Akatsuki & minisats (H-2A launched on May 20, 2010)

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Re: H-2A - Akatsuki (launched May 20, 2010)

http://www.planetary.org : Lou Friedman in Japan: Taking things slowly with IKAROS sail deployment
Jun. 5, 2010 | 10:30 PDT | 17:30 UTC

by Lou Friedman

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. I am disappointed, of course -- my own schedule is such that I must return to the U.S. on Sunday and thus I will miss the final deployment.

IKAROS operations center, June 4, 2010
In IKAROS operations at the Japanese Space Exploration Center on June 4, 2010, the team makes a decision to delay the full deployment of the sails. Credit: The Planetary Society


http://www.planetary.org : IKAROS sail deployment delayed until at least Tuesday
Jun. 6, 2010 | 15:08 PDT | 22:08 UTC

By Emily Lakdawalla

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, (posted here in Japanese), 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.

Lou explained in the coda to yesterday's update: "Most, but not all, of the data from the first stage appears to indicate that the deployment is going as planned. About 4-5 meters of the edges have been deployed. But there is some uncertainty and ambiguity in some of the deployment measurements. The team wants to run more simulations and analysis before initiating the final stage. The uncertainty relates to whether the whole configuration is deploying symmetrically and stably. They will run some more simulations and expect to schedule their final stage of deployment for Tuesday night Japanese time."

Apart from these concerns, however, the spacecraft's health remains excellent.

Google translated above mentioned link to the official JAXA statement :

06/0613: 13:15: small solar powered sail demonstration unit "IKAROS (Icarus)" Change of date re-sail deployment


www.planetary.org : Progress -- with pictures! -- on IKAROS' sail deployment
Jun. 9, 2010 | 07:19 PDT | 14:19 UTC

By Emily Lakdawalla

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:


IKAROS first stage deployment halfway complete (Cam 1)
A view from one of the four sail monitoring cameras on IKAROS on June 9, 2010 shows the folded sail being pulled outward from the spacecraft as it should be. Credit: JAXA / JSPEC


Small Solar Power Sail Demonstrator 'IKAROS'
Successful Solar Sail Deployment

June 11, 2010 (JST)

Japan Aerospace Exploration Agency (JAXA)

The Japan Aerospace Exploration Agency (JAXA) began to deploy the solar sail of the Small Solar Power Sail Demonstrator "IKAROS" on June 3 (Japan Standard Time). On June 10 (JST,) we have confirmed that it was successfully expanded and was generating power through its thin film solar cells at about 770 km from the Earth.


Congratulations JAXA.


Nice post, thank you :cool:

and i join you in congratulations, but let's see how it works :p ;)


http://www.planetary.org : IKAROS' deployable camera captures perfect sail photos and animation!
Jun. 15, 2010 | 18:50 PDT | Jun. 16 01:50 UTC

By Emily Lakdawalla

EDIT 10:35 PM: Animation added at the bottom of this post.

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:

IKAROS spacecraft from DCAM2
DCAM2 is a tiny camera deployed by IKAROS to photograph its sail after deployment; it captured this view after sail deployment was complete, transmitting the images wirelessly to the spacecraft. Credit: JAXA

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

IKAROS sail from DCAM2
One of the deployable cameras on IKAROS shows the IKAROS solar sail fully deployed. Credit: JAXA

( camera description and images )


DCAM2's view of IKAROS
A 32-frame animation from the deployable camera DCAM2 on IKAROS. The camera rotated as it receded, producing the apparent spin of the sail. Credit: JAXA




Pics from #IKAROS 2nd deployable camera released: http://is.gd/d7Dxw also show test of thin-film LCD sail patches

( Google translated )
June 28, 2010 [updated]
One camera captured images to release additional separation

Camera 1 was conducted on 19 separate 6 (DCAM1) add an image captured by the release experiment.

DCAM2 DCAM1 the camera because it was slower than the speed of separation, IKAROS able to get of photos from too close to.

