SpaceX’s Falcon 9 rocket is set for liftoff from Cape Canaveral on Tuesday carrying the U.S. Air Force’s next GPS 3-series navigation satellite destined for an orbit more than 12,000 miles above Earth.
The 229-foot-tall (70-meter) rocket is poised for launch from pad 40 at Cape Canaveral Air Force Station in Florida at 3:55:48 p.m. EDT (1955:48 GMT) Tuesday at the opening of a 15-minute launch window.
The Lockheed Martin-built GPS 3 SV03 satellite mounted atop the rocket is the third member of an upgraded generation of GPS navigation spacecraft, featuring higher-power signals that are more resilient to jamming, and additional broadcast frequencies to make the GPS network more interoperable with other navigation satellite fleets.
Unlike SpaceX’s previous launch of a GPS payload in 2018, the mission will fly a slightly different profile to reserve fuel for landing of the Falcon 9 booster. Read our mission preview story for more information.
The timeline below outlines the launch sequence for the Falcon 9 flight with the GPS 3 SV03 spacecraft.
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 40.
T+0:01:11: Max Q
The Falcon 9 rocket reaches Max Q, the point of maximum aerodynamic pressure, a few seconds after surpassing the speed of sound.
T+0:02:31: MECO
The Falcon 9’s nine Merlin 1D engines shut down.
T+0:02:35: Stage 1 Separation
The Falcon 9’s first stage separates from the second stage moments after MECO.
T+0:02:42: First Ignition of Second Stage
The second stage Merlin 1D vacuum engine ignites for a five-and-a-half-minute burn to put the rocket and GPS 3 SV03 into a preliminary parking orbit.
T+0:03:28: 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.
T+0:06:45: First Stage Entry Burn Complete
The Falcon 9 rocket’s first stage descends back to Earth as its engines fire for the entry burn before landing on SpaceX’s drone ship in the Atlantic Ocean.
T+0:08:07: SECO 1
The second stage of the Falcon 9 rocket shuts down after reaching a preliminary orbit. The upper stage and GPS 3 SV03 begin a coast phase scheduled to about one hour before the second stage Merlin-Vacuum engine reignites.
T+0:08:30: First Stage Landing
The Falcon 9’s first stage booster lands on SpaceX’s drone ship “Just Read The Instructions” positioned in Atlantic Ocean northeast of Cape Canaveral.
T+1:03:28: Second Ignition of Second Stage
The Falcon 9’s second stage Merlin engine restarts to propel the GPS 3 SV01 navigation satellite into an elliptical transfer orbit ranging in altitude between about 250 miles (400 kilometers) and 12,550 miles (20,200 kilometers), with an inclination of 55 degrees.
T+1:04:13: SECO 2
The Merlin engine shuts down after a planned 45-second burn to put the GPS 3 SV03 satellite in the proper orbit for deployment.
T+1:29:14: GPS 3 SV03 Separation
The GPS 3 SV03 satellite separates from the Falcon 9 rocket in an elliptical transfer orbit with an apogee, or high point, near the altitude of the GPS fleet, located around 12,550 miles (22,200 kilometers) above Earth.
A threatening layer of clouds stayed away from SpaceX’s launch pad at Vandenberg Air Force Base in California on Tuesday, allowing for clear viewing of a spectacular Falcon 9 launch carrying commercial and scientific satellites into polar orbit.
Final preparations began this weekend at NASA’s Stennis Space Center in Mississippi to load super-cold liquid hydrogen and liquid oxygen into the massive core stage of the Space Launch System heavy-lift rocket for the first time as soon as Monday.
The infrared space telescope and Sun-centric missions will launch on a rideshare Falcon 9 flight from Vandenberg Space Force Base on Monday, March 10. Liftoff happened Tuesday, March 11, at 8:10 p.m. PDT (11:10 p.m. EDT, 0310 UTC).
