Two US military satellites set to ride SpaceX’s Falcon Heavy rocket into geosynchronous orbit more than 22,000 miles above Earth were mated with their launch vehicle Friday at Kennedy Space Center ahead of a scheduled sunset launch this weekend.
Launch spectators on Florida’s Space Coast will be treated with not just a twilight launch, but the double landing of the Falcon Heavy’s two side boosters back at Cape Canaveral around 8 minutes after liftoff. Sonic booms will likely be heard across the spaceport and surrounding areas.
SpaceX is set to launch its fifth Falcon Heavy rocket, powered by 27 Merlin main engines, Saturday during a 38-minute window opening at 5:55 pm EST (2255 GMT). The weather in Florida is predicted to be favorable for launching, with an 80% probability of acceptable conditions. Forecasters from the US Space Force’s 45th Weather Squadron expect a few high clouds, northwest winds gusting above 20 mph, and a temperature around 48 degrees Fahrenheit.
Weather and sea conditions for the recovery of the Falcon Heavy’s payload fairing from the Atlantic Ocean could be less favorable, but it is not clear whether SpaceX would delay the mission to wait for better downrange weather.
The semi-classified mission for the Space Force is designated USSF-67. The Falcon Heavy will head east from Kennedy Space Center to kick off the roughly six-hour ascent to geosynchronous orbit, where the rocket will release its tandem payloads one at a time more than 22,000 miles (nearly 36,000 kilometers) over the equator. In that orbit, the satellites will circle the Earth in lock-step with the planet’s rotation.
SpaceX’s launch team test-fired the Falcon Heavy rocket’s 27 main engines Tuesday at Launch Complex 39A. The Falcon Heavy’s engines throttled up to generate 5.1 million pounds of thrust for nearly 10 seconds, then shut down to allow SpaceX to drain propellants from the triple-body rocket. Hold-down clamps kept the Falcon Heavy on the ground for the static fire test.
Teams lowered the rocket horizontally and returned it to a nearby integration hangar Thursday, where technicians installed the Falcon Heavy’s payload compartment Friday. The rocket’s payload fairing, with its two military satellites stacked on top of the other inside, rolled from an offsite satellite processing facility to the hangar at pad 39A earlier this week.
The payload integration set the stage for the fully-assembled Falcon Heavy to return to pad 39A ahead of Saturday evening’s launch window. SpaceX plans to raise the rocket vertically for final checkouts and propellant loading Saturday afternoon.
The Falcon Heavy held the distinction as the most powerful operational rocket in the world until November, when NASA’s Space Launch System moon rocket took off on its inaugural flight. The Falcon Heavy, still the world’s most powerful commercial rocket in service, stands 229 feet (70 meters) tall and measures nearly 40 feet (12.2 meters) wide with three Falcon rocket boosters connected together.
The two satellites on the USSF-67 mission will launch on missions supporting military communications and technology demonstration experiments.
The Space Force’s CBAS 2 satellite rides in the upper position of the dual-payload stack. CBAS 2 (pronounced “sea bass”) is the military’s second Continuous Broadcast Augmenting SATCOM mission, following the first CBAS satellite which was launched on a United Launch Alliance Atlas 5 rocket in April 2018.
According to the Space Force’s Space Systems Command, CBAS 2 “is a satellite destined for geosynchronous orbit to provide communications relay capabilities in support of our senior leaders and combatant commanders.”
A Space Force spokesperson said they could not release the identity of the manufacturer of the CBAS 2 satellite. Officials did not disclose any more details about the spacecraft’s mission.
“The mission of CBAS 2 is to augment existing military satellite communication capabilities and continuously broadcast military data through space-based satellite relay links,” Space Systems Command said.
The other payload on the USSF-67 mission is a ring-shaped spacecraft hosting multiple military tech demo experiments. Northrop Grumman developed the spacecraft, called the Long Duration Propulsive ESPA, or LDPE, to accommodate small military payloads onto a single satellite platform, providing “an affordable path to space for both hosted and separable payloads,” said the Space Force’s Space Systems Command.
“This bus carries hardware for five independent missions, eliminating the need for each mission to wait for a future launch opportunity,” Northrop Grumman said. Northrop Grumman assembled the spacecraft at its Gilbert, Arizona, satellite production facility. All five of the LDPE 3A payloads will remain attached to the spacecraft throughout their missions, a Space Force spokesperson told Spaceflight Now.
