OSIRIS-REx Asteroid Sample Return

[IonStorm]

5 minutes ago, Jetski said:

If I'm reading the mission profile right (debatable since im technically at work and playing with my phone) It's a sort of touch and go, 5 seconds of contact then off again.  Maybe simulate it very simply by nosing up and deploying a stock whip antenna into the asteroid, then off again.  

Excellent, it is exactly a touch and go. Our sampler is even called TAGSAM (Touch And Go Sample Acquisition Mechanism).  However, since the real asteroid is ~3E+7 times the mass of the spacecraft (6E+10 kg/2E+3 kg) in KSP a Class E asteroid would be ~2E+3 times the mass of the spacecraft.  Even if KSP asteroids had gravity, it is way too small to allow the semi-stable orbit OSIRIS-REx can achieve around Bennu.  

Also, in planetary encounters the size of the planet is arbitrarily large compared to the spacecraft.  Even tiny Bennu is ~80x the maximum length of the spacecraft (500m/6m).  I think a Real Solar System is a more elegant solution.  But you are welcome to try with a scaled down mission too (perhaps 183kg, 27cm x 27cm x 29cm cubesat).  

[mralext20]

5 minutes ago, IonStorm said:

I think a Real Solar System is a more elegant solution.

and the modders can do this. they can also add the miniscule amount of gravity to it. 

[IonStorm]

 

10 minutes ago, IonStorm said:

it is exactly a touch and go. Our sampler is even called TAGSAM (Touch And Go Sample Acquisition Mechanism).  

Here is TAGSAM in action https://videopress.com/v/rEhJ3Ugt and here is the nominal TAG sequence

Taken from http://dslauretta.com/2014/02/14/sampling-an-asteroid-a-game-of-laser-tag/ and http://dslauretta.com/2015/04/20/development-of-the-osiris-rex-sampling-system-tagsam-and-the-src/

[NathanKell]

7 hours ago, Jetski said:

If nobody better chimes in in the next day or so, I'll try to learn enough Kopernicus to hack a Gilly analogue into orbit. I haven't played with it before though, so hoping one of the better planet modders  jumps in :)  Looking at you @KillAshley and @NathanKell

Afraid my time is taken up by RealJob (i.e. KSP itself) at the moment. Should not be hard at all however.

 

@IonStorm awesome challenge, and awesome mission! Per some of the posts above, you might want to add a category for RSS/RO recreations. Because that will be rather different. :]

[Jetski]

Just now, NathanKell said:

Afraid my time is taken up by RealJob (i.e. KSP itself) at the moment. Should not be hard at all however.

 

@IonStorm awesome challenge, and awesome mission! Per some of the posts above, you might want to add a category for RSS/RO recreations. Because that will be rather different. :]

I have a really rough hack for RSS in place.  I'm trying to work out how to set up the correct epoch right now (also the inclination seems off), but if anyone wants to take a look and tell me what I'm doing wrong, here is a link to what I'm working on.  Install RSS (and ROO if you want), and go into GameData\RealSolarSystem\RSSKopernicus directory, make a folder called Bennu, and drop this in.  Should be called Bennu.cfg, right now it's a really ugly hack of the Pluto config from RSS.  Working on it though, and learning as I go!

[NathanKell]

You can get the actual ephemeris from JPL's HORIZONS. RSS uses 1 Jan 1951 minus a few minutes as the epoch (it's in the top of the general RSS settings file, IIRC) and we use Earth-equator-centric coords.

[Jetski]

3 minutes ago, NathanKell said:

You can get the actual ephemeris from JPL's HORIZONS. RSS uses 1 Jan 1951 minus a few minutes as the epoch (it's in the top of the general RSS settings file, IIRC) and we use Earth-equator-centric coords.

