PhysOrg: Japan to launch solar powered 'space yacht'

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PhysOrg: Japan to launch solar powered 'space yacht'

Post by bystander » Tue Apr 27, 2010 5:45 pm

Japan to launch 'space yacht' propelled by solar particles
PhysOrg Space Exploration - 27 April 2010
Japan is to launch a "space yacht" propelled by solar particles that bounce off its kite-shaped sails, the country's space agency said Tuesday.

A rocket carrying the Ikaros -- an acronym for Interplanetary Kite-craft Accelerated by Radiation of the Sun -- will blast off from the Tanegashima space centre in southern Japan on May 18.

"Ikaros is a 'space yacht' that gets propulsion from the pressure of sunlight particles bouncing off its sail," Yuichi Tsuda, space systems expert at the Japan Aerospace Exploration Agency (JAXA), told journalists.

The flexible sails, which are thinner than a human hair, are also equipped with thin-film solar cells to generate electricity to create "a hybrid technology of electricity and pressure", Tsuda said.
...
JAXA plans to control the path of Ikaros by changing the angle at which sunlight particles bounce off the silver-coloured sail.
...
The name of the spacecraft alludes to Icarus, the figure from Greek mythology who flew too close to the sun and fell into the sea, but Tsuda promised that "this Ikaros will not fly into the sun".

The same rocket will also launch Japan's first satellite bound for Venus, called the Akatsuki, or PLANET-C, which will work closely with Venus Express, a satellite sent earlier by the European Space Agency.
http://news.discovery.com/space/space-yacht-jaxa.html

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NS: Maiden voyage for first true space sail

Post by bystander » Wed May 12, 2010 5:44 pm

Maiden voyage for first true space sail
New Scientist - 12 May 2010
ICARUS'S wings melted when he flew too close to the sun. Here's hoping a similar fate doesn't befall his namesake, the solar sail due to be unfurled by Japan's aerospace exploration agency (JAXA) next week. If all goes to plan, it will be the first spacecraft fully propelled by sunlight.

Solar sails like IKAROS, short for Interplanetary Kite-craft Accelerated by Radiation Of the Sun, aim to move forward by harnessing the momentum of photons colliding with it. The idea may be decades old, but solar sails have remained largely untested. Several sails have been unfurled at the edge of space, and spacecraft like NASA's Mercury probe, Messenger, have used the pressure of sunlight to alter trajectories. But no spacecraft has used a sail as its primary means of propulsion.

Made of polyimide resin, IKAROS's sail measures 20 metres from corner to corner, but is just 0.0075 millimetres thick. To survive the launch and the trip into space, the gossamer sail will be folded accordion-style, then wrapped around the centre of the spacecraft.

To unfurl its sail, IKAROS will spin some 25 times per minute. The spacecraft's rotation will be used to extend four "arms" of folded material, and the rest of the sail will follow (see diagram). On 18 May, an H-IIA rocket will carry IKAROS into space along with its main payload, Japan's new Venus orbiter (see "Venus orbiter to fly close to super-rotating wind").

By piggybacking on the Venus launch, IKAROS will be able to get out of Earth orbit, where testing should be relatively simple. Solar sails that are tested in Earth's orbit must adjust regularly to maintain their orientation with the sun, says Bruce Betts of The Planetary Society in Pasadena, California, which hopes to launch its own sail, LightSail-1, into orbit as early as next year. "They're doing it the way we would like to do it," Betts says. "Interplanetary space is what solar sails are really designed for."

IKAROS's trip will probably last six months at the longest, says JAXA's Junichiro Kawaguchi. But it could pave the way for more missions. The spacecraft will carry thin-film solar cells on its sail to show that it can also generate power. If all goes well, the demonstration could lead to a "hybrid", sun-driven mission to Jupiter.
Image
Video: Solar sail

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NS: Venus orbiter to fly close to super-rotating wind

Post by bystander » Wed May 12, 2010 5:55 pm

Venus orbiter to fly close to super-rotating wind
New Scientist - 12 May 2010
Talk about flying close to the wind. Japan's first interplanetary spacecraft will begin its travels to Venus next week, to get the clearest ever view of massive gusts in the planet's atmosphere.

