How Soil Moisture Active Passive Spacecraft Works. Credit: NASA

Successful Launch of Delta II with SMAP Satellite!

by Viacheslav Pronskyi

SMAP Mission Logo. Credit: Spaceflight Now

On Saturday, January 31, 2015, United Launch Alliance (ULA) conducted successful launch of its Delta II launch vehicle with NASA’s Soil Moisture Active Passive (SMAP) environmental satellite into a sun-synchronous orbit from Space Launch Complex-2 at Vandenberg Air Force Base, California. SMAP mission was the 153rd Delta II launch, the 52nd launcher’s mission for NASA and the second of 13 planned ULA missions in 2015.

Delta II Readied for SMAP Launch. Credit: NASA

Delta II configuration for SMAP mission was 7320–10C, what means a 7000 series vehicle, 3 boosters, only two stages (no third stage) and 10-foot (3 meter) fairing diameter. Also flying on the Delta II, and deployed after SMAP release from the rocket’s second stage, is Educational Launch of Nanosatellite X, or ELaNa X, an auxiliary payload that comprises three Poly Picosatellite Orbital Deployers, or P-PODs, containing a total of four CubeSats. These four small satellites represent three separate missions:

  • ExoCube space weather satellite consisting of three CubeSat units (3U);
  • The GEO-CAPE ROIC In-Flight Performance Experiment, or GRIFEX, a technology validation mission also consisting of three CubeSat units;
  • FIREBIRD-II (A and B), a two-Cubesat space weather project that will study electron microbursts in the Van Allen radiation belts.
GRIFEX (left), ExoCube (up) and FIREBIRD-II (down) CubeSats.

SMAP three-year $916Mln mission is one of four first-tier missions recommended by the National Research Council’s Committee on Earth Science and Applications from Space. The accuracy, resolution, and global coverage of SMAP soil moisture and freeze/thaw measurements are invaluable across many science and applications disciplines including hydrology, climate, carbon cycle, and the meteorological, environmental and ecology applications communities. Future water resources are a critical societal impact of climate change, and scientific understanding of how such change may affect water supply and food production is crucial for policy makers.

The observatory will sweep above Earth in a near-polar orbit at an altitude of 685 km. Its 6-meter-wide, rotating antenna will allow the spacecraft to observe a 1,000-km-wide swath. This means SMAP will be able to map the planet’s equatorial regions every three days, and the higher latitudes every two days.

Soil Moisture Active Passive Spacecraft. Credit: NASA

NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, built the spacecraft and is responsible for the radar instrument, mission operations and other functions. The agency’s Goddard Space Flight Center in Greenbelt, Maryland is responsible for the radiometer. Launch operations are managed by the NASA Launch Services Program, headquartered at Kennedy Space Center in Florida.

Initially, NASA’s SMAP launch on the United Launch Alliance’s Delta II was scheduled for January 29, but due to high-altitude atmospheric winds it was postponed minutes prior to T-0. Later the mission was delayed to a targeted launch date of January 31 pending completion of minor repairs to the vehicle. During inspections following the January 29 launch attempt, minor debonds to the booster insulation, associated with cryogenic conditions experienced during tanking operations, were identified and a standard repair had to be implemented.

Soil Moisture Active Passive Infographics. Credit: JPL