Apollo 17 Mission Overview

Apollo 17 (CSM America and LM Challenger) Saturn V

1972 December 7-19 Eugene A. Cernan Ronald E. Evans Harrison H. Schmitt

12 days 13 hours 52 minutes Landing site: Taurus-Littrow

Landing Coordinates: 20.19 degrees North, 30.77 degrees East (Source: National Space Science Data Center)

APOLLO 17 MISSION REPORT EXCERPT 9.1 Lunar Roving Vehicle

The lunar roving vehicle satisfactorily supported the lunar exploration objectives. Controllability was good, and no problems were experienced with steering, braking, or obstacle negotiation. The navigation system gyro drift and closure error at the lunar module were negligible. All interfaces between the crew and the lunar roving vehicle and the stowed payload were satisfactory.

Deployment of the lunar roving vehicle from the lunar module was smooth and no significant problems were encountered. The chassis lock pins did not seat fully, but the crew used the deployment assist tool to seat the pins.

At the initial power-up, the lunar roving vehicle battery temperatures were higher than predicted; 95 degrees F for battery 1 and 110 degrees F for battery 2 compared to the predicted temperatures of 80 degrees F for each. This was partially due to the trans-lunar attitude profile flown, and partially to a bias in the battery temperature meter. Following adequate battery cool-down after the first extravehicular activity, temperatures for the remainder of the lunar surface operations were about as predicted.

The following lunar roving vehicle systems problems were noted:

a. The battery 2 temperature indication was off-scale low at the start of the third extravehicular activity.

b. The right rear fender extension was knocked off prior to leaving the lunar module on the first extravehicular traverse.

Mars Pathfinder/Sojourner mission overview 291

The battery 2 temperature indication was off-scale low at the beginning of the third extravehicular activity. This condition continued for the remainder of the lunar surface operation. The most probable cause was a shorted thermistor in the battery. The same condition was noted on ground testing of two other batteries. Electrolyte leakage through the sensor bond, as a result of elevated temperatures, may have caused the short. Temperature monitoring was continued using battery 1 as an indicator with temperature trends established from data on the first and second extravehicular activities for battery 2.

During the first extravehicular activity at the lunar module site, the Commander inadvertently knocked off the right rear fender extension. While still at the lunar module site, the Commander taped the extension to the fender. Because of the dusty surfaces, the tape did not adhere and the extension was lost. Lunar surface maps were subsequently clamped to the fender. This fix was adequate.

9.2 Lunar Communications Relay Unit and Ground-Commanded Television Assembly

The lunar communications relay unit provided satisfactory support from the lunar surface, and the ground-commanded television assembly produced good quality pictures at all times. Activation was initiated about 1 hour and 11 minutes after crew egress for the first extravehicular activity. Television coverage of crew egress was not available because the capability to televise from the lunar module was eliminated for Apollo 17 to save weight.

The system allowed ground personnel to coordinate lunar surface activities with the crew. The rover fender repair and the deep-core drilling were especially significant in this area. Television coverage, augmented by crew comments, was a valuable asset used in making an early determination of the actual experiment locations, sampling sites, traverse stops, geological features, and the landing point area. Panoramic reproductions of the television pictures were a significant contribution to a preliminary interagency geology report which was issued on 17 December 1972, two days prior to termination of the mission.

The lunar communications system failed to respond to uplink turn-on commands about 36 hours after lunar liftoff. The condition was expected because the lunar environment eventually exceeded the operational temperature limits of the equipment.

Total television operating time was 15 hours and 22 minutes.

MARS PATHFINDER/SOJOURNER MISSION OVERVIEW

Launch Vehicle: Boeing Delta II Pathfinder Spacecraft Mass: 895 kg Sojourner Rover Mass: 10.6 kg Launched: 1996 December 4 Landed: 1997 July 4

Landing Site and Coordinates: Ares Vallis; 19.33 degrees N, 33.55 degrees W Last Data Transmission: 1997 September 27 (Source: National Space Science Data Center)

Mars Pathfinder primary mission duration was established for 7 sols. It far surpassed this goal. The Pathfinder lander returned more than 16,500 images and the Sojourner rover returned 550 images. The rover performed more than 15 chemical analyses of surrounding rocks and soil, and the lander returned extensive data on the region's weather. Scientific findings from the instruments indicated that region of Mars once had liquid water on the surface and had a thicker atmosphere.

MARS EXPLORATION ROVER (MER) MISSION OVERVIEW

Launch Vehicle: Boeing Delta II Lander Mass: 348 kg

MER Mass: 174 kg (185 kg on-orbit dry mass) MER Spirit Launched: 2003 June 10

Landing Site and Coordinates: Gusev Crater; 14.57 degrees S, 175.47 degrees E MER Opportunity Launched: 2003 July 7

Landing Site and Coordinates: Meridiani Planum; 1.95 degrees S, 354.47 degrees E (Source: National Space Science Data Center)

The Mars Exploration Rovers' primary mission duration was established for 90 sols. They far surpassed this goal. Spirit and Opportunity continued to operate past 900 sols. NASA repeatedly extended the missions of these rovers and provided operating funds to JPL to perform on-going mission operations. Both rovers returned irrefutable scientific evidence of the previous presence of water. They also returned unprecedented data on Mars' weather and composition of soils and rocks. The rovers also validated mechanical and electrical systems for mission longevity.

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