For over three decades, the Hubble Space Telescope has captured stunning images of distant galaxies and stars, allowing astronomers to probe the evolution of the universe and its most mysterious cosmic phenomena.
But all that may come to an end around 2034. That's when the telescope, which is slowly drifting down toward Earth, is expected to burn up as it plunges through the atmosphere.
A rich entrepreneur has told NASA that he wants to prevent that.
Jared Isaacman, a private astronaut who has orbited Earth in a SpaceX capsule, basically has said he'd foot the bill to take a maintenance crew to Hubble if NASA would greenlight such a mission, potentially saving the space agency hundreds of millions of dollars.
After initially fast-tracking a study of the idea in 2022, the space agency has remained mum. In response to repeated inquiries by NPR, a NASA spokesperson said in an email that "we expect to provide an update on this study in late spring/early summer."
Then, on Wednesday, the spokesperson said, "we're working to share something this week."
Internal NASA emails obtained by NPR through a Freedom of Information Act request show that about a year ago, longtime Hubble experts were asked to weigh in. They expressed concerns about the risks of what was being proposed.
In recent months, Isaacman has made some pointed public remarks, saying in interviews and on social media that this trip to Hubble should be a "no brainer" and "this should be an easy risk/reward decision."
In a best-case scenario, a successful private mission could improve Hubble's ability to point at celestial objects and, by boosting its orbit, extend its life by years.
In a worst-case scenario, however, an accident could leave the multibillion-dollar telescope broken — or, even more tragically, tethered to the dead bodies of the astronauts sent to repair it.
Isaacman has said if the mission isn't done, "politics" will be to blame. In January, he wrote: "I am a bit concerned that the 'clock' is being run out on this game ... at this pace, there may not be a Hubble to save."
In a February interview, he suggested that some NASA insiders wanted a monopoly on the prestigious experience of getting to handle Hubble.
"Up until now, there's only been, you know, one group that would ever touch Hubble. And I think that they have an opinion of whether — of who should or shouldn't be allowed to touch it," Isaacman said. "I think a lot would say, 'I'd rather it burn up' than, you know, go down a slippery slope of, you know, the space community growing. So I think that's a factor now, unfortunately."
Asked specifically about those remarks, a NASA spokesperson did not comment.
Isaacman's communications manager told NPR that an interview with him was not possible because of his training schedule. She referred questions to SpaceX's media team, which did not provide comment before publication.
Andrew Feustel, who performed three spacewalks to refurbish Hubble in 2009, says he found the mission proposal to be "quite a reasonable and admirable concept."
"The idea is good. I don't think anyone doubts it's possible," says Feustel, adding that he sees Isaacman as a pioneer who has done excellent work in space.
But no one has gone on a spacewalk from a SpaceX capsule yet, and the company has only just developed its spacewalking suits, so NASA has "no history on which to base future predictions of success," says Feustel.
He adds that it would be helpful to have a demonstration of the team's spacewalking, as well as the functionality of the new suit, to understand how these capabilities might be compatible with a Hubble repair.
To see what's feasible
The first demonstration of a private spacewalk could come within weeks, as part of a series of SpaceX flights that Isaacman is sponsoring called the Polaris Program, which aims to "rapidly advance human spaceflight capabilities."
Isaacman is known to be an avid pilot who flies jets, including ex-military aircraft, and in 2021 he funded and commanded the first all-civilian flight to orbit, called Inspiration4. Isaacman made his fortune through Shift4, a major payment processing company that he founded "in 1999 at sixteen years old in the basement of his parents' home," according to the company's website. He also co-founded Draken International, a military contractor that has a fleet of fighter jets.
In the first Polaris spaceflight, Isaacman and a crewmate will attempt to step outside a SpaceX capsule. This flight has been repeatedly delayed, with the Polaris Program saying that one delay, for example, was needed to provide "necessary developmental time" to ensure "a safe launch and return" and the completion of mission goals.
Things are getting exciting!! Our first week of EVA training is underway! 🐉 https://t.co/oOaDiP3JXv
— Sarah Gillis (@Gillis_SarahE) September 13, 2022
In 2022, SpaceX contacted NASA and suggested that the next Polaris flight after this planned spacewalk could involve a Hubble reboost and servicing mission — and that NASA would basically get it for free.
