[Ground-station] Ground-Station Digest, Vol 34, Issue 21

[anshul makkar]

Hi,

Not expert in this area and still learning, I found a help page :
http://gmat.sourceforge.net/docs/R2018a/help.html which talks about
configuring atmospheric models.

Also, a brief web research showed that people have used the GMAT
atmospheric model to configure their mission.

For my script "GEO to graveyard orbit", I am only using the Gravity
Field Force Model.

I can (based on your post I believe I need to ) introduce Atmospheric
model related coefficients and provide the deltaV comparative results.

Thanks
Anshul Makkar

On Sat, Jan 30, 2021 at 9:51 PM Thomas Parry via Ground-Station
<ground-station at lists.openresearch.institute> wrote:
>
> This is not my area of expertise at all. But I have heard people that do know what they're talking about say its very hard to analytically predict re-entry at low altitudes with real satellite geometries.
>
> With a spherical satellite everything is well behaved but with different drag coefficients at different angles from square-ish satellites the behaviour becomes chaotic and the window of possible solutions widens dramatically.
>
> Not really a useful answer but maybe a interesting thing to think about.
>
> Cheers,
> Thomas
>
>
> On Sat, 30 Jan 2021, 22:03 , <ground-station-request at lists.openresearch.institute> wrote:
>>
>> Send Ground-Station mailing list submissions to
>>         ground-station at lists.openresearch.institute
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>>         http://lists.openresearch.institute/listinfo.cgi/ground-station-openresearch.institute
>>
>> or, via email, send a message with subject or body 'help' to
>>         ground-station-request at lists.openresearch.institute
>>
>> You can reach the person managing the list at
>>         ground-station-owner at lists.openresearch.institute
>>
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of Ground-Station digest..."
>>
>>
>> Today's Topics:
>>
>>    1. GMAT vs. STK/HPOP - call for help (Michelle Thompson)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Fri, 29 Jan 2021 17:28:20 -0800
>> From: Michelle Thompson <mountain.michelle at gmail.com>
>> To: Michelle Thompson via Ground-Station
>>         <ground-station at lists.openresearch.institute>
>> Subject: [Ground-station] GMAT vs. STK/HPOP - call for help
>> Message-ID:
>>         <CACvjz2UOeHpUmGgtvqTS=Y4WQ4_XDLyQRu_7=qw13bY_hzevFg at mail.gmail.com>
>> Content-Type: text/plain; charset="utf-8"
>>
>> For the Debris Mitigation presentation to the FCC, we want to give answers
>> (and show our work) about how much delta-v we need for some of the proposed
>> orbits for minimum viable amateur spacecraft in the Amateur Radio Satellite
>> Service.
>>
>> There's a question that Jan King and I have about a critical altitude and
>> low surface_area:mass ratio spacecraft. It occurred to us that we really
>> might want to compare results across two or more software packages to build
>> some confidence.
>>
>> Jan has a set of results from a spreadsheet from SMAD.
>>
>> https://smad.com/
>>
>> The calculation under review is around 165km with a relatively lightweight
>> 6U spacecraft. It's acting like it wants to do some strange things. Is this
>> physics, or at a limit of the model?
>>
>> We have a couple of people who are good or are getting good at GMAT.
>>
>> https://software.nasa.gov/software/GSC-17177-1
>>
>> Question: Are the atmospheric models in GMAT good enough for this
>> calculation?
>>
>> Does anyone have access to STK/HPOP to run this calculation, for
>> comparison?
>>
>> https://www.agi.com/products/stk
>>
>> https://help.agi.com/stk/11.0.1/Content/hpop/hpop.htm
>>
>> Thank you,
>> -Michelle W5NYV
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>> URL: <http://lists.openresearch.institute/pipermail/ground-station-openresearch.institute/attachments/20210129/1a54774f/attachment-0001.html>
>>
>> ------------------------------
>>
>> Subject: Digest Footer
>>
>> _______________________________________________
>> Ground-Station mailing list
>> Ground-Station at lists.openresearch.institute
>> http://lists.openresearch.institute/listinfo.cgi/ground-station-openresearch.institute
>>
>>
>> ------------------------------
>>
>> End of Ground-Station Digest, Vol 34, Issue 21
>> **********************************************
>>