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== Overview == | == Overview == | ||
− | The Lunar Reconnaissance Orbiter (LRO) is the first mission in NASA's planned return to the moon. LRO | + | The Lunar Reconnaissance Orbiter (LRO) is the first mission in NASA's planned return to the moon. LRO will launch 2nd March, 2009, with the objectives to finding safe landing sites, locate potential resources, characterize the radiation environment and test new technology. |
The return to the moon will enable the pursuit of scientific activities that address our fundamental questions about the history of Earth, the solar system and the universe -- and about our place in them. It will allow us to test technologies, systems, flight operation and exploration techniques to reduce the risk and increase the productivity of future missions to Mars and beyond. It will also expand Earth's economic sphere to conduct lunar activities with benefits to life on our home planet. | The return to the moon will enable the pursuit of scientific activities that address our fundamental questions about the history of Earth, the solar system and the universe -- and about our place in them. It will allow us to test technologies, systems, flight operation and exploration techniques to reduce the risk and increase the productivity of future missions to Mars and beyond. It will also expand Earth's economic sphere to conduct lunar activities with benefits to life on our home planet. | ||
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Earth’s closest neighbor is holding a secret. In 1999, hints of that secret were revealed in the form of concentrated hydrogen signatures detected in permanently shadowed craters at the lunar poles by NASA’s Lunar Prospector. These readings may be an indication of lunar water and could have far-reaching implications as humans expand exploration past low-Earth orbit. The Lunar CRater Observing and Sensing Satellite (LCROSS) mission is seeking a definitive answer. | Earth’s closest neighbor is holding a secret. In 1999, hints of that secret were revealed in the form of concentrated hydrogen signatures detected in permanently shadowed craters at the lunar poles by NASA’s Lunar Prospector. These readings may be an indication of lunar water and could have far-reaching implications as humans expand exploration past low-Earth orbit. The Lunar CRater Observing and Sensing Satellite (LCROSS) mission is seeking a definitive answer. | ||
− | === | + | === required add-ons === |
− | * [http:// | + | * [http://orbithangar.com/searchid.php?ID=2601 Atlas V heavy] V2 by Kev33 |
− | * [http:// | + | * [http://koti.mbnet.fi/jarmonik/Orbiter.html IMFD 5.1m] |
− | === | + | === optional add-ons === |
* [http://orbithangar.com/searchid.php?ID=3165 Attitude MFD] | * [http://orbithangar.com/searchid.php?ID=3165 Attitude MFD] | ||
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== Spacecraft Specifications == | == Spacecraft Specifications == | ||
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== Spacecraft Controls == | == Spacecraft Controls == | ||
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== Procedures == | == Procedures == | ||
Accuracy of burns in this mission is '''CRITICAL'''. | Accuracy of burns in this mission is '''CRITICAL'''. | ||
+ | During this mission, especially after the TLI burn, we will be using the tools TransX or IMFD to get the '''DIRECTION''' of our burns, and using IMFD map to monitor in real time the '''MAGNITUDE''' of the DeltaV we are imparting. For this mission, usually the AUTOBURN button is '''NOT''' your friend. | ||
+ | The precession of the Moon's axis is not modelled in Orbiter. | ||
+ | You may wish to edit your config/Moon.cfg file and change the LAN and SidRotOffset lines to | ||
+ | SidRotOffset = -4.52701 | ||
+ | LAN = 5.2775 | ||
+ | This will ensure a more accurate orientation of the Moon for the LRO | ||
+ | simulation. | ||
=== Launch === | === Launch === | ||
− | Fire up the '''01 - AV020 LRO launch | + | Fire up the '''01 - AV020 LRO launch''' scenario in the LRO scenarios folder |
This is a night launch so visibility is poor until after the TLI burn. | This is a night launch so visibility is poor until after the TLI burn. | ||
− | The scenario starts at UTC | + | The scenario starts at UTC 03/02/2009 05:25:00. |
− | Launch time is UTC | + | Launch time is UTC 05:26:27. |
