SPOKANE — The head of the space-probe mission to Titan said yesterday that much of the data from a botched experiment designed by a University of Idaho professor was recovered by radio telescopes on Earth.

Huygens mission manager Jean-Pierre Lebreton said in Paris that analysis of the data from the Doppler Wind Experiment will take longer than expected because of the glitch.

"All of the scientific objectives of DWE are going to be made from the ground," Lebreton said in a telephone interview. "We got a good signal which could be detected on the Earth."

Thursday, Idaho scientist David Atkinson said that someone failed to turn on a radio receiver for the instrument he needed to measure the winds on Saturn's largest moon. Because of that error, data transmitted by the gear on the Huygens lander were not received by the Saturn-orbiting Cassini spacecraft for relay to Earth.

"It was human error — the command to turn the instrument on was forgotten," the University of Idaho scientist said in an e-mail from Germany, the headquarters of the European Space Agency.

Atkinson spent 18 years designing the experiment for the unmanned space mission to Saturn. He did speculate Thursday that some of the data beamed toward Cassini from the moon's surface might reach Earth.

He proved correct, but Atkinson yesterday said that analyzing the data on Earth will require much more work.

67-minute delay

One of the biggest issues is that it took only 0.2 seconds for a radio signal to travel from the probe to the orbiting Cassini spacecraft above Titan, Atkinson wrote from Germany, where he continued to work on the project. It takes more than 67 minutes for a radio signal to travel from Titan to Earth, he wrote. "This sounds simple enough, but to actually change all of our experiment software, calculations, and methods to account for it is going to take some work," Atkinson wrote. "There are other issues too. The geometry, the distance, etc. No show stoppers, just lots of issues and considerations we're not prepared for."

Lebreton said an investigation showed clearly that a remote-control command to activate the receiver was not sent, which prevented the data from being collected by Cassini. He did not say who was responsible for the error.

But he noted that the equipment on the Huygens probe worked perfectly.

"The probe sent a clean signal and this allowed us to do the experiment from the ground using radio telescopes," Lebreton said.

The mission to study Saturn and its moons was launched in 1997 from Cape Canaveral, Fla., a joint effort by NASA, the European agency and the Italian space agency. On Jan. 14, Huygens transmitted the first detailed pictures of Titan's frozen surface.

Waiting in vain

Atkinson and his team were at headquarters in Darmstadt, Germany, waiting for their wind measurements to arrive.

The probe was to transmit data on two channels, A and B, Atkinson said. His Doppler wind experiment was to use Channel A, a very stable frequency.

But the order to activate the receiver, or oscillator, for Channel A was never sent, so the entire mission operated through Channel B, which is less stable, Atkinson said.

"I [and the rest of my team] waited and waited and waited," he wrote, as the probe descended. "We watched the probe enter and start transmitting data, but our instrument never turned on."

Atkinson wrote in his e-mail that fellow scientists rushed to comfort him and his team.

Most of his team has returned home, but Atkinson has remained in Germany because he still has a task to perform — reconstructing the entry and descent trajectory of the probe.

He said the overall space mission was a huge success.