Jun 10 1980
From The Space Library
JSC said that a NASA board investigating the April 18 flash fire in a space suit backpack [see April 22) had found where the fire started and had recommended 11 changes to improve system safety. Apparently, when a technician during a test in the crew systems laboratory switched the secondary oxygen pack to the "spacewalk" position, ignition occurred in a V -shaped passage restricting oxygen flow between a shutoff valve and a chamber in the pack's regulator module. In the accident, which destroyed an unoccupied Shuttle space suit and life-support backpack, Hamilton Standard technician Robert A. Mayfield was severely burned but was recovering.
After five weeks of engineering detective work (including more than 2,000 unsuccessful attempts to reproduce the fire), the board had not found the exact cause, but reported to JSC Director Christopher C. Kraft, Jr., the four most probable causes of the fire. heating by compression or shock of a thin section of aluminum between the flow-restrictor passage; and the adjacent cavity; heating by compression or shock of contaminants in the flow restrictor; heating of internal surfaces through mechanical shock from incoming high pressure oxygen, or heating of particles; similar heating of shutoff valve O rings. The regulator module had undergone 19 cycles with high-pressure oxygen before the accident. The board found that all procedures followed during the April 18 test were proper.
Technicians at JSC's White Sands Test Facility could not duplicate the failure, although they cycled four regulator modules from the same factory batch 2,228° times. Disassembly after the tests revealed contamination inside the modules. The board recommended redesign, design reviews, inspections, and collection of high-pressure oxygen data to establish standards for equipment design and use. (JSC Release 80-039; NASA Release 80-91)
NASA reported award to United Space Boosters, Inc., subsidiary of United Technologies Corporation, of a contract for a two-ship recovery force to retrieve used Space Shuttle solid-fuel rocket boosters from the Atlantic Ocean. This supplemented a contract under which the firm assembled and processed solid-fuel rocket boosters for flight. The ships would locate and retrieve expended booster casings, parachutes, and other equipment from the Atlantic and deliver them to a disassembly facility at Cape; Canaveral Air Force Station. The disassembly facility was on the eastern shore of the Banana River, a shallow area where an endangered species, the sea cow or manatee, made its home. The ships would use a 425-HP waterjet stern thruster instead of propellers that could maim or kill the manatees [see May 29].
The ships, UTC Liberty and UTC Freedom, were being built and would be delivered in October 1980 and January 1981; both would be used on each Shuttle mission, each retrieving one booster and its components. At liftoff, the boosters would burn simultaneously with the three-engine cluster on the Shuttle. After about two minutes they would be jettisoned and land in the Atlantic about 257 kilometers (160 miles) downrange from KSC, their descent being slowed by three parachutes on each casing. Each vessel would carry four parachute-rollers to handle the three main and single drogue parachutes on each booster and cranes to hoist aboard the collateral flight equipment. The ships would carry equipment to plug the nozzles, pump water out of the casings, and ready them for towing to the disassembly facility, where they would be cleaned and taken apart for shipment to Utah and reloading with solid-fuel propellant. Each casing could be used for up to 20 missions, reducing the cost of flight operations. The ships would also have sophisticated electronic communications and navigation gear such as radars, sonars, loran, direction finders, fathometers, and gyrocompasses. (NASA Release 80-89)
DFRC reported that it and the FAA had resumed wake vortex flight tests using an L-1011 widebody jet transport. The wake produced by a widebody aircraft could be severe enough to delay takeoffs and landings at airports; planned time separations were in effect because the wake could upset other aircraft landing or taking off. Diminishing the wake vortex could reduce traffic congestion, with significant savings in fuel and time.
Previous tests using a Boeing 747 [see October 29, 1979] showed that selected use of ailerons and spoilers on the aircraft could break up the vortex, an invisible flow of turbulent air streaming from flaps and wingtips in a tornado shape. Spoilers, normally used as speed brakes and to decrease aerodynamic lift after landing, would serve in flight to break up the vortex trailing from the flaps; ailerons, normally used for turning, would serve to break up the wing vortex. The L-1011 being tested was the Lockheed prototype with a direct-lift flight-control system using spoilers deflected upward at 8°; the proposed vortex alleviation system would not differ much from the system already in use on the L-1011. The tests would use a small highly instrumented NASA test aircraft for high-altitude recording of the L-1011 vortex, marked by smoke generators. (DFRC Release 80-7; NASA Release 80-92)
The Washington Star carried a Tass report that cosmonauts Vladimir Aksyonov and Yuri Malyshev had soft-landed in Central Asia after a visit to orbiting space station Salyut 6. The two were launched June 5 in a new transport vehicle called Soyuz T2. Salyut 6 had been occupied since April 9 by Leonid Popov and Valery Ryumin, who would probably remain in orbit to greet visitors to the Moscow Olympics, the dispatch said. (W Star, June 10/80, A-8)
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