NASA officials, who regularly send astronauts up to the International Space Station in SpaceX capsules, took this very seriously.
It's been 15 years since the final space shuttle mission to upgrade and service Hubble. Since then, the 34-year-old telescope has had a remarkable run of good health. A gyroscope, part of its pointing system, sometimes acts up, but NASA says it can operate the telescope without it. And astronomers still clamor to use Hubble, with demand for this powerful telescope far outstripping the available observing time.
NASA always faces competing priorities and budget constraints, however, and a mission to extend Hubble's life wasn't in the works.
So the space community was abuzz in September of 2022, when NASA held a press briefing with Isaacman and a SpaceX representative to reveal an agreement to study this idea.
"We're not making an announcement today that we definitely will go forward with a plan like this," cautioned Thomas Zurbuchen, who was then the head of NASA's science mission directorate. "We want to have a study to see really what would be feasible."
"The team is so excited"
Officials said then that the study would take about six months.
Internal emails show that they put together a team of Hubble experts at NASA's Goddard Space Flight Center to explore the options.
This mission would "essentially be funded by Jared Isaacman," a program manager in the astrophysics division named Barbara Grofic wrote to Sandra Connelly, the deputy associate administrator for NASA's science mission directorate, in December of 2022. "This is a fantastic savings for NASA, but also a very challenging concept for NASA legal and procurement."
Grofic wrote that results of a feasibility study would be presented to Connelly in a meeting the next day. "The team is so excited to present this tomorrow!" she wrote.
Emails show that Jared Isaacman and others from SpaceX and Polaris were scheduled to visit NASA's Goddard Space Flight Center about a month later, in January of 2023. The agenda included a tour of simulation facilities, discussion of the telescope and servicing missions, and reviews of hardware and electrical systems.
"Thanks so much for the great notes and such an enjoyable experience visiting the NASA facilities," Isaacman wrote in an email to SpaceX on Jan. 31, 2023, cc'ing top Hubble program managers at NASA. "We feel incredibly fortunate to play a small part in what we hope will become an exciting mission."
"On behalf of the Polaris team, we would love to participate in any preliminary undertakingst [sic] to reduce the risk and complexity of these specific efforts. Please let us know how best we can assist," Isaacman wrote.
Edward Cheng, a Hubble technology and servicing expert who used to work at NASA, says he participated early on during the feasibility study.
He says space shuttle astronauts used to stay at Hubble for a week and spend hours pulling out instruments and fiddling around with the telescope's guts, but the commercial space world currently doesn't have that kind of capability or expertise.
Still, he says, "for the timeframe that I think people were talking about for this mission, there were a few things that looked like they could have been promising."
After docking with the telescope, the Polaris mission could attach a box full of new hardware to the outside.
"We would then do some magic to wire it into the existing system, and this would in principle allow the pointing of Hubble to be improved," says Cheng. This addition could be helpful if the telescope's gyroscope situation worsens.
"In my mind, that was a plausible thing that you could get the team that was doing this SpaceX activity to consider doing — with appropriate support from the Hubble folks, the folks that know Hubble," he says.
Isaacman appears to have shared that view: In one interview, he said new hardware could essentially be built into the same mechanism that docks with Hubble, and that "we're talking about potentially just plugging in a couple cables here" to hook it up to data and power.
Going on a short spacewalk to do that would mean leaving the safety of the vehicle, Isaacman said, but such an enhancement would let the telescope take better advantage of the longer lifespan that an orbital boost would give it.
"This is a real thing"
In March of 2023, emails show that NASA was arranging for an independent review of the feasibility study.
"The study ends shortly and NASA HQ wants a review of the servicing aspects of the study by a panel that includes several astronauts," one Hubble manager wrote to Feustel.
"Let me assure you that this is a real thing," the manager added, "with a potential mission in a year and a half or so."
In addition to Feustel, the review panel included John Grunsfeld, an astronaut and astronomer who has been called "the Hubble repairman" because of his spacewalks during three separate shuttle missions. Keith Kalinowski, a retired Hubble operations expert, and Dana Weigel, who is currently NASA's program manager for the international space station, also weighed in.
