SpaceX is set to kick off a busy week of launch preparations at Kennedy Space Center for the first of five planned Falcon Heavy rocket missions this year, targeting a dusk departure no earlier than Thursday evening from Launch Complex 39A on a flight for the U.S. Space Force.

The mission for the Space Force, designated USSF-67, will deploy two military spacecraft into a high-altitude geosynchronous orbit more than 22,000 miles (nearly 36,000 kilometers) over the equator. It will be the fifth flight of a Falcon Heavy rocket, one of the most powerful launchers in the world, and the first of five Falcon Heavy missions on SpaceX’s schedule for 2023.

Technicians inside SpaceX’s rocket integration hangar near pad 39A have mated the three booster cores for the Falcon Heavy, and the transporter-erector needed to carry the rocket to the rocket to the pad rolled into the hangar Saturday. Ground teams plan to lower the Falcon Heavy onto the transporter-erector and roll it to the launch pad in preparation for a test-firing of its 27 Merlin main engines early in the week.

The Falcon Heavy will roll back inside the hangar after the engine test-firing to receive its payload compartment, containing two Space Force satellites encapsulated inside the rocket’s nose cone. Then SpaceX will roll the fully-assembled launcher back to pad 39A and raise it vertical for final countdown preparations.

The launch is scheduled for no earlier than Thursday, during a launch period running from 5 p.m. to 10 p.m. EST (2200-0300 GMT on Thursday into Friday). The exact launch time will be revealed closer to the launch date, but liftoff is expected to occur around 6 p.m. EST, shortly after sunset on Florida’s Space Coast.

The Falcon Heavy will head east from Kennedy Space Center, running on 5.1 million pounds of thrust from its 27 kerosene-fueled engines. The rocket’s two side boosters are reused from the most recent Falcon Heavy launch — the Space Force’s USSF-44 mission on Nov. 1 — and the center core booster is a brand new element.

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. SpaceX will not attempt to recover the center core because it will devote all of its propellant to accelerating the USSF-67 payloads into space.

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 over the equator, where the upper stage will complete its third and final engine firing.

Then the rocket will release its two satellite payloads into geosynchronous orbit, where the satellites will orbit in lock-step with Earth’s rotation.

There are two main payloads on the USSF-67 mission. Publicly available mission patches from the Space Force suggest one of the satellites is the Space Force’s second Continuous Broadcast Augmenting SATCOM, or CBAS, spacecraft. The military’s first CBAS communications satellite — pronounced “sea bass” — launched in 2018 on a United Launch Alliance Atlas 5 rocket.

When the first CBAS satellite launched in 2018, U.S. military officials described it as a communications relay station designed to keep commanders in contact with senior government leaders. “CBAS will augment existing military satellite communications capabilities and broadcast military data continuously through space-based, satellite communications relay links,” the military said in a brief description of the 2018 mission.

CBAS is expected to ride in the forward, or upper, position inside the Falcon Heavy rocket’s payload shroud, which will separate from the launcher a few minutes after liftoff to fall into the Atlantic Ocean for recovery and reuse.

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, 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.

The Space Force said the prototypes and experiments on the LDPE 3A platform will “advance warfighting capabilities in the areas of on-orbit threat assessment, space hazard detection, and space domain awareness,” but military officials have released no additional details on the payloads.

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 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.

SpaceX aims to launch as many as 100 missions this year, which would mark an increase from the 61 flights the company completed in 2022. There are five Falcon Heavy launches planned in 2023, all from pad 39A at Kennedy Space Center. The Falcon Heavy launches are scheduled alongside numerous Falcon 9 rockets and the potential debut of SpaceX’s new Starship mega-rocket.

There are two more Falcon Heavy missions scheduled for launch in the spring. One will launch the first ViaSat 3 internet satellite to beam broadband service over the Americas for Viasat, and the other will launch the USSF-52 mission for the Space Force.

Later in the year, SpaceX plans to launch the Jupiter 3 satellite to provide internet services for EchoStar’s Hughes Network Systems. That launch is expected no earlier than May.

NASA’s robotic Psyche asteroid explorer is slated to depart Earth on a Falcon Heavy rocket during a launch period opening Oct. 10. The Psyche mission, delayed from 2022, will enter orbit around the metal-rich asteroid Psyche in 2029.

SpaceX has a backlog of 12 Falcon Heavy missions over the next few years, including the five launches planned in 2023.

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.