Apr 10 1975
From The Space Library
The first ground-test hardware for the Space Shuttle, a hydraulic actuator for the main engine, had arrived at Marshall Space Flight Center for functional checkout, MSFC announced. Each of the Orbiter's three main engines would use two of the actuators to gimbal the engine for steering control. After checkout the actuator-one of 8 to be tested-would be sent to the National Space Technology Laboratories where the main engines would be tested. (MSFC Release 75-68)
Dust storms had been observed on the moon every sunrise and sunset by a three-axis microparticle detector left on the moon by Apollo 17 astronauts during their December 1972 mission, a Nature magazine article reported. The article, based on a report by scientists at Goddard Space Flight Center, said the GSFC scientists suspected that the dust was being lifted from the lunar surface and then driven away from the rising or setting sun by electrostatic fields associated with the transition from day to night, or vice versa.
The finding supported a theory advanced 20 yr ago by Dr. Thomas Gold of Cornell Univ., who had suggested that electrostatic forces transported dust from lunar highlands to lowlands, accounting for the smooth appearance of the lunar seas. Although the Apollo landings had shown that those seas had been formed by lava flooding rather than deep dust accumulations, their surface was covered with very fine dust. Also, because neither wind nor rain existed on the airless moon, some other process must have been responsible for the evident erosion. Electrostatic levitation was being suggested as one possible explanation. Because the lunar vacuum acted as an insulator, the dust cloud hugged the surface, reaching only between 20 and 30 cm high, explaining why it had been detected from a low angle by instruments on the lunar surface but never by orbiting astronauts or earth-based equipment. (Hughes, Nature, 10 April 75, 481-2)
The Air Force's new B-1 bomber broke the sound barrier for the first time while making its sixth flight test, from Vandenberg Air Force Base. During the 6-hr 23-min mission, the B-1 also took on fuel from a KC-135 tanker for the first time and opened its weapons-bay doors. (AP, W Star, 11 April 75, 4)
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