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.
SpaceX delivered 56 more Starlink internet satellites into the company’s global internet constellation after liftoff of a Falcon 9 rocket from Cape Canaveral Wednesday, bringing the total number of Starlinks launched to 4,217 spacecraft.
Returning to port late Thursday under the cover of darkness, SpaceX’s rocket recovery platform has moored at a dock in Jacksonville, Florida, for unloading of charred debris from Tuesday’s crash landing of a Falcon 9 booster.
Another countdown for United Launch Alliance’s next Delta 4-Heavy rocket mission ended without a liftoff Wednesday after a computer sequencer detected a potential problem just before engine ignition.
