Re: Question About Atmospheric Drag

On 2024-04-24 22:35, Jah, Moriba via Seesat-l wrote:
> My guess is that it’ll be on the order of 100 or 1000 because the 
> dominant difference is atmospheric density.
> 

But note that densities above 100 km or so can vary greatly due to solar 
activity. If you really want to do this well, you need to refer to a 
high altitude atmospheric model, especially if the two satellite orbits  
are compared at different points in the solar cycle, or you have data 
for the same satellite at different times.

See, e.g.,  https://www.swpc.noaa.gov/impacts/satellite-drag

Regards
Marshall


> Moriba Jah, Associate Professor
> The University of Texas at Austin
> Aerospace Engineering and Engineering Mechanics Department
> Mrs. Pearlie Dashiell Henderson Centennial Fellowship in Engineering
> Oden Institute for Computational Engineering and Sciences
> 512-471-0717 | moriba_at_utexas.edu
> 
> Kayla Kitashima
> Executive Assistant
> team.moriba_at_outlook.com
> ________________________________
> From: Seesat-l <seesat-l-bounces_at_lists.seesatmail.org> on behalf of 
> Jah, Moriba via Seesat-l <seesat-l_at_lists.seesatmail.org>
> Sent: Wednesday, April 24, 2024 10:33:17 PM
> To: Anthony Mallama <anthony.mallama_at_gmail.com>; Seesat-L 
> <seesat-l_at_satobs.org>
> Subject: Re: Question About Atmospheric Drag
> 
> It’s just orbital velocity and atmospheric density ratios right?
> 
> Moriba Jah, Associate Professor
> The University of Texas at Austin
> Aerospace Engineering and Engineering Mechanics Department
> Mrs. Pearlie Dashiell Henderson Centennial Fellowship in Engineering
> Oden Institute for Computational Engineering and Sciences
> 512-471-0717 | moriba_at_utexas.edu
> 
> Kayla Kitashima
> Executive Assistant
> team.moriba_at_outlook.com
> ________________________________
> From: Seesat-l <seesat-l-bounces_at_lists.seesatmail.org> on behalf of 
> Anthony Mallama via Seesat-l <seesat-l_at_lists.seesatmail.org>
> Sent: Wednesday, April 24, 2024 10:22:30 PM
> To: Seesat-L <seesat-l_at_satobs.org>
> Subject: Question About Atmospheric Drag
> 
> Hi,
> 
> I am trying to estimate the ratio of the drag on a satellite at 550 km
> versus one with the same shape at 350 km. Can anyone inform me? Thanks.
> 
> Best regards,
> 
> Tony Mallama
> 
> 
>
<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.avast.com%2Fsig-email%3Futm_medium%3Demail%26utm_source%3Dlink%26utm_campaign%3Dsig-email%26utm_content%3Dwebmail&data=05%7C02%7C%7C14355372de5446808d1208dc64d017cb%7C31d7e2a5bdd8414e9e97bea998ebdfe1%7C0%7C0%7C638496092113747838%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C20000%7C%7C%7C&sdata=QGsFBFJ0kWKbcttVe1ggYukGbguUjZNnhWipSpHDPgI%3D&reserved=0<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.avast.com%2Fsig-email%3Futm_medium%3Demail%26utm_source%3Dlink%26utm_campaign%3Dsig-email%26utm_content%3Dwebmail&data=05%7C02%7C%7C14355372de5446808d1208dc64d017cb%7C31d7e2a5bdd8414e9e97bea998ebdfe1%7C0%7C0%7C638496092113756003%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C20000%7C%7C%7C&sdata=1US92jGAyCSQDYuR%2BzkdQjIYAXDzjoRMb6BpIArBASE%3D&reserved=0<https://www.avast.com/sig-email?utm_medium=email&utm_
source=link&utm_campaign=sig-email&utm_content=webmail>>>
> Virus-free.https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.avast.com%2F&data=05%7C02%7C%7C14355372de5446808d1208dc64d017cb%7C31d7e2a5bdd8414e9e97bea998ebdfe1%7C0%7C0%7C638496092113761103%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C20000%7C%7C%7C&sdata=q3WHACmK5a8lGXnZ9dTnEGVvDNm85eChc95u3zB9B7c%3D&reserved=0
>
<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.avast.com%2Fsig-email%3Futm_medium%3Demail%26utm_source%3Dlink%26utm_campaign%3Dsig-email%26utm_content%3Dwebmail&data=05%7C02%7C%7C14355372de5446808d1208dc64d017cb%7C31d7e2a5bdd8414e9e97bea998ebdfe1%7C0%7C0%7C638496092113764864%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C20000%7C%7C%7C&sdata=59g56lhs05vKhEi3votDrCe7Z1em1O01mKTgHM9DN2k%3D&reserved=0<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.avast.com%2Fsig-email%3Futm_medium%3Demail%26utm_source%3Dlink%26utm_campaign%3Dsig-email%26utm_content%3Dwebmail&data=05%7C02%7C%7C14355372de5446808d1208dc64d017cb%7C31d7e2a5bdd8414e9e97bea998ebdfe1%7C0%7C0%7C638496092113768665%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C20000%7C%7C%7C&sdata=zdkCje3kh8bybk%2FX6FE9BqhB6EM9Lbz2Oi8aNvT0lGw%3D&reserved=0<https://www.avast.com/sig-email?utm_medium=email&utm_
source=link&utm_campaign=sig-email&utm_content=webmail>>>
> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
> 
> _______________________________________________
> Seesat-l mailing list
> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.seesatmail.org%2Fmailman%2Flistinfo%2Fseesat-l&data=05%7C02%7C%7C14355372de5446808d1208dc64d017cb%7C31d7e2a5bdd8414e9e97bea998ebdfe1%7C0%7C0%7C638496092113772380%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C20000%7C%7C%7C&sdata=dTXtTUVXKJW1QIFioNXqzjcyFJXYimBmmYQxNAKndPY%3D&reserved=0<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.seesatmail.org%2Fmailman%2Flistinfo%2Fseesat-l&data=05%7C02%7C%7C14355372de5446808d1208dc64d017cb%7C31d7e2a5bdd8414e9e97bea998ebdfe1%7C0%7C0%7C638496092113776065%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C20000%7C%7C%7C&sdata=vBsOuMM%2BxGstMAhyy6qlEZLCHGHT8ssz29TGeP7aQHs%3D&reserved=0><https://lists.seesatmail.org/mailman/listinfo/seesat-l>
> 
> _______________________________________________
> Seesat-l mailing list
> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.seesatmail.org%2Fmailman%2Flistinfo%2Fseesat-l&data=05%7C02%7C%7C14355372de5446808d1208dc64d017cb%7C31d7e2a5bdd8414e9e97bea998ebdfe1%7C0%7C0%7C638496092113779769%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C20000%7C%7C%7C&sdata=Zbax%2BhWGwkzRfk7uKSQtE%2BZkNqy2LfCcKSE%2BwUE%2FNcE%3D&reserved=0<https://lists.seesatmail.org/mailman/listinfo/seesat-l>
> 
> _______________________________________________
> Seesat-l mailing list
> https://lists.seesatmail.org/mailman/listinfo/seesat-l

_______________________________________________
Seesat-l mailing list
https://lists.seesatmail.org/mailman/listinfo/seesat-l