The Nuclear Spectroscopic Telescope Array (NuSTAR) Small Explorer mission is the first orbiting telescope to focus light in the high energy X-ray region of the electromagnetic spectrum (E > 10 keV), with an effective bandpass of 3–79 keV. The observatory provides a combined improvement in sensitivity and spatial/spectral resolution by factors of 10 to 100 over previous missions that have operated at these energies. The NuSTAR General Observer (GO) Program solicits proposals for basic research relevant to the NuSTAR mission. 

NuSTAR Cycle 10 will commence on or about June 1, 2024, and last for a nominal period of 12 months. Based upon the outcome of the 2019 NASA Astrophysics Senior Review process, NuSTAR operations are currently funded through September 30, 2025. Further details on the Cycle 10 program may be found on the NuSTAR GO Program website (http://nustar.gsfc.nasa.gov). 

Observing time will be made available to scientists at both U.S. and non-U.S. institutions. Individuals may submit proposals for three general types of observations: "standard-mode", "Target-of-Opportunity" (ToO, see Section 1.3.4), and "Large Programs" (LP, see Section 1.3.5). In addition to proposals for ToO observations submitted in response to this program element, unsolicited requests for ToO observations may be made through the NuSTAR Science Operations Center. Note that unsolicited ToO requests are ineligible for funding under the NuSTAR GO Program.  

Deadline for Proposals: Jan. 25, 2024