### Author Topic: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010  (Read 230729 times)

#### Robson68

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #20 on: 05/02/2010 01:39 PM »
Really excited about Jaxa's work off late, they seem to be very forward thinking.

Just out of interest, is anyone aware of how much power is expected from the sail?

#### Satori

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #21 on: 05/03/2010 10:21 PM »
The poster and leaflet for the launch of AKATSUKI by H-IIA Flight 17 are ready.

We have also prepared wallpapers for a computer and browser dress-up (Firefox.)

Why don't you place a poster in your room, office or classroom, and put wallpaper on your PC desktop to support the launch!

Poster

Flier

AKATSUKI 1/30 scale paper craft

Wallpaper and Dress-up for your browser (You need to register with the JAXA club.)

Dress-up for your browser  (Personas for FireFox)

« Last Edit: 05/03/2010 10:22 PM by Satori »

#### DiggyCoxwell

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #22 on: 05/04/2010 06:15 PM »
Really excited about Jaxa's work off late, they seem to be very forward thinking.

Just out of interest, is anyone aware of how much power is expected from the sail?

If you have a reasonable math skills then try this equation to help yourself get the answer:

a = 2Isr/cm

a = acceleration
I = solar radiation intensity (watts/meter squared) i.e.  1400 W/m^2
s = surface area of sail
r = reflection efficiency
m = mass
c = speed of light
« Last Edit: 05/05/2010 05:24 PM by DiggyCoxwell »

#### Robotbeat

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #23 on: 05/04/2010 06:21 PM »
Really excited about Jaxa's work off late, they seem to be very forward thinking.

Just out of interest, is anyone aware of how much power is expected from the sail?

If you have a reasonable math skills then try this equation to help yourself get the answer:

a = 2Isr/m

a = acceleration
I = solar radiation intensity (watts/meter squared) i.e.  1400 W/m^2
s = surface area of sail
r = reflection efficiency
m = mass
I believe he's talking about electrical power. The sail is going to only be partially covered in solar panels (just a tiny fraction of the total sail's area), it's going to be closer to the Sun than the Earth is (if it's near Venus, that means the 1370W/m^2 is doubled), and will use thin-film solar cells, which are usually only 10% efficient at best.

It will be hard to guess how much power is to be expected, since the insolation is unknown, the surface area of the solar arrays is unknown, and the efficiency of the cells is unknown. Unknown to us, that is. We can make educated guesses at these quantities, but that's about it, unless someone fills us in.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

#### DiggyCoxwell

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #24 on: 05/05/2010 05:32 PM »
Really excited about Jaxa's work off late, they seem to be very forward thinking.

Just out of interest, is anyone aware of how much power is expected from the sail?

If you have a reasonable math skills then try this equation to help yourself get the answer:

a = 2Isr/cm

a = acceleration
I = solar radiation intensity (watts/meter squared) i.e.  1400 W/m^2
s = surface area of sail
r = reflection efficiency
m = mass
c = speed of light
I believe he's talking about electrical power. The sail is going to only be partially covered in solar panels (just a tiny fraction of the total sail's area), it's going to be closer to the Sun than the Earth is (if it's near Venus, that means the 1370W/m^2 is doubled), and will use thin-film solar cells, which are usually only 10% efficient at best.

It will be hard to guess how much power is to be expected, since the insolation is unknown, the surface area of the solar arrays is unknown, and the efficiency of the cells is unknown. Unknown to us, that is. We can make educated guesses at these quantities, but that's about it, unless someone fills us in.

We'll have to get Robson68 to reply to know for sure.

But here's an example of how small the acceleration of a hypothetical solar sail will be:

but if m = 100kg.
I = 2700 W/m^2 (near Venus)
s =100 m^2
r = 0.9

a = (2)2700(0.9)(100) / 3.0 x 10^8 (100)

The acceleration is tiny. It would take you a week to accelerate to a DeltaV of about 10m/s (jogging speed)

#### Robson68

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #25 on: 05/05/2010 05:58 PM »
We'll have to get Robson68 to reply to know for sure.