The Venus Climate Orbiter, called AKATSUKI, aims to find out why blistering winds zip around the planet at speeds of up to 400 kilometres per hour. The upper clouds can circle the planet in four days or even less, and no one knows why. The effect is called "super-rotation", because the bulk of the atmosphere is rotating much faster than the planet itself. Venus takes 243 Earth days to make one rotation.

To investigate, AKATSUKI will move roughly in sync with the winds during part of its orbit, so it can track a patch of atmosphere for about 24 hours at a stretch. Five cameras will snap the planet at different wavelengths. "By combining the images from these cameras we can develop a three-dimensional model of the Venus atmosphere," says mission scientist Takeshi Imamura. This will be the first time such measurements have been taken on a planet other than Earth, he adds.

AKATSUKI will be particularly well equipped to study slower winds that move north and south from the planet's equator, which may well play a significant role in the atmosphere's rotation. The European Space Agency's Venus Express, which is in orbit around the planet, can already see these meridional winds. "But the error bars are quite wide," says ESA's Håkan Svedhem. "We can't really tell anything about the seasonal or day-to-day variability."

Plans for joint observations using the two spacecraft are in the works.

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Re: PhysOrg: Japan to launch solar powered 'space yacht'

Post by neufer » Wed May 12, 2010 9:28 pm

http://en.wikipedia.org/wiki/Landscape_with_the_Fall_of_Icarus wrote:
<<Landscape with the Fall of Icarus is a painting in oil on canvas (73.5 cm × 112 cm) long thought to be by Pieter Bruegel, although following technical examinations in 1996, that attribution is regarded as very doubtful. It is probably a version of a lost original by Bruegel, however. Largely derived from Ovid, the painting itself is described in W. H. Auden's poem Musée des Beaux-Arts, named after the museum in which the painting is housed in Brussels.
Image
In Ancient Greek mythology, Icarus succeeded in flying, with wings made by his father Daedalus, using feathers secured with wax. Icarus chose to fly too close to the sun, melting the wax, and fell into the sea and drowned. His legs can be seen in the water, just below the ship. The sun, already half-set on the horizon, is a long way away; the flight did not reach anywhere near it.

The ploughman, shepherd and angler are mentioned in Ovid's account of the legend; they are: "astonished and think to see gods approaching them through the aether", which is not entirely the impression given in the painting. There is also a Flemish proverb (of the sort imaged in other works by Bruegel): "And the farmer continued to plough..." ("En de boer ploegde verder...") pointing out the ignorance of people to fellow men's suffering. The painting may, as Auden's poem suggests, depict humankind's indifference to suffering by highlighting the ordinary events which continue to occur, despite the unobserved death of Icarus.
  • In Breughel's Icarus, for instance: how everything turns away
    Quite leisurely from the disaster; the ploughman may
    Have heard the splash, the forsaken cry,
    But for him it was not an important failure; the sun shone
    As it had to on the white legs disappearing into the green
    Water; and the expensive delicate ship that must have seen
    Something amazing, a boy falling out of the sky,
    had somewhere to get to and sailed calmly on
    .
    >>>>
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Space: Japan Launches New Venus Probe and Solar Sail

Post by bystander » Fri May 21, 2010 3:38 am

Japan Launches New Venus Probe and Solar Sail
Space.com - 20 May 2010
A powerful new Japanese spacecraft and experimental solar sail blasted off together on Thursday (Eastern Time) to start a six-month trek to explore Venus and cosmic parts beyond.

One mission is aimed at uncovering the secrets of Venus and its cloud-covered surface, while the other could become the first interplanetary solar sail to successfully fly in space. The Japan Aerospace Exploration Agency (JAXA) is backing both spaceflights.

A Japanese H-2A rocket lifted off with the Venus Climate Orbiter, named Akatsuki, as its main payload at precisely 5:58:22 p.m. EDT (2158:22 GMT). By coincidence, it was early Friday morning local Japan time at the Tanegashima Space Center at the time of launch.

