Mars Pathfinder

Chronology

Mission timeline

1. December 4, 1996, 06:58:00 UTC

   Launch

   Launched on a Delta II 7925

   Mars Pathfinder was launched on a Delta 7925 (a Delta II Lite launch vehicle with nine strap-on solid-rocket boosters and a Star 48 (PAM-D) third stage) at 6:58:00 UT (1:58 a.m. EST) on 4 December 1996, and the launch/orbital information page gives the same instant as 1996-12-04T06:58:00Z. That page also prints Decay Date: 1996-07-04, five months before the launch it prints at the head of the same page and one year before the 4 July 1997 landing; the wrong value is recorded rather than repaired, and this record takes the landing date from the master catalog page. NASA PDS independently gives 6:58 am UTC and launch complex 17B, agreeing at minute precision.

   Earth
2. July 4, 1997, 16:56:55 UTC

   Landing

   Bounced to a stop in Ares Vallis

   The lander dropped to the ground in 3.8 seconds and impacted at 16:56:55 UT (12:56:55 p.m. EDT) on 4 July 1997 at a velocity of 18 m/s and bounced about 12 meters (40 feet) into the air, bouncing at least another 15 times and rolling before coming to rest approximately 2.5 minutes after impact and about 1 km from the initial impact site. The launch/orbital information page places the lander at Latitude: 19.330 degrees, Longitude: 33.550 degrees with an epoch beginning 1997-07-04 16:56:00, one round minute before the second-precision time the master catalog page prints. The PDS IMP dataset identifies 19.17° N, 33.21° W as the USGS cartographic solution and 19.30° N, 33.52° W as the two-way-ranging/Doppler inertial solution. The PDS mission description uses the cartographic coordinate and says the lander came to rest about 12 miles southwest of the target. NSSDCA reports 19.330° N, 33.550° W and about 1 km from initial impact; its coordinate relation to the PDS solutions is not established, so the values and reference points remain separate.

   Mars
3. July 6, 1997, 05:40 UTC

   Deployment

   Sojourner rolled onto the surface

   After some maneuvers to clear an airbag out of the way, ramps were deployed and the rover, stowed against one of the petals, rolled onto the surface on 6 July at about 05:40 UT (1:40 a.m. EDT). NSSDCA gives the rover its own page under the name Sojourner Rover, which this record models as a vehicle of the lander rather than as a mission of its own. GCAT deepcat gives the rover as D00734, Name Sojourner, PLName MFEX Rover, parent D00727, and the cruise stage as D00729, which is where this record's third vehicle comes from. NASA PDS separately dates rover deployment at 05:37 UTC; NSSDCA describes rolling onto the surface at about 05:40 UT. The three-minute source time difference is retained unresolved.

   Mars
4. September 27, 1997

   Loss of contact

   Communications lost for unknown reasons

   Images were taken and experiments performed by the lander and rover until 27 September 1997 when communications were lost for unknown reasons. The landing site in the Ares Vallis region of Mars is at 19.33 N, 33.55 W. The lander has been named the Sagan Memorial Station. NASA PDS says the final science data arrived on 27 September and suggests a dead battery combined with increasing winter cold; NSSDCA describes the communications loss as for unknown reasons. The cause remains an attributed hypothesis.

   Mars

Mission architecture

Vehicles

• Sagan Memorial Station · Lander

  Destinations: Mars

  • Sojourner Rover · Rover

    Destinations: Mars

• Mars Pathfinder cruise stage · Other