David Atkinson spent 18 years designing an experiment for the unmanned space mission to Saturn. Now some pieces of it are lost in space. Someone forgot to turn on the instrument Atkinson needed to measure the winds on Saturn's largest moon.
"The story is actually fairly gruesome," the University of Idaho scientist said in an e-mail from Germany, the headquarters of the European Space Agency. "It was human error -- the command to turn the instrument on was forgotten."
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. Last Friday, Huygens, the European space probe sent to the surface of Saturn's moon Titan, transmitted the first detailed pictures of the frozen surface.
Atkinson and his team were at European space 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."
Some data may have survived
Officials for the European Space Agency said last week they would investigate to learn what happened. They were not available for comment on Thursday, nor did NASA officials immediately respond to telephone messages.
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.
There is hope that some of his data survived.
"We do have Channel B data and although driven by a very poor and unstable oscillator, we may be able to get a little bit of data," he wrote.
Also, he said some of the Channel A signal reached Earth and was picked up by radio telescopes. "We now have some of this data and lots of work to do to try to catch up," he wrote.
Even so, he said the overall space mission was a huge success, and the Europeans in particular were thrilled with the success of their Huygens probe.
"In total, the core of our team has invested something like 80 man years on this experiment, 18 of which are mine," Atkinson wrote. "I think right now the key lesson is this -- if you're looking for a job with instant and guaranteed success, this isn't it."