[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

R: AO-40: more successful ARCJET operations



HI  Peter,

The AOS of AO40 on orbit 301 went at 19:32 UTC in JN70ES instead at 19:16
UTC and so with 16 min of delay....The ArcJect work fine !!
In order to match the time of the AOS and all of my AZ and EL angles
recorded during my orbit 301 tracking,i have changed only the Mean Anomaly
from MA=140.46836 to MA=136.000 and this will be probably OK for traking
purposes on the next orbit 302
Have a nice venture in your efforts to rise the perigee.

Best 73 de i8CVS Domenico


----- Original Message -----
From: Peter Guelzow <peter.guelzow@arcormail.de>
To: <amsat-bb@AMSAT.Org>; <forum@amsat-dl.org>
Sent: Saturday, June 23, 2001 12:08 PM
Subject: [amsat-bb] AO-40: more successful ARCJET operations


> Dear All,
>
> The arc-jet thruster has been invoked on Orbit 296, MA 118-135,
> which gave about 1 hour of thrusting gas only.
>
> The S2 TX is OFF from MA 100-180 to spare power for the ATOS. The gas
> generator for the ammonia draws about 120 - 130 W of power when cycled on
> by the thermostat.
>
> The IHU-2 is running and logging telemetry into a circular buffer and
> and hold about 2.5 days worth of data. Downloaded telemetry from this 1h
> burn indicated positive power budget and everything looks nominally.
>
> The thrust on orbit 296 started at MA 121.4 and lasted for 3618s. The
> acceleration is guestimated to be 54E-6 m/s^2 , and the direction of
> acceleration is towards alon 274, alat -2 (the current attitude).
>
> Give or take the unknowns, the expected outcome of this was:
>
>                      Before            After
>   --------------------------------------------
>   Epoch year            2001              2001
>   Epoch time       173.12145         173.16312
>   Inclination         5.2833         5.2833592
>   R.A.A.N          180.71591         180.70361
>   Eccentricity      0.815077         0.8150139
>   Arg perigee      288.69088         288.71333
>   Mean Anomaly         121.4         140.46836
>   Mean motion MM   1.2711484         1.2710861
>   Revolution             296               296
>   SMA                36003.6         36004.773
>
>   Perigee height     279.754          282.2427    <<<  +2.5 km
>   Apogee height    58971.166         58971.024
>   --------------------------------------------
>
> So the perigee was raised by this 1h burn by about +2.5 km, but only a
> thrust rate of 50% was used.
>
> Since everything went so well, the computer onboard AO-40 was commanded
> to initiate 2h "burns" starting around apogee on orbit 297 for the next
> three orbits.
>
> The first 2-hour burn stopped at Orbit 297 MA 142, which is 2001 Jun 23
> 0154 utc. Again, all telemetry is looking good and we may soon expand to
> 4h "burns" and possibly increase the thrust level as well.
>
> While we haven't yet seen the latest NORAD data, some effects of the
> changing orbit should be soon noticeable.
>
> Indeed, we all are very happy with the successful results of the ATOS
> (Arcjet Thruster on OSCAR Satellite) so far.
>
> Some more information about the ATOS system is available here:
>
> http://www.irs.uni-stuttgart.de/RESEARCH/EL_PROP/PROJ/e_atos.html
>
>
> best 73s
>  Peter DB2OS for the AO-40 team
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>





----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home