[QUOTE]
Jun. 10, 2010 | 20:46 PDT | Jun. 11 03:46 UTC
JAXA finally issued the formal announcement: they successfully expanded IKAROS' square sail! Not only that, but the sail's thin-film solar cells are generating power! Hooray for JAXA and hooray for IKAROS! They haven't demonstrated actual solar sailing yet -- that's still to come, and may be weeks in the future -- but with today's announcement they've achieved their stated minimum success goals for the mission, so it's definitely time to celebrate!
There's pictures to prove the sails have deployed. First, here's a diagram to orient you. Remember that the cameras are bolted to the spacecraft, and are looking out along the sail, so the photos will show you a very severely foreshortened view of the deployed sails:
[IMG]http://planetary.org/image/20100611_ikaros_5_lg.jpg[/IMG]
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[B]IKAROS sail monitoring camera view following deployment[/B]
[I]credit: JAXA / JSPEC[/I]
OK, so, here you go -- here are the four photos showing the four sail corners -- scroll down and I'll explain what you're seeing:
[IMG]http://planetary.org/image/005_001_lg.jpg[/IMG]
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Successful sail deployment for IKAROS (cam 1)
[IMG]http://planetary.org/image/005_002_lg.jpg[/IMG]
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Successful sail deployment for IKAROS (cam 2)
[IMG]http://planetary.org/image/005_003_lg.jpg[/IMG]
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Successful sail deployment for IKAROS (cam 3)
[IMG]http://planetary.org/image/005_004_lg.jpg[/IMG]
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Successful sail deployment for IKAROS (cam 4)
Credit: JAXA / JSPEC
These may not look like you expected them to, but here's why I believe JAXA when they say it looks good (not that I wouldn't have believed them anyway, but I feel like I can see it for myself). The biggest thing is that all four images look pretty much the same. If there had been an issue with deployment, it very likely would have affected one sail more than another; but I see all four sails occupuying basically the same part of the field of view. The other important thing is that each sail is attached to the spacecraft by two pairs of guylines, which come together at the corner of the square gap in the sail immediately in front of the camera. All of those guylines -- all sixteen of them -- appear taut or nearly so, suggesting that the sail is fully expanded and tugging evenly on the lines.
In addition to the guylines, there are also two flat tapes in each image, which are not taut. My understanding (I'll have to check with Lou to be sure) is that those are electronic connections between the sail and the spacecraft. Those are what are carrying the power that is now being generated by the thin-film solar cells on the sails.
Finally, each image contains a little stick in the left foreground; those are the rollers that formerly held back the sails in their folded condition. Releasing those is what triggered the second stage of sail deployment, allowing the sails to expand.
According to the IKAROS blog, first stage deployment was completed on June 8; the second stage was commanded on June 9, by which time the spacecraft was 7.4 million kilometers (46 light-seconds) from Earth. Their first indication that deployment had worked was from the reduction in the spacecraft's spin rate, noted in its telemetry. Then the camera images came down, confirming deployment. Finally, on June 10, the expansion was complete, with the sail cleanly stretched; and that's when they confirmed the successful operation of the thin-film solar cells and the achievement of minimum mission success.
So, COOOL!! And, again, congratulations! Planetary Society Executive Director Lou Friedman has this to add: "The successful deployment of a solar sail by the IKAROS team is a great accomplishment and major step toward solar sail flight. Congratulations to JAXA's Japan Space Exploration Center team for a terrific job. The Planetary Society and our LightSail team admire the work done by IKAROS and look forward to them achieving their goal of controlled solar sail flight. We plan to join them in the ocean of space soon."
Finally: I wish I could have some of this cake, which was evidently enjoyed in IKAROS mission control earlier today:
[IMG]http://planetary.org/image/20100611-cake.jpg[/IMG]
[/QUOTE]
:toot: :dance: :pcgaming: :toot: :siren: :pcgaming: :toot: :dance: :pcgaming: :toot: :dance: :toot: :siren: :dance: :siren: :toot:
Tin foil in space.
Edit:
With bits of string.
Damn that some awesome cake.
[QUOTE=firstblood;22535682]Tin foil in space.
Edit:
With bits of string.[/QUOTE]
This is science at its best!
