Director's Discretionary Program
Triggering pages CXC staff:
Please read and time your triggering appropriately
Submission of TOO triggers and DDT requests with response windows
starting at less than 5 days will trigger
pagers/phones for selected CXC personnel - some 24 hrs per
day 7 days per week and some between 8-22H (EDT/EST) 7 days
per week. Please be sure that your program requires rapid
turn-around before submitting requests with response windows
starting at 5 days or less, and to the extent possible please submit such requests during normal EDT/EST weekday working hours.
TOOs/DDT requests with Medium turn-around times having response start
windows from 5 to 30 days trigger pagers/phones on weekend
days as well as on work days from 8-22H EDT/EST. To the extent
possible please submit such triggers/requests during normal
EDT/EST weekday working hours.
Modeled on the HST approach, up to 5% of the total Chandra observing
time will be reserved for CXC Director's Discretionary Time(DDT)
observations. This allocation of time shall include unanticipated,
non-peer reviewed TOOs.
Proposals for DDT should be confined to unique scientific
opportunities for which the scientific return might be compromised
by waiting to propose during the next Chandra Call for
Proposals. Proposals which could reasonably go through the peer review process generally will not be favorably received. The request will be assessed by the CXC director in consultation with the NASA Project Scientist.
Proposals should be submitted using the DDT version of RPS.
A modest proprietary period (of up to 3 months) may be granted by
the CXC Director on request. Funding may also be provided for such
observations if deemed necessary to facilitate maximal scientific
return, following a simple, ad-hoc review. If funding is requested a cost
proposal may be submitted at any time using the same procedures
as for observing proposals. The cost proposal should not be submitted until
after the proposal has been approved and is due after the observation is
Chandra Pitch Angle Restrictions:
Please note that new restrictions on the satellite
pitch angle are in place.
BEFORE SUBMITTING A REQUEST for either a TOO or DDT observation:
- Use the PRoVis tool to investigate
Chandra spacecraft roll, pitch and visibility for your target as a function of date.
Check the pitch angle
for your desired target and observing date(s)
to be sure your target can be observed.
- If necessary, view the MaxExpo
web page to estimate the maximum uninterrupted Chandra exposure time as
a function of pitch.
- Download ObsVis
to examine the Chandra instrument Field of View displayed on the sky.
The following links provide instruction and information regarding DDT
Information about DDT Observations
Proposing a New DDT Observation