The Akatsuki spacecraft's name means "Dawn in Japanese. If all goes well, it should arrive at Venus in December.

JAXA hoped to launch Akatsuki and its Ikaros solar sail companion earlier this week, but low clouds and foul weather prevented a liftoff initially scheduled for Tuesday morning (local Japan time).

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PS: All's well on IKAROS and Shin-en

Post by bystander » Sat May 22, 2010 4:35 am

All's well on IKAROS and Shin-en
Planetary Society - 21 May 2010
Today JAXA posted a very brief mission status update on the IKAROS spacecraft, launched yesterday along with Akatsuki. Brief is good; all's well. Here's the report:
The Japan Aerospace Exploration Agency (JAXA) acquired the signal transmitted from the IKAROS at the Usuda Deep Space Station and confirmed its solar power generation and stable posture, and established communications. We will turn on onboard devices one by one.
Meanwhile, UNITEC-1, the third spacecraft launched with Akatsuki and IKAROS toward Venus has a new name: Shin-en, which, according to Junya Terazono, means "abyss." That's a terrific name for the first student-built spacecraft to be headed to deep space. Here's the Google translation of their update:
UNITEC-1, announced the successful launch and a nickname!(2010/5/21)

21 today, finally UNITEC-1, nicknamed "peas Shin" is traveled into space!

Pray for a safe journey ahead.
"Peas Shin" -- Google choked on the translation, as it often does with proper names of spacecraft (Akatsuki, for instance, often becomes "Somehow" in Google translation, and then there's Hayabusa, which is typically rendered as "It is quick, the ぶ"). So, if you're wandering around a Google translated page about Shin-en and you see "Peas Shin," just do the proper translation in your head!

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China launched solar powered 'space junk'

Post by neufer » Sat May 22, 2010 12:54 pm

http://en.wikipedia.org/wiki/Space_debris wrote:
Known orbit planes of Fengyun-1C debris one month after its disintegration by the Chinese ASAT.
Image

<<China suffered widespread condemnation after their 2007 anti-satellite missile test, both for the military implications as well as the huge amount of debris it created. This is the largest single space debris incident in history, estimated to have created more than 2,300 pieces (updated 13 December 2007) of trackable debris (approximately golf ball size or larger), over 35,000 pieces 1 cm (0.4 in) or larger, and 1 million pieces 1 mm (0.04 in) or larger. Particularly worrying is the fact that the test took place in the most densely populated part of space, as the target satellite orbited between 850 kilometres (530 mi) and 882 kilometres (548 mi). Since the atmospheric drag is quite low at that altitude, the debris will persist for decades. In June 2007, NASA's Terra environmental spacecraft was the first to perform a maneuver in order to prevent impacts from this debris.>>
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PS: Initial checkout of IKAROS complete

Post by bystander » Wed May 26, 2010 3:37 am

Initial checkout of IKAROS complete
Planetary Society - 25 May 2010
JAXA has posted a short update on their solar sailcraft IKAROS, stating:
  • IKAROS moves to Verification Experiment Phase

    The Japan Aerospace Exploration Agency (JAXA) completed the initial operation check....We will take a few weeks to carry out the first verification experiments, namely deployment of the solar sail and solar power generation by thin film solar cells
.

My interpretation of this update (and let me be clear, this is just an interpretation, based on no more information than what I posted above) is that the all the instrument and systems checkouts have been completed, and the spacecraft is operating normally; so now they are ready to proceed toward the delicate operation of sail deployment.