The default camera view is Ground Observer. You have just over a minute to set up the camera to your personal preference. | The default camera view is Ground Observer. You have just over a minute to set up the camera to your personal preference. | ||
− | At UTC | + | At UTC 05:26:17 press the '''p''' key to start the launch countdown and |
1st stage auto-pilot. | 1st stage auto-pilot. | ||
Line 165: | Line 81: | ||
Click '''Set''' | Click '''Set''' | ||
Click '''Tgt''' and enter '''Moon''' | Click '''Tgt''' and enter '''Moon''' | ||
− | Click '''Nxt''' | + | Click '''Nxt''' 5 times so that ''Realtime'' is highlighted. |
− | + | Click '''+''' to change it to ''Off-Axis''. | |
− | + | Click '''Nxt''' until the ''Tej'' parameter is highlighbted. | |
− | Click '''+''' to change it to ''Off-Axis'' | + | Click '''+''' or '''-''' repeately until the ''dV'' parameter reaches a minimum. This should be about ''3.59k'' |
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− | Click ''' | ||
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− | Click '''+''' or '''-''' | ||
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Select IMFD in the right MFD also. | Select IMFD in the right MFD also. | ||
Click '''MNU''', then '''PG'''. Enter '''0''' for the ''MFD ID''. Click '''Map'''. | Click '''MNU''', then '''PG'''. Enter '''0''' for the ''MFD ID''. Click '''Map'''. | ||
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Click '''MOD''' 3 times, then click '''Nxt''' so that ''Accuracy'' is highlighted. | Click '''MOD''' 3 times, then click '''Nxt''' so that ''Accuracy'' is highlighted. | ||
Click '''-''' twice so that ''accuracy'' is set to ''Max''. | Click '''-''' twice so that ''accuracy'' is set to ''Max''. | ||
− | Click '''MOD''' | + | Click '''MOD''' to return to the map display. |
− | Wait until the ''TEj'' parameter in the left display is ''1k'' | + | Wait until the ''TEj'' parameter in the left display is ''1k'' |
In the left MFD, Click '''MOD''', and ''Offset Disabled'' should be highlighted. | In the left MFD, Click '''MOD''', and ''Offset Disabled'' should be highlighted. | ||
Click '''+''' twice and ''Vel. Frame'' should be displayed. Click '''Nxt''' until ''Lon'' is highlighted. | Click '''+''' twice and ''Vel. Frame'' should be displayed. Click '''Nxt''' until ''Lon'' is highlighted. | ||
− | Click '''Set''' and enter ''' | + | Click '''Set''' and enter '''100'''. Click '''Nxt''' and ''Lat'' should be highlighted. |
− | Click '''Set''' and enter ''' | + | Click '''Set''' and enter '''35.9'''. Click '''Nxt''', then '''Set''', and enter '''7.28M''' for ''Rad''. |
− | Adjust the ''Rad'' and ''Lat'' parameters to get the ''PeA'' and '' | + | Adjust the ''Rad'' and ''Lat'' parameters to get the ''PeA'' and ''Rin'' parameters in the right MFD as close |
− | as possible to '' | + | as possible to ''216k'' and ''90'' degrees. Repeat as necessary. Click '''Pg''', then '''BV''', then '''AB'''. |
Disengage the ''Prograde'' autopilot. | Disengage the ''Prograde'' autopilot. | ||
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=== Lunar targeting/LCROSS === | === Lunar targeting/LCROSS === | ||
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When you reach 32M altitude above the Earth, the Centaur engine will automatically purge of all fuel and control switches over to the LCROSS propulsion system. You may initate the engine purge manually by pressing '''B'''. It is '''critical''' that you get your targeting done for LCROSS before this time, as once that happens, your deltaV budget is severely limited. | When you reach 32M altitude above the Earth, the Centaur engine will automatically purge of all fuel and control switches over to the LCROSS propulsion system. You may initate the engine purge manually by pressing '''B'''. It is '''critical''' that you get your targeting done for LCROSS before this time, as once that happens, your deltaV budget is severely limited. | ||
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Click '''+''', then '''Nxt''' four times until ''Delta Velocity'' is highlighted. | Click '''+''', then '''Nxt''' four times until ''Delta Velocity'' is highlighted. | ||
Click '''Set'''. Click '''TGT''', and type '''Moon'''. | Click '''Set'''. Click '''TGT''', and type '''Moon'''. | ||
− | Click '''Nxt''' | + | Click '''Nxt''' four times until ''dVf'' is highlighted. |
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Click '''Set''', and enter '''0'''. | Click '''Set''', and enter '''0'''. | ||
