NASA's $159 million Comet Nucleus Tour (CONTOUR) spacecraft was given up for good today. Efforts to make contact with the errant probe have been concluded. No signal from the NASA spacecraft was heard after repeated sessions using space agency Deep Space Network antennas. Mission managers say they will not try to contact the lost-to-space probe again.
The comet probe was hurled into space in early July, nudged into an Earth parking orbit.
In the six weeks after launch, mission operators and navigators guided the solar-powered craft through 23 propulsive maneuvers, positioning it precisely for the 50-second rocket burn that was to send CONTOUR toward close-up encounters with at least two comets.
On August 15, CONTOUR's onboard solid-propellant rocket motor fired to push the craft onward to flybys of Comet Encke in 2003 and Comet Schwassmann-Wachmann 3 in 2006.
But shortly after firing its onboard solid-propellant rocket motor on August 15, CONTOUR fell silent. Ground-based telescope equipment later spotted three individual objects flying on a path similar to the probe's trajectory. Speculation has centered on the craft breaking up at the end of the kick stage motor firing - an engine that was later determined by project officials to have under-performed.
Formal close down
"Given what we suspected about CONTOUR's condition, and that we haven't received a signal after several contact attempts, we don't believe the spacecraft is recoverable," said Edward Reynolds, CONTOUR project manager at the Johns Hopkins Applied Physics Laboratory (APL), which built and managed the CONTOUR mission for NASA.
CONTOUR was one of a line of Discovery-class, econo-class spacecraft designed and built in cheaper, better, faster mode.
"At this point the project will recommend to NASA that efforts to contact the spacecraft should end, and the project will formally close down," Reynolds said in an APL press statement.
CONTOUR team members gave a low-probability of chance in hearing from the spacecraft. The effort this week was undertaken as the team thought the spacecraft's multidirectional pancake beam antenna would
be better positioned to receive signals from Earth.
On December 17 and on December 20, mission operators at APL sent several "transmit" commands through DSN antennas. Those signals were targeted at the suspected location of the largest piece of CONTOUR - now about 42.5 million miles (68 million kilometers) from Earth.
After 16 total hours of sending and watching, no signal came back.
CONTOUR II?
"A lot of people worked hard to build CONTOUR and prepare for this mission, and we're deeply disappointed that it didn't work out," APL's Reynolds added. "The interest in CONTOUR was remarkable; people from around the world told us how excited they were about the chance to learn more about comets than any mission had taught before. We hope this team will have another opportunity to make that happen," he said.
Some talk has begun on building another comet-catcher: CONTOUR II. Such a mission could be flown to the original targets of the first probe in a 2006 time frame, although budget considerations and spacecraft mission priorities will ultimately decide the fate of a CONTOUR II.
Meanwhile, a NASA CONTOUR mishap board -- appointed in August -- continues its investigative work into the failure.
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