From: Jan Wee <jwee@mail.arc.nasa.gov>
Subject: Update on Mars Mission
Date: Thu, 02 Jan 1997 17:21:40 -0600
Dear discuss-lfm members,
Just in case you haven't had time to access the NASA JPL
Mars Pathfinder web site and check on how Mars Pathfinder
is doing, here is the latest update.
Hope everyone had a relaxing break if you were on vacation
over the holidays! We are all looking forward to the start of
our Planet Explorer Toolkit debate which will begin next week
on Monday, Janaury 6th. Thanks to all who have posted their
Planet Explorer Toolkit proposals and yes, even to those of you
who posted after the December 20th deadline. We plan to include
all your ideas (even if you got caught in the holiday rush!)
Welcome back to LFM!
Jan Wee
*************************************************************************
MARS PATHFINDER MISSION STATUS
December 18, 1996
12:00 p.m. Pacific Standard Time
Sojourner, a 10-kilogram (22-pound) rover tucked away on a petal of the
Mars Pathfinder spacecraft, got a 'wake up' call on Dec. 17 from flight
controllers at NASA's Jet Propulsion Laboratory. After waking up, Sojourner
conducted an internal health check and sent data back to the flight team
that all was well.
The Pathfinder flight team was ecstatic with the rover data, which
showed that all systems within the rover were operating normally. In
addition, data from the rover's main science instrument -- the alpha
proton x-ray spectrometer -- showed that it was operting properly.
"The rover woke up, did its internal health check, sent the lander
its status data and went back to sleep, all as planned," said
Art Thompson, rover operations team member. "All subsystems were
verified as being in good health."
Pathfinder continues to perform very well on its 500 million-kilometer
(310 million-mile) journey to Mars, the team reported. Currently the
spacecraft is 4 million kilometers (2.5 million miles) from Earth, traveling
at a speed of 3.1 kilometers per second (7,000 miles per hour). Its
destination, Mars, is currently about 190 million kilometers (118 million
miles)
away. All temperatures and power utilization of the lander and cruise
stage remain at their predicted levels for this phase of the mission.
The spacecraft was spun down from 12.3 rpm to 2 rpm on Dec. 11. Flight
controllers first instructed the spacecraft to turn to a Sun angle of
50 degrees and an Earth angle of 32 degrees. This allowed them to use
all four operating Sun sensors. The spacecraft executed the commanded
spin down to the normal cruise spin rate of 2 rpm in steps of 2 rpm
at a time.
Once the normal spin rate was established, the team turned on the
spacecraft's star scanner on Dec. 12. Star scanner data allows the
spacecraft to establish full, three-axis knowledge of its orientation
in space. This is the normal cruise attitude control mode and the
one in which all trajectory correction maneuvers will be performed.
While Sun sensor #5 continues to work well after a software fix, the
flight team continues to investigate the cause of the loss of Sun sensor
head #4. The team expects to reach a likely conclusion on the cause of
the problem within the next month or two.
Dave Gruel, Pathfinder flight director at JPL, conducted the Dec.16
health check of the lander science instruments, including the atmospheric
sensor instrument and meteorology (ASI/MET) package and the imager.
Temperature, pressure and accelerometer readings from the
atmospheric/meteorology
instrument verified it was in normal working order. Power and dark current
measurements received from the imager while it was imaging the darkness
around it, confirmed that the instrument was working properly, Gruel said.
Richard Cook, Pathfinder mission operations manager at JPL, reported
today that Pathfinder has been fully checked out for this phase of
the mission and that all subsystems are "go" for a successful seven-month
cruise to Mars.
The next major in-flight event will be Pathfinder's first trajectory
correction maneuver, which is scheduled for Jan. 4, 1997.
Provided courtesy of:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov