Do look up! NASA unfurls massive shiny solar sail in orbit
- Reference: 1725446527
- News link: https://www.theregister.co.uk/2024/09/04/nasa_acs3_solar_sail/
- Source link:
The Advanced Composite Solar Sail System (ACS3) [1]was launched on April 23 from New Zealand aboard Rocket Lab’s Electron hardware and – after months of careful checking – was successfully unfurled at 1333 EDT (1033 PDT) on Thursday, August 29. Such is the compact nature of the spacecraft that the whole thing fit inside a 23x23x34 centimeter (9x9x13 inch) CubeSat before being deployed.
"The sail will appear as a square about half the size of a tennis court," NASA Ames [2]reported .
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"Now, with the sail fully extended, the Solar Sail System may be visible to some keen skywatchers on Earth who look up at the right time. Stay tuned to NASA.gov and @NASAAmes on social media for updates on how to catch the spacecraft passing over your area."
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The sail is orbiting much higher than the International Space Station's orbit. This is to avoid the drag of the Earth, since while the ISS regularly uses thrusters to move upwards and away from atmospheric drag, ACS3 produces a tiny amount of thrust, so must be further out. Once testing is complete NASA hopes to use this demonstrator to change altitudes without the need for propellant.
Solar sails were first discussed in the 17th century, by astronomer Johannes Kepler in a letter to Galileo which suggested that some force emanating from the Sun was causing comets to stream tails of debris away as they circled the star. "Provide ships or sails adapted to the heavenly breezes, and there will be some who will brave even that void," he is [6]quoted as saying.
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It's a leaf on the wind, watch how it soars. Pic: [8]NASA - Click to enlarge
NASA proposed a 2015 solar sail mission, dubbed Sunjammer after the 1964 short story by science fiction legend Arthur C Clarke describing an off-planet sailing race. Sadly the NASA mission was canceled for budgetary reasons a year before launch.
[9]NASA solar sail boom demonstrator reaches orbit
[10]NASA solar sail to be Siriusly visible in orbit from Earth
[11]NASA solar sail tech is ready – now who's up to use it in a mission?
[12]I've seen things you people wouldn't believe. Spacecraft with graphene sails powered by starlight and lasers
In principle the idea of solar sailing is pleasingly simple, and the sails have proved somewhat steerable as they can be rotated or reefed to maneuver. And while the thrust is tiny, it accumulates in the frictionless fields of space and a solar-powered spacecraft has already reached another planet.
In May 2010 the Japanese space agency JAXA launched IKAROS, a probe using a 14x14 meter (46×46 ft) sail that was intended to prove the efficacy of the technology. Under constant acceleration the spacecraft was able to fly by Venus before the end of the year, earning it the world record as the first interplanetary sailing craft in 2012.
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For NASA, once the current demonstration flight is carried out, the next step is to build the [14]HIPERSail [PDF] system, which will be around six times the size of the ACS3 and will be used to prove the technology's worth for interplanetary missions. Just don't expect any crewed missions using sails – unless they crack cryogenics as well. ®
Get our [15]Tech Resources
[1] https://www.theregister.com/2024/05/02/nasa_solar_sail_boom_demonstrator/
[2] https://blogs.nasa.gov/smallsatellites/2024/08/29/nasa-composite-booms-deploy-mission-sets-sail-in-space/
[3] 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=2ZtiEIyonb2P5fVKwFPcogAAAAdI&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%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=4&c=44ZtiEIyonb2P5fVKwFPcogAAAAdI&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=33ZtiEIyonb2P5fVKwFPcogAAAAdI&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[6] https://galileo.ou.edu/exhibits/galileo-and-the-quest-for-other-worlds#:~:text=Astronomer%20Johannes%20Kepler%20told%20Galileo,writers%20took%20up%20the%20challenge.
[7] https://regmedia.co.uk/2024/09/04/sail1.jpg
[8] https://www.nasa.gov/smallspacecraft/what-is-acs3/
[9] https://www.theregister.com/2024/05/02/nasa_solar_sail_boom_demonstrator/
[10] https://www.theregister.com/2024/04/19/nasa_solar_sail/
[11] https://www.theregister.com/2024/02/14/nasa_solar_sail_is_ready/
[12] https://www.theregister.com/2020/05/09/lightsails_graphene/
[13] 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=44ZtiEIyonb2P5fVKwFPcogAAAAdI&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[14] https://soma.larc.nasa.gov/stp/tdmo/pdf_files/HIPERSail_NASA_LaRC_0517p.pdf
[15] https://whitepapers.theregister.com/
Re: ‘Edge’
But, but! What about the elephants?
Mine is the one that is only just visible and is slightly blueish-purple.
Re: ‘Edge’
I thought it was turtles all the way down?
Re: This is of course fake news ....
And we're expected to believe that the Japanese have sailed to Venus, which is TOWARDS the sun?
Which way is this "solar wind" blowing, exactly?
Re: This is of course fake news ....
>Which way is this "solar wind" blowing, exactly?
Tacky, very tacky
And then on the gripping hand
The Mote in God's Eye... the Moties'll get a surprise if we beat them to it!
