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Testing 'Moon Dust' for Astronauts

By Arthur J. Snider
Daily News Science Writer

When the first space ship lands on the moon, will it come to a jarring halt on a solid foundation – or will it sink into a sea of dust?

Until recent years, it was generally accepted that the large flat areas of the moon were covered with hardened lava spewed up by volcanoes or transferred by the great heat of meteorite bombardments.

This is no longer agreed upon. There are some scientists who warn that moon dust may run many feet deep.

But even if there should be dust in depth, there is now some suggestive evidence that a secure landing is possible. A moon dust project at the Armour Research Foundation shows that the grains conceivably could be compacted in a way that would support considerable weight.

ARF engineer Ernest T. Selig is creating simulated moon dust depths of various densities and then conducting penetration and static weight bearing experiments to determine strength characteristics.

It has been found that at a density of 50 pounds per cubic foot, for example, the moon dust is in a relatively unstable state and moves readily at the slightest jarring.

At a high desnity, however, the dust is relatively hard, has great strength, and could support buildings or vehicles.

Not known, of course, is the actual dust density on the moon. When this is determined by impaction of rocket payloads or remote control analysis, there will be available from the wrok of Selig a good indication of how much weight can be supported on landing.

To simulate moon dust, Selig uses a white silica flour prepared by grinding silica sand into fine, powdery particles. Experiments are conducted in a vacuum chamber in order to simulate the absence of atmosphere on the moon. No effort is made to duplicate the moon’s gravitational pull or temperature.

The same compaction of dust can be obtained in a vacuum chamber as may exist on the moon. The vacuum chamber removes the film of air surrounding dust particles. This creates a higher internal friction and increases the resistance of particle to movement. On the airless moon, a similar condition probably prevails.

Armour Research Foundation also is developing a lunar drill to penetrate the moon’s surface and gather samples of soil, rocks, and minerals for remote control analysis.