SOFIA is the Stratospheric Observatory for Infrared Astronomy - a world class astronomical observatory for infrared and submm astronomy. It is an airborne observatory with projected flight hours as much as 960 hours/year (8 hour nights) for 20 years.
The Upper Deck of the U.S.R.A. operated B747 SOFIA may in the future facilitate experiments for serendipitous research during regular deployments, or in support of ongoing mid-IR and submm observations with the main telescope. Preferentially, this research will support NASA's and DLR's mission goals.
The SOFIA Upper Deck may, for example, facilitate some of the same instruments as currently
developed for the NSF/NCAR HIAPER aircraft , which unlike SOFIA has short dedicated missions with a focus on specific atmospheric processes.
Serendipitous research on SOFIA should exploit the capability for long-term monitoring at altitude. In addition, short-term programs in astronomy could benefit from the low extinction near the horizon (higher meteor rates), a better scintillation than on the ground (occultation observations), a much lower water vapor absorption (near-IR and mid-IR spectroscopy and photometry), a high cosmic ray background, and the unique ability to provide interactive experiments, for example for the
collection of interplanetary dust particles and aerosols in the atmosphere.
Unique Earth Science research is possible due to frequent transitions of the tropopause.
There are also unique opportunities for education and public outreach, by facilitating student experiments, providing in-cabin video, and for sightings of transient phenomena on the sky (elves, aurora, fireballs).
No decision has yet been made to support such use of the Upper Deck at the present time. Better insight is needed into how the use of the Upper Deck as a multi-user research facility can help achieve NASA's roadmap goals, what would be the requirements, and how that research can be done without interfering in any way with the operations of the astronomical observatory.
There are 10 windows tilted at 27.8 degrees upward, which permit viewing ±40 degrees in azimuth and between 0 - 68 degrees in elevation, if equipped with the right window materials. This includes any position on the sky that can be reached by the SOFIA telescope. One observatory facility instrument (a water vapor monitor) has been installed permanently on the Upper Deck on the one before last window on the left hand side facing the cockpit,
creating a precedent for other installations. The back of the upper deck also houses vacuum pumps that will pump on science instrument cryostat vacuum enclosures. There is a large mostly empty space, and ample power, while any weight acts as counter weight to balance the telescope.