[amsat-bb] Re: Phase 3
domenico.i8cvs at tin.it
Sun Sep 22 03:29:41 PDT 2013
----- Original Message -----
From: "pabutusa at gmail.com" <rob at pabut.org>
To: "i8cvs" <domenico.i8cvs at tin.it>
Sent: Sunday, September 22, 2013 5:01 AM
Subject: Re: [amsat-bb] Re: Phase 3
Are you sure the kick motors on ao10/13 were solid ???? I was pretty sure
the were liquid because the could be fired multiple times to tweak the
orbit. I also remember seeing pictures of technicians I'm hazmat suits
fueling the bird.
--> Rob, ka2pbt
The solid propellant motor of OSCAR-10 was designed to fire
only one time at the apogee and change the orbit inclination to
around 67 degrees into a Molniya orbit but unfortunately the
onboard 400 Newton kick motor did not function entirely
correctly, due to collision with launch vehicle after separation
- hence the not-quite-Molniya-orbit with only inclination of
OSCAR-13 uses a bi-propellant hydrazine and nitrous oxide
400 Newton motor system and behaved flawlessly during the
two post launch burns.
Oscar-13 was launched into a highly elliptical equatorial orbit,
a "Geostationary Transfer Orbit", with a perigee height of
240 km. Over the next 7 days it was re-oriented to point the motor
along-track such that apogee velocity could be increased by
150 m/s. This increased perigee height to 1100 km, and freed
the satellite from buffeting and atmospheric drag.
During the next 2 weeks it was oriented "upwards" so that a burn
at apogee would increase inclination to 58°, and perigee height to
Two weeks later, 1988 July 22 15:00 utc the mode-B transponder
was switched on for general use.
The pictures you have seen referes to charge the fluid bi-propellant
hydrazine and nitrous oxide toxic fuel into OSCAR-13 and later
on to charge the liquid propellant into AO40 made with UMDH
and nitrogen tetroxide.
On Sep 21, 2013, at 22:15, "i8cvs" <domenico.i8cvs at tin.it> wrote:
> ----- Original Message -----
> From: "Angus McLeod" <amcleod at caribsurf.com>
> To: <amsat-bb at amsat.org>
> Sent: Saturday, September 21, 2013 9:27 PM
> Subject: [amsat-bb] Re: Phase 3
>> As far as I know, the kick-motors used on the Phase-3 birds were NOT
>> cardboard tubes packed with homemade gunpowder. They were commercial
>> grade motors obtained from the commercial aerospace industry. If I am
>> wrong about this, and someone can jump in with facts, I'd be glad to
> Hi Angus,
> The kitch apogee motors for OSCAR-10,and OSCAR-13 were solid propellant
> 400 Newton trust motors donated to AMSAT-DL by the Messerschmitt Aerospace
> Company in Germany.
> The kick apogee motor for AO40 was a liquid propellant made with UMDH and
> nitrogen tetroxide but it failed to work because unfortunately someone
> before the flight forgot to remove the safety red cover over the exost
> valve of the fuel system and this is why after many attemps to overcome
> the problem the satellite got an explosion inside wich damaged most part
> of transponders.BTW AO40 worked fantastic in Mode U/S ,Mode L/S
> and Mode L/K for a long time until the main battery and the spare battery
> system suddently failed in short circuit.
> 73" de i8CVS Domenico
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