SpaceX raised a Falcon 9 rocket vertical Tuesday on pad 39A at NASA’s Kennedy Space Center, positioning the launch vehicle for a flight Wednesday carrying 57 more Starlink Internet satellites and two commercial Earth-imaging microsatellites for BlackSky.
The 229-foot-tall (70-meter) launcher was supposed to take off last month, but SpaceX called off a launch attempt June 26. The company said the “team needed additional time for pre-launch checkouts.”
In the end, SpaceX delayed the launch 12 days, and the company opted to shuffle order of its launches.
A Falcon 9 rocket successfully launched June 30 from pad 40 at Cape Canaveral Air Force Station — a few miles to the south of pad 39A — with a U.S. military GPS navigation satellite. The Falcon 9 rocket loaded with the Starlink and BlackSky satellites rolled back to its hangar near pad 39A to await the mission’s next launch opportunity.
With the Falcon 9 standing atop pad 39A again Tuesday, SpaceX’s launch team planned perform final checkouts on the rocket and commence the countdown early Wednesday.
The Falcon 9 will be filled with super-chilled, densified kerosene and liquid oxygen propellants beginning around 35 minutes prior to liftoff, which is timed for precisely 11:59:11 a.m. EDT (1559:11 GMT) Wednesday.
There’s a 60 percent chance of acceptable weather for a midday launch Wednesday, according to the U.S. Space Force’s 45th Weather Squadron. Central Florida is in a typical summertime pattern of strong afternoon and evening thunderstorms, but forecasters said Tuesday that the latest computer model runs suggested storms may develop a bit earlier in the day Wednesday.
“While the launch window’s timeframe is still more favorable than later in the afternoon, some showers and storms moving in from the northwest cannot be ruled out,” forecasters wrote. “Because of this, the primary concern for the launch window is the cumulus cloud rule and the surface electric field rule.”
If the weather conditions cooperate, nine Merlin engines will build up to produce 1.7 million pounds of thrust, driving the Falcon 9 launcher toward the northeast from Florida’s Space Coast on the way to an orbit inclined 53 degrees to the equator.
The first stage booster launching Wednesday will make its fifth trip to space. It first flew from the Kennedy Space Center in March 2019 on an unpiloted test flight of SpaceX’s Crew Dragon spacecraft, then launched again from Vandenberg Air Force Base in California in June 2019 with three Canadian radar observation satellites.
The reusable booster also launched two Starlink missions from Florida earlier this year, according to SpaceX.
The first stage’s nine engines will fire for around two-and-a-half minutes during launch, then the booster will fall away from the Falcon 9’s upper stage. The booster will deploy four titanium grid fins for aerodynamic stability, and then fire three of its engines for a burn to target landing on SpaceX’s drone ship “Of Course I Still Love You” holding position in the Atlantic Ocean…