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Mars Pathfinder Fact Sheet

Mission Summary Mission Description Major Mission Characteristics
Spacecraft Characteristics Flight System Characteristics Science Payload Characteristics
Microrover Characteristics Mars Pathfinder Mission Management

Mission Summary

Artist's Rendition Of Mars Pathfinder Landing At Night (D. Carroll)

Artist's Concept Of Lander And Microrover On Mars

The Mars Pathfinder Mission is the second launch in the Discovery Program, a NASA initiative for planetary missions with a maximum three year development cycle and a cost cap of $150M (FY92) for development. The Mars Pathfinder is managed for NASA by the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California.

The mission is primarily an engineering demonstration of key technologies and concepts for eventual use in future missions to Mars employing scientific landers. Pathfinder also delivers science instruments to the surface of Mars to investigate the structure of the martian atmosphere, surface meteorology, surface geology, form, and structure, and the elemental composition of martian rocks and soil. In addition a free-ranging surface rover is deployed to conduct technology experiments and to serve as an instrument deployment mechanism.

Mission Description

The flight system is launched on a Delta II-7925 launch vehicle which includes a payload assist module (PAM)-D upper stage, from the Cape Canaveral Air Station. The mission launch window is a 29-day period beginning on December 2, 1996.

After launch, the spacecraft requires 6 to 7 months to reach Mars, depending upon the exact launch date. During this phase, a series of four trajectory correction maneuvers (TCMs) are performed, in order to fine tune the flight path. Tracking, telemetry, and command operations with the spacecraft are conducted using the giant dish antennas of the NASA/JPL Deep Space Network (DSN). Upon arrival at Mars on July 4, 1997, the spacecraft will enter the martian atmosphere, and then deploy the parachute, rocket braking system, and air bag system for a soft, upright landing. At this point the primary data-taking phase begins, and continues for 30 martian days or sols (24.6 hours).

During this time, the microrover is deployed and operated for at least 7 sols. If the lander and rover continue to perform well at the end of this period, an extended mission may continue for up to one martian year for the lander, and the microrover for up to 30 sols.

Major Mission Characteristics

Launch Period
December 2 - 31, 1996
Launch Vehicle
Delta II - 7925
6-7 Months
Primary Mission
Land On Mars - July 4, 1997
Complete Surface Mission
August 1997
End Of Project
September 1998

Interplanetary Trajectory

MPF Trajectory To Mars

Entry Descent Landing (EDL)

MPF Entry, Descent And Landing

Spacecraft Characteristics

Spacecraft Parts Indentification

MPF Lander Line Drawing

Flight System Characteristics

Launch Mass
890 kg (Includes Propellant)
Entry Mass
570 kg
Lander Mass
360 kg
Basic Design
Command And Data Handling
Integrated Attitude and Information Management System (AIM)
R6000 Computer with VME bus, 22 Millions Of Instructions Per Second (MIPS), 128 Mbyte mass memory
Solar powered cruise stage and lander
Telemetry And Command
  • Surface operations telemetry rate via High Gain Antenna (HGA), X-Band:
    • 6 kb/s to 70-m Deep Space Network
  • Surface operations command rate via HGA, X-Band:
    • 250 b/s
  • Monopropellant hydrazine used for cruise
  • Eight 4.4-N thrusters
  • Total delta-v of 130 m/s

Science Payload Characteristics

 Instrument Mass Power
 Atmospheric Structure Instrument/Meteorology Experiment (ASI/MET)

2.04 kg
 3.2 W
 Imager For Mars Pathfinder (IMP)

5.20 kg
 2.6 W
 Alpha-Proton X-Ray Spectrometer (APXS)

0.74 kg
 0.8 W

Microrover Characteristics

Rover Sojourner

Total Mass
16 kg
Mobile Mass
11.5 kg including APXS deployment mechanism and APXS Instrument
Lander-Mounted Rover Equipment Mass:
4.5 kg including ultra-high frequency (UHF) modem and support structure.
Autonomous Navigation
On board, using laser striping for obstacle detection
Mobility System
Six-wheel, rocker bogie suspension
Command And Telemetry
UHF link with lander
Aft and fore cameras, APXS, APXS deployment mechanism
0.25-M2 Solar panels, peak power 16 W-hours: primary battery, 50 W-hours
Thermal Control
Three radioisotope header units (RHUs)
Computer Characteristics
80C85, 0.1 MIPS; 0.5 Mbyte RAM mass storage; 0.5 kg, 1.5 W
Surface Ops Time
10 A.M. to 2 P.M. each martian day (sol)

Mars Pathfinder Mission Management

NASA Program Manager
Donald Ketterer
NASA Program Scientist
Joseph Boyce
JPL Project Manager
Anthony J. Spear
JPL Project Scientist
Dr. Matthew P. Golombek

JPL Homepage

Mars Pathfinder Homepage

NASA Homepage

TELEPHONE (818) 354-5011

This Document Was Last Updated: 19 March 1997