But here's an example of how small the acceleration of a hypothetical solar sail will be:

but if m = 100kg.
I = 2700 W/m^2 (near Venus)
s =100 m^2
r = 0.9

a = (2)2700(0.9)(100) / 3.0 x 10^8 (100)

The acceleration is tiny. It would take you a week to accelerate to a DeltaV of about 10m/s (jogging speed)

[/quote]

Sorry for the confusion folks, yes acceleration (power, lol). Jogging speed will be enough for me, you cant run before you walk.

I guess the biggest hurdle is will it deploy correctly, lets hope so (fingers crossed). As I mentioned I am really impressed with JAXA. I hope they receieve some good fortune for Hayabusa, staggering achievement really.

#### TheFallen

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #26 on: 05/06/2010 02:06 AM »
Akatsuki and IKAROS are now encapsulated in the H-2A rocket's payload fairing

http://www.jaxa.jp/countdown/f17/topics_e.html

Next up should be the move to the Vehicle Assembly Building so the payload could be mated with the H-2A itself...

11 Days and counting
« Last Edit: 05/06/2010 07:33 AM by TheFallen »

#### TheFallen

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #27 on: 05/07/2010 05:49 AM »
Better-quality pics of the encapsulation

http://www.stp.isas.jaxa.jp/venus/index.html
« Last Edit: 05/07/2010 05:49 AM by TheFallen »

#### TheFallen

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #28 on: 05/08/2010 07:34 AM »
Akatsuki and IKAROS about to be transported to the VAB for mating to H-2A rocket

And here are photos showing the aluminum plates containing 63,248 names and a Planetary Society-provided DVD containing 89,000 names (that were submitted online between December of last year and March 22) being installed onto IKAROS

#### TheFallen

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #29 on: 05/10/2010 07:14 PM »
Good-quality photos of the VAB move and H-2A mating

http://www.stp.isas.jaxa.jp/venus/
« Last Edit: 05/11/2010 12:25 AM by TheFallen »

#### yoichi

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #30 on: 05/11/2010 07:30 AM »
http://www.jaxa.jp/countdown/f17/live/index_e.html

JAXA will broadcast the launch of the Venus Climate Orbiter "AKATSUKI" and the Small Solar Power Sail Demonstrator "IKAROS" by the H-IIA Launch Vehicle No. 17 (H-IIA F17) from the Tanegashima Space Center through the Internet.

From 6:15 a.m. on May 18 (Tue) (about 75 minutes)
*The above schedule is subject to change due to the preparation status and weather conditions.

#### Fuji

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #31 on: 05/12/2010 04:21 AM »
One of the piggy back payloads Negai☆″, developed by Soka university.

#### Spiff

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #32 on: 05/12/2010 12:24 PM »
With Akatsuki, IKAROS, and 4 minisats, no less than 6 spacecraft are put on an interplanetary orbit in a single launch. Is this a record?
I always consider space to be the FIRST frontier.

#### TheFallen

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #33 on: 05/12/2010 08:01 PM »
Actually, I think only 3 of the 6 spacecraft (Akatsuki, IKAROS and UNITEC-1) will be on an interplanetary trajectory.  The 3 minisats (Negai, WASEDA and KSAT) will be released before Akatsuki separates from the upper stage

#### Skyrocket

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #34 on: 05/12/2010 10:34 PM »
Actually, I think only 3 of the 6 spacecraft (Akatsuki, IKAROS and UNITEC-1) will be on an interplanetary trajectory.  The 3 minisats (Negai, WASEDA and KSAT) will be released before Akatsuki separates from the upper stage

That is correct.

#### TheFallen

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #35 on: 05/17/2010 03:21 AM »
Photos showing the H-2A rocket rolling out to the launch pad

http://h2a.mhi.co.jp/mission/results/f17countdown_en.html
« Last Edit: 05/17/2010 06:10 AM by TheFallen »

#### Chris Bergin

##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #36 on: 05/17/2010 10:17 AM »
Moved for live coverage

#### Robotbeat

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #37 on: 05/17/2010 12:50 PM »
How long after launch until Ikaros is deployed?
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

#### Skyrocket

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #38 on: 05/17/2010 01:11 PM »
How long after launch until Ikaros is deployed?

According to the launch plan after 43 minutes and 27 seconds

#### yoichi

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##### Re: LIVE: H-IIA - Akatsuki - Venus Climate Orbiter (PLANET-C) - May 20, 2010
« Reply #39 on: 05/17/2010 03:45 PM »