Latest word on the Pathfinder

From: Jan Wee <>
Subject: Latest word on the Pathfinder
Date: Thu, 26 Jun 1997 14:33:21 -0500

Dear discuss-lfm members,

Found this latest Mission Status Report on the Pathfinder
via the NASA JPL site...

There is also a great PDF PRESS KIT available
detailing the Pathfinder Mission.  Check it out!

PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011 

                         Mars Pathfinder Mission Status
                                June 26, 1997

Mars Pathfinder, now eight days away from landing on the 
surface of Mars, performed the last of its scheduled trajectory 
correction maneuvers at 10 a.m. Pacific Daylight Time on
Wednesday, June 25. 

The correction maneuver was performed in two phases occurring 
45 minutes apart. The first burn, lasting just 1.6 seconds, 
involved firing four thruster engines on one side of the vehicle. 
The second burn lasted 2.2 seconds and involved firing two 
thrusters closest to the heat shield. The combined effect of 
both burns changed Pathfinder's velocity by 0.018 meters per
second (0.04 miles per hour), which places the spacecraft on 
target for a July 4 landing in an ancient flood basin
called Ares Vallis. Pathfinder is scheduled to land at 
10:07 a.m. PDT (in Earth-received time).  The one-way light 
time from Mars to Earth is 10 minutes, 35 seconds, so in 
actuality, Pathfinder lands at 9:57 a.m. PDT. 

If necessary, a fifth trajectory correction maneuver may 
be performed just before Pathfinder hits the upper atmosphere 
of Mars. The maneuver would be carried out either 12 hours or 
six hours before Pathfinder reaches the atmosphere at 10 a.m. 
PDT in Earth-received time. The flight team will make a 
decision to proceed with the final correction maneuver 
the evening before landing. 

A final health check of the spacecraft and rover was performed 
on June 20. All spacecraft systems, including science 
instruments and the critical radar altimeter, remain in
excellent health from the last check about six months ago. 
The rover received a "wake up" call, woke up on command 
from the lander, then accepted a software upgrade. Flight 
controllers next loaded the 370 command sequences that will be 
required by Pathfinder to carry out its surface operations

The spacecraft is now ready to begin its entry, descent 
and landing phase. It will be commanded into that mode 
at 1:42 p.m. PDT on June 30 by an onboard sequence. 

Mars Pathfinder is currently about 180 million kilometers 
(111 million miles) from Earth and about 3.5 million 
kilometers (2.2 million miles) from Mars. After 202 days 
in flight, the spacecraft is traveling at about 18,000 
kilometers per hour (12,000 miles per hour) with 
respect to Mars.