Hubble will transition to single-gyro mode to gain a few more years of operational life
- Reference: 1717605908
- News link: https://www.theregister.co.uk/2024/06/05/hubble_to_transition_to_singlegyro/
- Source link:
The observatory has six gyroscopes, installed during the final Space Shuttle servicing mission in 2009, but over the years, three have failed. A fourth began showing signs of wear, resulting in the spacecraft dropping into safe mode in April. That event has now resulted in engineers [1]deciding the time has come for the HST to transition into a mode whereby it can be pointed using only one gyro.
The mode requires other instruments onboard the spacecraft to be used for pointing the telescope as well as a single gyroscope. According to NASA, the technique was already demonstrated in 2008 "with no impact to science observation quality."
[2]
However, the agency noted that "there are some expected minor limitations." It will take longer for the observatory to slew and lock onto a science target, and it won't be able to track moving objects closer than Mars, "though these are rare targets for Hubble."
[3]
[4]
The optimism of NASA officials needs to be balanced with comments from the scientific community. The Space Telescope Science Institute concluded in a [5]2016 paper [PDF] that "Entry into RGM [Reduced Gyro Mode] will reduce the scientific productivity of HST by ~25 percent, preclude several existing science observing strategies, reduce synergies with other observatories, and decrease the likelihood of responding to time critical events."
Without another servicing mission scheduled, managers do not have much choice.
[6]
The failing gyros are not the only issues to have beset Hubble. In recent years, engineers have also had to deal with computer [7]problems that sent the telescope offline for more than a month in 2021.
[8]Hubble plays spin the bottle with last few gyros
[9]4 more years! Intelsat, Northrop Grumman extend satellite servicing contract
[10]Hubble Space Telescope hasn't had any visitors for 15 years
[11]Hubble Space Telescope has gyro problems again
NASA hopes that switching to a single gyro mode will extend the observatory's operational life for many years to come, even if its efficiency might be lowered. It also extends the period for a potential servicing mission or reboost in the future.
The spacecraft was outfitted with a Soft Capture Mechanism during the final Space Shuttle servicing mission in 2009. Once the Hubble finally reaches the end of its operational life, an uncrewed vehicle will dock with it to perform a controlled reentry.
A [12]2005 study estimated that more than 2,000 kg of debris could survive reentry, meaning targeting will be essential. ®
Get our [13]Tech Resources
[1] https://science.nasa.gov/missions/hubble/nasa-to-change-how-it-points-hubble-space-telescope/
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2ZmDf@rydTSESWco5oZRpIwAAAMI&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZmDf@rydTSESWco5oZRpIwAAAMI&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ZmDf@rydTSESWco5oZRpIwAAAMI&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[5] https://www.stsci.edu/files/live/sites/www/files/home/hst/about/space-telescope-users-committee/presentations-and-documentation/_documents/2019_may/GYRO_Science_Considerations.pdf
[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZmDf@rydTSESWco5oZRpIwAAAMI&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[7] https://www.theregister.com/2021/07/16/hubble_telescope_fixed/
[8] https://www.theregister.com/2024/06/04/hubble_gyro_issues/
[9] https://www.theregister.com/2024/05/24/intelsat_and_northrop_grumman_deal/
[10] https://www.theregister.com/2024/05/14/15_years_hubble_servicing/
[11] https://www.theregister.com/2024/04/29/hubble_space_telescope_has_gyro/
[12] https://adsabs.harvard.edu/full/2005ESASP.587..527S
[13] https://whitepapers.theregister.com/
Might be worth sending an apology card to NASA if you have a reason to be concerned.
For maximum irony, they should target the debris near the homes of prominent Flat Earthers.
Unable to focus on objects closer than Mars...
Welcome to my world - even with glasses.
It must be the old age.
It’ll come down to a couple of questions.
1) If we do nothing, can HST still give useful data? And if so for how long?
2) What replacements need to be made; can these be done with an automated mission?
3) If no, and it needs a manned mission to replace ‘xyz’ does NASA have the ability to do this?
4) If yes, hypothetically can either Space-X or Boeing, technically or be willing could get a crew to rendezvous with the ISS and have the ability to replace the faulty components.
5) It is very, very unlikely, but what are the abort modes? As I understand it HST is not in the same orbital place as the ISS, so if there was a major issue with the flight, can they get there?
6) Considering all of this, might it not be better or more cost effective* to launch an unmanned mission to dock with and de-orbit the HST safely?
* and I’d be OK with this, if there was somne definite and funded plan to replace the HST with something better. Otherwise it isn’t impossible to send a mission to attach to it and lift its orbit by 50-100 Km. It’ll be good for the next 100 years. Except, we still have the gyro issue. No point extending its life it it can't perform good science.
Ultimately it’s going to come down to ‘can we sent people to replace the failing components, and take the risk that this entails’? Or not?
1 to 5 are out for various reasons and 6 is the option they going to use, as per the penultimate paragraph of the article :-)
6) Considering all of this, might it not be better or more cost effective* to launch an unmanned mission to dock with and de-orbit the HST safely?
Could a system like that bring it down to an orbit where humans could repair it, then send it back up again?
We can already get there... Just needs the funding/permission.
Of course it also needs the ability to do a spacewalk, which should be demonstrated on Polaris Dawn.
Given the energy involved it would be a real shame not to go and boost it into a parking orbit rather than deorbit
"A 2005 study estimated that more than 2,000 kg of debris could survive reentry, meaning targeting will be essential. ®"
That's targeting to where there isn't any one in the area right? ... Right?