In the early hours of January 30, NASA will launch the Soil Moisture Active Passive (SMAP) observatory atop a ULA Delta II rocket from Vandenberg Air Force Base in California. The narrow, three-minute launch window begins at 6:20 AM PST (9:20 AM EST). The initial launch on January 29 was scrubbed due to wind conditions.
Over the next three years, SMAP will begin collecting data on Earth’s top soil moisture as well as track freeze/thaw cycles in order to get the clearest sense of global water availability that has ever been seen. The implications of these data will be widespread, including the improvement of flood prediction, weather forecasting, drought monitoring, crop growth, and the tracking of carbon, water, and energy cycles.
“On a global scale, there are important gaps in knowledge of where water is stored, where it is going, and how fast it is moving,” the mission’s executive summary states. “Global measurements from space open a vision for the advancement of water science, or hydrology. This vision includes advances in understanding, data, and information that will improve the ability to manage water and to provide the water-related infrastructure that is needed to provide for human needs and to protect and enhance the natural environment and associated biological systems.”
The rocket carrying the SMAP spacecraft will be boosted by three motors that will jettison 1 minute, 39 seconds after liftoff. The second stage engine will have a series of planned starts and cutoffs until it separates at 51 minutes, 58 seconds after liftoff before landing in the Pacific Ocean.
After separation from the rocket, SMAP will then open its solar array, begin its maneuvers and come online. It will take a couple of weeks for the spacecraft to reach its final orbit position, which is 685 kilometers (426 miles) above Earth’s surface. The first 90 days will be spent testing SMAP’s instruments before the science phase of the mission begins.
NASA’s broadcast will begin at 4:00 AM PST (7:00 AM EST), with a news conference to follow at 9:00 AM PST (12:00 PM EST). You can watch on NASA TV or tune in right here: