Huygens mission ends
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: January 14, 2005
NASA's Cassini Saturn orbiter has turned back toward Earth and started transmitting stored data from Europe's Huygens probe, which was still broadcasting a faint carrier signal from the surface of the moon Titan more than two hours after touching down and well after Cassini had turned away.
The carrier signal, detected by an Earth-based radio telescope network, confirmed the spacecraft survived atmospheric entry and reached the surface of Titan around 7:45 a.m. EST (1245 GMT), within 11 minutes or so of the predicted impact time.
At Saturn's distance of 751 million miles, the carrier was 50 quadrillion times weaker than the FM radio signal picked up by a car radio, according to an engineer at the Jet Propulsion Laboratory in Pasadena, Calif. The signal continued until well after Cassini dropped below Titan's horizon two hours after touchdown, surprising scientists at the European Space Agency's Space Operations Center in Germany.
The Cassini orbiter spent the morning out of contact with Earth, aiming its high gain antenna at the Huygens landing site to collect the entry probe's priceless science data. The orbiter was programmed to turn back toward Earth a few minutes before 10 a.m. EST and officials confirmed the Cassini started transmitting stored data as expected. But the first actual science data from Huygens' suit of instruments was not expected to show up on the ground until around 11:15 a.m.
"This is clearly an engineering success," said ESA project scientist Jean-Pierre Lebreton. "But at this moment, we cannot say more. ... We have not seen any real data yet."
Titan is the sixth world in the solar system, after the moon, Venus, Mars, Jupiter and an asteroid, that has been visited by a robotic emissary from Earth. But Titan is by far the most distant such planetary outpost.
"This whole thing of approaching Titan, descending down through its atmosphere and landing on its surface to me is like out of Jules Verne," said Carolyn Porco, the Cassini imaging team leader. "It's like a combination of 'Journey to the Moon' and '20,000 Leagues Under the Sea,' all wrapped up together, it's that kind of adventure in my mind.
"We've just extended our reach twice as far as we had before when we talk about physically making contact. ... This is a big moment and because of this, we can now look in the sky and when we see Saturn, we can say we've been there and we've made our mark. In that sense, the solar system, with this one event today, has become a very much smaller place. And that is very big."