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Hubble goes to one-gyro mode, limiting the telescope’s observational capabilities; NASA rejects private repair mission

Story Musgrave on the shuttle robot arm during the last spacewalk of the 1993 Hubble repair mission
Story Musgrave on the shuttle robot arm during
the last spacewalk of the 1993 Hubble repair mission

After the third safe mode event in six months, all caused by issues with the same gyroscope, engineers have decided to shift the Hubble Space Telescope to what they call one-gyro mode, whereby the telescope is pointed using only one gyroscope, and the remaining working gyro is kept in reserve.

The spacecraft had six new gyros installed during the fifth and final space shuttle servicing mission in 2009. To date, three of those gyros remain operational, including the gyro currently experiencing problems, which the team will continue to monitor. Hubble uses three gyros to maximize efficiency but can continue to make science observations with only one gyro. NASA first developed this plan more than 20 years ago, as the best operational mode to prolong Hubble’s life and allow it to successfully provide consistent science with fewer than three working gyros. Hubble previously operated in two-gyro mode, which is negligibly different from one-gyro mode, from 2005-2009. One-gyro operations were demonstrated in 2008 for a short time with no impact to science observation quality.

While continuing to make science observations in one-gyro mode, there are some expected minor limitations. The observatory will need more time to slew and lock onto a science target and won’t have as much flexibility as to where it can observe at any given time. It also will not be able to track moving objects closer than Mars, though these are rare targets for Hubble.

This NASA press release is carefully spun to hide the simple fact that in one-gyro mode, the telescope will simply not be able to take sharp pictures. For many observations, such a spectroscopy, this inability will have little impact, and such observations are a major part of what Hubble does. For observations of the planets, such as Mars, Jupiter, Saturn, Uranus, and Neptune, sharp pictures however will now be impossible. For interstellar and galactic imagery there will also be an impact. Astronomers will be able to obtain data, but it will not be as good as before, and will have a larger margin of uncertainty.

In a sense, Hubble is now in the same position it was from 1990 to 1993, after launch and prior to the 1993 repair mission that gave it the equivalent of eyeglasses to fix its incorrectly ground mirror. During that time astronomers used it to do some good work, but in general the telescope was crippled.

The need for a repair mission to give Hubble new gyroscopes has now become essential. Thus, the Polaris Dawn mission of Jared Isaacman, scheduled for this summer, where he will do the first private spacewalk, has now become even more significant. If successful Isaacman will lay the foundation for doing his proposed Hubble repair mission, using the same Dragon capsule and SpaceX spacesuits. That mission would use the grapple attachment point placed on Hubble during the 2009 repair mission, and would involve attaching new gyros to the outside skin of Hubble.

To make that repair mission possible there will be many engineering challenges that need solving, but it will would be madness for NASA to reject Isaacman’s proposal should his spacewalk go off without problems. Unfortunately, according to NASA officials, they are presently doing exactly that, and they are doing it before his mission even flies.

[Mark Clampin, director of NASA’s astrophysics division] said NASA, after assessing that study and other concepts, would not pursue a commercial servicing mission. “Our position right now is that, after exploring the current commercial capabilities, we are not going to pursue a reboost right now,” he said.

He said his concern was the risk that a private mission might damage the telescope. “Our assessment also raised a number of considerations, including potential risks such as premature loss of science and some technology challenges,” he said. An example of those risks he offered was contamination of Hubble’s mirror from volatiles like thruster plumes.

The NASA/SpaceX study did not offer a recommendation for or against carrying out the mission, Clampin said, and the study only looked at “notional concepts” for upgrades such as installing new gyroscopes that did not go into technical detail. “For the time being, we are stepping back.”

However, he did not rule out reconsidering a private reboost or servicing mission at some later point. “While the reboost is an option for the future, we think we need to do some additional work to determine whether the long-term science return will outweigh the short-term science risk.”

It seems to me that this decision by NASA is exceedingly premature. But then, NASA’s management is run by paper-pushers who don’t like to take risks, and often are more interested in creating giant gold-plated projects — such as Webb, Mars Sample Return, the Roman Space Telescope — that are always over budget and years behind schedule, but continue to feed NASA’s budget with oodles of cash. Actually getting things launched to achieve real space achievements is generally not their first priority.

