Japan to launch Ikaros May 18

slade_x

http://www.newscientist.com/article/mg20627603.800-maiden-voyage-for-first-true-space-sail.html

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 in space to test deployment, 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 their orientation with the sun regularly to build energy, 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, paving the way for an eventual interplanetary mission. "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.

Other Sources:

http://www.planetary.org/explore/topics/ikaros/


http://inhabitat.com/2010/04/28/japan-gears-up-to-launch-%E2%80%9Cikaros%E2%80%9D-solar-sail-spacecraft/

Solar backpacks and sun-fueled vehicles are impressive, but a solar-powered spacecraft just blows our minds. Japan’s Aerospace Exploration Agency, or JAXA, plans to launch a spacecraft powered by solar sails. The craft, appropriately dubbed Ikaros (Interplanetary Kite-Craft Accelerated by Radiation of the Sun), will make its journey into deep space on May 18th.
Read more: Japan Will Soon Launch Solar-Powered Spacecraft, "Ikaros" | Inhabitat - Green Design Will Save the World


Though solar sail-powered crafts have been used before, Ikaros is the first to attempt to enter deep space. The craft’s 46-foot sails come equipped with solar cells thinner than a human hair. When solar particles hit the cells, they generate power for Ikaros. Mission controllers on the ground will steer the craft by adjusting the sails’ angles, ensuring optimal amounts of radiation are reaching the solar cells.
Ikaros’s pricetag is in the realm of $16 million dollars. And while it’s certainly an ambitious project, there are no guarantees the fuel-free space explorer will work. A rocket will transport Ikaros to space on May 18th, along with Japan’s first satellite to Venus. Stay tuned to see how Ikaros fares when the spacecraft finally gets its day in the sun

Read more: Japan Will Soon Launch Solar-Powered Spacecraft, "Ikaros" | Inhabitat - Green Design Will Save the World

Helix

0.0075mm thick

i cant even imagine how thin that is

ynotdu

JAXA H-IIA carrying AKATSUKI and IKAROS launches at second attempt

May 20th, 2010 by Chris Bergin The Japanese Space Agency JAXA have launched the Venus Climate Orbiter “AKATSUKI” and the Small Solar Power Sail Demonstrator “IKAROS” – along with several university-developed secondary payloads – via their H-IIA Launch Vehicle. Launch from the Tanegashima Space Center (TNSC) on Thursday was originally scrubbed due to unacceptable weather earlier in the week.


Overview:
The H-IIA Launch Vehicle No. 17 is a “H2A202″ model with two solid rocket boosters (SRBs). The fairing design is 4S (4 meters in diameter.) Mitsubishi Heavy Industries, Ltd. is in charge of the launch service of the H-IIA.
The vehicle is set to release its main payload, the Venus Climate Orbiter “AKATSUKI” (AKATSUKI), into its scheduled orbit first, before injecting five other secondary payloads into their respective orbits.
See Also



AKATSUKI (PLANET-C) is the next planetary exploration project for the Martian orbiter NOZOMI. This project’s main purpose is to elucidate the mysteries of the Venusian atmosphere.
“Though often referred to as Earth’s sister planet in terms of size and mass, Venus is actually very different. It is veiled in carbon dioxide, with a high temperature and thick sulphuric-acid clouds,” noted the mission overview.
“Clarification of the causes for this environment will provide us with clues to the understanding of the birth of Earth and of its climate changes. Therefore, Venus is a very important subject for exploration.
The spacecraft has a mass of 500lbs and a life expectancy of 4.5 years, as it travels in an elliptical orbit, 300 to 80,000 km away from Venus’s surface.
This wide variation in distance will enable comprehensive observations of the planet’s meteorological phenomena and of its surface, as well as observations of the atmospheric particles escaping from Venus into space,” added overview materials. “It will also be possible to take close-up photos of Venus, and to observe the storm winds that blow on the Venusian surface, at speeds that reach 100 m a second – 60 times the speed at which Venus rotates.
“This phenomenon remains the biggest mystery of Venus, as it cannot be explained meteorologically. AKATSUKI will employ infrared light to observe and elucidate the mysteries surrounding the atmosphere under the clouds and the conditions on the planet’s surface. In addition, it will confirm the presence of active volcanoes and thunder.”
IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) is a Solar Sail that gathers sunlight as propulsion by means of a large membrane. The IKAROS mission aims at verifying that a spacecraft can fly only by solar powered sail, and that thin film solar cells can generate power.
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.
Also flying as a secondary payload is UNITEC-1 – classed as the world’s first deep space satellite via university development.
Other university payloads also make up the secondary payload manifest, with WASEDA-SAT2 – a QR code image shooting experiment, KSAT – observation experiments of atmospheric vapor distribution for predicting localized heavy rain, and Negai – Space verification of the advanced information processing system using commercial FPGA launching on Monday.
The three satellites, WASEDA-SAT2, KSAT, and Negai have been installed on the JAXA Picosatellite Deployer (J-POD).
The H-IIA F17, which will be launched from Launch Pad 1 of the Yoshinobu Launch Complex, will fly over the Pacific Ocean, then jettison its solid rocket boosters, the payload fairing, and the first stage.
After the first-time combustion of the second stage engine is cut off, three small secondary payloads on the J-POD (WASEDA-SAT2, KSAT, and Negai) will be separated. After the second cutoff of the second stage engine, the AKATSUKI will be injected into the Venus transfer orbit.
The H-IIA will continue its coast flight and separate the IKAROS and UNITEC-1 from the Payload Attach Fitting (PAF900M, the PAF primarily for the main payload, AKATSUKI.)

The rocket launchs and first stage seperation is caught by a camera on the second stage of the Rocket:

KevinVonSpiel

Helix wrote: »

0.0075mm thick

i cant even imagine how thin that is

A typical strand of garden spider silk has a diametre of about 0.003 mm in diameter... or so some some halfway trustworthy looking page states.

ynotdu

Japan's 'space yacht' starts sailing

by Staff Writers
Tokyo (AFP) June 11, 2010
Japan said Friday its kite-shaped "space yacht", designed to float through space using only the power of the sun, successfully started sailing with solar power generation.

ynotdu

nice images i just found of Ikrass's seperation from the payload section of the craft that launched it amongst the other probes{including another one off to Venus} The seperation camera was for the use of engineers to ensure it seperated cleanly,but the camera only had a battery life of fifteen minutes!:)



unfortunatly most of the mini earth orbit satellites onboard seem to have been lost.
after a google translation search it seems the image below the launch vehicle on post #3 is actually the seperation of the Akatasuki Venus orbitor on its seperation {which seperated before Ikrass} in the sequence.information is sketchy due to the need for Japanese sites translation.All i could confirm was that Ikrass and Akatasuki are sending signals,the others seem lost but no absolute confirmation.