Akatsuki Venus Climate Orbiter |
Akatsuki Venus Climate Orbiter |
Mar 13 2010, 11:29 AM
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#601
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
I thought it was time to start a separate thread on this mission, launching soon
some good medium-resolution images of the spacecraft are available on JAXA digital archives http://jda.jaxa.jp/jda/p3_e.php?time=N&...mp;mission=4066 |
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May 5 2016, 05:26 PM
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#602
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Director of Galilean Photography Group: Members Posts: 896 Joined: 15-July 04 From: Austin, TX Member No.: 93 |
Like in Akatsuki, sometimes the rockets for the attitude thrusters and the main thrusters use the same fuel system, with the attitude thrusters using the fuel as a monopropellant (one-part) (like in the Martian, where Watney drips the fuel on a catalyst) but the main thrusters using the fuel together with an oxidizer as a bipropellant (two-part), typically hypergolic (self-igniting when mixed). When used as a bipropellant, the reaction is much more energetic, and provides greater thrust. When used as a monopropellant, the reaction is less energetic, but only requires pumping one liquid. The simplicity of only having to pump one fluid matters when you have multiple attitude thrusters around a probe. The thrust bipropellant provides is worth the additional weight and complexity if the delta-V required is high enough, like orbit insertion.
-------------------- Space Enthusiast Richard Hendricks
-- "The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke Mother Nature is the final inspector of all quality. |
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May 5 2016, 10:23 PM
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#603
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Member Group: Members Posts: 817 Joined: 17-April 10 From: Kamakura, Japan Member No.: 5323 |
Page-6
Schedule on 6 December 2015 6/Dec daytime attitude change 7/Dec 04:30 Usuda station visible starts 08:22 Akatsuki enter Venusian shadow 08:51- fire attitude control engines, data acquisition/confirmation 11:30 12:00 explanation to the presss re firing afternoon transfer to Camberra station afternoon attitude change Note: At time of press conference the only known fact will be the result of engine firing. Whether or not the intended orbit insertion is a success can only be confirmed during 7-9 December. About that confirmation a seperate press conference is scheduled for 18:00 on 9 December. P |
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