SpaceX took on a bold new challenge Monday, launching a “classified spacecraft payload” for the United States’ National Reconnaissance Office for the first time. Mission NROL-76, which is likely a spy satellite owing to the nature of the agency, will have a big effect on SpaceX’s role in future defense and intelligence missions.
The company launched a Falcon 9 rocket from launch pad LC-39A at Kennedy Space Center at 7.15 a.m. Eastern, landing the rocket back on solid ground moments later. There were some concerns that the weather could have an adverse effect, but ultimately the launch occurred without any issues. High altitude wind shear, the measure of variations in wind speed along a straight line, was at 98.6 percent of the theoretical limit.
“Winds aloft are unusually high (still within structural safety bounds),” Elon Musk posted on Twitter three minutes prior to launch. “Worrying, but not a showstopper.”
The company did not land this Falcon 9 on a droneship. The autonomous landing platforms, stationed in the ocean, have developed something of a following in fan communities, but this time around SpaceX landed the rocket on the Landing Zone 1 area at Cape Canaveral Air Force Station around ten minutes after liftoff:
Nearly 300 feet in diameter, the zone was first successfully used by SpaceX to land a Falcon 9 rocket 16 months ago, and since then two more rockets have landed on the pad, the most recent occurring February 19.
Monday’s launch is the 10th time SpaceX has successfully landed a rocket, an achievement that will help bring costs down for more ambitious missions. The Falcon 9 costs $62 million, but the fuel only costs between $200,000 and $300,000. Saving the rockets helps the company plan for its long-term goal of regular trips to Mars.
The NROL-76 launch was initially scheduled for Sunday, but just 52 seconds before takeoff, SpaceX halted the launch due to an issue with a first stage sensor. The company places hundreds of sensors throughout the various stages of the rocket, aimed at giving detailed readouts of the mission status. The sensor in question did have backup sensors measuring the same parameters, but because its readings were out of an acceptable range, the company took extra precaution and pulled the plug.
Observers have speculated that, due to the rocket’s trajectory and the nature of the mission, the satellite will be placed into a highly elliptical Molniya orbit. This gives the satellite more dwell time at its highest point of orbit, allowing the craft to spend more time above the Northern Hemisphere:
The nature of launching a satellite into this orbit means the company can conserve propellant by launching the payload at a lower altitude. As landing on solid ground requires more fuel than landing on a droneship, this has led followers to conclude that the unusual orbit is the likely approach.
Unfortunately, due to the classified nature of the mission, SpaceX cut the webcast before viewers could watch the satellite deploy.
Rewatch the liftoff and landing here: