[QUOTE]With its May 18 launch date fast approaching, Japan’s [URL=http://www.jaxa.jp/projects/sat/ikaros/index_e.html]IKAROS[/URL] hybrid sail mission is at last getting a bit of press attention, long overdue in my opinion. The Daily Mail, at least, has just run a [URL=http://www.dailymail.co.uk/sciencetech/article-1269478/Space-yacht-craft-travel-solar-waves-sets-sail-Venus.html]story[/URL] on IKAROS, which will combine two mission concepts within a single spacecraft. Its solar sail works conventionally, using the momentum of photons from the Sun to accelerate the craft. But the JAXA designers have added thin film solar cells on the sail membrane. These produce the electricity that could be used in future (and larger) iterations to drive an ion engine.
But IKAROS (Interplanetary Kite-craft Accelerated by Radiation of the Sun) is a demonstrator, not only taking the sail concept into space but pushing it into interplanetary regions. Launched in tandem with the Venus Climate Orbiter [URL=http://www.jaxa.jp/countdown/f17/index_e.html]AKATSUKI[/URL], the spacecraft will deploy its sail a month after launch on the way to Venus, and having swung by the planet, will test out its propulsion and navigation systems. Kelvin Long, head of [URL=http://www.icarusinterstellar.org/]Project Icarus[/URL], was the first to forward me the link to the Daily Mail story, and that reminds me to note that despite the similarity in names, IKAROS bears no relation to the interstellar probe design Kelvin’s team is developing.
Not that the interstellar community doesn’t have high hopes for sail concepts, and it’s safe to say that anyone interested in the problems of deep space propulsion will rejoice at the launch of IKAROS. What we need at this juncture, with reams of theoretical work compiled, is to start gathering data from live missions. Perhaps the most obvious issue for IKAROS and any other design is sail deployment. The IKAROS sail is a square membrane with a diagonal distance of 20 meters, made of polyimide some 7.5 micrometers thick, with the solar cells, steering devices and dust-counter sensors fitted directly to the membrane.
[IMG]http://www.jspec.jaxa.jp/e/activity/images/ikaros/pic_07_l.jpg[/IMG]
[B]Image: [/B]The IKAROS sail, a hybrid design with attached solar cells. Credit: JAXA.
Osamu Mori, project leader for IKAROS, describes the sail membrane in this [URL=http://www.jaxa.jp/article/special/explore/mori01_e.html]interview[/URL]:
"Polyimide resin allows us to create a much lighter sail. As well as being extremely strong, it doesn’t need glue, because it can be joined using heat sealing. Polyimide resin is originally yellow, but one side of IKAROS’s sail is silver. This is because aluminum is vapor deposited on one side of the film, in order to reflect sunlight more efficiently. In addition, the film is reinforced in such a way as to prevent it from splitting all the way if it’s ripped. If the solar sail is torn, its performance will decline slightly, but it can still continue its space travels."
One way to deploy a sail is to use conventional mast and boom construction, but you pay a penalty in weight and complexity. The IKAROS team had a different idea. The sail, wrapped and folded around the body of the spacecraft, will be spun up to 20 revolutions per minute. Spinning the spacecraft will allow centrifugal forces to unfurl the sail, and spin-stabilization will likewise keep the weight down due to the lack of a supporting truss. JAXA’s sail team has conducted experiments both on the ground and aboard a balloon, where the sail membrane was spread in a near-vacuum.
Mori adds that sail orientation and navigation is going to prove an interesting issue. IKAROS could change the direction of the sail with an onboard thruster but can also maneuver solely with solar power, changing the reflectivity of various parts of the sail by ‘frosting’ the film. The part of the sail with reduced reflectivity thus generates less acceleration, so the sail’s attitude can be controlled. In addition, IKAROS will carry a dust counter and an instrument to observe gamma ray bursts.
Japan’s plans for the hybrid sail/cell design are quite ambitious. JAXA’s Jupiter and Trojan Asteroids Exploration Program was born in 2003 and chose solar sail technologies for the mission. IKAROS is thus a demonstrator not only for sail concepts in general but for the specific issues that a Jupiter mission will face. At 5 AU, a sail in Jupiter space receives only 4 percent of the amount of sunlight it would in Earth orbit, drastically reducing the effectiveness of a conventional sail. This is the reason for the solar cell experiment, which would drive an ion engine needed for maneuvering a larger Jupiter-bound sail.
But first things first. The IKAROS demonstrator will need to prove itself in terms of deployment, navigation, attitude control and power generating capabilities, teaching us whether future hybrid designs using ion propulsion are indeed feasible. We’ll begin to learn more on May 18, when IKAROS and AKATSUKI blast off from the Tanegashima Space Center.
[/QUOTE]
Source: [url]http://www.centauri-dreams.org/?p=12309[/url]
Sounds pretty future-tech.
IKAROS = fucking awesome name.
Now we just need to fire a few lasers at the sail and see what happens :science:
Is it just me or are we advancing too quickly :v:?
