HST Cycle 28 Director's Discretionary Time Submission
Up to 10% of the available HST observing time may be reserved for Director's Discretionary (DD) allocation. A DD proposal is appropriate when a truly unexpected transient phenomenon occurs or when developments since the last proposal cycle make a time-critical observation necessary. The pool of orbits for in-cycle DD proposals is limited and typical proposals are less than 5 orbits, although larger requests can be considered under exceptional circumstances.
Director's Discretionary Proposals might be appropriate for
- followup of newly-discovered unexpected transient phenomena, or when developments since the last proposal cycle make a time-critical observation necessary;
- or the timely follow-up of new discoveries that will provide a critical link in the understanding of the phenomena, particularly those important for planning future observations with major facilities.
- Requests to reserve target of opportunity targets that have not yet been discovered are not appropriate for Director's Discretionary Proposals.
Proposers wishing to request Director's Discretionary (DD) time should first check the Real-time list of all Approved DD Programs. This list is updated nightly.
Please note: All scheduling requirements must be specified, including timing requirements that would require disruptive (< 3 week) or ultra-disruptive (< 2 day) turn-around times for activation. The limitation on each of these is described in HST Cycle 29 Observation Types and Special Requirements. Proposals that imply a time requirement, e.g., "as soon as possible", but do not specify a disruptive or ultra-disruptive activation time, will be returned.
Once a proposal is approved, STScI will give proposers a formal deadline for submission of the Phase II. Any subsequent request for changes may jeopardize the execution of the program and will be accepted only under highly exceptional circumstances.
DD proposals must now be submitted and will be reviewed in an anonymous format. The review process is similar to that used in HST Cycle 29 Anonymous Proposal Reviews, except the review of the team expertise will be done internally by the Science Policies Group. There is no need to submit a separate Team Expertise and Background document.
Proposers should use the Astronomer's Proposal Tool (APT) to submit their DD programs. To download and install APT, go to the APT page. For help on using APT to prepare and submit a Phase I program, go to the HST Cycle 29 Proposal Roadmap. You will be providing the "Coverpage" information via the APT tool and you will attach your scientific justification and observation description as a PDF attachment to your submission. More detailed information is included below as well as in the Phase I Roadmap.
Templates for the PDF attachment of the Scientific Justification can be found on the Current Cycle PDF Preparation page. Page limitations should follow the Page Limits for the PDF Attachment for proposals of the same-sized proposal category, as shown on HST Cycle 29 Guidelines and Checklist for Phase I Proposal Preparation.
Upon completion of your DD submission, your program will be transferred to the STScI for processing by our DD team. If you run into problems submitting a DD Request, send please contact the helpdesk for investigation/resolution.
Please refer to the section on Director's Discretionary Time proposals in HST Cycle 29 Proposal Categories for policies regarding this type of proposal.
Proposals for DD time must be sufficiently detailed for adequate evaluation. The required level of detail is the same as for proposals submitted for the regular observing cycles, as described in the current Hubble Space Telescope Call for Proposals for Cycle 29. Among other things,
- both the proposed observations and the use of DD time must be explicitly justified,
- there must be an adequate description of how the proposed observations relate to the current state of knowledge,
- and the proposed observations must be described in sufficient detail to allow technical evaluation.
Summary of APT DD Required Items
Observation information (repeat for as many observations as required)
|Proposal Justification Information (see also HST Cycle 29 Preparation of the PDF Attachment)|