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  • Steve White

    While Mr. Isaacman won’t be allowed to put a glove on Hubble, NASA could certainly use Falcon 9/Dragon to put a couple of NASA astronauts up there to do the repair. That’s certainly within their realm of expertise. If Mr. Musk wishes to be just a bit mischievous, he could offer to do the flight for actual cost.

  • DJ

    It seems to me that China is able to launch quite a few science missions. The US not so much.

  • sippin_bourbon

    Is it fear? Or are they hoping some one other than SpaceX can provide the ability to get there.
    Lockheed Martin built it. And, last I saw, they are part owner of a Launch company, and their partner in that company has a new vehicle…

    Just my cynicism showing again, but I believe this is more about who will repair it, not how.

    If, after a few more Starliner successes, if we see a new proposal and study, centered around the CST-100 system, then we will know.
    I am not the only person that thinks this. I have heard some other bloggers/podcasters also suggesting that this is about preventing private/commercial space touching the HST. That sacred cow must be kept pure.

  • Steve Richter

    Sounds like a job for private space. Build, launch and deploy a Hubble+ telescope. Then charge a fee for astronomers to use it.

  • Jeff Wright

    As if astronomers had any money to do so.
    How about I build a toll both at the end of your driveway and you pay to drive to work?

  • Joe

    NASA is jumping the gun here but I do expect that at the higher management levels. It isn’t that private mission to Hubble is a bad idea, it just makes NASA look bad. They knew that this type of failure would happen. They should have been developing repair contingencies not based on any specific vehicle, but on mission parameters. Alas, that isn’t how things are done (there are a few in NASA who want to do things that way but I digress).

    I’ve been involved in a lot of projects that don’t want you talking about them as it might make a firm look bad if a schedule slips or something worse. We can’t show the reality of Space. We can only show the wins. That isn’t useful to anyone in the long run.

  • Jeff Wright

    This is why I wanted an Americanized Energiya Buran type shuttle-2.

    The orbiter would just have insertion engines –and perhaps jets so as not to be dead stick.
    Though the SSMEs would not be re-used, it means you don’t need an orbiter to launch.

    Hypersonic test craft could be side-mount—and a Buran type shuttle-2 would continue to update Hubble.

    I don’t like capsules for anything except coming back from beyond Earth orbit.

    I nice big orbiter gives you stability.

    A capsule attached to great big Hubble reminds me a bit of a certain Gemini-Agena mission where things got away from them quickly.

    With an orbiter, the dog wags the tail.

    Yes, maybe Starship will allow for servicing missions one day–but a simpler shuttle 2 orbiter with X-33 type metal heat shields is what I want to ride in.

    It could glide at least.

  • Clark

    Jeff Wright – We lost two of the five orbiters NASA built. Tell me again how “stabile” those spacecraft were, then tell me how many capsules we’ve lost to launch/re-entry.

    The space shuttle program was an abject failure. The future is landing vertical on hot engines and landing legs.

  • sippin_bourbon

    “How about I build a toll both at the end of your driveway and you pay to drive to work?”
    This is how left leaning, tax loving governments work.
    But your analogy is even close to what he is suggesting.

    If you build that road, out of your own pocket, and people choose to travel it, you should have the privilege to charge a toll.
    That is what he is suggesting.

    If you make a proposal to use Hubble, you have to have a budget. There are grants for US based applicants. All others must pay.
    Telescope time is not free, just as super-computer time is not free, unless you own it.

    If someone thinks there is a business model in an Orbital Telescope as a Service, and then build and launch it, they can charge what they like. There appears to be a successful business model for Earth observation (Planet) and Private Communications (Starlink and others). It is not too far-fetched to assume people will pay for this either.

  • GeorgeC

    Seems to me Nasa could well fund a prize to create a simulated damaged telescope and another prize to adapt general purpose humanoid robots to repair same
    Any repair process could therefore be feasible for human or robot or both.

  • pzatchok

    A falcon Heavy could carry a large service module and the capsule out to the Hubble and service it. Just like the shuttle did.

    They just have to prove they could depressurize/pressurize it.

    Or they could go real wild and flip the capsule upside down so the entry door is inside the service module and the service modules has the pressure door on it.

