(U) National Environmental Monitoring Satellite System (NEMSS)

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)

Overview: (U)
(U) NEMSS is a concept for a future environmental monitoring satellite constellation that augments NPOESS systems and may involve international cooperation.  The concept envisions using GEO communications links from LEO to relay near real-time environmental data to ground stations regardless of location.  

Description: (U)
(U) NEMSS is an evolutionary concept that includes using advanced sensors on satellites at LEO and GEO orbits to provide a wide range of data to help eliminate timeliness and refresh rate deficiencies.  An important objective is to reduce the sensors' and satellites' size and weight with micro satellite technologies.

(U) NEMSS will most likely use sensors including visible cloud imagers as well as IR.  Augmenting DMSP visible imagery, the refresh rate at the equator would be reduced from 4 hours to 2 hours with 3 NPOESS satellites, and 1 hour with additional NEMSS satellites.  NEMSS will include several dedicated EM satellites, including a solar wind monitor at the Lagrangian libration oribit (called L1), a scintillation satellite, and solar monitors in earth or possibly Venus' or Mercury's orbit.  
 
(U) An optimal configuration to help solve the refresh rate deficiency would place NPOESS and NEMSS satellites in equally spaced orbits.  Another option would place additional satellites in GEO to observe a specific theater of operations, where the rate deficiency is most acute.  

(U) Although NEMSS will have to be a single and national level program, the concept will probably require international cooperation to save costs. The GEO portion of NEMSS could use satellites from Europe, India, Russia and Japan, and the LEO portion satellites from Europe, Russia and China.  Costs will also rise if the U.S. has to launch all the satellites in the constellation.  There could also be commercial contributions to reduce costs.          

User Impact: (U)
(U) To be supplied.

Programmatics: (U)
(U) Operational.

Related Initiatives: (U)
(U) DMSP, GOES, NPOESS, POES

Related Requirements: (U)
(U) None.

Related Categories: (U)
(U) Space Systems

Road Map Placements: (U)
(U) ENVIRONMENTAL MONITORING.

Lead Office: (U)
(U) Air Force.

Date of Information: (U)
21 November 1997

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)