Venus Express |
Venus Express |
Apr 28 2010, 03:50 PM
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#371
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Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
I guess you would want to do it, for operational purposes, at a nice fraction of the 24 hours.... 18, 12, 6 hrs perhaps?
I found myself trying to explain these aero-passes to someone with both arms stuck out like a windmill the other day |
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Apr 29 2010, 02:27 PM
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#372
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Member Group: Members Posts: 247 Joined: 17-February 07 From: ESAC, cerca Madrid, Spain. Member No.: 1743 |
Exactly right. The desired orbit period is based as much on operations (cost for staffing outside of normal working hours) as it is on science.
And if you are sticking out your arms to explain this, then you're doing it exactly right. We look goofy in our conference room when we're talking about it, three or four people twisting their arms around. -------------------- --
cndwrld@yahoo.com |
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Apr 29 2010, 04:29 PM
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#373
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
I would love to see a photo of that.
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Apr 30 2010, 11:50 AM
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#374
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Member Group: Members Posts: 247 Joined: 17-February 07 From: ESAC, cerca Madrid, Spain. Member No.: 1743 |
I don't have a photo of that. So here's a photo of my radar hat, when I worked on Magellan. Careful observers will note the attention to detail, with the radiometer cone on the left side, and the altimeter antenna on the right ear.
I hope they've renovated building 230 since then. -------------------- --
cndwrld@yahoo.com |
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Apr 30 2010, 01:21 PM
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#375
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Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
Impressive. Looks like your focused brain energy blew out the fluorescent light above you!
-------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
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Apr 30 2010, 01:54 PM
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#376
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Apr 30 2010, 02:36 PM
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#377
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Junior Member Group: Members Posts: 46 Joined: 6-January 10 From: Toronto, ON Member No.: 5163 |
I don't have a photo of that. So here's a photo of my radar hat, when I worked on Magellan. Careful observers will note the attention to detail, with the radiometer cone on the left side, and the altimeter antenna on the right ear. Great attention to detail. -------------------- Twitter: @tanyaofmars
Web: http://www.tanyaofmars.com |
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Apr 30 2010, 03:20 PM
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#378
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Senior Member Group: Members Posts: 1582 Joined: 14-October 05 From: Vermont Member No.: 530 |
From the bygone era when engineers wore ties.
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Apr 30 2010, 03:28 PM
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#379
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Member Group: Members Posts: 593 Joined: 20-April 05 Member No.: 279 |
It's a good thing you didn't try it outside in the rain.
Andy |
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Nov 23 2010, 02:51 PM
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#380
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Member Group: Members Posts: 247 Joined: 17-February 07 From: ESAC, cerca Madrid, Spain. Member No.: 1743 |
Venus Express (and all the other ESA operating missions) has been extended until 2014. Excellent news for people working on the mission.
More information is in the ESA press release at: http://www.esa.int/esaCP/SEMR1MIRPGG_index_0.html -------------------- --
cndwrld@yahoo.com |
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Nov 23 2010, 05:29 PM
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#381
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Director of Galilean Photography Group: Members Posts: 896 Joined: 15-July 04 From: Austin, TX Member No.: 93 |
You had mentioned earlier upthread about using drag to lower the orbit once approved for an extended mission. Any details yet on that?
-------------------- 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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Nov 24 2010, 08:52 AM
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#382
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Member Group: Members Posts: 247 Joined: 17-February 07 From: ESAC, cerca Madrid, Spain. Member No.: 1743 |
Regarding the orbit lowering, the current aerodrag campaigns are useful science and a good precursor for it. But the spacecraft wasn't designed for the dynamic pressures of high levels of drag. And using low levels of drag, within everyone's comfort zone, means that the orbit lowering would take a long, long, long time. During which not much science would get done. The drag is at pericenter, which is also where most of the science data is taken. And the attitude for drag lowering wouldn't allow pointing the instruments where needed.
So my current impression is that things are still being discussed, but any serious orbit lowering with drag passes would fit better at the very end of mission. Surprises then don't forfeit a lot of science. So 2014 or later, depending when our fuel and money run out. -------------------- --
cndwrld@yahoo.com |
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Oct 10 2011, 11:40 AM
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#383
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Member Group: Members Posts: 247 Joined: 17-February 07 From: ESAC, cerca Madrid, Spain. Member No.: 1743 |
To put this issue to bed in the forum, Venus Express will not be doing aerobraking before end of mission.
ESA held a full review board to look at the question of performing aerobraking with Venus Express. After a lot of good work, it was decided that it just wasn't worth it. At least, right now. The original idea was to use aerobraking to drop the orbit from a 24 hour period to an 18 hour period, making use of the regular periods when the pericenter altitude dropped quite low. Instead of raising the pericenter height as is done now, well before hitting atmosphere, could we use the periods of low pericenter height to use atmospheric drag to slow the spacecraft at pericenter, which would drop the apocenter, and reduce the orbit period to a level where the science would be better. Turns out that the allowed dynamic pressure on the spacecraft would not be enough to get the orbit down to 18 hours, or even close. Therefore, there was no scientific justification for the added expense and added risk. However, the idea of doing hard aerobraking after the end of the science mission is still very much under consideration. Just as the dying Magellan spacecraft was used many years ago, Venus Express may end its active life by becoming an aerobraking test bed. -------------------- --
cndwrld@yahoo.com |
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Jan 10 2012, 11:43 AM
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#384
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Member Group: Members Posts: 247 Joined: 17-February 07 From: ESAC, cerca Madrid, Spain. Member No.: 1743 |
I am very happy to mention that a special issue of Icarus will be coming out in February that is dedicated to advances in Venus science, primarily due to Venus Express data. This issue is largely based around presentations for meetings in 2010.
The 40 papers that make up the issue can already be viewed on-line. The contents can be browsed at http://www.sciencedirect.com/science/journal/00191035/217/2 -------------------- --
cndwrld@yahoo.com |
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Jan 10 2012, 08:56 PM
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#385
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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 |
too bad they are not free to access
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