I actually had that JPL page open   I'm working out how to reconcile this:

EPOCH=  2455562.5 ! 2011-Jan-01.00 

with the RSS Jan 1951 epoch.  was hoping I could just subtract seconds, but it seems there's more to it, as though I have to find out where the planet is going to be at that point.  Once again, KSP is forcing me to actually learn stuff about how orbits are described...

[IonStorm]

12 minutes ago, NathanKell said:

Afraid my time is taken up by RealJob (i.e. KSP itself) at the moment. Should not be hard at all however.

 

@IonStorm awesome challenge, and awesome mission! Per some of the posts above, you might want to add a category for RSS/RO recreations. Because that will be rather different. :]

Super idea, and I'm delighted at how excited the community is over this.  

Get engaged at:

• https://www.facebook.com/OSIRISREx
• https://twitter.com/OSIRISREx
• https://www.youtube.com/OSIRISREx
• https://www.instagram.com/osiris_rex/
• https://plus.google.com/+OSIRISRExMission/posts
• http://dslauretta.com
• And apps
  • http://www.cox7.com/video/osiris-rex-mobile-app/
  • http://www.lockheedmartin.com/us/products/osirisrex.html

[NathanKell]

You should be able to get the ephemeris for any epoch...

[Jetski]

2 minutes ago, NathanKell said:

You should be able to get the ephemeris for any epoch...

      

I certainly don't want to derail this thread into a Kopernicus tutorial, but the short version is that I plug in the given values from JPL (below), and it places Bennu where it would be Jan 01 2011.  I think.  I open a new game in KSP, and it's 1951 in game time, but Bennu is in the 2011 position.  I'm studying how to get the following values for a 1951 timestamp.

 Orbit
        {
            referenceBody = Sun
            semiMajorAxis = 168505699001.10720825
            eccentricity = 0.2037451146135014
            inclination = 6.03493867976381
            meanAnomalyAtEpochD = 101.70394725713800
            longitudeOfAscendingNode = 2.06086819910204
            argumentOfPeriapsis = 66.22306886293201
            color = 0.278, 0.268, 0.274, 1.0
        }

[IonStorm]

24 minutes ago, NathanKell said:

You can get the actual ephemeris from JPL's HORIZONS. RSS uses 1 Jan 1951 minus a few minutes as the epoch (it's in the top of the general RSS settings file, IIRC) and we use Earth-equator-centric coords.

The JPL database is a good summary, but http://arxiv.org/pdf/1409.4704v1.pdf has the state of the art on Bennu.

[NathanKell]

@IonStorm that's wrt the ecliptic and presumably J2000?

[Jetski]

11 minutes ago, IonStorm said:

The JPL database is a good summary, but http://arxiv.org/pdf/1409.4704v1.pdf has the state of the art on Bennu.

That's actually where I started, I'll try to make sure the numbers are coming from there  Here's the first draft.  I strongly suspect the inclination is off possibly because RSS has the entire ecliptic at a slant.  Unless that orbit looks right to you... But working on it.  And then I'm going to fly there

 

 

Edited March 29, 2016 by Jetski

[IonStorm]

11 minutes ago, Jetski said:

That's actually where I started, I'll try to make sure the numbers are coming from there  Here's the first draft.  I strongly suspect the inclination is off possibly because RSS has the entire ecliptic at a slant.  Unless that orbit looks right to you... But working on it.  And then I'm going to fly there

Very cool!!  The inclination does look steep by eye, but you'd need to measure it.

[Matuchkin]

11 hours ago, IonStorm said:

It is bigger than a Class E asteroid and smaller than Gilly (but I usually go to Gilly)

You should get Realism Overhaul, with its planet expansion pack (featuring a lot of asteroids and comets, including Churyumov-Gerasimenko, Halley, etc). Seriously, it is completely amazing. It even has Sedna. Friggin' SEDNA.

