LRO / LCROSS

[BrianJ]

Well, there was me thinking the LRO launch was going to be just another boring Moon probe .....until I found out about the LCROSS mission which is co-manifested on the same Atlas401! In brief, the plan is to smack the Atlas upper stage (Centaur) into the Moon while LCROSS gathers data on the impact before hitting the Moon itself. And since I'm a sucker for smashing things into planets(or moons, or asteroids - Smart-1, Deep Impact), I couldn't resist this one ........

Mesh work in Anim8or is pretty much there, just need to transfer it over to Gmax for texturing. Here's how the LRO / LCROSS stack is looking at the moment...

I haven't been able to find many actual photos of the spacecraft under construction (there's a couple on the Northrop-Grumann site) - hopefully more will be available nearer the launch date. If anyone finds any good photos, please post a link!

Add-on should be ready in plenty of time for launch at the end of October.

More info about the missions here:
LRO
http://lunar.gsfc.nasa.gov/
http://lro.gsfc.nasa.gov/library/tooley-scobjectives-51906.pdf

LCROSS
http://lcross.arc.nasa.gov/
http://lcross.arc.nasa.gov/docs/LCROSS_Presentation.pdf

Cheers,
Brian

 

[TSPenguin]

Nice work!
The mission sounds interesting. Isn't it great to find out about this sort of things through an orbiter addon?!

 

[Urwumpe]

Looks really interesting, but I fear you will need to make your own launcher for that mission, as the LCROSS spacecraft remains attached to the upper stage for 58 days. I don't know any existing Atlas V add-on, which could do this.

 

[Notebook]

Lovely model, BrianJ.

N.

 

[Jrquinlisk]

Looks really interesting, but I fear you will need to make your own launcher for that mission, as the LCROSS spacecraft remains attached to the upper stage for 58 days. I don't know any existing Atlas V add-on, which could do this.

Couldn't you use [ame="http://www.orbithangar.com/searchid.php?ID=2682"]this multistage Atlas V addon[/ame] and just define the two spacecraft as separate payloads?

 

[BrianJ]

Isn't it great to find out about this sort of things through an orbiter addon?!

Indeed. No better way to get your head around the essentials of a mission than trying to make it work in Orbiter! Doing a bit of research is a very enjoyable part of the add-on making process, I find.

I fear you will need to make your own launcher for that mission

Yes, the Centaur/LCROSS combo will need it's own .dll - especially if I want the Centaur to do something more interesting than bounce off the Moon at impact. I think I'll stick to multistage2.dll for the 1st stage though (for the autopilot).

Lovely model, BrianJ

Thank you. It helped a lot to find some reasonably clear design drawings in one of the .pdf's.

Couldn't you use this multistage Atlas V addon and just define the two spacecraft as separate payloads?

The main drawback is that it is LCROSS that provides the RCS for attitude and TCM's while still attached to the Centaur, but using multitage2.dll the payloads don't exist as a vessel until they are jettisoned. Also, as previously mentioned, I want the Centaur to go splat-flash-boom when it hits! :-D

Cheers all,
Brian

 

[flying coffin]

Thank you very much Brian! I've been wishing for this addon, since I am
slightly involved with this project!

-Chris

 

[Bj]

wow, awsome model. :speakcool:

How long did it take for you to make that?

 

[BrianJ]

Thank you very much Brian! I've been wishing for this addon, since I am slightly involved with this project!

My pleasure, Chris. Thought you might appreciate this one I was thinking of dropping you a line to say "If you can find any design drawings, I'll do it." - and then I found some in a .pdf . Keep your ear to the ground and let us know of any interesting developments!...and if you could find out anything about the precise position and angle of the RCS thrusters, that would be really handy!

How long did it take for you to make that?

Thanks Bj. I've been tinkering around with it for maybe 3 or 4 weeks, so maybe 12-16 hours - not sure!

Cheers,
Brian

 

[BrianJ]

Just a little update and a couple of screenies: Meshes are pretty much done, .dll's are almost finalised (except for LCROSS) - still need to put together the multistage files for the AtlasV first stage, launch scenario, etc.

Cheers,
Brian

Pic:LCROSS/Centaur stack Lunar flyby (Moon texture by McWgogs)

LRO in Lunar orbit

 

[80mileshigh]

Though I've been aware of the mission, I've only just noticed your work here Brian and the model looks fantastic.

I recommend people watch the video 'LRO/LCROSS Mission Sequence' on the LRO multimedia page. It provides a good depiction of the Centaur impact.

