Earlier this month, President Donald Trump signed an executive order giving the Department of Defense jurisdiction over the Roosevelt Reservation, a 60-foot-wide stretch of federal land that runs through New Mexico, Arizona, and California.

The Department of the Interior previously maintained the nearly 110,000-acre swath of federal land before the "emergency withdrawal and transfer of administrative jurisdiction" on April 15. The order excludes the jurisdiction of "Federal Indian Reservations."

The Army requested the jurisdiction transfer to increase patrols by federal personnel and implement security measures and infrastructure to "curb illegal cross-border activities," like illegal immigration and drug and human trafficking, according to a DOI statement.

The April 11 order outlines a phased rollout, starting by testing the implementation of a controlled perimeter in a "limited sector of federal lands" in New Mexico.

For the next 45 days, soldiers will detect and patrol routes and apprehend trespassers in the area. They will also construct temporary barriers and install signs to indicate the boundaries of the military zone.

Following the initial assessment and the Army's acceptance of jurisdiction, the federal land will become a "national defense area," granting the Pentagon the authority to establish and enforce security measures around it.

The 170-square-mile stretch of land will be considered an extension of Fort Huachuca in Arizona — despite not being physically connected to all of it — and remain under control by the Army for three years, according to the DOI press release.

"Our southern border is under attack from a variety of threats," Trump said in the memo. "The complexity of the current situation requires that our military take a more direct role in securing our southern border than in the recent past."

While under the Army's control, the militarized zone, known as the "New Mexico National Defense Area," will be governed and defended like any other military base, allowing US troops to search and temporarily detain trespassers before appropriate civilian or federal law enforcement officials take over.

Military personnel will also work alongside US Customs and Border Patrol agents at the southern border "to repel unlawful mass migration, narcotics trafficking, migrant smuggling, human trafficking, and other cross-border criminal activities," per a Pentagon press release.

Though thousands of military personnel have already been deployed to the southern border, the Posse Comitatus Act bars active-duty troops and federalized National Guardsmen from acting as domestic law enforcement.

The US military could be authorized to enforce civil or criminal law on US soil through the Insurrection Act of 1807, which provides a statutory exception to the PCA in specific circumstances of civil disorder or armed rebellion. To enact it to stop migrants, however, would be an extraordinary use of the federal law.

Since Border Patrol agents and civilian law enforcement are only allowed to apprehend migrants, the vast majority of troops deployed to the border have been tasked with "enhanced detection and monitoring," Gen. Gregory Guillot, the commander of the US Northern Command, said.

Some personnel "operating in close proximity to the border" have been armed with rifles or pistols, Guillot said. Military officials have sought authorization for troops to shoot down suspected cartel drones surveilling the border.

Thousands of active-duty troops aren't the only military assets the Trump administration is using to ramp up its crackdown.

Two US Navy warships, several military aircraft, and over 100 combat vehicles have been deployed to support the Pentagon's southern border operation.

On April 1, Defense Department officials estimated the cost of militarization at the US-Mexico border since January 20 at roughly $376 million, or about $5.3 million per day.

Traditionally seen as a steward protecting public federal lands, the DOI emphasized the "environmental crisis" at the border — not caused by the accelerated military build-up or deferred mitigation efforts, but by the migrants themselves.

The department said "repeated foot traffic, unregulated vehicle use, and the creation of informal trails or camps" cause harm to "ecologically sensitive areas along the southern border."

"Securing our border and protecting our nation's resources go hand in hand," Secretary of the Interior Doug Burgum said during a visit to New Mexico. "This transfer reflects Interior's commitment to public safety, national security, and responsible stewardship of our public lands."

In May 2012, Huntington Ingalls Industries was awarded the contract to build USS Tripoli, and the warship launched five years later in 2017 from Pascagoula, Mississippi.

It is the third vessel to bear the Tripoli name, a tribute to the first recorded land battle the US fought overseas when Marines landed on Tripoli's shores in 1805.

Initially planned to join the Navy's fleet a year behind schedule in 2019, the Tripoli's commissioning was pushed to 2020 due to "unspecified technical difficulties" and delays brought on by the COVID-19 pandemic.

The Tripoli is the second America-class amphibious assault ship delivered to the US Navy. The 45,000-ton vessel measures 844 feet in length and 106 feet in width, similar in size to its predecessor, the Wasp-class amphibious warships.

Powered by two marine gas turbines, the warship has a speed of 22 knots or about 25 mph. The assault carrier is armed with surface-to-air missile systems, two automated gun-based close-in weapon systems, and seven heavy twin machine guns.