JAXA posted this graphic along with the update. It seems to indicate that "deployment start" has been "completed," but I'm not sure exactly what "deployment start" means in this context! I can't imagine that, given the content of the text update, the sails have actually been deployed.
  • Image

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Re: PS: Initial checkout of IKAROS complete

Post by neufer » Sun May 30, 2010 2:05 pm

bystander wrote:
  • Image
[youtube]http://www.youtube.com/watch?v=7_6HOqBk ... ded#at=112[/youtube]Image
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PS: Photo proof of good progress on IKAROS sail deployment

Post by bystander » Mon May 31, 2010 10:27 pm

Photo proof of good progress on IKAROS sail deployment
Planetary Society - 31 May 2010
The images below are self-portraits by IKAROS. While I think it is automatically cool for spacecraft to take photos of themselves in places far beyond Earth, they usually do so for a purpose other than vanity. In this particular case, they're photo proof that the multi-step process of the deployment of IKAROS' square solar sail is going according to plan! I took them from this JAXA site.
  • Image Image Image Image
    IKAROS tip masses deployed (Cams 1, 2, 3 & 4) On May 28, 2010, the IKAROS spacecraft successfully
    released the four "tip masses" that will aid in the deployment of IKAROS' sail by centrifugal force. Each
    deployment was monitored by a camera. Two of the camera images contain artifacts, internal reflections
    caused by sunlight glancing into the camera optics. (ISAS/JAXA)
What exactly are we looking at? First, here's an explainer from the IKAROS press kit that shows the steps involved in the deployment process. I believe -- but am not certain -- that the photos above document the successful completion of the second step in the top row. My reasons for that have to do with the helpful spacecraft diagrams that JAXA posted along with the camera images (see below). If I have correctly interpreted the Google translation of the JAXA update, the sail monitoring camera images were taken on May 28.
  • Image
    IKAROS sail deployment diagram (ISAS/JAXA)

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PS: Taking things slowly with IKAROS sail deployment

Post by bystander » Tue Jun 08, 2010 12:45 am

Taking things slowly with IKAROS sail deployment
Planetary Society Blog - 05 June 2010
Nothing comes easy. The IKAROS team has put discretion before valor and decided to delay the final stage of the deployment. The first stage of the deployment went well but they want to analyze the measurements they are receiving more closely before committing the final stage.
...
The complexity of the deployment makes it easy to understand both the caution of the team and the dangers inherent in it. Readers who review the description, or who have seen the video animation can appreciate that the dynamics involved are hard to predict and hard to control. The sail itself is only 7.5 microns thick and very flimsy. The centrifugal force that controls the deployment can be made wobbly by just a little asymmetry in the way the sail unfolds from its stowed position. The two-stage spinning method of deployment is elegant, but complex. Caution is certainly warranted. There is, however, a counter-argument in favor of doing things as quickly as possible before something else in the complex system goes wrong.
Click to play embedded YouTube video.
IKAROS sail deployment delayed until at least Tuesday
Planetary Society Blog - 06 June 2010
This is just a brief update to yesterday's post to add a few sentences that Lou wanted to hold until JAXA had had a chance to issue an official statement. According to the official statement, ... it seems that the first stage of sail deployment, in which the tip masses drag the accordion-folded sails out to their greatest possible extent, has been successfully completed. All that remains is to release the four retaining bars which will allow the sails to unfold and assume the final square shape. But, the update goes on to say, they had some concerns that caused them to decide to delay deployment until at least Tuesday night Japan time.
IKAROS update: rotation rate inexplicably increasing
Planetary Society Blog - 07 June 2010
JAXA's end-of-Sunday update on IKAROS' status gives more details about an issue they are working on the spacecraft. The spacecraft itself is in perfect health, but its dynamics are different from what was expected. Here's the content of the update, which I edited from the Google translation and another version helpfully posted to unmannedspaceflight.com by user "akibow."

IKAROS is standing by after completion of the first-stage deployment, with the sails deployed about five meters. At present, the spin rate is increasing very slowly. This is worrisome to the IKAROS team, although the spacecraft is presently in no danger from the increased spin rate. The concern is that the team cannot explain the cause of the spin-up.

Engineers are working some possible explanations. For example, it could be caused by sunlight pressure on the tilted, folded blades -- that is, the spacecraft, which now has four long blades spanning 10 meters (as in the picture below), may be acting like a pinwheel. Alternatively, it could be caused by outgassing from the sail material. Other possibilities are also being explored. The team is pausing deployment to watch the spacecraft's behavior to attempt to discern the cause of the spin-up before meeting again to determine whether to proceed with the final deployment.

