The Keck Interferometer is funded by NASA. Proposals are accepted from all astronomers eligible to apply for Keck observing time. NASA will support use of the interferometer up to 50% more than the time dedicated by NASA for interferometry. That is, if NASA has allocated 10 nights a semester for interferometry, up to 5 additional nights in that semester will be available for TAC-allocated interferometry proposals. Additional nights beyond this level may also be supported at the discretion of the Keck Observatory Director.
Members of the California Institute of Technology, the University of California and the University of Hawaii communities should contact their Time Allocation Committee for information on applying for KI time and the appropriate deadlines.
For more information on submitting a proposal through NASA, and detailed guidelines on allowed scientific themes see here.
As a result of awards made through the NSF's Telescope System Instrumentation Program (TSIP), Keck Observatory telescope observing time is available the astronomical community. The TSIP nights are available for interferometry proposals, with no restrictions on science topics, and are administered by NOAO. See the NOAO Keck page for more details. The TSIP time on the Keck telescopes is not available for 2010A, but may be available in later semesters.