possible for Hubble. The telescope has been in orbit since 1990 and was last repaired 15 years ago by astronauts who boarded NASA’s space shuttles, which are now on display in museums.
NASA’s Clampin told reporters that “after exploring current commercial capabilities, we are not going to pursue a relaunch at this time.”
He said the assessment of Isaacman’s proposal raised a number of considerations, including potential risks such as a “premature loss of science” if Hubble was accidentally damaged.
NASA officials stressed that Hubble’s instruments are healthy and the telescope remains incredibly productive.
“We don’t think Hubble is running out of steam,” said Patrick Crouse, project manager for the Hubble Space Telescope at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We think this is a very capable observatory and poised to do exciting things.”
But he’ll have to do these exciting things with a new way to operate the system he uses to point to celestial objects.
That’s because authorities abandoned efforts to use a faulty gyroscope that repeatedly forced the telescope to suspend science and go into “safe” mode in recent months.
Hubble’s pointing system is so precise that NASA says it’s the equivalent of being able to keep a laser shining more than 200 miles away, for as long as Hubble takes a photo – up to 24 hours. This system has long relied on the use of three gyroscopes at once.
Now, however, to avoid having to use the sketchy gyroscope, NASA says Hubble will switch to a single-gyroscope mode of operation, a contingency plan that has been around for years.
“After performing a series of tests and carefully considering our options, we made the decision to have Hubble operate using only one of its three remaining gyroscopes,” Clampin said. “Operationally, we believe this is our best approach to supporting Hubble science throughout this decade and next.”
The scattered stars of the globular cluster NGC 6355, which resides in our Milky Way, seen in this Hubble Space Telescope image
ESA/Hubble & NASA, E.Noyola, R. Cohen
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ESA/Hubble & NASA, E.Noyola, R. Cohen
Using just one healthy gyroscope and keeping one in reserve as a backup will allow the telescope to continue sending back beautiful images of the universe, with some limitations. For example, Hubble will be less efficient and will not be able to track moving objects close to Earth, in the orbit of Mars.
But Clampin said “most of the necessary observations will be completely unaffected by this change.”
Astronomers are still clamoring to use Hubble, with proposals for what to observe far outstripping the time available at the telescope.
The launch of the James Webb Space Telescope in 2021 has not made Hubble obsolete, as the two telescopes capture different types of light.
Ultimately, NASA will have to decide what to do about Hubble, given that some of its large components would survive re-entering Earth’s atmosphere. The space agency has long considered sending some sort of mission that would monitor its descent and ensure that all of Hubble’s rubble would fall safely into an ocean.
Adding such a propulsion unit would mean NASA could also increase Hubble’s orbit, allowing it to live longer and take advantage of all the instruments that continue to operate. But NASA’s Clampin suggested it was time to consider options.
“Our latest prediction is that Hubble will re-enter the Earth’s atmosphere no earlier than the mid-2030s,” he said. “So we’re not going to see it go down in the next two years.”
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