 

[Missioncmdr]

Sounds like a fun mission to fly in Orbiter.

 

[flying coffin]

That looks Super Brian!

I noticed that there is an engineering place in here in Tempe called KinetX, which is
doing some of the navigation work for the Messenger spacecraft. I'll call them and see
if they know the reason for the thruster offset angles, since the folks here at ASU seem to be non-responsive :-(

-Chris

 

[BrianJ]

Thanks guys.

I recommend people watch the video 'LRO/LCROSS Mission Sequence' on the LRO multimedia page. It provides a good depiction of the Centaur impact.

Yes, it's quite a good overview of the mission. The add-on will have an ejecta plume on impact - just not quite as pretty as the one in the video!

Sounds like a fun mission to fly in Orbiter.

I reckon it should be quite interesting - simultaneous orbit insertion of LRO in polar orbit and Lunar gravity assist for LCROSS/Centaur to high inclination ~40 day Earth orbit for impact at Moon N. or S. pole after 2 orbits.Impact timed about 5-10 mins ahead of LRO along it's ground track.
(another MRO/Phoenix type photo opportunity?). And there's not that much dV to play with on the LCROSS/Centaur (about 300m/s, iirc), so better get that lunar flyby right!

I noticed that there is an engineering place in here in Tempe called KinetX, which is doing some of the navigation work for the Messenger spacecraft. I'll call them and see if they know the reason for the thruster offset angles

Thanks Chris I'm still wondering about this. I'd really like to get hold of any info about how the geometery of RCS systems in general are designed - maybe someone here on the forum can point to some info?

Since LRO has reaction wheels, I've simplified the RCS geometery so that they are balanced (exhaust visuals are correctly placed however) for convenience. The LCROSS/Centaur stack steers like a cow, though - all the RCS are up at the pointy end!

Cheers,
Brian

 

[toodoo213]

what a wonderful design! its gonna be a very exciting mission to put us back on the moon! cheers a lot Brian!

 

[BrianJ]

Just in time for the holidays....

"LRO / LCROSS" add-on now up on Orbit-Hangar
[ame="http://www.orbithangar.com/searchid.php?ID=3687"]LRO / LCROSS v.2[/ame]

Inc. LRO and LCROSS spacecraft, AtlasV401, pad LC-41, Lcross target markers, launch scenarios, operation and flight notes, etc.

Features inc. LRO - automatic Sun-tracking solar panel and Earth-tracking antenna, unrealistically visible laser altimeter, DLRE animation.
LCROSS - Visible Context Imager view (6deg fov fixed).
Centaur - Simple parking-orbit autopilot, auto fairing jettison, excess fuel purge, extra HUD info inc. LRO lunar orbit info(for targeting), impact effects and ejecta plume, deployable Lcross "bullseye" target graphic.
LC-41 pad - auto night lights, launch vapour, LOX venting.
etc...

Quite a challenging mission to fly in Orbiter, given the mission constraints on the LRO lunar orbit plane, impact timing and targeting for the Centaur impactor and LCROSS, limited dV available for the Centaur/LCROSS stack (which handles "like a VW steering a school bus"), lunar flyby, etc.

Launch is tentatively scheduled for 24th April 2009, although I can't see how the required LRO lunar orbit can be achieved unless launch is actually on 27th April. Launch scenarios for both dates are included in the add-on.
Hopefully we can do an updated version when launch time and mission timeline are confirmed.

Check the documents listed in the "External Reference Documents" section of the flight notes for detailed info about the mission requirements and possible trajectories.

And last but not least, a huge "Thank You" to my co-author Chris "Flying" Coffin at ASU for the enormous task of creating and compiling the step-by-step flight procedures document and help file. It's an education in itself on how to use IMFD and TransX in tandem. Cheers Chris

....and a very Merry Christmas to Orbinauts everywhere!

 

[astrosammy]

Great Addon. I got LRO into a perfect lunar orbit 10 times. But LCROSS always seems to be in a completely wrong Orbit. Maybe it's just because I'm using a newer version of TransX.

 

[flying coffin]

Can you tell us what the orbit is and how you got there? Perhaps
some improvement can be made to the docs. The initial targeting of
LCROSS and also the TLI burn is a little tricky. Maybe a screenshot of your
IMFD map display or Transx display would help too.

Thanks,

-Chris

 

[astrosammy]

OK, I'll take some screenshots now.

 

[Missioncmdr]

This looks great! Although it looks like getting LCROSS on target might be a little tricky.