NASA has successfully launched its Soil Moisture Active Passive (SMAP) satellite atop a United Launch Alliance Delta 2 rocket. The orbiter is designed to take high resolution moisture maps on a global scale, mapping the entire planet in the space of only two to three days. The maps will grant us an improved ability to forecast droughts, floods, and even aid agricultural workers in crop planning and rotation.
In order to take detailed moisture measurements of the entire world, SMAP will be placed in a near-polar sun-synchronous orbit, allowing the observatory to use Earth's natural spin to maximize the area that can be scanned by the satellite's instruments. The orbiter will use its L-band radar and L-band radiometer to scan the top 2 inches (5 cm) of our planet's soil with a resolution of around 31 miles (50 km).
Two previous launch attempts had to be scrubbed, the first due to high wind speeds at a height of 34,000 ft (10,363 meters), with the second launch cancelled due to minor repair work being needed to rectify a minor debond to the booster insulation of the Delta 2 rocket.
Today's launch saw no such complications. The weather balloons deployed to keep an eye on high altitude weather conditions reported all green, with no technical issues being encountered on the ground. The Delta 2 lifted off from the Vandenburg Air Force Base, California, at 6:22 am Pacific time, its three solid fuel rockets and main engine combining to propel the rocket skywards with a force of 600,000 lbs of thrust. The solid fuel boosters burnt for a full minute, with booster separation taking place 90 seconds into flight.
Image of SMAP soon after separation as shot from aboard the upper stage of the Delta 2 launch vehicle (Image: NASA, United Launch Alliance)
Main engine shutdown occurred 4 minutes and 21 seconds after launch, followed 6 seconds later by first stage separation. This was followed by separation of the protective fairing, housing the SMAP satellite, and after a series of two burns, deployment of the satellite itself. SMAP's solar arrays deployed successfully following separation, with telemetry confirming that the spacecraft was indeed drawing power from the twin arrays.
The upper stage of the launch vehicle fired once more, before successfully deploying three pea pod satellites – FIREBIRD, EXOCUBE AND GRIFEX – each of which will launch a number of cube sats. Once this deployment phase had been completed, the remnant of the Delta 2 rocket used the remainder of its fuel to de-orbit itself in a safe and controlled fashion.
Now in orbit, SMAP will provide moisture maps from a polar-orbit of 426 miles (686 km) altitude that will be instrumental in predicting floods, droughts, food shortages and expanding our understanding of our planet's water, energy, and carbon cycles.