NASA has announced it will end operations of its observatory on a plane, SOFIA or the Stratospheric Observatory for Infrared Astronomy. The mission, which is a collaboration with German space agency DLR, will come to a close at the end of its current mission extension on September 30, 2022.
SOFIA is a modified Boeing 747 airplane that flies at altitudes of over 7 miles, which is above most of the water vapor in the atmosphere. That allows it to observe without the water vapor distorting readings, and it has been fitted with instruments for looking in the mid to far-infrared. It has imaged beautiful nebulae and researched how stellar winds play a role in star formation, but its most famous finding was that there is liquid water on the moon’s surface.
However, despite these achievements, the overall performance of SOFIA has been disappointing. The Decadal Survey on Astronomy and Astrophysics 2020, the biggest overview of astronomy goals for the next decade, said there were “concerns about SOFIA, given its high cost and modest scientific productivity.”
NASA was spending $86 million per year on SOFIA, which is in a similar range to the budgets for NASA’s contributions to major telescopes like Hubble and Chandra. Compared to the huge amount of scientific data and research papers produced by these two telescopes, the contributions made by SOFIA were nowhere close.
It seems that some of the problems with SOFIA’s output are related to its unique position as an observatory on a plane. One big problem pointed to by the report is that major observatories require large teams of people to run, both to maintain the hardware and to collect the data. It’s trickier to coordinate getting this large staff onto a plane than it would be to have them coming and going from a ground-based facility.
Another problem is that the plane itself requires regular maintenance, so the observatory has to be frequently grounded to allow for this. This means that there was a lot of time in which SOFIA was not collecting science data. “Only a few percent of total yearly calendar hours are turned into peer-reviewed science, an order of magnitude less than other astronomical observatories,” the survey says.
SOFIA won’t fly after the end of September this year, but all the data it has collected will continue to be publicly available for researchers to access.