[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Mars Pathfinder Update - 06/26/97

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

            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 mission. 

     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. 

                            #####