Budget satellite drag sail shows space junk how to gracefully exit orbit
- Reference: 1692706585
- News link: https://www.theregister.co.uk/2023/08/22/student_satellite_sail_project/
- Source link:
SBUDNIC, an acronym chosen to be a play on "Sputnik," was put together by students at Brown University, Rhode Island, using low-cost off-the-shelf commercial components. The CubeSat design featured a drag sail made from Kapton polyimide film, and with structural supports of thin aluminum tubing, which deployed once the satellite was in orbit.
The project was intended to demonstrate a potential solution to the problem of low Earth orbit becoming a graveyard for more and more defunct satellites that have reached the end of their life, as The Register [1]detailed previously . If proved successful, the idea is that future satellites could incorporate a similar mechanism to help de-orbit them at the end of their life span.
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SBUDNIC was sent up aboard the [3]SpaceX Transporter 5 launch in May last year as part of a payload comprising a number of other small satellites. Its sail "popped open like an umbrella" at a height of about 520 kilometers above the Earth's surface, according to the project team, to create drag and cause its orbit to decay.
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The project [6]appears to have been successful in this respect, according to tracking data the team obtained from US Space Command. It indicated that SBUDNIC was about 470 kilometers (292 miles) above the Earth in early March, while other comparably sized satellites deployed to a similar orbit as part of the same mission were still at altitudes of 500 kilometers (310 miles) or more.
The decay of the CubeSat's orbit accelerated as it dropped lower, such that its last known altitude was just 146 kilometers (90 miles) on August 8, shortly after which it is assumed to have been destroyed by burning up in the atmosphere.
[7]Farewell, Aeolus: Doomed ESA weather sat reenters atmosphere over Antarctica
[8]Astroscale wants to be the world's friendly neighborhood space garbage collector
[9]NASA solar satellite burns up over the Sahara desert
[10]Student satellite demonstrates drag sail to de-orbit old hardware
Previous predictions had suggested that the drag device would reduce the orbital lifetime of SBUDNIC from over 20 years to as few as 6.5 years, but in reality it was brought down in about a year and a quarter.
"We were trying to prove that there are ways of de-orbiting space junk after mission life has ended that are not super costly," said Selia Jindal, one of the project leads who graduated from Brown University this year. "This showed that we can do that. We were successfully able to de-orbit our satellite so that it's no longer taking up space in Earth's orbit."
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The sail concept is orders of magnitude less costly than rival ideas for tackling orbital junk such as space tow trucks or nets to capture the junk and pull it out of orbit, according to Dheraj Ganjikunta, SBUDNIC's lead program manager who graduated last year.
"Rather than taking junk out of space after it becomes a problem, we have this $30 drag device you can just throw onto satellites and radically reduce how long they're in space," Ganjikunta said.
Of course, this requires future satellites to be designed to have a similar mechanism built in, and so does not help to address existing space junk, but every little presumably helps.
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SBUDNIC was a 3U CubeSat, meaning it was effectively the size of three 10cm cubes joined together. It was based around a $10 Arduino system plus 65 AA lithium batteries and included a variety of 3D-printed parts produced with consumer-grade printers. ®
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[1] https://www.theregister.com/2023/03/21/student_satellite_demonstrates_drag_sail/
[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=2ZOTbo@sgD62FgKj@g2K28gAAAlM&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://www.spacex.com/launches/transporter-5/
[4] 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=44ZOTbo@sgD62FgKj@g2K28gAAAlM&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[5] 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=33ZOTbo@sgD62FgKj@g2K28gAAAlM&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[6] https://www.brown.edu/news/2023-08-18/sbudnic-reentry
[7] https://www.theregister.com/2023/08/01/esa_aeolus_satellite/
[8] https://www.theregister.com/2023/06/16/space_junk_wef_astroscale/
[9] https://www.theregister.com/2023/04/22/nasa_satellite_rhessi/
[10] https://www.theregister.com/2023/03/21/student_satellite_demonstrates_drag_sail/
[11] 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=44ZOTbo@sgD62FgKj@g2K28gAAAlM&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[12] 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=33ZOTbo@sgD62FgKj@g2K28gAAAlM&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[13] https://whitepapers.theregister.com/
Re: It works only if the satellite electronics still work at the end of its mission time.
Maybe a spring loaded deploy system held closed with power. No power, then it pops open?
Re: It works only if the satellite electronics still work at the end of its mission time.
doesent sound like the ideal way to use what i'd imagine is a pretty short supply of power .
or is it ? lotta solar up there . But in that case , even when system dead solar might hold the deploy switch closed
Re: It works only if the satellite electronics still work at the end of its mission time.
OK, I'll install this on my Pixel phone to watch it "work" ...
Re: It works only if the satellite electronics still work at the end of its mission time.
Maybe some chemical "glue" that has a sticky life of a couple of years in-orbit?
Re: Retrofit?
I don't see why you couldn't come up with a sort of magnet, or grappling hook, or bolas sort of thing to attach this to non-equipped satellites. Combine it with a "hunter-launcher" (isn't there such a device in development?) and you've got the whole system.
Re: Retrofit?
Many a dissertation has been written on such systems as a spacecraft that could change orbits to rendezvous with defunct objects and give them a tug to expedite their descent. It usually comes out quite costly, but a decent academic exercise nonetheless.
Re: Retrofit?
Thing is, it's quite hard to find and get to those defunct satellites in orbit.
May I quote the venerable D Adams:
“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”
Re: It works only if the satellite electronics still work at the end of its mission time.
No. As a matter of fact, this sail can even be weaponized. You just create a maneuverable satellite that has a bunch of sails that saddle up to "target satellites" and attaches a sail to the target. (in Space, even epoxies work quite well.) In the case of some satellites, like Starlinks, you could probably use the sale to block the ion thrusters and let the starlink's own (larger) solar sails deorbit it.
Some issues remain...
Using a drag device might remove said dead satellite from orbit...BUT surely this can only be used on satellites that will 100% burn up during re-entry.
Also: if the drag system takes some time to actually de-orbit a bird, then there's the risk on an uncontrolled re-entry taking place that could result in pieces of space junk landing on/near to buildings which can cause a problem not only in terms of causing damage/injury/death to whatever/whoever is hit by it, but also the issue of how "irradiated" any solid pieces will be, which could cause a health issue.
Life’s a drag
And then you de-orbit!
It works only if the satellite electronics still work at the end of its mission time.
I mean, the issue is that it's a somehow active system. The sat has to be able to deploy it actively after its mission has come to an end. A malfunction that kills the whole control system on the sat will leave it in orbit and unable to deploy the self-killing device. Still it's better than not having it at all.