[amsat-bb] Re: ISS Height Profiles @ Heavens-Above.com

[Fabio Azzarello]

Thanks Robert!
Clear now.

73s
Fabio
iw8qku/5



On Fri, Jan 13, 2012 at 4:59 PM, Robert McGwier <rwmcgwier at gmail.com> wrote:

> These maneuvers are not done continuously around the orbit.  They are
> typically done in burns done at apogee and perigee if all they are doing is
> raising/lowering the orbit and minimizing any changes to the orbital plane.
>
> Think of it like this.  When I turn the propulsion on, I do not change my
> CURRENT instantaneous position while I am burning.  What I change is my
> velocity.  So if I burn the motor at apogee and the motor is firing along
> my velocity vector, then I am speeding myself up.  THIS RAISES PERIGEE
> because I will have the same height but my speed will cause the position on
> the OTHER SIDE of the orbit to be raised.  Similarly, I slow down at
> apogee,  perigee is lowered.  If I speed up at perigee, apogee is raised,
> ........
>
> Did this help?
>
> Bob
>
>
> On Fri, Jan 13, 2012 at 10:28 AM, Fabio Azzarello <iw8qku at amsat.org>wrote:
>
>> Hello everybody,
>>
>> ISS heights plots are available at the following link:
>>
>> http://www.heavens-above.com/OrbitHeight.aspx?satid=25544&startMJD=55610&lat=43&lng=11
>>
>> I've noticed that Apogee and Perigee heights have different behaviour
>> during reboosts (look at mid September for example),
>> could anybody help me to understand why?
>>
>> Thanks in advance,
>> 73s
>> Fabio
>> iw8qku/5
>> _______________________________________________
>> Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>
>
>
> --
> Bob McGwier
> Facebook: N4HYBob
> ARS: N4HY
>
>
>