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Falcon Heavy rocket on the launch pad for one of SpaceX’s most complex missions – Spaceflight Now

Falcon Heavy rocket on the launch pad for one of SpaceX’s most complex missions – Spaceflight Now

27 Merlin engines on three Falcon Heavy first stage boosters. Credit: SpaceX

The Falcon Heavy rocket’s first flight of 2019 is scheduled for Tuesday to begin SpaceX’s longest launch mission to date, a roughly six-hour climb into geosynchronous orbit more than 20,000 miles above the equator with a payload bundle for the U.S. Space Force. The powerful reusable rocket’s two side boosters will return to Cape Canaveral for landing.

The mission’s high-altitude target orbit means the Falcon Heavy’s upper stage will have to travel through the Van Allen radiation belts for about six hours before re-igniting its engine and deploying Space Force satellites.

The long-duration mission required SpaceX to make some modifications to the Falcon Heavy rocket. The most visible modification is the addition of gray paint to the outside of the kerosene upper stage fuel tank, which will help keep the fuel from freezing while the rocket spends hours in the cold environment of space.

The launch, designated USSF-44 by the Space Force, will mark the fourth flight of SpaceX’s Falcon Heavy, the most powerful rocket currently flying. But it’s the first Falcon Heavy mission since June 25, 2019, after a series of delays encountered by SpaceX customers.

The USSF-44 mission has been pushed back about two years from its original schedule of late 2020. The Space Force blamed problems with the satellites for the delay.

SpaceX’s Falcon Heavy rocket climbs the ramp to ramp 39A on Monday. Credit: SpaceX

The launch will be the first fully operational national security mission to fly on SpaceX’s heavy lifter. The last Falcon Heavy launch in June 2019 carried 24 experimental satellites for the military and NASA in the Space Test Program-2, or STP-2, mission. The STP-2 mission was billed as a rocket demonstration flight before future launches with more critical national security payloads.

“We worked side-by-side with SpaceX to ensure that the Falcon Heavy met all of our requirements and had a successful launch,” said Walt Lauderdale, USSF-44 Space Force mission director for launch. “This will be the first Falcon Heavy launch in over three years and we are excited to get these payloads into space. This launch is an important milestone and continues a strong partnership that solidifies a capability that will serve the nation for years to come.”

“This launch culminates years of effort by a dedicated team of mission-focused people from across the U.S. Space Force and SpaceX. The Falcon Heavy is an important element of our overall lift capability and we are very excited to be ready for launch,” said Brig. Gen. Stephen Purdy, executive officer for the Space Force’s Safe Access to Space program.

The space force has released little information about the satellites being launched on the Falcon Heavy rocket.

There are two payloads stacked on top of each other inside the Falcon Heavy’s nose cone. One is called the Shepherd Demonstration, and the other is a second Space Force Long-Duration Propulsion ESPA or LDPE 2 spacecraft, which itself has six payloads — three that will remain attached to the spacecraft and three that will deploy from LPDE 2 to perform their own missions.

SpaceX’s Falcon Heavy rocket heads to the launch pad on Monday for the USSF-44 mission. Credit: Michael Cain / Spaceflight Now / Coldlife Photography

A fully assembled Falcon Heavy rocket headed into Launch Complex 39A at NASA’s Kennedy Space Center on Monday afternoon, riding a transporter a quarter-mile from the hangar to the launch pad. SpaceX teams planned to lift the Falcon Heavy vertical overnight on pad 39A in preparation for liftoff on Tuesday during a 30-minute window opening at 9:41 a.m. EDT (1:41 p.m. GMT).

Forecasters are predicting a 90% chance of good weather for Tuesday’s launch, with light winds and little cloud. “The primary weather concern will be an unusual Atlantic shower or enhanced cumulus that washes over the coast,” the 45th Air Force Weather Squadron wrote in an outlook released Monday.

After receiving their supply of kerosene and liquid oxygen, Falcon Heavy’s three first-stage boosters fire their 27 main engines and shut down to produce 5.1 million pounds of thrust, about twice the power of any other operational rocket in the world. The rocket will head east from the launch site, arcing over the Atlantic Ocean before jettisoning its two side boosters two and a half minutes into the flight.

The side boosters will start their cold gas thrusters and re-ignite three engines each to reverse course and begin returning to Cape Canaveral Space Force Station for landing at two SpaceX recovery zones about 9 miles (15 kilometers) south of Pad 39A. The boosters will aim for near-simultaneous vertical landings less than 10 minutes after liftoff.

The main stage, which will shut down its engines for the first stage of flight, will burn for a longer period of time before jettisoning and falling into the Atlantic. It will not be found in the USSF-44 mission. The upper stage engine will complete the task of placing the USSF-44 payload into an equator-hugging geosynchronous orbit about 36,000 kilometers above Earth.

USSF-44 Mission Space Force patch. Credit. US Space Force

The rocket will launch the LDPE 2 and Shepherd Demonstration satellites into orbit to complete the Falcon Heavy launch sequence. The satellites will orbit in sync with the Earth’s rotation, meaning geosynchronous orbit is a popular location for military communications, early warning and reconnaissance satellites.

