Moon Explorers' Scientific Experiments

Press, Volume CIX, Issue 32145, 14 November 1969, Page 9

Moon Explorers' Scientific Experiments

(N.Z.P.A -Reuter—Copyright) CAPE KENNEDY, November 13. The Apollo 12 astronauts’ scientific experiments on the moon are expected to help to meet criticism that America’s lunar programmes are solely an engineering feat.

Several scientists have left the space programme in the last few months, alleging that science was taking a back seat to the ballyhoo of putting men on the moon.

But the rocks brought back from the moon by the Apollo 11 crew have caused great excitement among geologists and astronomers; though the lunar samples have not yet settled the arguments about the moon’s origins. Now that man has shown that he can land on the moon and return safely, the scientific aspects of the eight proposed Apollo lunar flights are expected to assume greater importance in the space programme.

Apollo 12 is setting the trend; its primary objects include “selenologicai inspection, survey, and sampling in a lunar sea area.” The mare area is on the western side of the so-called

Ocean of Storms, about 830 nautical miles west of Apollo Il’s landing site, in the Sea of TranquillityCommanders Charles Conrad and Alan Bean will leave behind a sophisticated set of instruments called “Alsep” (Apollo lunar surface experiments package). Investigation of the moon's geology will occupy almost all the of the astronauts’ second walk; the locations of the various samples to be collected will be photographed before and after they are taken; and the astronauts will also carefully describe the setting. The moon explorers will collect specimens believed to have been ejected from deep down in the moon’s craters; the material will tell experts something of the nature of the moon’s interior. Earthbased geologists who have been available to advise the astronauts will work with the information they bring back.

When the astronauts blast off from the moon they will leave behind instruments to measure the solar wind (charged particles from the sun that bombard the moon), the interplanetary magnetic field, and the moon’s physical properties. The Alsep instruments that will send back coded signals are the lunar surface magnetometer, lunar ionosphere

detector, lunar atmosphere detector, solar wind spectrometer, solar wind composition experiment, passive seismic experiment, and dust detector. The lunar surface magnetometer, in measuring the magnetic field at the lunar surface, will help to determine the electrical properties of the moon, aiding scientists’ investigation of the moon’s internal temperature and origins.

The instrument consists of three extremely sensitive magnet sensors and an electronics unit. The ionosphere and atmosphere detectors will study the charged particles and neutral particles in the lunar atmosphere. The ionosphere is expected to consist mainly of elements of solar wind, but might also include gas escaping from the moon, and material vaporised by the impact of meteorites; and the ionosphere detector will help to identify the ionised charges, elements and molecules. It will also measure the charged particles as the moon passes through the earth’s magnetic field. Measurements of the density, temperature and changes in the lunar atmosphere taken by the atmosphere detector are expected to help scientists to understand processes that shaped the lunar

surface, producing the apparent erosion that has taken place over millions of years. The solar wind spectrometer will provide information to help scientists understand the origin of the sun, and the physical processes at

■ work on it, by studying the i energy that it pours into . space. The solar wind’s electrons ■ and protons will be trapped ■ in seven cups that will meas- , ure the current produced. The passive seismic experi-

ment will measure moonquakes, surface tilt produced by tidal deformations, and meteorite impacts. A “seismic event” equivalent to the explosion of one ton of T.N.T. will be provided by the crashing of the lunar module ascent stage on the moon’s surface after the moon explorers have rejoined the Apollo mother ship. The experiment to determine solar wind composition will consist of a four-square-feet sheet of aluminium foil which will be exposed for 17 hours to catch solar wind particles, compared with the two hours of a similar experiment by the Apollo 11 crew. The Alsep dust detector, consisting of three solar cells will watch for dust or debris accumulation. All the Alsep instruments will be powered by nuclear batteries designed to provide electricity for continuous operation for one year. Another task of the moon explorers will be the snipping 111 unmanned spacecraft so of pieces from the Surveyor that scientists on earth may see how it has fared during two years and a half in the harsh lunar environment.

This assignment, however, can be carried out only if the lunar module lands within walking distance of the Surveyor’s crater.