- unless they crack cryogenics as well. ®
We have already "cracked" cryogenics (making things very cold by turning gases to liquid and back) but we have not yet cracked cryonics (freezing warm-blooded creatures without killing them)
Re: - unless they crack cryogenics as well. ®
Or they may be referring to storing cryogenic liquids in space, which plenty of current rockets already use as fuels, but the tricky part is keeping it at a cryogenic temperature for long periods of time, for interplanetary missions.
No one has really cracked that problem yet, although plenty are working on it.
Re: - unless they crack cryogenics as well. ®
Of course we will need _very_ big sails to overcome spaceship inertia (including heavy radiation shielding). And spare capacity to cope with meteorite damage.
Additionally, I would not want to go space travelling without some form of artificial gravitation (whether by constant acceleration or spinning; both have engineering "issues").
So, one or two other things to start thinking about while we perfect the sails & cryonics ;)
Re: - unless they crack cryogenics as well. ®
Is inertia really a big issue in a virtually frictionless environment? That strikes me more as something that will slow down acceleration, not halt it altogether.
I'd think the odd gravity pull here and there may have more impact.
Re: - unless they crack cryogenics as well. ®
The Principle of Inertia = Newton's first law of motion (the crucial one!)
Re: - unless they crack cryogenics as well. ®
Inertia isn't friction. Inertia is the inverse of momentum. To accelerate an inert object to a certain velocity requires Work applied for a period of Time. Work is Force applied over a certain Distance.
If you lean against a car parked on tarmac, it won't move - because you are not applying enough force to overcome its static friction - which involves rubber tyres and rough tarmac. If the car was parked in a puddle on a frozen lake ("assume friction to be zero"), it would move if you leaned against it.
Re: - unless they crack cryogenics as well. ®
Yes. It is.
Assuming you want to stop & start, or change course.
Re: - unless they crack cryogenics as well. ®
No, it isn't.
Inertia is not friction.
Inertia is the same as momentum, as far as the maths is concerned. The energy require to accelerate 1 kg inert object from rest to 1 m/s velocity is the same to decelerate* a 1 kg object from 1 m/s to 0 m/s velocity.
Unit of momentum is Kg * (M/S). Kilograms times Metres per Second.
Friction is a Force, unit Newton ( = Kg * (M/(S*S)). Kilograms times Metres per Second Squared.
Different unit. Different thing. Certainly they have a relationship, but they are not the same thing.
Re: - unless they crack cryogenics as well. ®
The crack's the problem indeed, sperm and eggs are ok, but whole tissues and organs tend to develop fractures on freezing (due to unevenness). Thaw'em up and they've lost structural integrity, fluids pore out, etc. Other approaches to suspended animation might work better ... to stay away from crack, as you reefer that solar sail in, roping the hemp through the lazy jack!
Re: - unless they crack cryogenics as well. ®
We've cracked that too [1].
[1]: https://newatlas.com/science/brains-frozen-thawed-chemicals-cryopreservation/
Re: - unless they crack cryogenics as well. ®
Maybe we have cracked cryonics in a Schrodinger kind of way. We don't know if they're dead or alive until we thaw them to find out.
Maybe we could get the military to read "Superiority"?
So..
.. [1]what music will we play for this?
Sadly it won't carry far without any atmosphere, so best play it here.
:)
[1] https://www.youtube.com/watch?v=DmT0m6MEYnk
No love for The Planetary Society ?
A whole article about solar sails, mentioning some prior efforts, and no mention of that by The Planetary Society ?
Ref: https://www.planetary.org/sci-tech/lightsail
correct area units
That's about 12.6 nanoWalses then.
[edit] "It's a leaf on the wind, watch how it soars" : just noticed this. Perfect, thank you
Now I understand
Something interesting to see in the sky over the next couple of days? No wonder my phone has been pinging repeatedly for the last 3 days with severe weather warnings for rain and thunderstorms.
Why can't the Met Office plan the rain for different days, when there's nothing to see?
We need Admiral Kutuzov to protect us from the lightsail riding Motie menace!
Re: Now I understand
Da...
97 degree 1000km sun synchronous orbit I think, with attitude control to turn the sail perpendicular to the sun when moving towards it and to face the sun when moving away.
Being a quasi-polar orbit, there ought to be a moment when every can get to see it flare Iridium style.
Re: towards / away from the sun
If you run around the surface of the sun staying directly under Earth and look up you will see a ring of sun synchronous satellites going around the Earth. The clever bit about sun synchronous orbits is they use the Earth's tidal bulges to twist around once per year so the satellites remain over the terminator all year round. To a first approximation sun synchronous satellites do not approach or recede from the sun.
To orbit raise a satellite you need thrust in the direction of motion to increase its velocity. To do this with a solar sail you set the sail at 45° to reflect sunlight behind the satellite. You can do this continuously all the way around so there is no need to turn and flash Earth.
JAXA
JAXA returned a sample from a comet, NASA did it a couple of years later. JAXA sent a solar sail powered craft to another planet, NASA will do it too. What are JAXA doing now because I want to see what NASA will try next.
Space Pirates
Sailing ships in space can only lead to space pirates
You want space pirates? This is how you get space pirates !
This is of course fake news ....
.... since the Earth is flat it is impossible for this to work. The only sails in space will be ships that have sailed over the 'Edge'!
-------------> Wasn't sure whether to go for 'Joke' or 'Troll'!