NASA’s Spitzer Space Telescope is slated to enter its “Beyond” phase on Oct. 1, 2016. Image Credit: NASA |
“Spitzer is operating well beyond the limits that were set for it at the beginning of the mission,” said Michael Werner, the project scientist for Spitzer said via an agency-issued release. “We never envisioned operating 13 years after launch, and scientists are making discoveries in areas of science we never imagined exploring with the spacecraft.”
In order to be able to communicate with Earth, Spitzer’s antenna must be pointed at ever-higher angles toward the Sun (so as to communicate back with Earth). This is required because Spitzer travels slower and behind the Earth.
Some of Spitzer’s autonomous safety systems needed to be overridden so as to enable the telescope to be able to operate on this level. Moreover, according to NASA, the spacecraft’s solar array will not be facing the Sun and, therefore, will receive less sunlight – and power. This will place the telescope’s batteries under greater stress.
“Balancing these concerns on a heat-sensitive spacecraft will be a delicate dance, but engineers are hard at work preparing for the new challenges in the Beyond phase,” said Mark Effertz, Spitzer’s spacecraft chief engineer with Lockheed Martin, one of the two companies that manufactured Spitzer (along with Ball Aerospace).
The telescope was launched atop a Delta II 7920H rocket on Aug. 25, 2003, from Cape Canaveral Air Force Station’s Space Launch Complex 17B. The spacecraft entered into service about four months later in December 2003.
The “Beyond” phase (also known by the more official designation of Cycle 13) is currently scheduled to begin on Oct. 1. This isn’t the first time Spitzer has had its mission extended.
In May 2009, after some six years of service, Spitzer’s supply of coolant (helium) was used up. This led to the aptly-named “Warm” mission. After the coolant was depleted, the telescope’s Infrared Spectrograph and Multiband Imaging Photometer stopped working, but the space-based observatory’s Infrared Array Camera (IRAC) didn’t. It persevered. In so doing, it allowed Spitzer to continue conducting science.
“With the IRAC team and the Spitzer Science Center team working together, we’ve really learned how to operate the IRAC instrument better than we thought we could,” said Giovanni Fazio, principal investigator of IRAC. “The telescope is also very stable and in an excellent orbit for observing a large part of the sky.”
It is hoped the Beyond phase of the mission will work until NASA can field the James Webb Space Telescope (JWST), which is currently slated to launch atop an Ariane 5 rocket in October 2018. Spitzer will also work to designate targets for the JWST as well as continue the search for more worlds beyond the Solar System.
Technicians that work on Spitzer have modified the heater cycling on the spacecraft, repurposed the telescope’s Peak-Up camera as well as the in-depth characterization of individual pixels in that camera. According to a report appearing on Caltech’s Spitzer website, this has “more than doubled Spitzer’s stability and targeting”. The various organizations working on the telescope hope this will aid it in finding exoplanets.
“When Spitzer launched back in 2003, the idea that we would use it to study exoplanets was so crazy that no one considered it,” said Sean Carey with NASA’s Spitzer Science Center. “But now the exoplanet science work has become a cornerstone of what we do with the telescope.”
Source: Spaceflight Insider
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