The first of two planned back-to-back SpaceX launches Sunday was called off because of bad weather during pre-flight processing, but the company pressed ahead with plans to launch an Argentine remote sensing satellite Sunday evening.
Launch of the SAOCOM 1B radar observation satellite atop a Falcon 9 booster with a previously flown first stage was targeted for 7:18 p.m. EDT from pad 40 at the Cape Canaveral Air Force Station. Also on board: two small hitch-hiker satellites added to the flight under a “rideshare” arrangement.
The launching will mark the 92nd flight of a workhorse Falcon 9, SpaceX’s 100th overall, when five earlier Falcon 1 flights are included along with three launches of triple-core Falcon Heavy boosters.
SpaceX had planned to launch two Falcon 9s just nine hours apart on Sunday, the shortest span between two orbit-class U.S. launches since 1966. The double header fell into place after a dramatic last-second “hot-fire abort” early Saturday of a United Launch Alliance Delta 4 Heavy rocket carrying a classified National Reconnaissance Office spy satellite.
Leading off the Sunday flight plan was a Falcon 9 set to carry 60 Starlink internet relay satellites into space from historic pad 39A at the Kennedy Space Center at 10:12 a.m. The SAOCOM 1B mission would follow suit from the nearby Air Force station.
But the Starlink booster was not hauled out of its hangar until early Sunday, and SpaceX later said in a tweet the team had called off the launch attempt “due to inclement weather during pre-flight operations.” The next opportunity to get the Starlinks off the ground is Tuesday at 9:29 a.m.
Despite the Starlink scrub and somewhat iffy weather, SpaceX pressed ahead with preparations for the evening launch of SAOCOM 1B. Forecasters called for a 40% chance of acceptable conditions.
The mission is intended to put SAOCOM 1B into orbit around Earth’s poles, the first such flight from Florida since 1969.
To reach a polar orbit from Cape Canaveral, the Falcon 9 will take off on a southerly trajectory and then carry out a “dogleg” maneuver once clear of Florida’s coast to bend the trajectory more directly south. The flight path will carry the rocket over Cuba.
In 1960, falling debris from a malfunctioning rocket reportedly killed a cow in Cuba, prompting protests in the island nation. All polar orbit missions since 1969 have taken off from Vandenberg where rockets remain above the Pacific Ocean all the way to orbit.
SpaceX initially planned to launch SAOCOM 1B from Vandenberg, but sought permission to move the flight to Cape Canaveral to ease ground processing issues.
The company presumably won government approval for the move in part because of the dogleg maneuver, which minimizes overflight of populated areas, the rocket’s high altitude by the time it reaches populated areas farther downrange and because the Falcon 9 features an automated flight safety system. The AFTS is designed to quickly terminate a flight if an impending catastrophic problem is detected.
The 6,720-pound SAOCOM 1B requires a polar orbit to enable its cloud-penetrating radar to observe the entire planet as it rotates below. The spacecraft will work in concert with an identical L-band radar mapper launched in 2018 along with Italy’s COSMO-SkyMed X-band satellites.
Bound for a 360-mile-high orbit, the $600 million SOACOM system is designed to monitor soil moisture and a range of other factors affecting the agricultural sector, collecting high-resolution data around the clock regardless of cloud cover.
“One of the main targets of the SAOCOM satellites is to provide information for the agriculture sector,” Raúl Kulichevsky, executive and technical director of CONAE, Argentina’s space agency, told Spaceflight Now.
“One of the things we develop is soil moisture maps, not only of the surface, but taking advantage of the L-band capabilities we can measure the soil moisture 1 meter below the surface of the land. So this is very important information.”