The High Energy Astrophysical Observatory-2 (HEAO-2), which was boosted last week into a letter-perfect 330-mile high orbit. Saturday sent back to waiting astronomers its first detailed x-ray photograph.

Primarily to make sure the $87 million laboratory's machinery was working properly, mission controllers pointed HEAO-2's x-ray telescope, the largest and most sensitive ever used, at Cygnus X-1, a well-known radiation source that astronomers think may be a black hole. The resulting picture encouraged scientists at the Harvard-Smithsoman Center for Astrophysics, which has been deeply involved in the project.

So Very Good

"We have some very good preliminary results... this first test went extremely well," Ethan Schrier, associated of the Harvard College Observatory and head of mission operations, said yesterday.

Reaching out to the edges of the known universe (10 billion light years), the observatory's x-ray telescope will be able to detect and study radiat resources at thousand times faint than those observed previously. Riccardo Giacconi, professor of Astronomy and director of the new satellite (dubbed the "Einstein Observatory"), said last week.

Giacconi, who viewed the launch from Cape Canaveral last week with about 20 other scientists from the Center for Astrophysics, said the mission, originally scheduled to last about a year, may run for more than three years depending on when the fuel needed to keep the telescope stable runs out.

Plans call for "Einstein" to take about 3000 pictures each year of a wide range of cosmic phenomena, including neutron stars, pulsars, quasars, clusters of galaxies, and the background radiation that some scientists believe is a remnant of the Big Bang, the explosion of matter that started the universe.

The next item on HEAO-2's agenda is a deep space survey, set for later this week. But for now, a hand written sign at the Center for Astrophysics says it all: "EINSTEIN WORKS GYG X-1 IMAGED!!!"