In April of 2023, Kalinowski emailed Patrick Crouse, the project manager for the Hubble Space Telescope mission, to say that he would be all in favor of a "well-planned" mission to reboost the telescope and install an enhancement to its pointing control system, if it would profitably extend the telescope's science life.
But a Polaris spacewalk to do that, Kalinowski wrote, "is unnecessary and risky."
A few days after that, Weigel wrote to Nicola Fox, the head of NASA's science mission directorate, wanting to make sure Fox understood that "SpaceX's view of risks and willingness to accept risk is considerably different than NASA's."
She hoped to talk with Fox about "the complexity of the construct that is needed to safely do a reboost and the extreme immaturity of the spacesuit." At the time, SpaceX's suit for spacewalking was still in development; SpaceX unveiled it just this month.
Grunsfeld was cc'd on that email, and he wrote that he agreed with those concerns — plus, he said, astronomers could still do a lot of good science with Hubble even if the telescope did lose another gyro at some point.
"The other issue is the need for reboost now versus later," Grunsfeld wrote. "Perhaps the opportunity with Polaris won't be there, but NASA can work with Congress and the Administration to request funds for a Hubble reboost or enhancement mission, using a commercial partner where NASA is in the drivers [sic] seat, and the maturity of the space systems is higher and lower risk."
No airlock, no robotic arm
To understand how different a Polaris mission would have to be from the five Hubble servicing missions performed by space shuttle astronauts, consider the fact that the SpaceX capsule has no airlock.
That means for an astronaut to step outside, the entire interior will have to be depressurized and exposed to the vacuum of space when the hatch opens.
During the first spacewalk attempt planned for this summer, Isaacman and a SpaceX engineer named Sarah Gillis plan to exit the hatch and move onto a nearby external structure that SpaceX is calling the "Skywalker." Their entire activity, from depressurising the capsule to repressurising it, is expected to last about two hours.
"We hope to learn an awful lot about our suit and the operation associated with it," Isaacman said during an online event earlier this month, which discussed the planned Extravehicular Activity, or EVA. "It's the first commercial EVA. It's the first time you don't have, you know, government astronauts undertaking such a mission."
Isaacman has said that "every one of the arguments" he's heard against the Hubble proposal is that "if you do an EVA, you know, there's a lot of risk in that."
He dismissed this concern. "That risk is being taken, no matter what," he said, arguing that his group plans to proceed with private spacewalks, so NASA should take advantage of this.
"I would say, like, this is beyond logical. This is so obvious to do," said Isaacman, "and if it's not, it's purely political, on why it wouldn't be done."
Risks versus benefits
But NASA officials know from painful experiences like the Columbia and Challenger disasters that accidents can kill astronauts.
And spacewalks can get unexpectedly dicey — one study of over 400 spacewalks since 1965 found that 22% experienced "serious incidents and/or close calls." In one disturbing close call in 2013, for example, an astronaut had his helmet start to fill with water.
Then there's the risk of damage to the telescope itself, which could threaten the 10 more years of science that astronomers currently expect to enjoy.
"Hubble is extremely healthy, still. The instruments are working really well," says Beth Biller, an astronomer at the University of Edinburgh who has served on an official committee of telescope users at the Space Telescope Science Institute, which manages the use of Hubble.
Hubble's older instruments are expected to have greater than "90% reliability" from now until 2030, and the newer instruments will have more than 95% reliability "well into the 2030s," according to a spokesperson with the institute.
NASA needs to protect its valuable space assets, and it seems that even a "simple" reboost and enhancement mission wouldn't really be simple.
Just getting up close to the orbiting telescope with a spacecraft is tricky, says Scott "Scooter" Altman, an aviator and astronaut who commanded two servicing missions to Hubble.
He says the space station is set up with equipment to help visiting spacecraft assess the exact distance to the outpost and how fast the incoming vehicle is closing in — allowing for a smooth connection rather than a miss, or worse, a collision — but Hubble doesn't have all that.
"It's not a trivial thing, rendezvousing with a non-cooperative target like Hubble," says Altman.
