Falcon 9 flight timeline for NROL-76 mission

April 29, 2017 Stephen Clark

SpaceX’s Falcon 9 booster is set for liftoff from Cape Canaveral on Sunday morning, but most of the launcher’s ascent into orbit will be under a news blackout at the request of the National Reconnaissance Office, the secretive U.S. government intelligence agency whose mission is riding on the rocket.

The 229-foot-tall (70-meter) rocket is poised for launch from pad 39A at NASA’s Kennedy Space Center in Florida at 7 a.m. EDT (1100 GMT) Sunday at the opening of a two-hour launch window.

The timeline of upper stage events after the release of the rocket’s payload fairing, scheduled for T+plus 2 minutes, 48 seconds, has not been released. SpaceX’s live coverage of the second stage’s progress will conclude then at the NRO’s request.

Meanwhile, the rocket’s first stage booster will flip around with the aid of cold gas thrusters, then reignite a subset of its engines for re-entry and landing burns, aiming for a vertical touchdown at Landing Zone 1 at Cape Canaveral Air Force Station, around 9 miles (15 kilometers) south of pad 39A.

Data source: SpaceX

T-0:00:00: Liftoff

After the rocket’s nine Merlin engines pass an automated health check, hold-down clamps will release the Falcon 9 booster for liftoff from pad 39A.

T+0:01:00: Mach 1

The Falcon 9 rocket reaches Mach 1, the speed of sound, as the nine Merlin 1D engines provide more than 1.7 million pounds of thrust.

T+0:01:08: Max Q

The Falcon 9 rocket reaches Max Q, the point of maximum aerodynamic pressure.

T+0:02:17: MECO

The Falcon 9’s nine Merlin 1D engines shut down.
The Falcon 9’s nine Merlin 1D engines shut down.

T+0:02:20: Stage 1 Separation

The Falcon 9’s first stage separates from the second stage moments after MECO.
The Falcon 9’s first stage separates from the second stage moments after MECO.

T+0:02:28: Ignition of Second Stage

The second stage Merlin 1D vacuum engine ignites for an approximately 6-minute burn to put the rocket and SES 9 into a preliminary parking orbit.
The second stage Merlin 1D vacuum engine ignites to place the NROL-76 payload into orbit.

T+0:02:48: Fairing Jettison

The 5.2-meter (17.1-foot) diameter payload fairing jettisons once the Falcon 9 rocket ascends through the dense lower atmosphere. The 43-foot-tall fairing is made of two clamshell-like halves composed of carbon fiber with an aluminum honeycomb core.
The 5.2-meter (17.1-foot) diameter payload fairing jettisons once the Falcon 9 rocket ascends through the dense lower atmosphere. The 43-foot-tall fairing is made of two clamshell-like halves composed of carbon fiber with an aluminum honeycomb core. The rest of the rocket’s ascent into orbit will not be broadcast by SpaceX at the NRO’s request, and further details about the mission timeline have not been released.

T+0:07:09: Stage 1 Entry Burn

A subset of the first stage’s Merlin 1D engines ignite for an entry burn to slow down for landing. A final landing burn will occur just before touchdown.

T+0:08:46: Stage 1 Landing

The Falcon 9 rocket’s first stage booster touches down at Landing Zone 1 at Cape Canaveral Air Force Station.

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.

Related Articles