Solar panels on the following image (SAP) fell on the edge of DCAM1 you can see the shadow of the camera.

-Barrel animation GIF images captured in succession will be available.
Like the image below IKAROS many succeeded in imaging and body image sail further!

In addition, DCAM1 device that controls the position varying surface reflectance properties of the test sail on "liquid crystal device," works made at the same time check. DCAM1 can see that the image moves from the liquid crystal device. Liquid crystal technology is being developed by JAXA in its own right, of course, will be tested first in space!
Conducting state (ON state) and specular sunlight, the energized state (OFF state) in order to diffuse, OFF state makes white people.
The attitude control experiments of the planned future, in synchronization with spin sail the ON / OFF Controls the switching experiment, the camera separation of this is to identify images, ON and device status OFF device status are taken alternately energized to line. Even in light of the utter, A and A, B, B, C and C, respectively compared, ON · OFF state is easy to understand.

Translation sux, but images are nice :)


http://www.jaxa.jp : Small Solar Power Sail Demonstrator "IKAROS" Successful Image Shooting by the Second Separation Camera
June 28, 2010 (JST)

Japan Aerospace Exploration Agency (JAXA)

The Japan Aerospace Exploration Agency (JAXA) took images of the deployed solar sail of the Small Solar Power Sail Demonstrator "IKAROS" by the second separation camera*1 on June 19, 2010 (Japan Standard Time, JST) and transmitted and confirmed the data over the next few days. During our image data confirmation process, we also made sure that the liquid crystal device*2, which is the engineering mission equipment, was also working properly.
The IKAROS was launched on May 21, 2010 (JST), from the Tanegashima Space Center.
We will continue to measure the power generation status of the thin film solar cells attached to the sail, and will verify acceleration by photon pressure and orbit control by their acceleration.?Through these activities, we will ultimately aim at acquiring navigation technology through the solar sail.

*1: The separation camera is in a cylindrical shape of about 6 cm both in diameter and height. It is detached from the satellite using a spring to take images and send them to the satellite through radio waves. The camera will never return to the satellite to be attached again. The camera detached this time was the separation camera 1 (DCAM1) and the camera separated last time was the separation camera 2 (DCAM2.) For image shooting by the cameras, please refer to the computer graphics on the following site.

*2 A liquid crystal device is a thin film device whose reflection characteristics on the surface change by turning on and off the power. It is experimental equipment to control the sail attitude only by solar light pressure without using fuel.

Image 2 taken by DCAM2
(Liquid crystal device operation status*3)

*3 When the power is on, sunlight makes specular reflections, and, when the power is off, it makes diffuse reflections. Consequently, when it is off, images become whiter. During the scheduled attitude control experiment, we will turn the power on and off in sync with the sail spin, but in the separation camera experiment this time, we switched the power on and off alternately to clearly see the difference. Thanks to the light conditions, you can easily see the difference between each of the solid blue circles A, B, and C, versus red dot circles A, B, and C.

Conceptual Diagram of Liquid Crystal Device Experiment

IKAROS Membrane


JAXA confirmation of acceleration by photon pressure :


Google translated :
Small solar powered sail demonstration unit "IKAROS (Icarus)" Confirmation of photon acceleration

July 9, 2010

Japan Aerospace Exploration Agency

Japan Aerospace Exploration Agency (JAXA) is May 21, 2010 (Japan Standard Time, and so on) was launched from Tanegashima Space Center in IKAROS in the application of acceleration, precise orbit determination performed by the photon after sail deployment (※ 1) confirmed it will be notified.
Thrust of the solar light pressure 1.12mN (2 ※), and the expected value of the street.
IKAROS which, in the interplanetary cruise, the demonstration unit became the largest exercise of photon acceleration.

