Space Research Carries On

WASHINGTON—Smaller payloads, alternative boosters and suborbital flights are making it possible for space scientists to carry out their experiments in the aftermath of the explosion of the space shuttle Challenger one year ago this month. NASA's billion-dollar budget for space science survived relatively unscathed for the current year, and officials are hopeful that the same will be true for fiscal 1988. But flight time, not money, is the biggest immediate problem for scientists, acknowledged John Holtz, assistant director of NASA's Astrophysics Division. "We need these alternatives to support the PIs [principal investigators] due to the lack of flight opportunities in the wake of the down time and extensions in the [shuttle] manifest," Holtz said. The astronomy and physics programs received the majority of the funds for space science, $528 million in fiscal 1987, with planetary exploration receiving $374 million and the life sciences $70 million. The space program relies heavily on the work of university-based researchers and their graduate students, who design many of the experiments and later help to analyze the data. In many cases, the projects serve as material for dissertations and theses. Since the next shuttle flight is, at best, still 13 months away, and the first scientific payload—the Hubble Space Telescope—is not scheduled to be launched until November 1988, a lot of graduate students will be out of luck if they wait for the next available payload on a future shuttle mission. Fill 'er Up NASA's decision to conduct practically all space exploration via the shuttle has contributed to the current problem, noted physicist Thomas Donahue of the University of Michigan, who also is chairman of the Space Science Board of the National Academy of Sciences. "With astronomical instruments," he said, "you either have to collect more light in order to get brighter images, which means bigger optics, or you have to have large structures in order to use interferometry and achieve nice spatial resolutions. Either way, the astronomical instruments tend to get big. Once the shuttle bay was established as a unit of measure for the space program, there was a tremendous temptation to fill the thing up." The Challenger accident was a particularly heavy blow to the large payloads needed for much of the planetary exploration program. There are slots for planetary missions listed on the shuttle manifest in 1989, 1990 and 1992 (with which NASA hopes to launch the Galileo mission to Jupiter, the Magellan mission to Venus and the Ulysses mission to study the solar poles), but obstacles remain that could delay indefinitely any or all of these missions. Without any shuttle bays to fill, NASA has begun trimming its payloads. First on the list is the Cosmic Background Explorer (COBE), a 10,000-pound payload to be placed into polar orbit to search for near-infrared radiation emanating from the creation of the universe. COBE will shrink by one-half in an attempt to get into space in 1989 atop an expendable Delta launcher that NASA is persuading the Air Force to surrender. Structural changes will have to be made, but no experiments will be dropped. Next on the list may be the Roentgen Satellite (ROSAT), a cooperative program with West Germany and the United Kingdom to make a full-sky survey in the X-ray portion of the spectrum. ROSAT is scheduled for a 1994 flight aboard the shuttle, but NASA is shopping around for an available Atlas-Centaur booster to be launched in late 1989 or early 1990. Although NASA would like to please the Europeans with an early flight, a British camera would probably have to be bumped to meet the new payload limitation. Suborbital Missions Suborbital sounding rockets will be pressed into service for some missions, Holtz said, although experimenters must make do with minutes rather than days of data collection. NASA has been launching about 30 a year (31 successes out of 33 attempts last year). Holtz hopes to increase that rate to 40 a year until the shuttle is fully operational, and is seeking an additional $10 million in the fiscal 1988 budget to purchase additional boosters. Scientific disciplines to be served include astronomy, solar and planetary physics, plasma physics and upper atmospheric physics. The problems with the shuttle will also give a boost to balloon launches, which have been plagued in the past few years by faulty materials. An improved version of the polyethylene material used to carry the payloads is expected to increase the success rate of the launches (only 26 of 36 were successful in 1986) as well as permit heavier payloads, up to 5,000 pounds. NASA officials hope to conduct 49 balloon launches this year. NASA is even using its research aircraft to fill the gap left by the shuttle. The Kuiper Airborne Observatory, a C-141 military transport equipped with a 91-centimeter telescope, is scheduled to make. 72 research flights this year to permit 29 groups of scientists to make measurements in the near-infrared and sub-millimeter wavelength spectral regions. The aircraft program has been yielding a scientific paper every two flights, noted Nancy Boggess, who manages infrared scientific programs at NASA. Last year, for example, despite the cancellation of an Astro payload (which would have conducted several ultraviolet experiments with equipment extended from the bay of the shuttle), the aircraft flew to New Zealand for infrared observations of Comet Halley and, for the first time, detected measurable amounts of water in a comet. Rhea is a freelance space writer in Washington, D.C.

Space Research Carries On

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