The reported spin rate of 7.4 rotations per minute is the same for the end of the day Sunday as it was for the end of the day Friday, so the rate of increase is clearly much smaller than 0.1 rotation per minute per day, for what that's worth.
  • Image
    IKAROS first stage deployment complete (ISAS/JAXA )
    Artist's concept of the IKAROS solar sail mission with the first stage of sail deployment complete.

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PS: IKAROS team proceeds with final stage of sail deployment

Post by bystander » Tue Jun 08, 2010 5:41 pm

IKAROS team proceeds with final stage of sail deployment!
Planetary Society Blog - 07 June 2010
Just a brief update on IKAROS: According to their blog (and with the help of Google Translate and "akibow" and "punkboi" at unmannedspaceflight.com) JAXA has decided to proceed with the final stage of IKAROS' sail deployment; in fact, if everything went well, it should already have happened. I'll look for news and post an update when I hear anything about how it went! This later post states that IKAROS is still healthy but seems to indicate that further news about the deployment will not be posted until Wednesday afternoon in Japan.

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PS: Progress on IKAROS sail deployment (with pictures!)

Post by bystander » Wed Jun 09, 2010 4:59 pm

Progress on IKAROS sail deployment (with pictures!)
Planetary Society Blog - 09 June 2010
Several pictures from the sail deployment monitoring cameras showed up on the IKAROS blog overnight. Here's one of four showing what looks like good halfway progress on the "first stage" of the deployment, when the tip weights were midway through pulling the folded sails outward. Lou Friedman tells me these were taken a couple of days ago.
Image
IKAROS first stage deployment halfway complete (Cam 1) (JAXA/JSPEC)
A view from one of the four sail monitoring cameras on IKAROS shows the
folded sail being pulled outward from the spacecraft as it should be.
This next image (posted slightly later) is a bit harder to interpret. First, the photo:
Image
IKAROS sail deployment (Cam 2) (JAXA/JSPEC)
This is a view from one of the sail monitoring cameras on IKAROS on June 9, following expansion of the sail.
On first glance, it looks like something has gone wrong, like a sail has kinked in half and two tethers have gotten tangled. But after comparing the view to the artwork of the solar sail, I think that the photo actually shows things looking as they should. We're looking at the sail with a very foreshortened perspective from a very wide-angle camera, much like the way the rovers' Hazcams see fish-eyed views of the terrain in front of them. There's a square hole in the center of the sail, and that occupies most of the foreground, with two tethers floating in that space, not yet pulled taut; one pointy corner of the square sail is in the far distance, washed out in the bright sunlight. We'll hopefully get a better view of the sails once they activate their two deployable cameras, which should obtain a less severely foreshortened view.

Anyway, this looks like great progress for JAXA!

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PS: IKAROS: Successful sail deployment & solar power generat

Post by bystander » Fri Jun 11, 2010 7:08 am

IKAROS: Successful sail deployment and solar power generation! Hooray!!
Planetary Society Blog - 10 June 2010
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 ... 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:
Image
Successful sail deployment for IKAROS (cam 1) (3 more)
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.

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PS: IKAROS' deployable camera captures perfect sail photos

Post by bystander » Wed Jun 16, 2010 3:00 am

IKAROS' deployable camera captures perfect sail photos
Planetary Society Blog | 15 June 2010
Emily Lakdawalla wrote:
I've been watching and waiting for these photos for days! We've already seen IKAROS' view of its deployed sails from cameras attached to the spacecraft, but, in a brilliant idea, the Japanese built IKAROS with two deployable cameras that could view the thing from a distance. They're two tiny little things, I think only about 5 centimeters across, that just get shot out (gently) from the spacecraft and wirelessly transmit their photos to it. And such photos! So cool!

First, a closeup:
And here's the money shot, the distant view -- so square, exactly as it should be! Awesome.