HOLY SHIT JUST SAW THAT CAKE
WANT
"They haven't demonstrated actual solar sailing yet -- that's still to come"
I'm no expert on this, but based on my knowledge of normal sails, doesn't extending them cause it to... you know... start sailing?
[QUOTE=Kybalt;22537939]"They haven't demonstrated actual solar sailing yet -- that's still to come"
I'm no expert on this, but based on my knowledge of normal sails, doesn't extending them cause it to... you know... start sailing?[/QUOTE]
Solar wind is not a storm, consider it a gentle breeze. It takes a while to gain momentum.
I saw the cake, the science, and thought immediately of Aperture Laboratories.
[QUOTE=mercurius;22538082]Solar wind is not a storm, consider it a gentle breeze. It takes a while to gain momentum.[/QUOTE]
Ah, so they ARE sailing, just very slowly.
Yes, that's the plan and I hope they will succeed in it. I heard they are going for a trip to venus.
At last!
I heard somewhere that this won't work. I forgot the explanation behind it. Why is this so important to space travel?
[QUOTE=mercurius;22538861]Yes, that's the plan and I hope they will succeed in it. I heard they are going for a trip to venus.[/QUOTE]
Technically, yes, but it carries no instruments to probe Venus.
Just equipment to probe the solar wind and cosmic wind and such.
[QUOTE=ProboardslolV2;22539156]I heard somewhere that this won't work. I forgot the explanation behind it. Why is this so important to space travel?[/QUOTE]
It uses solar wind as a propulsion source.
[QUOTE=Kybalt;22537939]"They haven't demonstrated actual solar sailing yet -- that's still to come"
I'm no expert on this, but based on my knowledge of normal sails, doesn't extending them cause it to... you know... start sailing?[/QUOTE]
Photons have near to 0 weight, it's going to take a while before movement becomes noticeable.
[QUOTE=ProboardslolV2;22539156]I heard somewhere that this won't work. I forgot the explanation behind it. Why is this so important to space travel?[/QUOTE]
It uses an unlimited fuel source and makes it possible for spaceships to reach speeds close to the speed of light even if it has an extremely slow acceleration.
It's good if you're thinking of sending a probe to explore the outside of our solar system and beyond.
[QUOTE=Electrocuter;22542909]Photons have near to 0 weight, it's going to take a while before movement becomes noticeable.[/QUOTE]
They don't have any weight, since they don't have any mass for a gravitational field to act on (although they are affected by gravity, with general relativity and shit.)
But they do have momentum, which is what the sail is used to exploit.
Sorry i think I missed the announcement of this mission, so from what I can gather, they've successfully deployed a solar sail?
[QUOTE=NorthernFall;22542989]Sorry i think I missed the announcement of this mission, so from what I can gather, they've successfully deployed a solar sail?[/QUOTE]
If you read the article, you might understand
[QUOTE=Kybalt;22538111]Ah, so they ARE sailing, just very slowly.[/QUOTE]
Slowly at first. Given enough time (like... a LONG time) you could eventually speed up to a significant fraction of the speed of light. Realistically you'd need a bloody big solar sail for that, though.
I just hope they come up with less problematic sail deployment methods in the future
Ahaha suck it bitches japan did it first
That thin little film is generating solar power?
Sounds like a good candidate for solar power satellite material.
[QUOTE=Used Car Salesman;22546208]That thin little film is generating solar power?
Sounds like a good candidate for solar power satellite material.[/QUOTE]
It's not, it's just a sail for solar wind, it has no other propulsion systems.
:toot:
My teacher uses tinfoil to fix her car
Now we can develop SPACE PIRATES and make ships that look like old-timey boats and SAIL THE SOLAR SEAS. ARRR
[QUOTE=BugsyXoX;22553011]My teacher uses tinfoil to fix her car[/QUOTE]
...And Japan uses tinfoil to make probes travel though space.
Tinfoil is awesome.
Solar sailing as a propulsion method is horribly inefficient, but i guess any progress is progress, right?
[QUOTE=Cheezy;22562313]Solar sailing as a propulsion method is horribly inefficient, but i guess any progress is progress, right?[/QUOTE]
It's okay for sending shit around the solar system, like small probes and such. The good thing is that it doesn't require any onboard propellant or energy source for an ion drive, so it's good for low-cost missions that take years instead of months.
It's still bound to be completely fucked over by any small piece of anything
If this works, oh yes am I glad to live in the 21st century.
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