On Wednesday evening, SpaceX’s Falcon 9 rocket successfully deployed the heavy Intelsat 35e satellite into space after lifting off from the Kennedy Space Center’s Launch Complex 39A in Florida. The satellite will contribute communications services over eastern North America, South America, the Caribbean, Africa, and Europe.
The mission was moved months ago from its original April date and rescheduled for Sunday, July 2, when it aborted just ten seconds before liftoff. SpaceX tried again the next day, but was forced to cancel “due to a violation of abort criteria.” The company spent July 4 reviewing all of the launch pad and rocket systems to avoid a third scrubbed attempt.
The first abort had been ordered in response to a guidance systems problem; John Insprucker, a SpaceX engineer and the launch host, said that something within the system was “out of limits” because the computer ended the countdown before the rocket’s engine began to ignite.
On Wednesday, Insprucker assured viewers that the problem had been resolved. “We have modified the limit,” he said, “to avoid a possible repeat of the abort.”
And indeed, everything went smoothly. The Falcon 9 lifted off at 7:37 p.m. Eastern and went through its necessary period of maximum dynamic pressure (when “the velocity of the vehicle and the density of the lower altitude of the Earth’s atmosphere combine to create the greatest loads on the Falcon 9,” Insprucker described) at 90 seconds after launch. Then the first stage’s engines shut down, the two stages separated, and the second stage’s engine ignited. Eventually, at 8:10 p.m. Eastern, the satellite was successfully deployed into orbit.
Weighing in at around 13,200 pounds, the Intelsat 35e satellite is an extremely heavy load for a rocket to carry. SpaceX knew that the Falcon 9 required so much fuel to hoist the satellite into the air that it wouldn’t have enough for a controlled landing back on Earth, so the company allowed the rocket’s first stage to fall into the sea.
This is in contrast to many recent instances in which SpaceX has managed to land and reuse rocket boosters, which was not a traditional practice until the company started doing it this year. Elon Musk, SpaceX’s CEO and founder, tweeted on June 3, “It’s starting to feel kinda normal to reuse rockets. Good. That’s how it is for cars & airplanes and how it should be for rockets.”
This successful Falcon 9 launch comes one day before Vice President Mike Pence visits the Kennedy Space Center to inaugurate the new National Space Council.
SpaceX has many other exciting launches planned for this summer; check out this updated calendar, and relive this mission below.