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PS: IKAROS Begins Attitude Control

Post by bystander » Fri Jul 02, 2010 9:28 pm

IKAROS Begins Attitude Control
Planetary Society Blog | 01 July 2010
The IKAROS spacecraft continues to perform its mission well as its team at the Japan Space Exploration Center moves closer to the first fully controlled solar sail flight. They have now released the second of their two deployable cameras (one news report called it a disposable camera, which I suppose is also true) which took this excellent picture of IKAROS.

This photo of the sail hovering in space fills me with awe.

Embedded in the sail material are both solar cells for generating solar power and liquid crystal devices (LCD), which can be electrically turned on and off. When the power is on, the sunlight reflection is specular (as in the blue circle in the picture) and when off, the reflection is diffuse (in the red dotted circle). The diffuse reflection causes the area to look white while the specular reflection causes it to look dark. The different reflections create different forces and allow the sail to be turned in a controlled direction, using only sunlight. The team plans to synchronize the LCD on and off with sail spin during the attitude control experiment.

The solar cell power output is also being monitored during the mission -- the success of the power generation will determine the feasibility of combining the solar sail with an electric engine to provide additional propulsion capability for outer planet missions.

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PS: IKAROS solar sail acceleration by photon pressure confir

Post by bystander » Fri Jul 09, 2010 8:44 pm

JAXA confirms acceleration of IKAROS solar sail by photon pressure
Planetary Society Blog | 09 July 2010
Image
DCAM2's view of IKAROS (Credit: JAXA)
A 32-frame animation from the deployable camera
DCAM2 on IKAROS. The camera rotated as it receded,
producing the apparent spin of the sail.
The Japanese space agency reported on their web site today that acceleration of the IKAROS spacecraft by solar pressure has been confirmed.

This is a significant milestone on their flight -- probably the next-to-last step before complete controlled solar sail flight is achieved (turning the spacecraft to add or subtract velocity in a controlled manner). As we have noted many times before, just sensing of acceleration from photon pressure is not new; the acceleration by sunlight pressure on spacecraft has been known about ever since the beginning of the space age. It is, however, a new proof of engineering -- harnessing the force of light pressure force to modify a sailcraft's path in a controlled way.

The IKAROS spacecraft continues to perform well, and the world-wide kudos which the Japanese Space Exploration Center (JSpEC) is receiving -- for this mission, and for the successful return of the Hayabusa sample capsule -- are well deserved. For those of our members living near New York, the JSpEC team will give a special report at a free public event organized by The Planetary Society on Wednesday, July 21.

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Space: Solar Sail Camera Spots Cosmic Explosion

Post by bystander » Fri Jul 23, 2010 1:27 am

Solar Sail Camera Spots Cosmic Explosion
Space.com | Science | 22 July 2010
A camera riding on the world's first deep space solar sail has caught managed to observe a violent gamma-ray burst — one of the most powerful explosions in the universe, Japanese space officials have announced.

The Ikaros solar sail detected the first gamma-ray burst with its onboard GAmma-ray burst Polarized light detector (GAP) on July 7, Japan Aerospace Exploration Agency (JAXA) said in an announcement.
...
The GAP can detect gamma-rays coming toward Ikaros from all directions, but can only carry out its polarized light analysis when the gamma-rays come in from the backside of the solar sail. The first gamma-ray burst detected did not allow for such an analysis.

Japan's Ikaros solar sail has months of sailing ahead, and scientists calculate that about 20 percent of gamma-ray bursts observed by GAP should allow for polarized light observations.

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Re: PhysOrg: Japan to launch solar powered 'space yacht'

Post by andrewgray » Tue Oct 26, 2010 5:09 pm

This idea about solar-space-yacht is amazing. And of course the JAXA campaign with Let's Solar Sail Carry Oue Message campaign's, it really is encourage another scientist to research in the solar sail idea. As I read on JAXA website this space-yacht has thin and light solar sail membrane will be deployed using the centrifugal force of spinning the main body of the IKAROS before its tension is set. The deployment is in two stages. The first stage is carried out quasi-statically by the onboard deployment mechanism on the side of the main body. The second stage is the dynamic deployment. As this deployment method does not require a strut such as a boom, it can contribute to making it lighter and thus can be applied for a larger membrane.

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Four sheets to the Solar Wind

Post by neufer » Tue Oct 26, 2010 6:11 pm

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Science: Japan's IKAROS Solar Sail Mission Extended

Post by bystander » Wed Jan 26, 2011 5:33 pm

Japan's IKAROS Solar Sail Mission Extended for a Year
Science Insider | Dennis Normile | 2011 Jan 26
Success is paying off for Japan's IKAROS solar sail mission: The team behind the spacecraft confirmed today that it flawlessly completed all the performance tests set for it during its planned 6-month life. As a reward, the Japan Aerospace Exploration Agency (JAXA) has extended the mission to March 2012.

"In half a year, we accomplished all the mission objectives," said mission manager Osamu Mori, of JAXA's Institute of Space and Astronautical Science in Sagamihara, near Tokyo. "Now we've set new objectives."

Launched 21 May along with JAXA's ill-fated Akatsuki Venus probe, IKAROS (the Interplanetary Kite-Craft Accelerated by Radiation of the Sun) successfully used centrifugal force to unfurl its 20 meter diagonal, 0.0075 milimeter thick polyimide sail and relied on the pressure of photons streaming from the sun for acceleration. Controllers tweaked the craft's attitude by turning liquid crystal devices on and off to vary the reflectance (and thus the photon pressure) across the sail. All of these accomplishments were spacefaring firsts, Mori says. (Two previous solar sail missions by other countries foundered on rocket failures.)

While sailing, the craft's suite of scientific instruments caught gamma ray bursts, collected data on space dust, and participated in very long baseline interferometry observations of celestial objects.

With the extended lease on life, the team will try new navigational tricks, such as varying the sail's angle toward the sun and changing the craft's trajectory. Mori called these "risky" maneuvers because they are not sure if the sail will remain fully extended. They intend to model the sail's behavior and the craft's response to plan future solar sail missions.

Their next solar sail project is already in the works. They intend to pair a solar sail 10 times larger than that of IKAROS with the ion engines that took the Hayabusa satellite to asteroid Itokawa and back for a mission to Jupiter. They are eyeing a 2019 or 2020 launch so this craft can rendezvous with planned U.S. and European missions for joint observations of the solar system's largest planet.

Separately, NASA on 21 January announced that its solar sail mission, NanoSail-D, once thought lost due to a malfunction, successfully deployed its sail and is working as planned. Solar sailing could usher in "a new age of discovery in the solar system," said Mori.
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Re: PhysOrg: Japan to launch solar powered 'space yacht'

Post by Beyond » Thu Jan 27, 2011 2:29 am

The last time i saw something like this was on a tv show called Deep Space Nine. I forget the title of that episode. They used a two man ship of ancient design on sail power only and apparently attained "light speed", but it happened slowly so they didn't realize it until the Cardassians wanted to know why they were in their part of space. Once they explained, everything was ok. At least as much as can be ok when it concerns the Cardassians, that is.

If the Japanese can build a big enough sail, one day their cameras may record it going into warp one. What a sight that would be!

As to those itty-bitty cameras, we all know how good the Japanese are with cameras. Like the Swiss are with watches.
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Re: PhysOrg: Japan to launch solar powered 'space yacht'

Post by victoriaw » Mon Jan 31, 2011 3:19 pm

Japon: mission réussie pour le cerf-volant solaire spatial "Ikaros"

