NASA launched a new class of hurricane monitoring microsatellites today – and did it sideways. At 8:37 am EST Dec. 15, a modified Orbital ATK L-1011 Stargazer aircraft dropped a Pegasus XL rocket from an altitude of 39,000 ft (11.900 m) over the Atlantic Ocean off the east coast of Florida as part of NASA's Cyclone Global Navigation Satellite System (CYGNSS) mission. The three-stage booster then fired its engines in midair before soaring into orbit with its payload of eight microsatellites designed to monitor hurricanes with a new generation of remote sensors.
According to NASA, the launch, which was delayed for two days due to technical difficulties with the hydraulic release mechanism, went off smoothly under good weather. The Stargazer took off from Cape Canaveral Air Force Station in Florida and proceeded to the drop zone about 110 nm (126 mi, 204 km) east-northeast of Daytona Beach. Meanwhile, a NASA F-18 chase plane from the Armstrong Flight Research Center in California monitored the midair launch.
Once released and the engines fired, it took only 13 minutes for the Pegasus third stage to reach orbit and deploy the first pair of eight CYGNSS microsatellites, with two more following every 30 seconds. NASA says that all eight were released by 8:52 am EST and contact was established with the entire constellation by 4:12 pm EST.
The CYGNSS launch marked the 43rd flight for Pegasus, which have launched 94 satellites since April 5, 1990. Designed to operate from almost anywhere on Earth, the Orbital ATK system uses an air drop from about 40,000 ft (12,000 m) to increase payloads while reducing operating costs. The rarefied air combined with a plane flying at three percent of orbital velocity replaces a first-stage rocket while removing the threat of weather delays almost entirely.
The CYGNSS mission consists of a constellation of eight small satellites developed by the University of Michigan that are designed to look deep into hurricanes for long periods of time and try to find out why they intensify so rapidly. It will do this by using direct and reflected GPS signals that allow for the precision fixing of the satellites' positions as well as measuring ocean surface roughness and wind speed. The hope is the eight satellites will give scientists a better understanding of air-sea interactions at the heart of hurricanes.
NASA says the first CYGNSS science data should be received next week, followed by a one or two month commissioning before the system is online for the start of the 2017 hurricane season.
The video below shows the launch of the Pegasus XL CYGNSS mission.