[net.ham-radio] ARRL 66: Oscar 10

ad7i@houxp.UUCP (Paul Newland) (08/06/83)

qst de ad7i
holmdel, new jersey, u.s.a.
hr arrl bulletin nr 66	from arrl headquarters
newington ct  july 28, 1983
to all radio amateurs bt

amsat attempted to fire the oscar 10 onboard kick motor for the final
orbit adjustment at 0032 utc on july 26.  the firing command was
transmitted and received but the motor did not fire.  amsat
speculates that when the ariane 3rd stage collided with oscar 10
about 53 seconds after separation back on the june 16 launch day,
helium pressurization plumbing was damaged.  helium under pressure is
used to operate the engine valves and to mix the hydrazine fuel
oxidant.  without pressure, the motor was unable to fire.  therefore,
amsat oscar 10 is in its final orbit.  

though not the orbit intended by amsat, oscar 10s present orbit is a
very useful one that will provide long distance and long duration
communication for many years.  arrl congratulates amsat on its
tremendous achievement and its professionalism in circumventing many
obstacles in reaching this final orbit.  we wish them many years of
continued success as oscar 10 becomes operational.

orbital parameters.  inclination 25.87 degrees, eccentricity 0.60434,
2.06 orbits per day, 699.546 minutes per orbit, 35500 km apogee and
3951 km perigee.  typical access time in north america is ten to
eleven hours per day  ar