in the Right MFD, click '''Plan''' so the green course line turns blue. | in the Right MFD, click '''Plan''' so the green course line turns blue. | ||
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− | Click the ''' | + | Click on the '''--''' button until the target is ''Moon'' |
− | + | Click '''VW''' once so the View is ''Manoevre'' | |
− | Click | ||
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− | + | Select TransX also in the Left MFD. | |
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− | + | In the Left MFD click '''FWD''', then '''VW''', so that the view is 'Encounter' | |
− | Click | + | In the Right MFD click '''++''' so Manoevre mode is ''On'' |
− | + | Click '''VAR''' 5 times so that ''Ch. Plane vel.'' is displayed | |
+ | Click '''ADJ''' so that ''Medium'' adjustment mode is entered. | ||
+ | Click '''--''' until the ''Min Alt.'' parameter in the Left MFD is over 216k | ||
− | + | Our goal here is to end up with an ''Inclination'' parameter in the left MFD as close as possible to 90 degrees, and the ''Min Alt.'' parameter as close as possible to 216k. | |
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− | + | In the Right MFD click '''VAR''' 3 times so that ''Prograde Vel'' is selected. | |
− | + | Click on '''ADJ''' 3 times for ''Super'' adjustment mode. | |
− | on | + | Click on '''++''' or '''--''' until ''Min Alt.'' is close to 216k and ''Inclination'' is close to 90 degrees in the Left MFD. |
− | + | Keep repeating these adjustments, using finer adjustment modes until you get as close as possible to the required parameters. Work quickly though, as the orbital debris is getting closer and we still have to target the LCROSS spacecraft. | |
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− | + | [[Image:Txlrotgt.jpg]] LRO Transx Encounter view | |
− | + | In the Right MFD click '''VW''' to get ''Target view'' | |
− | + | Use rotation mode to get the cross as close as possible to the center of the target. | |
− | + | '''Do NOT make the burn yet''' | |
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− | + | Use the planetarium view '''F9''' key to make sure you are pointed in a generally northerly direction (towards Polaris + or - 30 degrees or so) | |
− | + | If you are pointed in a southerly direction, the transx targeting will have to be re-done using '''++''' Ch. plane vel. instead of '''--''' | |
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+ | Set the Left MFD to IMFD. | ||
+ | Press the '''MNU''' button and select Map mode. | ||
+ | Press the '''TGT''' button and enter '''Moon''' | ||
+ | Press the '''Sel''' button until ''Ref Moon'' is displayed. | ||
+ | Watch the PeA parameter as you make a low dV burn with the Centaur engine '''Ctrl-numpad +''' When the Pea gets to +216k, STOP the burn with the | ||
+ | '''numpad *''' key. As it gets close you may with to use translation mode and the '''numpad-6''' key. There is no reverse translation. Don't overshoot by very much, if at all. Some dV will be added by LRO jettison which we will have to correct later. | ||
+ | [[Image:Lromaptgt.jpg]] IMFD map display after burn | ||
+ | Press the '''j''' key to jettison LRO. | ||
+ | On the Right MFD click '''VW''' twice to get back to ''Maneuver view'' | ||
+ | Click '''VAR''' until Maneuver Mode is displayed. | ||
+ | Click '''++''' to turn Maneuver mode ''Off'' | ||
+ | === Lunar targeting/LCROSS === | ||
+ | * Swingby of moon is passive (no thrusting) | ||
+ | * 81 days in post-swingby cruise orbit | ||
+ | * Current baseline is 3-month trajectory with south pole impact | ||
+ | * Two revolutions in high ecliptic inclination (~50 deg), 40-day period Earth orbit | ||
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+ | After the LRO is jettisoned, swing the Centaur around 180 degrees. Use the finely graduated scale on the hud, or Attitude MFD | ||
+ | to do this. When the Centaur is pointed 180 degrees from where it was when you made the LRO targeting burn, make another small burn, again watching | ||
+ | IMFD map so that the final PeA is about 2M on the opposite side of the moon. Select IMFD on the right MFD | ||
+ | Click '''MNU''', then '''Course'''. Click '''NXT''' 4 times so that ''Delta Velocity'' is highlighted. Click '''Set'''. | ||
+ | Click on '''TGT''' and enter '''Moon''' as the target. Click '''Nxt''' 5 times so that ''dVf'' is highlighted. | ||
