----- Original Message ----- From: "pabutusa@gmail.com" rob@pabut.org To: "i8cvs" domenico.i8cvs@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
Hi 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 27 degrees.
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 2500 km.
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.
73" de
i8CVS Domenico
On Sep 21, 2013, at 22:15, "i8cvs" domenico.i8cvs@tin.it wrote:
----- Original Message ----- From: "Angus McLeod" amcleod@caribsurf.com To: amsat-bb@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 hear.
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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