Re: [Orekit Users] Fwd: Sprite orbit-guesser on the web using Orekit?

[Michael Turner <michael.eugene.turner@gmail.com>]

On Fri, Jan 31, 2014 at 10:20 AM, Hank Grabowski
<hank@applieddefense.com> wrote:
> Sounds interesting.  What sort of assistance would you be looking for?

Between now and launch, I believe Zac has his hands full with the
ground station software. I don't want to distract him too much. I
think we only need basic starting-point data from him, e.g., about
PPOD deployment (timing, altitude, direction, etc.) and then Sprite
deployment (timing, relative velocities w.r.t. KickSat). For purposes
of predicting orbital decay, perhaps also ballistic coefficient of
Sprites at various angles.

Translating all that into orbit propagation is where I'm clueless. I'm
not an Orekit user. I've only contributed to the wiki at the level of
copy editing.

Zac is concerned that time might be too short to do anything useful.
I'm not so sure, but getting basic requirements worked out should help
with the estimate. I think he envisions a tasty graphical display --
e.g., a real-time graphic showing the globe and positions of Sprites
(and KickSat). My thought was more like this: tell people what times
of day would be best for trying to get reception, depending on where
they are. Where reception is successful, the results might be used to
update the orbital elements on a per-Sprite basis. At this point, I
don't know how much dispersion is expected in the Sprite fleet.

Regards,
Michael Turner
Executive Director
Project Persephone
K-1 bldg 3F
7-2-6 Nishishinjuku
Shinjuku-ku Tokyo 160-0023
Tel: +81 (3) 6890-1140
Fax: +81 (3) 6890-1158
Mobile: +81 (90) 5203-8682
turner@projectpersephone.org
http://www.projectpersephone.org/

"Love does not consist in gazing at each other, but in looking outward
together in the same direction." -- Antoine de Saint-Exupéry


On Fri, Jan 31, 2014 at 10:20 AM, Hank Grabowski
<hank@applieddefense.com> wrote:
> Sounds interesting.  What sort of assistance would you be looking for?
>
>
> On Thu, Jan 30, 2014 at 10:05 AM, Michael Turner
> <michael.eugene.turner@gmail.com> wrote:
>>
>> See forwarded e-mail below, from Zac Manchester, the lead on KickSat.
>>
>>   http://www.kickset.net
>>
>> I have Java web hosting (metawerx.net) and a little experience with
>> getting the demo code running, but I'm not an orbital mechanics expert
>> by any means. The SpaceX CRS 3 / ELaNa 5 launch is now scheduled for
>> March 1st, so there's about one month to do something here with
>> Orekit.
>>
>> I think it's an interesting problem -- a few hundred flat,
>> spin-stabilized femtosats, with high ballistic coefficents, deployed
>> radially from a sun-pointing, spin-stabilized cubesat. Being able to
>> predict their orbits even approximately might help those with ground
>> stations. Deviations from Orekit trajectory predictions might count as
>> exosphere density data (for all I know, which isn't much.)
>>
>>  If anyone wants to help out with this, please write me. Everybody
>> involved with KickSat Sprites would greatly appreciate it.
>> Contributors will be duly credited.
>>
>> Regards,
>> Michael Turner
>> Executive Director
>> Project Persephone
>> K-1 bldg 3F
>> 7-2-6 Nishishinjuku
>> Shinjuku-ku Tokyo 160-0023
>> Tel: +81 (3) 6890-1140
>> Fax: +81 (3) 6890-1158
>> Mobile: +81 (90) 5203-8682
>> turner@projectpersephone.org
>> http://www.projectpersephone.org/
>>
>> "Love does not consist in gazing at each other, but in looking outward
>> together in the same direction." -- Antoine de Saint-Exupéry
>>
>>
>>
>> ---------- Forwarded message ----------
>> From: Zac Manchester <zacinaction@gmail.com>
>> Date: Thu, Jan 30, 2014 at 4:03 AM
>> Subject: Re: Sprite orbit-guesser on the web using Orekit?
>> To: Michael Turner <michael.eugene.turner@gmail.com>
>>
>>
>> Hi Michael,
>>
>> Good to hear from you - hope things are going well. First off, the
>> launch date has slipped once again to March 1, and I'm told that date
>> is "very soft" and likely subject to further (possibly significant)
>> delays.
>>
>> Right now I'm working on getting my radio demodulator/decoder online
>> so that hams can just record audio files and upload them to be decoded
>> in the cloud. Ideally we could then plot all of the ground station
>> contacts on a google maps overlay or something.
>>
>> As for some kind of astrodynamics thing using Orekit, the obvious
>> thing to do is some kind of orbit propagation/estimation using the
>> tracking data we get. The issue I think is that we're likely to run
>> out of time with the launch coming up so quickly. If this is what you
>> want to focus on, I'd recommend trying to pipe the Orekit orbit
>> propagator output into a google earth or google maps visualization to
>> be displayed online. If you can take care of the graphics/web UI
>> stuff, I can handle the astrodynamics end.
>>
>> Have fun at the Brown conference - I've been to a couple and they're
>> always interesting. I think this one will be right up your alley.
>>
>> Best,
>> Zac
>
>