Space Shuttle. One entire lab devoted to life-science experimentation would be launched every 6 mo. Other small highly automated life-science experiments could be performed during Spacelab and Space Shuttle missions dedicated to other disciplines; NASA estimated that as many as 200 life-science flight experiments could be conducted in space during the 1980s.

The invitation stated that "in order to take maximum advantage of future research opportunities, NASA intends to involve a large cross section of the Life Sciences community in shaping scientific program objectives, in selecting spacecraft laboratory equipment, and in the planning and execution of Flight Experiments.

NASA estimated that approximately 200 scientists could participate as principal investigators of future flight experiments and that 50 of those could perform their research in space as crew members.

As part of the first phase of the life-science program, NASA requested that interested scientists suggest general topics for future research and identify equipment needed to carry out life-science investigations. (Winter letter, text; NASA Release 75–140; UPI, NYT, 9 May 75, 7)

The launch of Skylab 1 on 14 May 1973 had torn a temporary "hole" in the ionosphere, Physics Today reported. The journal said scientists speculated that the hole, a depletion of the total electron count, was caused by molecular hydrogen and water vapor from the exhaust of the Saturn V engines which had continued to burn well into the lower region of the ionosphere. The exhaust caused the oxygen atoms in the ionosphere to recombine, losing one electron each; the electrons were removed faster than could be replenished by the sunlight, thus the hole. The sun did replace the electrons, patching up the hole within 3 hr after the spacecraft passed.

The electron loss triggered by the Skylab launch was similar to ones caused, on a larger scale, by magnetic storms. Because the launch occurred on the second day of such a storm, scientists found it difficult to trace any radio interruptions-typical during decreases in the electron content of the ionosphere-to Skylab. (Physics Today, May 75, 17-18)

The Air Force Systems Command Newsreview reported that the Air Force had awarded an estimated $17 649 042 contract to McDonnell Douglas Corp.'s Douglas Aircraft Co. for the development, manufacture, and testing of a wide-body cargo aircraft fuselage segment using adhesive bonding instead of conventional riveting of the primary structures. Either the YC-14 or the YC-15, advanced mediumshort-takeoff-and-landing transport prototypes, would be used as the engineering baseline against which the technology could be developed and evaluated. The contract was AFSC's primary adhesively bonded structure (PABST) portion of the advanced metallic structures (AMS) program to improve structural integrity and durability of future aircraft while minimizing weight and costs of acquisition and maintenance. (AFSC Newsreview, May 75, 4)

• Flying magazine discussed "Relevant Research" at NASA: NASA had often been accused of neglecting aeronautics research in favor of space. But the $6.2 million for general aviation, of NASA's total $3.5 billion budget, was "a lot of money, even for a Government agency, and if used wisely. . .can make significant contributions in the many areas where technology advancements are sorely needed."

NASA was particularly well suited to investigate stalls and spins and weather prediction-two of the most prominent factors in general aviation accidents-as well as to develop simple autopilots and flightcontrol systems.

With the aircraft industry becoming increasingly competitive, NASA was "one place to seek help" to produce a technically superior product. NASA was responding to the need, allocating manpower and dollars to relevant general aviation research programs.

More important was the new attitude of NASA and industry toward communicating about capabilities and needs. In the past NASA did its research “in a vacuum, oblivious to the needs of the aviation community and to the unique conditions that constrained the industry's ability to apply NASA research results." But recently NASA initiated a series of workshops between key industry technical experts and their NASA counterparts, designed to coordinate industry technological problem areas and NASA research programs. Also, in 1974, NASA established the General Aviation Technology Advisory Panel and gave it equal stature with the committees and panels that constituted the influential NASA Research and Technology Advisory Council.

The atmosphere for effective communication and relevant research was improving. "While the threat of bureaucratic inefficiency and self-serving growth seems ever-present in Government endeavors, we see a conscientious effort on the part of NASA to apply their resources to the needs of general aviation." (Flying magazine, May 75)

June 1975

2 June: The Netherlands, Denmark, and Norway had signed preliminary contracts and memorandums of understanding with the U.S. to purchase 348 General Dynamics Corp. F-16 fighter aircraft for a total of $2.1 billion, Aviation Week and Space Technology reported. The countries were part of a four-nation consortium-with Belgium-to evaluate the F-16, French Dassault-Breguet Mirage FIE, and Sweden's Saab Viggen as possible replacements for the Lockheed Aircraft Corp. F-104 operated by these countries. The preliminary contract was contingent on a full commitment to the F-16 by all four countries by 15 June.

Aviation Week reported that Belgium had requested a two-week delay in making its choice but then announced its selection of the F-16 on 7 June after the countries had received assurance that the consortium would be permitted to produce, in Europe, 10% of all parts for the F-16. In addition, the four countries would produce 15% of the aircraft for sales to third world countries as well as 40% of the components for the aircraft bought by the consortium. (Av Wk, 2 June 75, 21; 16 June 75, 17; AFSC Release 280-75) Private industry and government agencies in the U.S. and in Europe were investing money in designs and prototypes of giant dirigibles that could carry cargo and passengers more cheaply than conventional aircraft, Newsweek reported. In May a 9-m-wide heliumfilled prototype dirigible named Skyship, shaped like a flying saucer, had been flight-tested at a Royal Air Force station in England; a flight model was expected to go into commercial operation within 3 yr. Shell Oil Co. had spent more than $1 million studying the possibility of developing dirigibles to transport natural gas, Newsweek said.

