Scientists are bracing for the loss of two key instruments aboard NASA's infrared Spitzer Space Telescope, which will considerably diminish the observatory's ability to image infant stars but unlock more time for more thorough studies of mysterious worlds outside the solar system.
Officials expect Spitzer will drain its supply of liquid helium some time next month, reducing the telescope's sensitivity to infant stars and distant galactic nuclei.
Engineers have calculated the helium will probably run out around May 12.
Spitzer, the last of NASA's Great Observatories designed to revolutionize astronomy, was launched in 2003 with about 95 gallons of frigid liquid helium chilled to about -457 degrees Fahrenheit. That number equates to 1.2 degrees Kelvin, nearly as cold as the point of absolute zero.
The spacecraft was launched at room temperature and the cryogenic helium began cooling the 33.5-inch-diameter telescope before operations began in late 2003.
The spacecraft was launched at room temperature and the cryogenic helium began cooling the 33.5-inch-diameter telescope before operations began in late 2003.
Sensors for the observatory's three science instruments are mounted inside a structure called the cryostat, which is actively cooled by vapors vented from the adjacent liquid helium tank.
The instruments must be maintained at such cold temperatures to see through relatively cool dust clouds and observe star-forming regions hidden from optical telescopes.
When Spitzer empties the liquid helium tank, the spacecraft will automatically detect the slight warming of the cryostat.
The instruments must be maintained at such cold temperatures to see through relatively cool dust clouds and observe star-forming regions hidden from optical telescopes.
When Spitzer empties the liquid helium tank, the spacecraft will automatically detect the slight warming of the cryostat.
The spacecraft will go into a planned anomalous condition, basically a standby mode.
It will take about a day to recover from the fault, and then the Spitzer ground team will begin monitoring the telescope as the cryostat warms to about 30 degrees Kelvin, still a bone-chilling -405 degrees Fahrenheit.
Assuming Spitzer runs out of helium in the middle of May, scientists hope to begin "warm" operations by the end of June.
Scientists will only be able to use part of the capacity of Spitzer's Infrared Array Camera, an instrument with four detector channels ranging from near-infrared to mid-infrared wavelengths.
Warm observations will be limited to two wavelengths in the near-infrared spectrum.
Scientists will only be able to use part of the capacity of Spitzer's Infrared Array Camera, an instrument with four detector channels ranging from near-infrared to mid-infrared wavelengths.
Warm observations will be limited to two wavelengths in the near-infrared spectrum.
Comments
No responses to “Spitzer Space Telescope to embark on new, warmer life”
Post a Comment