(1 ※) and photon acceleration, the pressure of photons of the sun (solar light pressure) to be accelerated by the body.
(2 ※) N (Newton) represents the force producing the acceleration of one meter per second to a mass of 1 kilogram (representing the spacecraft propulsion) units. 1.12mN is equal to gravity on Earth 0.114g of such a body.

Doppler measurements at the secondary sail deployment operations in Figure 1

Figure 1 shows the development of secondary production at Sail September 6, IKAROS radial velocity (3 ※) measured values (Doppler measurement) and calculated (without photon acceleration) and we represent the difference.
Since we have calculated taking into account photon acceleration, the absence of photon acceleration graph becomes horizontal, when there is a photon acceleration tilts. Conducted a second deployment 9:36 (Universal Time), about an hour of missing data, we have deployed for the operation, you can see clearly that the change in slope before and after.

Figure 2 Estimated Seiruparameta IKAROS orbit determination based on the results

Sail-run cross-section ratio in the spin-orbit plane projected area / ground specular reflectivity sail-area manufacturing specular light / solar light incident

planetary.org : JAXA confirms acceleration of IKAROS solar sail by photon pressure
Jul. 9, 2010 | 12:15 PDT | 19:15 UTC

by Louis Friedman

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.

http://www.spaceflightnow.com : Japanese craft goes solar sailing in deep space
Posted: July 9, 2010


An innovative solar sail launched in May has been accelerated by sunlight, successfully demonstrating a new fuel-saving propulsion technique in interplanetary space, the Japanese space agency announced Friday.

An analysis of radar tracking data showed the Ikaros spacecraft began a gradual acceleration as it unfurled its kite-like solar sail June 9, the Japan Aerospace Exploration Agency said in a statement Friday.

"The small solar power sail demonstrator Ikaros, which successfully deployed its solar sail, was confirmed to accelerate by solar sail receiving solar pressure," JAXA posted on its website. "This proved that the Ikaros has generated the biggest acceleration through photon during interplanetary flight in history."


http://www.planetary.org : Congratulations to the IKAROS team for their "8th Web Creation Award"
Oct. 13, 2010 | 15:07 PDT | 22:07 UTC

By Emily Lakdawalla

his news is a little old but worth mentioning: On September 9, the Japanese solar sail mission, IKAROS, won a Web award in Japan for their work to publicize the mission via Twitter. The Google translation of the particular award they won is the "Anxious people Web award" but I was told that a more accurate translation is "Remarkable" rather than "Anxious."

8th Web Creation Award
"Ikaroskun," the Twitter persona of the Japanese solar sail mission IKAROS, was awarded this medal in the 8th Web Creation Awards. Credit: Morita_photo (http://twitpic.com/photos/morita_photo)


www.jaxa.jp : Date of AKATSUKI injection to Venus orbit
November 18, 2010 Updated


JAXA decided to emit jets from the orbital maneuvering engine (OME) of the AKATSUKI at 8:49:00 a.m. on Dec. 7 (Japan Standard Time, all the following dates and time are in JST) to inject the orbiter into the Venus orbit. Under the current schedule, the OME jet emission will be completed at 9:01:00 a.m. on the same day, and the Venus orbit will be determined around 9:00 p.m. also on the same day after some attitude control maneuvers including the Earth pointing maneuver of the Z axis.
The AKATSUKI will study the Venus atmosphere for about two years after being injected into the Venus orbit.


www.jpl.nasa.gov : Scientists Chosen to Help on Venus Climate Orbiter
November 19, 2010

NASA has established a Venus Climate Orbiter Participating Scientist Program to complement scientific return of the Japan Aerospace Exploration Agency (JAXA)-led Venus Climate Orbiter, or "Akatsuki" mission. The Participating Scientist Program will fund two scientists in residence to live in Japan and five Participating Scientists to conduct joint research with the Venus Climate Orbiter science team.
Based on peer-reviewed proposals submitted to NASA, NASA and JAXA are pleased to announce the following joint selections of U.S. Participating Scientists:
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