This appendix includes information that illustrates the concerns described in Chapter 2 of the unclassified text regarding the future of the United States satellite nuclear detonation detection monitoring capabilities—in particular, the potential capabilities under various scenarios of future satellite systems. Missions of the U.S. Nuclear Detonation Detection System (USNDS) are to support treaty monitoring, warfighting, and space control. System requirements are set in various regions of the atmosphere and space, from the earth’s surface through outer space, to meet mission requirements. Each mission comprises a subset of the USNDS functions: detect, identify, locate, estimate yield, and characterize.
The Air Force satellite constellations enabling the ability to meet the mission requirements are the Global Positioning System (GPS) and the geostationary Defense Support Program (DSP) satellites. The nuclear detonation detection sensor packages provided by DOE/NNSA are the NDS on GPS and the ARII (Advanced RADEC II) plus optical sensors on DSP.
Over the past decade, DOE/NNSA research and development investments have resulted in improved sensors for monitoring nuclear detonations in all environments which are responsive to USAEDS monitoring requirements for the CTBT. Air Force plans for upgrading GPS (Blocks II F and III) and for the replacement of the geostationary DSP—(with the Space-Based Infrared System, or SBIRS-D110)—are advancing, and may not take advantage of this improved nuclear detonation monitoring capability. The future of the nuclear-detonation detection sensors on GPS upgrades and DSP replacements is highly uncertain. For example, RADEC sensors are not included on at least the first two SBIRS satellites, and may not be included on any future SBIRS constellation. Similarly, exactly what nuclear detonation detection capability, if any, will be carried on future GPS Block III satellites remains uncertain. At the time of this writing, the Air Force has reportedly committed through a written memorandum of agreement with DOE/NNSA to carry enhanced NDS payloads on GPS Block II F and Block III satellites. If so, and the commitment is carried out, the GPS-enhanced nuclear-detonation detection capability, supportive of CTBT monitoring, will be sustained beyond 2020.
It is urgent that decisions regarding future nuclear detonation detection satellite capabilities be reviewed now.
1 The information presented here is adapted from a briefing received by the committee from DOE/NNSA NA-22 on September 30, 2009.
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