[sci.astro] Ulysses Update - 11/13/90

baalke@mars.jpl.nasa.gov (Ron Baalke) (11/15/90)

                     ULYSSES MISSION STATUS
                        November 13, 1990
 
     Today, the Ulysses spacecraft is about 22 million miles from
Earth, traveling at a heliocentric velocity of about 86,000 miles per
hour.  Switch-ons of science instruments will conclude this
week as the last of the nine experiments onboard the Ulysses
spacecraft are activated.
 
     On Wednesday, November 14, the Heliospheric Instrument
for Spectra, Composition and Anisotropy at Low Energies (HISCALE)
will be turned on.  On Friday and Saturday, November 16-17,
various segments of the final science experiment, the Solar-Wind
Plasma instrument, will be activated.  Both of these instruments
study ions in the solar wind streaming away from the Sun.
 
     In other spacecraft activities, today a pair of
maneuvers were being performed with the craft's thrusters which
will point the large dish of Ulysses's high-gain antenna more
closely at Earth.  Also today, the X-band radio transmitter has
been turned on.  Tentatively the spacecraft on November 15 will
begin transmitting its data to Earth with the X-band transmitter
through the high-gain antenna; until now it has sent radio
telemetry with its S-band transmitter.  X band is at a higher
frequency and permits data to be sent at faster rates.
 
     Ground controllers have continued to study a slight
wobble which has been noticed in the spinning spacecraft since
the deployment of its axial boom nine days ago.  The motion --
just under 1/2 degree from side to side -- does not affect
spacecraft operations or radio communication.  The mission team
nonetheless was considering possible corrective action.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | baalke@mars.jpl.nasa.gov
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |