JPL Kept on Edge of Seat by Magellan

Scientists on Friday released additional photos of Venus from data collected before the Magellan spacecraft started misbehaving last week, but they had to admit they still don’t know what has caused the craft to break off communications with Earth for two long periods.

And they said they expect more problems in the days ahead as they try to unscramble the mystery, although some indicated that Magellan’s antics are getting a little old.

“My heart can’t stand this,” said project manager A. J. (Tony) Spear of the National Aeronautics and Space Administration’s Jet Propulsion Laboratory in Pasadena.

“I’ve received two phone calls in the night, and I expect another,” Spear said, referring to the two times that Magellan has turned its antenna away from Earth--on Aug. 16 for 14 hours and again on Tuesday for 17 hours. “I think it’s likely to happen again.”

Engineers have come up with several theories as to Magellan’s problems. None of them would be unsolvable, officials told a press conference Friday.

The latest theory, advanced by both Spear and the spacecraft’s engineer, John Slonski, is that the solid rocket that maneuvered Magellan into orbit around Venus earlier this month failed to separate properly and either damaged the spacecraft or is even dangling below. But both men said later they do not think it likely that will turn out to be the problem.

And so the inquiry has gone, day after day, as scientists and engineers struggle to understand why the craft continues to turn its back to Earth. But that is the story of the conquest of space, Spear said: “Moments of terror and moments of great happiness.”

“I’m betting my life that we’re going to be turning on the spigot” and Magellan will soon be sending great amounts of data back from Venus, Spear said. For now, however, scientists are left with one long strip of images captured before the problems began, and they have spent the last few days studying those images.

“There is quite a lot of data from this one strip,” project scientist Stephen Saunders said.

Saunders released several radar images from the strip, including a detailed view of a crater about 20 miles in diameter. He said the crater is similar to those on other planets and the Earth’s moon, caused by objects from space, but there is one key difference.

The bottom of the crater appears dark, indicating that it is very smooth, Saunders said.

He said the crater probably flooded with lava sometime after it was formed more than 100 million years ago. That does not answer the old question of whether Venus is still active volcanically, but it does mean it has been active in the relatively recent geological past.

The images from Venus released Friday came too late for one scientist who had pushed hard for many years for the Magellan project. Harold Masursky, 66, a geologist with the U.S. Geological Survey in Flagstaff, Ariz., who had been involved in nearly every planetary mission that the United States has carried out, died earlier the same day at his home in Flagstaff after a long illness.