Aerospace Provides Improvement in Soil Moisture Active Passive (SMAP) Minotaur IV Launch Vehicle Trajectory

Corporate Staff
posted November 30, 2012


The SMAP observatory employs a dedicated spacecraft with an instrument suite that will be launched on the ICBM-derived Minotaur IV vehicle into a 680-km near-polar, sun-synchronous orbit. SMAP instrument includes a radiometer and a synthetic aperture radar operating at L-band with the ability to sense the soil conditions through moderate vegetation cover. The instrument measurements will be analyzed to yield estimates of soil moisture and its freeze/thaw state.

Value Added

Aerospace presented preliminary results of a Minotaur IV+ launch vehicle orbital injection error study to the SMAP project to the Jet Propulsion Laboratory. Aerospace used the reference trajectory produced by Nick Martin and navigation errors provided by Orbital Sciences Corporation. Results showed an order of magnitude improvement in injection accuracy from the performance presented in the Minotaur IV users’ guide. A subsequent e-mail from Orbital confirmed that injection errors on previous Minotaur launches were close to the estimate provided by Aerospace. This result is significant to SMAP, because the project had been carrying a large propellant mass margin to correct injection errors.