Most satellites that go into geosynchronous orbit are launched by launchers in an egg-shaped orbit. This requires the spacecraft to use its own propulsion resources to orbit at an operational altitude above the equator.

Some launches place their satellites directly into geosynchronous orbit. The Atlas 5 and Delta 4 rockets built by United Launch Alliance, SpaceX’s rival in the US launch industry, have already accomplished this feat. But Tuesday’s launch will be SpaceX’s first attempt to place a payload directly into geosynchronous orbit.

SpaceX has tested its long-duration coasting capability on previous flights, including the launch of the Falcon Heavy in the STP-2 mission in 2019, which lasted three and a half hours from liftoff to final burnout of the upper stage engines. In December 2019, SpaceX conducted a long-duration six-hour shore experiment on the Falcon 9 rocket’s upper stage after launching a resupply mission to the International Space Station.

The Shepherd Demonstration satellite on the USSF-44 mission “hosts payloads that develop technologies and accelerate risk reduction efforts to inform programs of record,” the Space Force says. A military spokesman said the Shepherd Demonstration satellite carries the Space Force’s multiple payloads and is based on an “ESPA ring,” a circular structure with ports for experiments and instruments.

A Space Force spokesman declined to provide additional details about the Shepherd Demonstration mission in response to questions from Spaceflight Now.

The LDPE 2 spacecraft was built by Northrop Grumman, and is similar to the LDPE 1 satellite launched in December 2021 on a ULA Atlas 5 rocket. LDPE 2 has six payloads on peripheral ports, apparently similar to the design of the Shepherd Demonstration spacecraft, and has its own propulsion system for maneuvering in space. The spacecraft is capable of launching small satellites into orbit, and a Space Force spokesperson confirmed to Spaceflight Now that three of the LDPE 2 payloads will separate as free fliers in geosynchronous orbit.

One of the small “subsatellites” riding on LDPE 2 is believed to be Tetra 1, a small microsatellite built by Millennium Space Systems, a subsidiary of Boeing. Military officials said in a 2020 statement that the Tetra 1 satellite was assigned for launch on the USSF-44 mission and was designed to “prototype the mission and tactics, techniques and procedures in and around geosynchronous Earth orbit.”

The US Space Force’s Tetra 1 satellite. Credit: Millennium Space Systems/Boeing

The LDPE 2 host spacecraft can also carry two Lockheed Martin CubeSats on a demonstration mission to test maneuverability and navigation capabilities for future small satellites in geosynchronous orbit. Two small LINUSS satellites — short for Lockheed Martin In-space Upgrade Satellite System — have been assigned to fly on the USSF-44 mission in early 2021, according to orbital debris assessment report published on the website of the Federal Communications Commission.

The LINUSS A1 and A2 satellites, owned by Lockheed Martin and built by Tyvak Nano-Satellite Systems, are designed to separate from the LDPE 2 spacecraft about two months after launch and then maneuver using their miniature propulsion systems. After separating a few hundred miles apart, one of the satellites will approach its companion to within just 160 feet (about 50 meters).

The demonstration will test capabilities that could be used in future satellite servicing missions or on inspection spacecraft that could approach other objects in orbit. the LINUSS mission will also demonstrate embedded high-performance imaging, small satellite propulsion, inertial measurement units, machine vision, 3D printed components and reconfigurable flight software, Lockheed Martin said. The company said it developed the LINUSS mission using internal funding.

LINUSS CubeSats measure about 8 inches by 8 inches by 12 inches and weigh about 47 pounds (21.5 kilograms) at launch.

Spaceflight Now asked the Space Force last week whether the Tetra 1 spacecraft and two LINUSS satellites remain on the USSF-44 mission and whether they represent the three payloads that will separate from the LDPE 2 spacecraft. A Space Force spokesman declined to confirm whether three satellites still assigned to launch USSF-44.

Artist’s concept of the LINUSS A1 and A2 satellites in orbit. Credit: Lockheed Martin

The space force says the LDPE program allows the military to more affordably send small and secondary payloads into geosynchronous orbit, helping to accelerate the service’s “pivot to new, more resilient space architectures.”

“This capability has broad potential to fill gaps in our space systems architecture and provide useful services to our mission partners with frequent and low-cost orbital access,” said Brig. Gen. Tim Sejba, the Space Systems Command’s program executive officer for space domain awareness and combat power.

“LDPE 2 contains various payloads that advance technology related to communications and weather sensing in space,” a Space Force spokesman said.

The next military mission to fly on the Falcon Heavy rocket, named USSF-67, will launch the LDPE 3 spacecraft and the Space Force communications satellite in tandem. That launch is scheduled for January and will use the same Falcon Heavy side boosters that flew on the USSF-44 mission, assuming a successful recovery at the landing zones at Cape Canaveral Space Force Station, the Space Force said.

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Follow Stephen Clark on Twitter: @StephenClark1.





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