Hastened by the Soviet move into Afghanistan, the emerging United States-China partnership is soon to take a great leap forward, as the Chinese acquire American "eye in the sky" satellite technology.
In the wake of US Defense Secretary Harold Brown's just-completed China Visit , President Carter's science adviser, Dr. Frank Press, is to lead a US mission to Peking Jan. 20. One of its aims is to finalize Chinese purchase of a US Landsat ground station and a separate communications satellite.
Future transfers of "dual use" technology -- with both civilian and military application -- are also to be discussed in Peking when Dr. Press, NASA administrator Robert A. Frosch, and others meet with China's top scientists in a regularly scheduled session of the US-China Joint Commission.
NASA and Pentagon experts here reject charges by the Soviets, and by US critics of the budding China-US defense relationships, that China's purchase of Landsat and its expected future purchase of a US communications satellite in orbit have major military significance. Secretary Brown said on ABC television's Issues and Answers Jan. 13 that there are still no US plans to sell China arms "and they in fact did not raise on this trip the request to purchase weapons systems or arms from us."
Mr. Brown called the emerging China-US relationship "strategic cooperation," but "not an alliance." The message of his visit to China for the Soviets and others, he said, was that since 1970 China and the US had moved "from enmity through conversation to friendship and potential partnership," with parallel, not joint, planning.
China's purchase of a $10 million ground station for Landsat-D, a new spacecraft to be sent into orbit in 1981, was not a spur-of-the- moment decision resulting from the Soviet military drive into Afghanistan. Neither was the sale of the communications satellite and other high-technology programs now being processed.
Basic agreement for these NASA-supervised satellite programs actually was reached between NASA administrator Frosch and China's Academy of Space Technology during a visit to China by space agency officials in late 1978.
A Sino-US "umbrella" accord on science and technology, which President Carter and Chinese Vice-Premier Deng Xiaoping signed Jan. 31, 1979, laid the goundwork for a number of multipurpose technology deals.
"It's misleading," says Dr. William P. Raney, chief engineer of NASA's division of space and terrestrial applications, who escorted visiting Chinese scientists on a visit to US Landsat installations last year, "to say the Chinese can use Landsat for military intelligence purposes.
"Of course almost any technology improvement, including a better truck, can be used for military purposes. But to so use their Landsat ground station, the Chinese would have to strip it and take out its computers and other sensitive equipment. Then they couldn't use the equipment for Landsat's normal purposes, which they badly need and want."
Since 1972 the US has launched three of the 2,100-pound spacecraft. Landsats 2 and 3 are in orbit now, but Landsat 2, NASA says, is wearing out and will be replaced by the improved Landsat-D in 1981.
The two Landsats, in orbits 180 degrees apart, together provide total coverage of all parts of the earth every nine days. All earth features, from a wheat field to a factory producing cars or tanks, emit radiation. Landsat's earth-viewing telescope picks up this radiation. From 560 miles out in space the satellite's detectors can distinguish between one type of vegetation or another, or between densely populated cities and thinly populated farmland, or between clean and polluted water.
Landsat transmits data to NASA's Goddard Space Flight Center at Greenbelt, Md. There, a computerized signal-deciphering system translates the data into color-coded images and tapes.
The Earth Resources Observation System data center at Sioux Falls, S.D., prepares colored maps for users. The maps enable them to predict crop trends (and so plan distribution and trade in food and livestock), find new sources of fresh water, predict and study floods, locate oil and mineral sources, and to do numerous other things.
In 1976-78, Landsat surveyed world wheat crops to estimate harvest yields. Its estimate of the Soviet wheat crops was accurate within 1 percent of official Soviet figures released later, though NASA officials acknowledge such accuracy cannot be attained with smaller grain fields like those in China.
The first three Landsats could accurately identify earth features within about 180 feet from 560 miles altitude. According to Dr. Raney, Landsat-D will give China and other users considerably greater resolution than that, but still far short of that needed for precision military intelligence use.
No Soviet-bloc states have been permitted to buy Landsat technology.