    Or they could leave the capsule empty during launch and flight and have 2 people inside the service trunk with the pressure door and all they need to fix Hubble.
    Then they could climb into the capsule to come back down. That way they could use the service truck over the course of a few days repairs and depressurize the capsule just once.

  • pzatchok

    But a temporary gyro scope strap on system would be the cheapest and fastest.

  • Jeff Wright

    To Clark.
    You fly shuttle 2 heads up and use LFBs and the STS failure modes are dealt with.

    Starship has to work perfectly or you’re dead.

  • Mitch S.

    Since we’re talking about rescuing Hubble, I’m wondering if a consensus was ever reached regarding the Columbia breakup.
    Would it have been possible to send a rescue shuttle? At the time it was said there was no way to get something up before Columbia ran out of life support, but I’ve heard some people dispute that.

  • Alex Andrite

    … hmmmm …
    Sorry folks, but to look back into the past 300 million (?) years, ?
    Ah well. Fix the gyro thingy.
    Beautiful pictures anyway.

    The Heavens do Proclaim, do they not ?

  • Jeff Wright

    We might have another rescue scenario if a helium leak in Starliner’s “doghouse” forced an evac to ISS.

    To me, capsules are horse and buggy.

    A couple of things of note from….two good articles:

    “Engineers create complex concentrated alloy for use as a high temperature coating for hydrogen combustion engines,”


    “Researchers debut novel manifold design theory.”

    The latter describes a flat manifold design which–if using the coating described in the other article, might allow a return of the linear aerospike–even if X-33/VentureStar itself remains dead.

    There is a TSTO space plane concept called Space Liner that might benefit from the above described tech.

    It is an all rocket VTOHL combo.

  • Rob Crawford

    So Hubble’s abandoned property. He can salvage it, repair it, and re-fly it.

  • wayne

    Going to drop this in here, it’s been stuck on “747 views” for like’ 5 years, which I find to be impossible.

    “The Saga of the Hubble Space Telescope and the Visionaries Who Built It”
    WGBH Forum
    Robert Zimmerman at the Explorers Club (June 30, 2008)

  • wayne: It doesn’t surprise me at all that no one is watching this presentation by me. It was one of the worst I ever gave, going way too long.

  • Edward

    NASA once again lacks imagination.
    From the Space News article:

    He said his concern was the risk that a private mission might damage the telescope. “Our assessment also raised a number of considerations, including potential risks such as premature loss of science and some technology challenges,” he said. An example of those risks he offered was contamination of Hubble’s mirror from volatiles like thruster plumes.

    All these risks existed with the Space Shuttle, too. In fact, the Shuttle’s greater mass required longer thruster action for maneuvers near Hubble than a much smaller and lighter Dragon would require. There is no reason why private astronauts cannot be trained just as well as NASA astronauts or that NASA astronauts cannot perform the operations as crew members on a private mission.

    In the television mini-series From the Earth to the Moon, one astronaut said that NASA lost the Apollo 1 crew because of a failure of imagination, that no one imagined the problem that occurred. Here we have the American public imagining itself as a rescuer of one of America’s great national treasures, but NASA fears the attempt.

    On the other hand, it is possible that NASA is considering performing the very same mission by hiring a private spacecraft, such as Dragon or Starliner, and flying their own astronauts.
    Jeff Wright,
    We all wanted NASA to replace the Space Shuttle with a better reusable vehicle, one that better fit the needs of America’s space program. Instead, Congress directed NASA in the design of its next national rocket, the SLS, an expendable rocket and capsule, just like the ones we had stopped using half a century ago because they were too expensive.

    Oh, look at that! Congress lacks imagination, too.

    Falcon 9 and Electron are showing that low cost can lead to high demand. Falcon 9 is also reusable and has a rapid turnaround time between launches. Falcon 9 launches dozens of times a year, and Electron is already launching more often than monthly. Even the Space Shuttle was supposed to be inexpensive, reusable, and have a rapid turnaround time, which shows us that we have known for more than half a century that rapid, low cost launches using reusable hardware are the right way toward extensive space exploration and utilization.

    Unfortunately, governments have different priorities than We the People.

  • wayne

    Scott Manley
    Hubble’s Failing Gyros (6/14/24)

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