NPOESS Electrical Engineering Model Test Bed Reduces Risk for Satellite Integration and Test

Northrop Grumman Aerospace Systems (NGAS), based in Southern California is the prime contractor for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) and leads an industrial team under contract to the tri-agency NPOESS Integrated Program Office.

NPOESS has inaugurated a critical tool that will reduce the risk associated with developing the spacecraft for the NPOESS program. The Electrical Engineering Model Test Bed (EEMTB) is a high-fidelity electrical model of the NPOESS satellite, consisting of subsystem engineering models and sensor engineering development units integrated in a flight-like electrical configuration. It is capable of ‘test as you fly,' real-time, closed-loop testing to validate the spacecraft design and substantially reduce risk during integration and test.

The spacecraft design will be validated through continuous testing as the subsystems are added to incrementally build up the test bed over the coming months. The test bed marks NPOESS' transition to the final phase of spacecraft development. NPOESS has completed the EEMTB early integration 34 months ahead of spacecraft integration and test, giving ample opportunity to find and fix problems to ensure successful satellite integration and test. The EEMTB has very high fidelity with the following features:

• Validates the satellite design and reduces integration risk in a hardware-in-the-loop real-time closed-loop environment

– Key Spacecraft Subsystem Engineering models (Ems) and complete set of Sensor Engineering development units (EDUS) connected with flight-like harness

– Vehicle Dynamics Simulator closing the loop to provide on-orbit NPOESS Satellite test environment

– Common EGSE, C&T Database and test procedure between EEMTB & I&T