3rd time’s the charm for SpaceX comsat launch – WSAW


Posted: July 8, 2017 at 2:45 am

(CBS) — After last-second delays Sunday and Monday, a SpaceX Falcon 9 rocket finally roared to life and streaked away from the Kennedy Space Center Wednesday evening, boosting a high-power Intelsat communications satellite toward orbit in the California rocket builder’s third flight in less than two weeks.

The launching capped a particularly intense few days for SpaceX, beginning with the successful recovery of a Dragon cargo ship that splashed down early Sunday in the Pacific Ocean, bringing back more than 4,100 pounds of experiment samples and other equipment after a month-long visit to the International Space Station.

With the Dragon safely back on Earth, company engineers in Florida attempted to launch the Falcon 9 that evening only to be stopped at the T-minus 10-second mark because of a guidance and navigation system glitch. A second attempt Monday also was aborted at the 10-second point because of an undisclosed problem.

SpaceX founder Elon Musk ruled out a July Fourth launch attempt, instead ordering company engineers to spend the holiday reviewing telemetry and critical systems because, as he tweeted, “only one chance to get it right.”

The Falcon 9 was cleared early Wednesday for a third launch try and this time around, it was clear sailing and the 229-foot-tall rocket thundered to life at 7:38 p.m. EDT (GMT-4) and climbed away from historic pad 39A at the Kennedy Space Center atop 1.7 million pounds of thrust.

Mounted atop the rocket in a protective nose cone was the Boeing-built Intelsat 35e communications satellite, the fourth in a series of high-power Intelsat relay stations, this one bound for an orbital slot 22,300 miles above the Atlantic Ocean to provide service primarily to Latin America, the Caribbean and western Africa.

Arcing away to the east, the Falcon 9 put on a spectacular twilight show, climbing out of the thick lower atmosphere and rapidly fading from view as it consumed its load of kerosene and liquid oxygen propellants, losing weight and steadily accelerating.

About two minutes and 46 seconds after liftoff, the engines shut down and the first stage fell away. The single engine powering the rocket’s second stage then ignited to continue the climb to orbit.

Unlike the three most recent Falcon 9 flights, no attempt was made to recover the rocket’s first stage. Because of the weight of the payload — nearly 15,000 pounds — and the demands of the satellite’s orbit, no propellant was left over for the rocket firings needed to bring the first stage back for a landing.

Instead, the spent stage simply fell back into the atmosphere to break up before impact in the ocean below. So far this year, SpaceX has launched 10 Falcon 9s and recovered seven booster stages, three at the Cape Canaveral Air Force Station and four on off-shore drone ships. No attempt was made to recover the other three stages due to the payload weights and trajectories, including the one launched Wednesday.

In any case, the second stage engine was expected to fire for nearly six minutes to complete the climb to an initial, highly elliptical orbit. A second firing was planned later to complete the job.

The satellite’s on-board thrusters will be used later to put the relay station into a circular orbit 22,300 miles above the equator where all such communications stations operate. At that altitude, satellites take 24 hours to complete one orbit, thus appearing as stationary targets for antennas on the ground.

If all goes well, the new satellite will go into service in the second half of August.

This was the 38th launch of a SpaceX Falcon 9 rocket since the booster’s debut in 2010, the 10th so far this year and the ninth from pad 39A at the Kennedy Space Center.

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3rd time’s the charm for SpaceX comsat launch – WSAW

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