Once the set of science exposures and any additional target acquisition
or calibration exposures required for the science program have been determined, they must be converted into a total number of orbits. Generally, this is a straightforward exercise involving tallying up the overheads on the individual exposures and on the selected pattern (see ), packing the exposure and overhead times into individual orbits, and tallying up the results to determine the total orbit request. This process may need to be iterated, in order to seek the most efficient use of the orbit time.
For information on the observatory policies and practices with respect to
orbit determination, please refer to the Call for Proposals/Phase I Proposal Instructions at:
Below, we provide a summary of the NICMOS
specific overheads, and give an example to illustrate how to calculate orbit requirements for Phase I Proposals.