Pilot’s G-suit

Posté le 8 décembre 2009 de Toni G.

… or ANTI-G COVERALLS

When in flight, the body can have trouble adjusting to stresses produced by rapid changing of speed or direction. In situations such as seat ejection, ditching, or parachute opening shock, the short duration of the excessive force has little effect on the body.

However, changing the direction of flight produces stress forces equal to several times the normal pull of gravity for much longer periods of time. These longer duration forces can have dangerous effects. At 5 g’s (5 times the force of gravity), the aircrewman’s body is exposed to a force that increases its weight 5 times.

This increased weight has many effects. Your body is pushed down into your seat. Your arms and legs feel like lead, and operation of equipment becomes more difficult. The extra weight on your internal organs causes stomach and chest pain. Most important, however, is the effect on your circulatory system. At 5 g’s, your heart cannot pump enough blood to your head. When this happens, you will pass out. Wearing anti-g coveralls will help prevent this from happening.

The Navy uses two models of anti-g coveralls (commonly called « G » suits). These coveralls provide protection against blacking out, loss of vision, and lowered mental efficiency caused by high g-forces experienced in high-performance aircraft. Figure 11-4 shows a typical anti-g coverall. Anti-g coveralls compress your legs and stomach to prevent blood from pooling in your lower body.

This increases your stress tolerance an average of about 2 g’s. Without an anti-g coverall, you may be able to withstand about 4.5 to 5.5 g’s without losing vision or blacking out. With a coverall, you can withstand 6.0 to 7.0 g’s.

This protection is available only for sustained accelerations of 4 to 5 seconds. Anti-g equipment does not offer protection in snap maneuvers where 10 to 12 g’s are applied in about 1 second. Such extreme forces for a short time are not as harmful to the body as are lesser forces sustained for a longer time.

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NASA finds out more water than expected on the moon

Posté le 14 novembre 2009 de Toni G.

The argument that the moon is a dry, desolate place no longer holds water.

Secrets the moon has been holding, for perhaps billions of years, are now being revealed to the delight of scientists and space enthusiasts alike.

NASA today opened a new chapter in our understanding of the moon. Preliminary data from the Lunar CRater Observation and Sensing Satellite, or LCROSS, indicates that the mission successfully uncovered water during the Oct. 9, 2009 impacts into the permanently shadowed region of Cabeus cater near the moon’s south pole.

The impact created by the LCROSS Centaur upper stage rocket created a two-part plume of material from the bottom of the crater. The first part was a high angle plume of vapor and fine dust and the second a lower angle ejecta curtain of heavier material. This material has not seen sunlight in billions of years.