The telescope's power-producing solar panels stick out like wings, and if a spacecraft ran into one and broke it, says Cheng, "that would be quite important. That could be a game changer."
And a spacewalk around Hubble would come with its own risks to the instrument.
Not only does the SpaceX capsule have no airlock, it also has no robotic arm, which past servicing missions depended on.
Whenever the space shuttle would visit Hubble, it would retrieve the telescope with its arm and firmly mount the instrument onto a platform in the shuttle's huge cargo bay. This platform could revolve and position the telescope to make things easier for the spacewalking astronauts, who moved around it and anchored their feet in special plates.
Without that kind of anchoring framework, floating in space makes it difficult to work, says Altman.
"How do you get yourself to a place where you are able to use both your arms and hands to do something, with your feet fixed? That's going to be a challenge, I think," says Altman. "It was a challenge for us."
"Sorry, Mr. Hubble"
When astronauts worked on Hubble in the past, they had to face all kinds of difficulties, while keenly aware of the risk that they might break something.
Altman, recounting how a spacewalking crewmate struggled to loosen a bolt during a repair attempt, recalled his relief when the bolt finally broke free and he knew that "we're not the crew that killed the Hubble Space Telescope, the most incredible scientific instrument ever deployed by humans."
Soon after, as the team had trouble getting new gyroscopes in, Altman says he thought, "Great, we don't get the gyros in. We're going to be the crew that killed Hubble again." But the NASA team successfully worked through that difficulty too.
"There were just things where the Hubble threw us curves, where we thought, 'We've trained, we've choreographed everything' — but still something different happened and we had to respond on the fly, in conjunction with ground control," says Altman.
During the last servicing mission, Grunsfeld accidentally bumped his foot into one of the telescope's antennas, knocking off a small piece at the end.
"Oh no, I hope the antenna's OK," Grunsfeld said, groaning in dismay. "Oh, I feel terrible."
It turned out to be fine. As Grunsfeld turned back to the airlock, leaving Hubble for the last time, he apologized.
"Sorry, Mr. Hubble," he said. "Have a good voyage."
Hubble Hugger
The Hubble Space Telescope has a unique place in the hearts of both the public and NASA. Once the butt of jokes because of its flawed mirror, it became a scientific triumph, producing thrilling images like the "Pillars of Creation," an iconic picture showing dense clouds of dust and gas where new stars are forming.
That's part of why the five Hubble servicing missions flown by NASA astronauts were some of the most prestigious space missions ever.
"Probably my proudest moment and the peak of my spaceflight career was the day we deployed Hubble with everything that we had tried to do completed on that telescope," Altman says. "We had overcome these obstacles we had every day, to finally put it back on its voyage of exploration with a complete upgrade."
But the telescope is aging, even as it continues to be constantly bombarded with potentially damaging radiation from space. A reboost or enhancement might become moot if critical components break.
"I'm very wary, truly, of predicting failures — and I'll forever be a Hubble Hugger — but there does come a time when you have to ask whether putting more money and effort into making more Hubble data might provide less return on investment than putting the same money and effort into new missions," Kalinowski wrote in an email to a Hubble manager at NASA.
Over the years, NASA workers have pondered all kinds of possible missions to Hubble, with various kinds of spacecraft, both robotic and with a crew. And during the final servicing mission, astronauts added a ring-like piece of docking hardware to the telescope to make it easier for some future spacecraft to latch on.
Partly, that was because NASA was thinking about what happens to Hubble at the end of its life.
Certain heavy telescope components — like its large glass mirror — would survive a fiery plunge down into the atmosphere. So there's long been discussions about somehow putting a propulsion unit onto the telescope, to control its descent and make sure any debris ends up falling into an ocean.
Such a deorbiting mission could cost hundreds of millions of dollars.
Isaacman has suggested that paying that money, and losing Hubble, is the less-than-ideal alternative to his vision of letting Polaris have a go at extending Hubble's life. But NASA officials do have options.
Cheng, the Hubble technology development expert, even thinks it's possible that NASA might find a way to justify the risk of Hubble pieces falling to Earth in an uncontrolled way. The agency could write up a waiver to existing policies, so as not to spend the money on de-orbiting it.
"It's not inconceivable to me," he says, "to just let it fall."
