Release Towards Titan Successful

Titan on Dec. 13, 2004 showing linear cloud features and dark Xanadu. Click image for larger view
Credit: NASA/JPL

The European Space Agency’s Huygens probe successfully detached from NASA’s Cassini orbiter today to begin a three-week journey to Saturn¿s moon Titan. NASA’s Deep Space Network tracking stations in Madrid, Spain, and Goldstone, Calif., received the signal at 7:24 p.m. (PST). All systems performed as expected and there were no problems reported with the Cassini spacecraft.

After a seven-year and 3.2 billion km journey from Earth to Saturn separated and continued its journey alone toward Titan, Saturn’s largest moon.

Huygens was cut loose from Cassini and coasted toward Titan for 20 days, to arrive at its destination on 14 January.

"The joint ESA/NASA team has done all that had to be done to be ready for release. We are looking forward to receiving data on 14 January at ESA’s Spacecraft Operations Centre in Darmstadt, Germany.", said Claudio Sollazzo, ESA’s Head of Huygens Spacecraft Operations Unit at NASA/JPL in Pasadena, California.

Titan on Dec. 13, 2004 highlighting clouds over Xandadu, the darker west region. Click image for larger view
Credit: NASA/JPL

The Huygens probe was bolted to Cassini and has been riding along during the nearly seven-year journey to Saturn largely in a "sleep" mode. Huygens will be the first human-made object to explore on-site the unique environment of Titan, whose chemistry is assumed to be very similar to that of early Earth before life formed. Huygens will tell us whether this assumption is correct.

"We wish to congratulate our European partners as their journey begins and wish them well on their descent to Titan," said Robert T. Mitchell, Cassini program manager at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. "We are very excited to see the probe off and to have accomplished this part of our job. Now we’re ready to finish our part — receiving and relaying the Huygens data back to Earth."

"Today’s release is another successful milestone in the Cassini- Huygens odyssey," said Dr. David Southwood, director of science program for the European Space Agency. "This was an amicable separation after seven years of living together. Our thanks to our partners at NASA for the lift. Each spacecraft will now continue on its own but we expect they’ll keep in touch to complete this amazing mission. Now all our hopes and expectations are focused on getting the first in-situ data from a new world we’ve been dreaming of exploring for decades."

The Huygens probe will remain dormant until the onboard timer wakes it up just before the probe reaches Titan’s upper atmosphere on Jan. 14, 2005. Then it will begin a dramatic plunge through Titan’s murky atmosphere, tasting its chemical makeup and composition as it descends to touch down on its surface.

Simulation of Cassini pointing away from Titan. Click image for larger view
Credit: NASA/JPL

"We will have to wait patiently for the most exciting phase of our mission, when Cassini will send back to Earth the Huygens data. The Huygens descent will be accomplished in less then two and half hours and, if the probe survives the impact with the surface, we could expect up to two extra hours of science results before the onboard batteries die out" said Jean-Pierre Lebreton, ESA’s Huygens Mission Manager and Project Scientist, preparing to follow the separation from NASA/JPL in Pasadena.

At about 1200 km above the surface of Titan, the Huygens probe will begin a dramatic plunge through Titan’s thick haze, with the task to analyze the chemical makeup and composition of the moon’s atmosphere as it descends to touchdown on its surface.

The data gathered during this 2-1/2 hour descent will be transmitted from the probe to the Cassini orbiter.
Afterward, Cassini will point its antenna to Earth and relay the data through NASA’s Deep Space Network to JPL and on to the European Space Agency’s Space Operations Center in Darmstadt, Germany, which serves as the operations center for the Huygens probe mission. From this control center, ESA engineers will be tracking the probe and scientists will be standing by to process the data from the probe’s six instruments.

On Monday, Dec. 27, the Cassini orbiter will perform a deflection maneuver to keep it from following Huygens into Titan’s atmosphere. This maneuver will also establish the required geometry between the probe and the orbiter for radio communications during the probe descent.