72-044 Apollo 17 site selection

NASA Manned Spacecraft Center, Houston, Texas 77058

FOR RELEASE: Upon Receipt RELEASED AT NASA HEADQUARTERS William W. Pomeroy

RELEASE NO: 72-44

APOLLO 17 SITE SELECTION

A combination mountainous highlands and lowlands valley region of the Moon designated Taurus-Littrow has been selected as the exploration site for the Apollo 17 mission, presently scheduled to carry out the sixth and final U.S. manned Apollo lunar landing in December 1972.

Apollo 17 is scheduled to be launched no earlier than December 6. The launch window, about 4 hours long, will open at approximately 9:38 p.m. EST. The landing point selected by the National Aeronautics and Space Administration is about 20° north and 30 ° east of the center of the Moon as viewed from Earth. The site is named for the Taurus Mountains and for the crater Littrow, both of which lie to the north of the site o This site was selected for consideration after a thorough search through the large amount of high resolution photography from Apollo 15.

Taurus-Littrow is a keystone site in the Apollo Program, having been selected to help fill in the major gaps in the developing model of the Moon as based upon Apollo 11, 12, 14, 15 and expected Apollo 16 data. The current model shows a complex Moon which formed about 4-1/2 billion years ago and which was subjected to intense cratering. Apollo 14 and 15 data show that one of the last large basins, Imbrium, was formed by an impact 3.9 billion years ago. It was not until the period from 3.2 to 3.7 billion years ago, however, that the great basins, formed during the intense cratering phase, became flooded by molten lavas originating in the lunar interior o One of the key questions remaining is to understand what happened in the period between 3.7 and 4.5 billion years. Similarly, it is important to understand whether or not the Moon has been thermally inactive for the last 3.2 billion years.

The Taurus-Littrow site is situated just beyond the southeast edge of Mare Serenitatis. Mare Serenitatis is one of the largest lunar mascons. Large, steepsided mountains of light-colored highlands dominate the terrain and are expected to provide samples older in age and different in composition from those returned from the Mare Imbrium basin on Apollo 14 and 15. Nature has already helped in the sampling as one of the sample sites is a rock slide which contains the debris which has fallen into the valley from high up on a 7000-foot mountain.

The targeted landing point itself will be on the other prime sampling objective which is the very dark non-mare material filling the valleys between the mountains. On occasion the dark material is found in small troughs on the mountainsides, indicating that it once thinly covered the mountains but has eroded off the steep slopes. This observation, plus the presence of volcanic-looking cinder cones, first reported by the Apollo 15 Command Module Pilot A1 Worden, indicates to lunar-scientists that the dark material is an explosively produced volcanic ash. The apparently low crater density in the area covered by the dark material also leads geologists to believe it to be among the youngest lunar volcanics. The explosive nature of the volcanism indicates a relatively high content of volatiles or gases, both of which have been exceedingly rare in all lunar samples seen thus faro If the Moon, as the preferred models indicate, has indeed cooled from the outside in, these youngest lunar volcanics should be derived from the greatest depths and may give the first good samples of the deep lunar interior.

The astronauts will use the Lunar Rover Vehicle to transport them to prospective important locations determined prior to the mission and to other points they might select during their exploration. Contingency walking traverses will also be planned to accomplish as many of the scientific objectives as possible.

The astronauts will deploy an advanced version science station, the Apollo Lunar Surface Experiments Package (ALSEP), containing a Heat Flow Experiment similar to that deployed on Apollo 14 and planned for Apollo 17 as well as four new experiments. In addition, two new surface traverse experiments, not powered by the ALSEP Central Station, will be deployed. These new experiments represent second generation scientific approaches to difficult lunar problems.

Three of the six new experiments represent new or improved geophysical techniques of exploring the hidden subsurface properties of the Moon. These experiments are: (1) Traverse Gravimeter, (2) Seismic Profiling, and (3) Surface Electrical Properties. The Traverse Gravimeter will measure variations in subsurface structure and furnish data on such problems as whether the mountains have deep roots or are merely deposits on a uniform subsurface. The Seismic Profiling and Surface Electrical Proper ties Investigations will measure the physical properties of the lunar interior down to about a kilometer in depth, and will indicate subsurface electrical and mechanical properties, the extent of subsurface layering and the degree of energy scattering at the landing site. Underground water, should it exist, will also be detectable.

A new ALSEP experiment, the Tidal Gravimeter, to study both the response of the moon to the earth's tidal pull and its response to gravity waves, should they exist in space, will be a fundamental contribution to astrophysics. Two other new experiments will also be part of the ALSEP. A mass spectrometer will measure the constituents of the lunar atmosphere -- the findings of which may be correlated with the mass spectrometers carried previously in lunar orbit; a lunar ejecra and meteorites experiment will determine the frequency and energy of the small meteorites and their ejecta which constantly impact and modify the Moon.

Three new experiments are added to the Apollo 17 orbital science payload. These replace the geochemical investigations and the mass spectrometer. Apollo 17 will be the third mission to carry a large set of orbital sensors in the Service Module. However, three new experiments are under development and production to replace the mass spectrometer, Alpha, x-ray and gamma experiments as well as the subsatell ite carried on Apollo 15 and planned for Apollo 16. The first of these, a Lunar Sounder, is a pulsed radar sounder and has the potential for identifying electrical properties and layering of the lunar crust overflown by the spacecraft.

The Lunar Sounder will provide the opportuniay to study detailed physical properties of the Moon up to depths of one and a half kitometers and if it exists, to aid in the location of subsurface water. The second, the infrared Scanning Radiometer will provide, for the first time, a high resolution thermal map of portions of the Moon. Thirdly, a Far Ultraviolet Spectrometer will measure the compositional and density variation of the lunar atmosphereo Since this experiment has the capability of measuring these variations as a function of atmosphere height, it will greatly extend the knowledge of the lunar atmosphere that was gained through the use of the original mass spectrometers on Apollo 15 and 16.

The SIM (Scientific Instrument Module) camera system flown successfully on Apollo 15, and planned for flight on Apollo 16, will also be carried on Apollo 17. This system contains the 24" Panoramic Camera, a 3" Mapping Camera and a Laser Altimeter. The Apollo 17 ground track will permit some new areas of the Moon to be investigated and photographed. In addition, where Apollo 17 overflies areas covered by previous missions, the difference in sun angle will provide the photo-geologists with photographs of lunar features at new illuminations. This will greatly aid them in their scientific investigations.

Apollo 17 will be commanded by Navy Capt. Eugene A. Cernan with Navy Cmdr. Ronald E. Evans, Command Module Pilot, and Dr. Harrison H. Schmitt, civilian scientist-astronaut, Lunar Module Pilot.

- end - February 16, 1972