The U.S. Air Force was investigating dirigibles as a means of ferrying missiles from silo to silo, and the Navy was studying their ability to track submarines.

A reason for the resurgence of interest in lighter-than-air craft was the energy crisis. Airships require hardly any fuel to get aloft and use very little for propulsion, and they also produce less noise and less atmospheric pollution.

New designs for dirigibles included the substitution of inert helium for highly flammable hydrogen as the lifting gas, and the replacement of the familiar cigar shape with other configurations to do away with the problem of instability near the ground. (Newsweek, 2 June 75) U.S. helicopter manufacturers were increasing production to capitalize on heavy worldwide demand for helicopters, Aviation Week and Space Technology reported. In 1974 U.S. manufacturers exported 420 helicopters at a value of $124 million, an increase of $39 million over 1973 sales and double 1971 sales. (Av Wk, 2 June 75, 114)

• Luna 22, launched 29 May 1974 by the U.S.S.R., had been in lunar orbit more than a year. Tass reported that, after 3296 orbits of the moon,

the planned program for a comprehensive exploration of the moon and near-moon space had been fully carried out and additional exploration was continuing. All systems aboard the spacecraft were functioning normally. (Tass, FBIS-Sov, 18 June 75, U1)

2-7 June: Three NASA scientists and two Europeans conducted a Spacelab simulation mission aboard NASA's Galileo II airborne laboratory. The series of five night flights was designed by NASA and European Space Agency representatives to permit Spacelab mission planners to evaluate experiment techniques and operations. The simulations, part of a study program called the Airborne Science Spacelab Experiments System Simulation (ASSESS), would provide valuable information on the interaction between scientific investigators on the ground and experiment operators aboard Spacelab and would aid in estimating the training needed by Spacelab experiment operators.

Experiments flown in the simulation mission included infrared observations of the earth's upper atmosphere, Venus, stars, and other celestial features, and ultraviolet measurements of planetary atmopheres. (NASA Release 75-177; ESA Releases, 27 May 75, 18 June 75) 3 June: Explorer 49-Radio Astronomy Explorer B, launched 10 June 1973 into lunar orbit to measure galactic and solar radio noise at frequencies below ionospheric cutoffs and beyond terrestrial background interference by using the moon for occultation, focusing, or aperture blocking for increased resolution and discrimination-had completed nearly 2 yr of successful operation and was adjudged successful.

Explorer 49's lunar orbit, away from the noisy environment of earth, had increased the effectiveness of the instrumentation. The spacecraft had been able to detect very weak solar-noise bursts up to 13 mhz and as low as 25 khz. Its predecessor, Explorer 38-Radio Astronomy Explorer A, launched 4 July 1968-had been able to observe relatively intense solar-noise bursts only in the 200 khz to 9 mhz range because of its orbit within the earth's magnetosphere. Explorer 49 also was able to observe and follow solar bursts out of the ecliptic plane.

Data from Explorer 49 had verified two major magnetospheric noise regions, one on the morning side of the earth and the other on the evening side. In addition, spacecraft data showed that intense noise occurred in the 8 to 12 pm time zone with less intense noise in midmorning. The intense late-evening noise was generated within 10 000 to 12 000 km of the earth's surface, and the dayside emission seemed to come from an altitude of less than 4000 km. (NASA MOR, 3 June 75)

3-6 June: A Kennedy Space Center team tested a parachute system designed to lower an instrumented probe through the dense atmosphere of Venus to its surface. The tests-made for Ames Research Center in preparation for a Pioneer mission to Venus in 1978 were conducted in KSC's Vehicle Assembly Building, an ideal wind-free testing facility. Full-scale 3.7-m parachutes with simulated pressure vessels weighing 204 kg were dropped 13 times from heights of up to 137 m to the floor of the VAB with impact cushioned by a honeycomb cardboard impact arrester. The performance of the parachute system was monitored photographically during the drop to determine the aerodynamic trim characteristics of the parachute.

The 1978 Pioneer-Venus mission would include the launch of two separate spacecraft toward Venus. The first would orbit the planet collecting data for about 250 days; the second would carry one large probe, which would use the parachute to descend to the surface, and three small probes decelerated by aerodynamic drag only. The parachute on the largest probe would be used to separate an instrumentbearing pressure vessel and stabilize it for a series of critical scientific measurements as it passed through the Venusian cloud layer. None of the probes was designed to communicate with earth after impact. (KSC Release 98-75; Lockyer, Public Affairs Office, interview, 6 Oct 75)

*Does not include a supplemental request for pay increases introduced as H.R. 13172 and signed into P.L. 94-303 on 1 June 1976.