TOKYO — Le cerf-volant expérimental japonais "Ikaros" a réussi comme prévu à se déplacer durant plusieurs mois dans l'espace grâce aux particules et à l'énergie solaires, une première mondiale, s'est félicité mercredi l'Agence d'exploration spatiale japonaise (Jaxa).
"Ikaros a achevé sa mission principale et rempli ses fonctions", a déclaré la Jaxa.
Ikaros, qui avait été lancé en mai 2010 par une fusée nippone H-2A, en même temps qu'une sonde vénusienne, a ensuite déployé sa voilure de 14 mètres de côté, selon les données fournies par l'agence.
Durant quelque six mois, l'engin s'est déplacé de façon autonome dans l'espace, permettant à la Jaxa de valider la pertinence de diverses technologies d'exploitation de l'énergie solaire et de navigation spatiale.
La voile de cet objet spatial expérimental, dont la texture est plus fine qu'un cheveu, est couverte de cellules photovoltaïques et de matériau spécial sensible aux particules.
Ikaros a progressé ainsi selon un "mode hybride, couplant électricité et pression", d'après la Jaxa qui envisage désormais de développer un nouveau modèle, bien plus large, pour poursuivre ses recherches en la matière.
Ce cerf-volant interstellaire, désormais en "phase post-opérationnelle", va continuer d'évoluer dans l'espace encore pendant environ un an, pour fournir diverses autres données.
Quant à la sonde Akatsuki lancée simultanément et qui devait rejoindre Venus, elle n'est pas arrivée à destination. La Jaxa a annoncé le mois dernier qu'elle avait échoué à rejoindre l'orbite de la "planète ardente". Toutefois, une nouvelle tentative devrait être effectuée dans environ six ans.

The kite experimental Japanese "Ikaros" succeeded as planned to move for several months in space with particles and solar energy, a world premiere, on Wednesday welcomed the Japan Aerospace Exploration Agency (JAXA). "Ikaros has completed its primary mission and fulfilled its duties," JAXA said.
Ikaros, which was launched in May 2010 by a Japanese H-2A rocket, along with a Venus probe, then deployed its 14-meter wing side, according to data provided by the agency. In about six months, the craft moved independently in space, allowing the JAXA validate the appropriateness of various technologies for the exploitation of solar energy and space navigation.
The sail of this experimental space object, its texture is finer than a human hair is covered with photovoltaic cells and special material sensitive to particles.
Ikaros has progressed well according to a "hybrid mode, combining power and pressure," according to JAXA is now planning to develop a new, much wider, to continue his research on the subject.
This kite interstellar now "post-operational phase" will continue to evolve in space again for about a year to provide various other data.
As for the Akatsuki probe was launched simultaneously and reach Venus, she did not arrive at their destination. JAXA announced last month that it had failed to reach the orbit of the "burning planet". However, another attempt should be made in about six years.
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PhysOrg: Japan to launch solar powered 'space yacht'

Post by victoriaw » Wed Feb 16, 2011 4:17 pm

This photo taken by the Ikaros solar sail spacecraft shows a crescent-shaped Venus on the right as well as the spacecraft's sail and cords.

I'm trying to get this image in a better definition. Does anyone found it?
Last edited by victoriaw on Tue Aug 30, 2011 4:11 am, edited 2 times in total.
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Re: PhysOrg: Japan to launch solar powered 'space yacht'

Post by neufer » Mon Mar 12, 2012 1:09 am

http://www.planetary.org/blog/article/00003413/ wrote: (Spoken)All right! Hop on the yacht and let's travel through the solar system!

(1st)
The sun sparkles in the sea of space
Spinning around, the world's first space yacht
IKAROS
No matter what happens, it's a challenge! You'll keep on going!
Believing in distant, great dreams
Dreams infinitely far off, out into space
Come on, take off! Recharge your courage!
Spread your sails with all your might
Let's set forth into the future, catching the light of hope!

(2nd)
Your polished membrane makes electricity with solar cells
Your flashing crystals
Your sails are thin, but they're tough polyimide
Vast, vast space... what could be up ahead?
Believe in the path you take
An epic voyage through the sea of far space
So journey on, pushed on by light
Steer as you will
A silver sparkle blooming like a flower in the dark

(Spoken)
"DCAM1, DCAM2, thank you for taking photos out in space! No matter how far we go, the three of us will always be together. Forever and forever!"
I'll grow larger, and go on adventures, farther and farther! Next is Jupiter, my dream and the dream of big brother Hayabusa!

(3rd)
These passions I shut up within my heart for so long
It's time to open them up, right now!
Passing through the darkness of outer space
Come on, let's work together
Full of dreams, I spread my sails wide
Into the unlimited future, catching the light of hope!
Art Neuendorffer