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MSL Cruise Phase
climber
post Dec 4 2011, 06:52 PM
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QUOTE (elakdawalla @ Dec 4 2011, 05:19 PM) *
Someone else pointed this out to me on the Atlas fairing on the Juno launch -- I think it's an Atlas V thing, and is normal.

Yes, very visible indeed! Must be normal if already hapened before but quite a big device.


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Paolo
post Dec 4 2011, 07:04 PM
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QUOTE (Mars Attack @ Dec 4 2011, 03:57 PM) *
I'm a bit concerned about the reported reset of the MSL computer and safemode due to a star tracker. If this reset had happened in the middle of the upcoming trajectory correction burn, originally schedules a week or so post anomaly, wouldn't this have been disastrous?


beside the fact that missing the first trajectory correction would still leave plenty of time to recover, I think star trackers are not used during burns in order not to mislead them into tracking particles or small debris.


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centsworth_II
post Dec 4 2011, 07:18 PM
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QUOTE (ElkGroveDan @ Dec 4 2011, 10:42 AM) *
There is extra fuel aboard and my understanding is that due to a precise initial burn they have already delayed the first TCM by a month or so...
I saw this too, but it confuses me. As I understand it, the initial burn aimed away from Mars and the 1st TCM was to aim at Mars. How could a precise burn aiming away from Mars affect the timing of the first TCM?


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djellison
post Dec 4 2011, 08:23 PM
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From http://trs-new.jpl.nasa.gov/dspace/handle/2014/41883


QUOTE
The first three TCMs will be jointly optimized to reduce propellant consumption and fulfill
planetary protection requirements, with TCM-3 being the first TCM that is targeted to the final
entry interface point
. TCM-4 and TCM-5 will be used to improve the delivery accuracy at the entry
interface, while TCM-6 is a contingency maneuver opportunity that is not needed to achieve the
required entry interface accuracy, but is available to correct an unplanned late anomaly


My understanding is that TCM 1 was only ever about backing out injection errors...and as they are so small, there's no need for it.
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Guest_Oersted_*
post Dec 4 2011, 08:43 PM
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QUOTE (Hiwayman @ Dec 4 2011, 04:56 PM) *
Sorry for this being posted in the wrong forum, but the launch topic is closed. Did anyone notice the "umbilical" or "hose like" aperture that was still attached to the fairing during launch? It was about 10' - 15' ft from the top of the nose and protruded out about 3-4 feet? Not all cameras caught it, but it was clearly visible on the camera that showed the fairing separation, and another ground based camera. Once the fairing was ejected, the aperture went with it, so it became a mute point, but it sure looked like it was something that should have been left on the ground rather than fly with the vehicle. Did anyone see it? It obviously did not affect the trajectory as it was close to perfect.


At NASASpaceflight.com they have a drinking game going on for every time this question is being asked (ps: better to ask a question about it than just assuming it is an error):...
http://forum.nasaspaceflight.com/index.php?topic=27385.360

QUOTE
QUOTE
QUOTE
???
I was rewatching the curiosity launch and noticed a thin bent tube rocket firing on the side of the fairing right before fairing sep...what is the engineering and aerospace reasoning for this?
LH2 vent fin

Atlas V launch drinking game: when someone asks this question, drink. When someone answers accurately, drink. If Jim is first, drink again.


And as to what it actually is, it is called the LH2 vent fin.

Supremely uncatastrophical explanation here:

"Its a LH2 vent fin — a small pipe. The RL-10 engine, which powers the second stage of the rocket and is enclosed inside the fairing, uses liquid hydrogen as fuel. The LH2 is constantly boiling off producing gas, some of it is used to keep the tank pressurized, the rest must be vented overboard as a gas (it is not ignited) to avoid an explosive situation in the enclosed and confined interstage area while the RL-10 engine is inactive.
After the fairing is jettisoned, the H2 gas is simply vented directly to space causing the flare/glow that you see.
As far as any thrust is concerned resulting from the venting, it is trivial compared to the muscle of the RD-180 engine which powers the first stage — there is a lot of control authority from it."

Engineering drawings here:
http://forum.nasaspaceflight.com/index.php?topic=26327.345
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nprev
post Dec 4 2011, 08:49 PM
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Yeah, it really was a sweet launch...and major kudos again, Doug, for the Eyes On The Solar System sim of the journey.

Best...Christmas...toy...EVER!!! smile.gif


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Mars Attack
post Dec 4 2011, 11:00 PM
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Mr. Doug Djellison, any chance that you could expand your totally awesome sim of the MSL journey to include a realtime EDL phase so all of us can watch a second by second, sweat producing and heart stopping animation all the way to the touchdown. Just a suggestion. Thanks for all you do for this forum.
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djellison
post Dec 4 2011, 11:12 PM
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We hope to - but it's entirely a matter of budgets. I can't promise anything. I will say that it is highly unlikely that such a thing would be driven by realtime telemetry during EDL for a wide range of reasons to long to discuss here. It would likely be driven by a predicted series of events, with key moments triggered manually at JPL.
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climber
post Dec 5 2011, 11:38 AM
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QUOTE (djellison @ Dec 5 2011, 12:12 AM) *
We hope to - but it's entirely a matter of budgets. I can't promise anything. I will say that it is highly unlikely that such a thing would be driven by realtime telemetry during EDL for a wide range of reasons to long to discuss here. It would likely be driven by a predicted series of events, with key moments triggered manually at JPL.

Doug, I didn't tell you yet but yes, your "sim" is one order of magnitude better than the one we had for MER...which was already awesome.
Regarding realtime (I was about to ask actually) we have some experience there with live comments been off set with the images (like "we should be on the ground by now..."), the parachutte deployment been "decided" by the real hardware and then been informed when it actually happened "parachutte deployed xxx second later than calculated). I guess we know this but anyway.
So, if buget's ok...we'll be glad to have us the feeling of been there instead of only eating peanuts.


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punkboi
post Dec 7 2011, 05:57 AM
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You can now view MSL's current position in space on JPL's Solar System Simulator

http://space.jpl.nasa.gov/


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Syrinx
post Dec 7 2011, 07:56 AM
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http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showac=1

MSL and inner planets. Long journey ahead.
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Lucas
post Dec 7 2011, 02:56 PM
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For the impatient among us... wink.gif

http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showac=1

in very good agreement with the "countdown" clock at the MSL site (obviously!)
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pospa
post Dec 14 2011, 02:32 PM
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T +18 days - MSL has about 9% of its cruise done and starts to collect first scientific data - RAD instrument is on.

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punkboi
post Dec 14 2011, 10:27 PM
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Where is Curiosity now? There's now a dedicated page on its mission website

http://mars.jpl.nasa.gov/msl/mission/whereistherovernow/


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Guest_Lunik9_*
post Dec 26 2011, 09:28 AM
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New sunspot 1387 erupted during the late hours of Christmas Day, producing an M4-class flare and hurling a Coronal Mass Ejection - CME toward Earth and Mars.

The CME is expected to deliver a glancing blow to Earth's magnetic field on Dec. 28th at 1200 UT and a direct hit to the planet Mars on Dec. 30th at 1800 UT.
Using onboard radiation sensors, NASA's Curiosity rover might be able to sense the CME when it passes the rover's spacecraft en route to Mars. unsure.gif

Here on Earth, NOAA forecasters estimate a 30-to-40% chance of geomagnetic storms on Dec. 28th when the CME and an incoming solar wind stream (unrelated to the CME) could arrive in quick succession. High-latitude sky watchers should be alert for auroras on Wednesday night.

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