The LDPE 3A spacecraft on the Falcon Heavy rocket launching this weekend includes two “demonstration prototype” payloads from the Space Systems Command, the military said. One of them, called Catcher, comes from the Aerospace Corporation. Catcher is a prototype sensor to provide “local space domain awareness insights,” Aerospace Corporation said. It is based on a previous Aerospace Corporation-developed instrument called Energetic Charged Particle-Lite, or ECP-Lite, to demonstrate new miniaturized technology that can diagnose adverse effects of radiation, charged particles, and other space weather events on spacecraft in orbit.
The other Space Systems Command payload on the LDPE 3A spacecraft is called WASSAT. According to Sandia National Laboratories, WASSAT is a prototype wide-area sensor consisting of four cameras to search for and track other spacecraft and space debris in geosynchronous orbit, where communications, missile detection, intelligence-gathering, and weather monitoring satellites operate.
The military’s Space Rapid Capabilities Office has three payloads on the LDPE 3A spacecraft, including two operational prototypes for space situational awareness missions, and one “operational prototype crypto/interface encryption payload providing secure space-to-ground communications capability,” Space Systems Command said. in a statement.
The Space Force has launched two previous LDPE missions, one on an Atlas 5 rocket in 2021 and another on the Falcon Heavy’s USSF-44 mission Nov. 1. Northrop Grumman developed the maneuverable LDPE spacecraft by modifying a ring-like structure often used to connect small satellites to their launchers, adding solar panels, computers, rocket thrusters and instrumentation to the adapter.
SpaceX debuted the Falcon Heavy rocket on a test flight Feb. 6, 2018, that sent a red Tesla Roadster into interplanetary space. Two Falcon Heavy missions flew on April 11, 2019, and June 25, 2019. Those missions carried into orbit a commercial Arabsat communications satellite and 24 military and NASA spacecraft, respectively.
The next Falcon Heavy launch didn’t take off until three-and-a-half years later, following delays in spacecraft assigned to fly on SpaceX’s heavy-lifter. The USSF-44 mission Nov. 1 was the first SpaceX launch to deploy payloads directly into geosynchronous orbit. The six-hour mission profile required SpaceX to make some changes to the Falcon Heavy rocket, including the addition of gray paint on the outside of the upper stage’s kerosene tank to help ensure the fuel did not freeze as the rocket coasted in the cold environment of space.
The same strip of gray paint is on the upper stage of the Falcon Heavy rocket for the USSF-67 mission.
The side boosters on the USSF-67 mission will jettison from the center core stage about two-and-a-half minutes into the flight. The two rocket boosters will flip around to fly tail first, then reignite a subset of their engines to propel themselves back toward Cape Canaveral. The rockets will return to near-simultaneous landings on SpaceX’s recovery zones at Cape Canaveral Space Force Station about eight minutes after liftoff.
The core stage, which will throttle back its engines for the first phase of the flight, will fire almost four minutes before jettisoning to fall into the Atlantic.
An upper stage engine will finish the task of maneuvering into an equator-hugging geosynchronous orbit. The upper stage is expected to fire its engine three times, with a coast of roughly six hours between the second and third burns. The rocket will climb through the Van Allen radiation belts to reach the mission’s target orbital injection altitude approximately 22,000 miles above the equator, where the upper stage will complete its third and final engine firing before payload deployment.
“This is a complex mission and truly represents what assured access to space is about and is why we’re so enthusiastic about this upcoming launch, our second Falcon Heavy in just months,” said Maj. Gen. Stephen Purdy, the Space Force’s program executive officer for assured access to space.
The USSF-67 mission is SpaceX’s first mission awarded by the Pentagon’s National Security Space Launch Phase 2 contract. ULA and SpaceX won rights in 2020 to launch the military’s most expensive and critical space missions over a period of five years. The Space Force awarded SpaceX a $316 million contract to launch the USSF-67 mission.
The Falcon Heavy rocket ton the USSF-67 mission will reuse the two side boosters from the USSF-44 launch in November. Both boosters will be making their second flights to space, while the rocket’s center core is brand new. The core stage will not be recovered on Saturday.
“The efficiencies garnered from reusability benefit all customers, adding flexibility to a dynamic launch queue and cost savings,” Space Systems Command said.
SpaceX and the Space Force have agreed to refurbish and reuse the side boosters from the USSF-44 and USSF-67 missions for the next Falcon Heavy launch for the military. That launch, named USSF-52, is scheduled to take off no earlier than April.
Email the author.
Follow Stephen Clark on Twitter: @StephenClark1.