SAN FRANCISCO — A NASA space-based telescope that has been gathering imagery of comets, asteroids and distant galaxies since it was launched in December received a last-minute reprieve in late September. Just as the hydrogen used to cool the detectors on the Wide-field Infrared Survey Explorer (WISE) ran out, the space agency’s Planetary Division stepped forward with $400,000 to continue the mission, albeit in a limited manner, for one month, said NASA spokesman J.D. Harrington.
Without the hydrogen coolant, only two of the WISE mission’s four infrared detectors will operate. However, those two detectors still will be useful in finding asteroids in the main belt between Mars and Jupiter and near Earth objects, the asteroids and comets moving relatively close to Earth’s orbit, said Ned Wright, WISE principal investigator and professor of physics and astronomy at the University of California, Los Angeles.
Amy Mainzer of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., is leading the extended mission, known as the Near-Earth Object WISE (NEOWISE) Post-Cryogenic Mission.
If the data from the first month of the NEOWISE mission prove useful, the Planetary Division will continue funding the effort to find near Earth objects for three additional months, Harrington said.
“The possible four-month extension is what it would take to complete one full scan of the solar system,” Harrington said.
In May, a NASA astrophysics review panel rejected plans for a more ambitious extension of the WISE mission. At the time, program managers proposed spending $6.5 million on a three-month extension of the $320 million WISE mission. That program, known as Warm WISE, would not have been limited to a search for near Earth objects, but would have included efforts to gather and analyze data on all the original targets of the WISE mission, including asteroids, comets, galaxies and failed stars known as brown dwarfs.
During the first six months of its mission, WISE surveyed the entire sky in four wavelengths of infrared light, discovering 19 comets and more than 33,500 asteroids, including 120 near Earth objects. On-board telescopes completed a second survey covering half the sky in the same wavelengths during the last three months, Harrington said.
In addition to asteroids and comets, the telescope observed brown dwarfs as well as hidden galaxies that are dark in visible light but shine bright in the infrared range of the spectrum.
The NEOWISE mission also should allow the telescope to study the closest brown dwarfs to the sun, as well as revisit previous targets to see how they have moved since they were first spotted.
The science results from the first half of the WISE telescope’s sky survey will be released in spring 2011, NASA officials said.
“The science data collected by WISE will be used by the scientific community for decades,” said Jaya Bajpayee, NASA’s WISE program executive at the agency’s headquarters in Washington. “It will also provide a sky map for future observatories like NASA’s James Webb Space Telescope.”
NASA launched the WISE telescope on a2 rocket Dec. 14, 2009, to begin a 10-month mission to completely map the sky.
The WISE spacecraft, built by Ball Aerospace & Technologies Corp. of Boulder, Colo., carries a 40-centimeter telescope built by the Space Dynamics Laboratory of Logan, Utah. The WISE mission is managed by the Jet Propulsion Laboratory.
Tariq Malik contributed to this story from New York.