[QUOTE=Black-Ice;21651181]Is it just me or are we advancing too quickly :v:?[/QUOTE]
Progress can never be too fast.
Dammit, I want my fusion drive by 2020.
[QUOTE=Black-Ice;21651181]Is it just me or are we advancing too quickly :v:?[/QUOTE]
There is no such thing as advancing too quickly. Advance or stay in the stone age, bitch.
A lot of stuff has happend these 100 years, imagine all the stuff 100 years in the future, and we're progressing even faster.
I wish I could see it. :frown:
[QUOTE=Black-Ice;21651181]Is it just me or are we advancing too quickly :v:?[/QUOTE]
Evolve or die.
And fusion by 2020 muafucka!!
Valkyrie rocket!!!
[QUOTE=Mislum;21651262]A lot of stuff has happend these 100 years, imagine all the stuff 100 years in the future, and we're progressing even faster.
I wish I could see it. :frown:[/QUOTE]
According to Moore's Law we'll have computers as powerful as a human brain by 2020, and as powerful as the sum total of human minds by 2040.
Mind uploading anyone? And if that doesn't work, other SCIENCE! will make us live longer :science:
[QUOTE=Mislum;21651262]A lot of stuff has happend these 100 years, imagine all the stuff 100 years in the future, and we're progressing even faster.
I wish I could see it. :frown:[/QUOTE]
At the rate we're progressing, none of us will, or we all will.
Through super duper cybernetic heart surgery!
[QUOTE=Eudoxia;21651298]According to Moore's Law we'll have computers as powerful as a human brain by 2020, and as powerful as the sum total of human minds by 2040.
Mind uploading anyone? And if that doesn't work, other SCIENCE! will make us live longer :science:[/QUOTE]
Thread music!!
[media]http://www.youtube.com/watch?v=vOd-T58qHLA[/media]
[QUOTE=bravehat;21651283]Evolve or die.
And fusion by 2020 muafucka!!
Valkyrie rocket!!![/QUOTE]
Commercial fusion expected after 2050.
[QUOTE=Swebonny;21651478]Commercial fusion expected after 2050.[/QUOTE]
Excuse me, I said SCIENCE!
Artificial Intelligences will do it :downs:
[img]http://images1.wikia.nocookie.net/__cb20080425014649/memoryalpha/en/images/5/5f/Bajoran_lightship_%28aft%29.jpg[/img]
We're going to Cardassia.
That is awesome. I wasn't aware that they were trying to do this!
japan is cool when it's not weird
Alright, the US has asteroids and Mars, Japan gets Venus, and various companies share Earth orbit. This is shaping up to be a pretty nice future.
I saw this back on some NatGeo show a while ago. Pretty interesting concept.
So what's propelling it?
[QUOTE=bravehat;21651350]Thread music!!
[URL="http://www.facepunch.com/#"]View YouTUBE video[/URL]
[URL]http://youtube.com/watch?v=vOd-T58qHLA[/URL]
[/QUOTE]
How the fuck is that music relevant to this thread?
[QUOTE=ASmellyOgre;21654378]Alright, the US has asteroids and Mars, Japan gets Venus, and various companies share Earth orbit. This is shaping up to be a pretty nice future.[/QUOTE]
Don't forget that someone, hopefully Europe will start strip mining Jupiter :v:
[editline]01:10AM[/editline]
[QUOTE=Dr Magnusson;21658733]How the fuck is that music relevant to this thread?[/QUOTE]
...because we are now at the point we have surpassed organic evolution and as such have to take over.
"evolution, it's reversed
Now it's up to me"
and the album name Destroy. Erase. Improve.
[QUOTE=Wakka;21658630]So what's propelling it?[/QUOTE]
Solar wind, baby. :c00lbert:
Excellent!
[QUOTE=Black-Ice;21651181]Is it just me or are we advancing too quickly :v:?[/QUOTE]
Not too quickly, but yes, we're advancing faster than we used to. More technology opens the door to new technologies, which opens the doors to more new technologies, and so on and so forth.
I can't wait until we can reach out into space and really study a far off planet. Not just landing on Pluto or something, I mean actually going to a star and landing on its planets. That would be the greatest thing ever.
[QUOTE=Black-Ice;21651181]Is it just me or are we advancing too quickly :v:?[/QUOTE]
Progression.
Godhood or bust.
[QUOTE=Wakka;21658630]So what's propelling it?[/QUOTE]
The sun has an atmosphere that stretches well beyond the orbits of the planets, and it's filled with particles ejected from the sun. As they stream off at near-lightspeed velocities, anything they hit they'll exert a force on, almost exactly like wind on Earth does. Wind is just a stream of air particles exerting a force on whatever they hit.
The difference is, the part of the Sun's atmosphere we are in is extremely thin, but the wind moves much faster and is made up of charged particles and photons rather than air molecules.
[QUOTE=Black-Ice;21651181]Is it just me or are we advancing too quickly :v:?[/QUOTE]
Fucking damn slow if you ask me. It's like 40 years since we visited the moon and we still haven't actually got a single useful thing from outside our atmosphere so far. (with our own effort)
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