Date: Fri, 18 Apr 2008 14:00:00 (PDT)
Subject: An Update to the Handling of Spitzer DDT Proposals

An Update to the Handling of Spitzer Director's Discretionary Time  
Proposals

Since the Cycle-5 selections were announced, Director's
Discretionary Time (DDT) proposals have been coming in at four
times the previous rate.  To handle this influx we have updated 
our DDT proposal handling process.  This is described in detail at

http://ssc.spitzer.caltech.edu/geninfo/ddt/what.html .

In previous cycles, adding DDT programs to the schedule merely  
delayed the execution of previously selected science.  In Cycle-5 
a delay in execution could translate into observations never being
executed, given the uncertainty in the cryogen end date.  

***DDT proposals for Cycle-5 must be extremely compelling science 
and must include a description of the long-term legacy value of 
the observations for the Spitzer mission.*** 

In other words, proposers must explain why in the future (e.g., 
over the next decade or so) it will be important for these 
observations to exist.

DDT proposals will be handled as follows:

1. The SSC will determine if the proposal falls in the category 
of urgent, new science that could not possibly have been submitted 
for Cycle-5.  These proposals will be handled through the normal 
DDT review process and, if accepted, will be given scheduling 
priority 1.

2. Proposals that do not meet the urgent and new criteria will be
put on-hold and evaluated as a group on a quarterly basis (July,
October, January).  Proposals accepted in this category will
nominally be assigned priority 3, unless a specific recommendation
is made during the review process for higher or lower scheduling
priority. (All cycle-5 observations were assigned scheduling  
priorities. Priority 1 and 2 observations are currently being
entered into the scheduling pool.  2200 hours of priority 3
observations are on-hold until the pool becomes depleted of
priority 1 and 2 AORs.)

Proposers will be told that their proposal is being reviewed  
immediately or placed into the quarterly review pool.  DDT 
requests must include:

1. a strong scientific justification;
2. a description of the long-term legacy value of the program;
3. completed Astronomical Observation Requests (AORs), if possible;
4. a justification for why the request was not submitted during 
the Cycle-5 Call for Proposals.

Please consult the DDT web page 

http://ssc.spitzer.caltech.edu/geninfo/ddt

for more information.  If you have any questions regarding DDT 
proposals or their submission, please email the Helpdesk at 
help@spitzer.caltech.edu.

Spitzer Science User Support