Proposals for Director's Discretionary Time (DDT) observing projects are welcome at any time. Up to 7% of the observing time may be used for such projects. Usages for DDT, as opposed to the normal annual proposal Cycle, may include the following:

  • Newly discovered celestial phenomena, such as stellar explosions or new comets. Be sure to check the list of approved Target of Opportunity programs from the current Cycle to see if your idea is potentially covered, and consider contacting the proposer or Director to find out if it is already being done.
  • Time-critical observations in support of other projects or missions that were not anticipated during the prior Call.
  • Experimental techniques for which pilot observations are needed.
  • Observations that fill gaps in flight plans that would otherwise be "dead legs".
  • Short (one to two hour) observations that are necessary to complete a publication or PhD dissertation.

Other possibilities not included in this list may be considered by the Director.

DDT proposals will be confidential unless mutually decided by the Director and the PI otherwise. DDT proposals will be handled in a manner similar to regular proposals, so the documentation from the previous or current Call for Proposals should be consulted. This document describes only policies and procedures specific to DDT.

As of May 2021 the process for submitting SOFIA DDT proposals has changed. DDT proposals should now be submitted using the USPOT software . When a regular observing call is open, a selection will be offered in USPOT between the regular call and DDT requests (labeled Cycle 75). Please always use the latest USPOT version - as of November 2021, version 4.4.1.

To request a DDT observation on SOFIA, therefore please simply generate and submit a proposal via the USPOT tool (as for regular Cycle proposals). In USPOT, please select the US queue, independent on the affiliation of the DDT PI. Please selectc Cycle 75 - DDT as the Cycle ID. qPlease follow, in applicable parts, the instructions for content and format in the most recent regular cycle Call for Proposals (Some aspects, such as Thesis Enabling Programs, are not applicable and the biographical sketches etc., may be simplified. However science justification, feasibility and nominal AORs are required as for regular proposal cycles.) Target duplications with approved programs and instrument Reserved Observations Catalog targets must be clearly justified and will only be allowed after review and inputs from the existing observation's PIs/leads.

The SMO is monitoring the proposal submission daily and will get back to you with a decision as soon as possible. You can verify the successful submission of your proposal by checking the "My Proposals" page in DCS .

Once accepted, a DDT project will quickly enter Phase II (described in the annual Calls), wherein a detailed observing plan is developed with the relevant Instrument Scientist. Flight planners will assess how to accommodate the new observations, and the Director will weigh the consequences of inserting the new projects against the scientific promise of the displaced observations. Even if a DDT program is accepted, observing time is not guaranteed to be performed because the full impact is not known until Phase II and preliminary flight planning is complete.

Because DDT projects usually address time-critical phenomena that are of high interest to the community, there will generally not be any exclusive use period where the data can only be accessed by the proposing team. In exceptional circumstances the SMO Director can grant a short exclusive use period (typically no more than 3 months). Requests for such should be addressed in the "Feasibility and Path to Publications" section.

When developing an observing plan that requires a rapid response, keep the following issues in mind and include relevant justification in your proposal.

  • A turnaround time as fast as 10 days is possible, and sometimes an even more rapid turnaround can be accomplished. For a highly-justified observation, the single most important factor in determining the speed and complexity of observatory response is the state and availability of the required scientific instrumentation (SI). If the new observation uses the SI already on the observatory, the fastest and easiest response is possible. Proposers are welcome to request specific observatory schedule information (including planned observing campaigns for the near future) through the Helpdesk.
  • Facility science instruments (FORCAST, FIFI-LS, and HAWC+) are at the disposal of the science center and should generally be ready for usage with varying requirements on readiness to fly.
  • Principal Investigator instruments (EXES, GREAT) may be requested as part of a DDT proposal, but their availability cannot be guaranteed because they require the SI team for operations. It is not required to work with the PI team when developing a proposal utilizing their instrument, but such contact is recommended in particular for urgent observations.
  • The most disruptive observing proposals to the already-accepted observing program and staff schedules are those that require urgent and/or coordinated observations with multiple instruments. Be sure to justify such observing proposals carefully.
  • For fast turn-around DDT requests, please briefly discuss the utility of observing with each of the Facility Science Instruments -- especially the ones currently on the aircraft or planned for the near-term flight series.

A list of accepted DDT projects is here .