+ | Click '''Set''' and enter '''0'''. | ||
+ | In the Left MFD click '''PG''' then '''Plan'''. The green line of our orbit should turn blue. | ||
+ | In the Right MFD click '''+''' repeatedly. The ''RIn'' parameter in the Left MFD should increase. | ||
+ | If not, Click '''-''' until it does. | ||
+ | Also watch the ''PeA'' parameter. Do not let it go negative. | ||
+ | When ''PeA'' gets too low, click '''Nxt''' on the Right MFD so that ''dVp'' is highlighted. | ||
+ | Click '''-''' until ''PeA'' in the Left MFD is back to around 2M. Setting '''Adj''' to 10x may be necessary, | ||
+ | but return it to 1x when finished. | ||
+ | Keep repeating these adjustments until ''Rin'' is close to 90 degrees and ''PeA'' is close to 2M. This is just a ball bark "rough in" to make our transx tageting easier. The numbers do not have to be exact. '''Work quickly''' though. Liberal use of the '''Pause''' function is encouraged. | ||
+ | In the Right MFD, click '''Pg''', then '''BV'''. | ||
+ | Use rotation mode to align the cross in the center of the target and then select translation mode and use '''CTRL-numpad +''' to burn until ''BT'' is close to ''0''. AutoBurn is not recommended. | ||
+ | Once this is done, in the Left MFD click '''PG''', then '''Plan''', so the orbit line turns green again. | ||
+ | Select Transx in both MFD's.Select moon as the target in the right MFD, as in the LRO targeting. | ||
+ | Click the '''FWD''' button for stage 2, make sure the view is ''Setup'' and select the target as ''Escape''. | ||
+ | Click the '''FWD''' button again for stage 3, and select the target as ''Moon'' | ||
+ | Click the '''VW''' button for Sling Direct view. | ||
+ | On the Left MFD, click the '''FWD''' button for stage 2, if not already there. | ||
+ | Click the '''VW''' button for slingshot view, if not already there. | ||
+ | There will be a green line extending from the center of the moon to hopefully past the edge. This is an edge-on view of our current approach to the moon. | ||
+ | We need to fine tune this approach to give us a lunar gravity assist which will result in a highly inclined orbit around the earth with a period of 40 days | ||
+ | On the Right MFD, click the '''VAR''' button twice to bring up the ''Inc. angle'' parameter | ||
+ | Click on '''--''' several times until the dotted yellow orbit is about the same size as the solid green line. | ||
+ | It does not have to be superimposed in the same place, but of a similar diameter. | ||
+ | On the Left MFD the dotted yellow line should be on the same side (more or less) of the moon as the green line. If it is on the opposite side, | ||
+ | click on the '''++''' button until it is on the same side. | ||
+ | On the Right MFD, click on '''VAR''' four times until the ''outward angle'' parameter is shown. | ||
+ | Adjust this parameter, and the Inc. angle parameter until the dotted line is superimposed | ||
+ | on the solid green line in the slingshot view. | ||
+ | This is our current trajectory. Now we need to adjust the trajectory to impact the moon in 2 orbits with a 40 day period. | ||
+ | On the Right MFD, click '''VW''' so that the setup view is shown | ||
+ | Click '''VAR''' 3 times so that ''Orbits to Icept'' is shown | ||
+ | Click '''++''' 4 times so that the ''Orbits to Icept'' parameter is 2.0 | ||
+ | Now we must figure out what our ''Enc. MJD'' should be. Take the current MJD and add 85 to it. (5 days to reach the moon, then 2 orbits of 40 days each.) For the Feb 28 (UTC) launch this would be 54890 + 85 = 54975. This is the ''Enc. MJD'' we will be shooting for. | ||
+ | Click '''VW''' again in the right MFD to get back to ''sling direct'' view. | ||
+ | Adjust the Inc Angle to get as close as possible to the desired MJD. | ||
+ | Click '''VAR''' so that ''Outward angle'' is displayed. | ||
+ | Click '''ADJ''' twice so that the increment is ''Fine'' | ||
+ | Adjust ''Outward angle'' to get the Cl. App. as close as possible. | ||
+ | My current solution is Inc Angle of -115.18 degrees and Outward angle of -47.54. Enc MJD is 54978.5013, and Cl. App is 1.747M<br> | ||
+ | Your Mileage may vary. | ||
Once a solution has been reached, click '''BCK''' twice on the Right MFD. | Once a solution has been reached, click '''BCK''' twice on the Right MFD. | ||
Line 353: | Line 294: | ||
closer to the moon. | closer to the moon. | ||
− | == | + | == [[LRO_part_2]] == |
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