 

 

[IonStorm]

13 minutes ago, Matuchkin said:

You should get Realism Overhaul, with its planet expansion pack (featuring a lot of asteroids and comets, including Churyumov-Gerasimenko, Halley, etc). Seriously, it is completely amazing. It even has Sedna. Friggin' SEDNA.

That is awesome, and sounds way beyond my abilities (and available time).

Edited March 30, 2016 by IonStorm

[Matuchkin]

Just now, IonStorm said:

That is awesome, and sounds way beyond my abilities.

Wha, wha... you're a NASA employee. You're supposed to be a saint!

Anyway, to be serious. Realism overhaul is extremely rewarding. With the correct ways of playing, you can get anywhere quite easily, and have an actual challenge while constructing ships.

Oh, and I think you will love this: 

Anyway, I think I should return to the thread topic, before the thread gets locked. Thank you for your consideration, and please continue this discussion in the private message series I sent you, if you want to.

[Delta_8930]

An interesting challenge might be to use a rocket with one solid rocket booster, as is the case with the AV-411 that will launch this mission.

[Jetski]

3 hours ago, NathanKell said:

@IonStorm that's wrt the ecliptic and presumably J2000?

From the PDF: Sun-centered, Earth ecliptic & equinox of J2000.0

I tried following some info found in the RSSKopernicusSettings.cfg, and plugging that into the JPL tool.  I think I may have gotten a bit closer to the correct orbit and inclination.  I offset Bennu's inclination by the value of Earth inclination, seems closer. Still not sure if I'm in the right spot in the orbit. Not sure if the heightmap is still glitching and turning it into a spikey ball.  Not sure I have the foggiest idea how to mess with mods.

Here's the latest Bennu config.  

To use it:

1. Install RSS from CKAN, or install RSS and Kopernicus independently.  And whatever other junk you want.
2. Make a folder called Bennu in the \GameData\RealSolarSystem\RSSKopernicus folder.
3. just dump the config file (bennu.cfg) the Bennu folder.
4. Load up KSP
5. Profit!

Here's a savegame that puts you around April 2016

Best of luck.  If it's super buggy, feel free to edit the config or tell me what I'm doing wrong, I'll try flying to it tomorrow with a probe and infinite fuel.  It's getting late and I have to work early 

Now somebody please put together a decent Atlas rocket so we can play with this.  Also I'll see how hard making a stock solar system version of Bennu is later, for people like me who aren't good enough to play well with RSS.  Maybe even spin this off into a for reals Bennu mod.  If anyone wants to help with parts

 

 

Edited March 30, 2016 by Jetski

[NathanKell]

Yeah, you'll need to convert to Earth-equator relative but sun-centered and the Jan 1951 epoch we use. Or better yet do it with Principia; the orbit won't be correct 65 years later anyway. @eggrobin poke

[NathanKell]

Darnit I got my suffixes wrong. -ides not -is. >.>

[Spheniscine]

6 hours ago, Delta_8930 said:

An interesting challenge might be to use a rocket with one solid rocket booster, as is the case with the AV-411 that will launch this mission.

I wonder why they're doing that? I guess it compensates with gimbals or vernier thrusters or something, but what advantages does it have?

Edited March 30, 2016 by Spheniscine

[KillAshley]

17 hours ago, Jetski said:

If nobody better chimes in in the next day or so, I'll try to learn enough Kopernicus to hack a Gilly analogue into orbit. I haven't played with it before though, so hoping one of the better planet modders  jumps in :)  Looking at you @KillAshley and @NathanKell

 

EDIT;

OK so read some of the posts, and i think I understand what you guys need, should be pretty simple. I'll grab a quick cfg that'll do what you want. A cfg like this is simple and should only take 5 mins....unless i get distracted lol

Edited March 30, 2016 by KillAshley

[Mr. Quark]

You got distracted did you? xD

[KillAshley]

50 minutes ago, Kandjk said:

You got distracted did you? xD

maybe ...i decided to make it look a little nicer, a gilly clone makes me cringe inside lol