Stephen Clark reports: A SpaceX Falcon 9 rocket rumbled into the sky Wednesday from NASA’s Kennedy Space Center in Florida, flexing the rocket’s muscles and lofting a massive Intelsat satellite to orbit supporting wireless communications, television broadcasting and trans-Atlantic data relays.
Recovering from back-to-back countdown aborts earlier in the week, the two-stage, 229-foot-tall (70-meter) launcher lit nine Merlin 1D main engines and rocketed away from pad 39A at the Florida spaceport at 7:38 p.m. EDT (2338 GMT) Wednesday.
The slender white booster pivoted 1.7 million pounds of thrust from its main engines to steer eastward from the Space Coast, powering through the speed of sound as the kerosene-fueled first stage climbed above the stratosphere.
The nine-engine first stage shut down less than three minutes after liftoff, and the booster dropped away with the help of pneumatic pushers for a destructive plunge into the Atlantic Ocean.
Wednesday’s mission — the third SpaceX launch in 12 days — carried the Boeing-built Intelsat 35e communications satellite toward a perch in geostationary orbit 22,000 miles (36,000 kilometers) over the equator.
The commercial spacecraft weighed around 14,900 pounds (6,761 kilograms) at launch, the heaviest payload SpaceX has ever launched to such a high orbit. SpaceX committed all of the Falcon 9’s propellant to send the Intelsat satellite into the highest orbit possible, a ride designed to minimize the spacecraft’s own fuel consumption as it maneuvers into its final operating position.
The lift requirement left no fuel in the Falcon 9’s first stage to brake for landing, and the rocket was not equipped with landing legs or fins needed for an intact recovery.
Two firings of the upper stage’s single Merlin engine placed the Intelsat 35e spacecraft into a temporary oval-shaped orbit that ranges as far as 26,700 miles (43,000 kilometers) from Earth, according to Elon Musk, SpaceX’s founder and chief executive.
After a half-hour trek across the Atlantic, the Falcon 9 deployed Intelsat 35e around 32 minutes into the flight. An on-board camera beamed back a live view of the satellite receding into the blackness of space.
Intelsat confirmed later Wednesday night that the spacecraft radioed controllers via a ground station, suggesting the satellite was healthy following the fiery journey into space.
“Thanks Intelsat!” Musk tweeted. “Really proud of the rocket and SpaceX team today.”
Wednesday’s launch wrapped up a busy two weeks for SpaceX, in which the company deployed 12 satellites on three Falcon 9 rockets, including a previously-flown booster that sent the first Bulgarian-owned communications spacecraft into orbit June 23 from pad 39A.
Two days later, a Falcon 9 rocket took off from Vandenberg Air Force Base in California and successfully placed 10 next-generation Iridium voice and data relay satellites into orbit.
SpaceX intended to launch the Intelsat 35e mission Sunday, but software errors led to computer-triggered aborts at T-minus 10 seconds during back-to-back countdowns Sunday and Monday.
John Insprucker, the Falcon 9’s principal integration engineer who provided launch commentary on SpaceX’s webcast, said ground software halted Monday’s launch attempt because a measurement in the first stage avionics system did not match a pre-programmed limit in a ground database.
He said engineers confirmed the rocket was OK to fly without any changes to flight hardware, and officials modified the limit for Wednesday’s launch attempt.
The countdown Wednesday sailed through the T-minus 10 second software readiness check, and the rocket’s 32-minute ascent appeared to go smoothly.
The weight and destination orbit of Intelsat 35e maxed out the lift capability of the current configuration of SpaceX’s Falcon 9 rocket, according … (read more)
via Spaceflight Now