OHM Europa Clipper 241110

[BrianJ]

BrianJ submitted a new addon:

Europa Clipper - The Europa Clipper spacecraft.

View attachment 41073

Europa Clipper spacecraft, launch and post-launch scenarios.
Simulated EIS imaging (D3D9 Graphics Client only).
Installation and operation notes in Doc/Europa Clipper/ folder.

Launch scenario requires FalconHeavy for Orbiter 2016

Read more about this addon...

 

[gattispilot]

Nice. I know I made a Europa Clipper also.

 

[francisdrake]

An excellent addon! The model is amazingly detailed. The vessel is rich in features, including a fuel-saving reaction wheel control and automatic pointing the camera to the target.

Minor quibbles:
Some Shift-keys are intercepted, which interferes a bit with keyboard MFD control (e.g. Shift-P and Shift-M).

In the flyby scenarios Earth is pre-selected as orbit reference.
Maybe it would be better to pre-select the flyby-planet in one Orbit MFD (and a moon as target object), and show the orbit around the sun in the other MFD:


When in Jupiters orbit at high time acceleration, the vessel periodically flips head-over-heels, when target-pointing is active. It think this is triggered when the target changes its apparent moving direction. For example when Europa is visually moving from right-to-left, then reaches the outer point of its visual track, and starts moving back from left-to-right.

Here is shot of Europa, taken with the NAC camera in the second orbit from approximately 71.000 km. Very nice!

 

[BrianJ]

Nice. I know I made a Europa Clipper also.

So you did! I must have missed that. Nice model too Ah well, always room for one more in the Orbiter universe, I guess.

Minor quibbles:
Some Shift-keys are intercepted, which interferes a bit with keyboard MFD control (e.g. Shift-P and Shift-M).

Gah! I can never get that right ;-)

In the flyby scenarios Earth is pre-selected as orbit reference.
Maybe it would be better to pre-select the flyby-planet in one Orbit MFD (and a moon as target object), and show the orbit around the sun in the other MFD:

Didn't think of that. Nice touch.

When in Jupiters orbit at high time acceleration, the vessel periodically flips head-over-heels, when target-pointing is active. It think this is triggered when the target changes its apparent moving direction. For example when Europa is visually moving from right-to-left, then reaches the outer point of its visual track, and starts moving back from left-to-right.

EIS->Tgt puts the spacecraft in (something like) correct attitude for imaging. EIS (+Y) points at the target and (+Z) is +orbit-normal (relative to target), so yes it will do a somersault if your inclination relative to target flips (as it will in this case).
I really implemented it for keeping the right attitude during a flyby.

Here is shot of Europa, taken with the NAC camera in the second orbit from approximately 71.000 km. Very nice!

Cool. Lots of "Kodak moments" (do people still use that expression?) with this mission.

I'll do an update soon.
In the meantime, I'm just approaching Jupiter with 1400m/s dV left, and wondering if there is some kind of general strategy for "winding down" my orbit at Jupiter using Ganymede/Europa flybys

Cheers,
BrianJ

 

[francisdrake]

In the meantime, I'm just approaching Jupiter with 1400m/s dV left, and wondering if there is some kind of general strategy for "winding down" my orbit at Jupiter using Ganymede/Europa flybys

I tried to rendezvous with Europa for a negative swing-by using the SyncOrbit MFD, but it is out of range of this MFD.
The Clipper has such an elongated orbit. When coming in from its apogee, it takes 8.5 Ms (98 days).
Europa will make more than 5 orbits in this time, so the rendezvous is beyond the end of the orbits listed in the MFD.

I guess we would either need an extended SyncOrbit MFD, or a separate copilot app to calculate rendezvous times.

If we were able to set up a rendezvous, we could aim for a close flyby on the way in. If the flyby is on the 'inside' of Europas orbit (the side facing Jupiter), we could shed a bit of speed during the flyby. See the 'lose speed' trajectory below:

 

[BrianJ]

I haven't done any planning for my Jupiter arrival yet. I'm going to arrive about 20 days early anyway (compared to nominal). I read/heard the Ganymede flyby on arrival does save a chunk of dV, so I guess I shall aim for something similar while getting the perijove down to Europa's orbit.
I reckon its TransX all the way, for me.

If we were able to set up a rendezvous, we could aim for a close flyby on the way in. If the flyby is on the 'inside' of Europas orbit (the side facing Jupiter), we could shed a bit of speed during the flyby. See the 'lose speed' trajectory below:

View attachment 41083

Doesn't it depend on whether you're coming from inside or outside the orbit? (now that I say that, it sounds like a pretty dubious statement) Anyway, the Ganymede flyby on arrival is on the side facing away from Jupiter, and it slows you down a bit....
I need to play with TransX
I haven't even had one Europa flyby yet.

Cheers.
Brian

 

[MarkWatney2015]

I have saved some prelaunch state vectors of Clipper from HORIZONS depicting its Jupiter orbit phases from 2030 up to its planned Ganymede crash on September 2034 (before it was deleted and replaced with an incomplete postlaunch data that runs only until 2031). Will try to make scns for them later

 

[BrianJ]

Thanks! They only had data up to the 1st orbit after JOI when I looked.

 

[BrianJ]

Here is a new .dll module that avoids the +Shift key problem.

 

[BrianJ]

BrianJ updated Europa Clipper with a new update entry:

241110

Fixed +Shift keypress conflicts.
Added appropriate MFD settings to flyby scenarios.

Read the rest of this update entry...