The America-class fleet was designed to prioritize aviation capabilities and lacks a well deck to launch amphibious craft.

In its place, the assault carriers have an extended hangar deck and wider high bay areas, which allow more room for aircraft and aviation fuel. The ships also have two aircraft elevators and additional space for aviation maintenance facilities.

The Tripoli's flight deck can accommodate up to nine CH-53K King Stallion heavy transport helicopters flown by Marines. In a standard configuration, the Tripoli can carry up to 10 F-35B fighters, 12 Ospreys, and 16 military helicopters.

Amphibious warships typically operate as helicopter carriers designed to support near-shore operations. The America-class vessels, however, were modified with a more durable, heat-resistant flight deck to launch F-35B stealth fighters.

Taking its aviation capabilities even further, the US Navy used the Tripoli to test the "lightning carrier" concept, tasking the amphibious assault ship to function as a full-fledged carrier.

In 2022, the Tripoli departed its homeport in San Diego for the Western Pacific, spending the first few months of its seven-month maiden deployment putting the experimental concept to the test.

The assault carrier carried 20 F-35B stealth fighters on board — the most ever loaded aboard a big-deck warship.

"We refer to the ship as 'assault carrier 7,' and 'assault' is traditional for an LHD and LHA," Capt. Joel Lang, then-commander of the Tripoli, told reporters at the time. "Typically, the air combat element is a blend of rotary and tilt-rotor in order to enable that assault force to go ashore. We are proving the tactics and the techniques and the procedures to employ the 'lightning carrier' concept."

Produced by US defense manufacturer Lockheed Martin, the fighter jet has a stealth design to vastly reduce its ability to be tracked by radar and is touted as one of the world's most advanced fighters. The F-35B variant has a powerful propulsion system that gives it the unique capability of vertical takeoff and landing.

Developed by Rolls-Royce, the lift fan delivers an additional 20,000 pounds of thrust on top of the aircraft's engine thrust, allowing it to land and take-off like a helicopter.

The F-35B allows Marine aviators to operate aboard smaller flattops and makeshift airstrips, especially on expeditionary missions. With far more advanced capabilities and avionics, the F-35B is set to replace the US military's only other STOVL fighter jet, the McDonnell Douglas AV-8B Harrier, which is expected to retire by 2027.

While the Navy doesn't intend on substituting full-fledged carriers with "lightning carriers," operating smaller flattops bolsters the fleet's air power — at a much lower cost.

An America-class assault ship costs about $3.4 billion, nearly a quarter of the cost to manufacture a new Gerald R. Ford-class carrier, which costs around $13 billion, though the latter possesses more advanced capabilities and carries over 60 aircraft.

"One day, you can have F-35Bs on the flight deck; the next day, you could have MV-22s, and you can be putting Marines ashore," Vice Adm. Karl Thomas, then-commander of the US 7th Fleet, said following the concept testing. "And so it just is a very versatile instrument."

The "lightning carrier" concept could play a larger role in deterring China, which now has the world's largest navy.

Despite still being in the experimentation phase, Thomas said he believes that an assault carrier carrying 14 F-35Bs is "much more capable" than either of China's operational aircraft carriers, the Liaoning and Shandong, "both from a sortie-creation perspective as well as just a sheer capability."

Last December, China unveiled its own massive assault ship, the Sichuan, which can launch fighter jets or drones. The first Yulan-class landing helicopter assault ship has a flight deck as large as three football fields, about as long as the US Navy's America-class LHAs but 60 feet wider. China, however, does not have a carrier-based stealth fighter yet.

Recognizing the operational flexibility of assault warships, the Navy aims to expand its amphibious fleet to at least 31 vessels — 10 of which must be big-deck LHAs.

Two more America-class LHAs — USS Bougainville and USS Fallujah — are currently being built at HII's Mississippi shipyard. The fifth-in-class USS Helmand Province was named last May and has yet to start construction.

Last May, HII was awarded a $9.6 billion contract to ramp up construction on the Navy's amphibious fleet. The deal includes the construction of three San Antonio-class amphibious transport docks and the next America-class big-deck ship.

"Upgrading our fleet with amphibious combat vehicles capable of supporting sea denial and maritime operations will further bolster our ability to support deterrence efforts and respond to contingencies in the Indo-Pacific," Lt. Gen. Roger B. Turner, commander of III Marine Expeditionary Force, said in a statement.

In 1999, NASA selected Boeing to design a reusable orbital test vehicle to monitor and repair satellites closely.

Over the next four years, the X-37 underwent several design iterations to achieve a more aerodynamic design than the Space Shuttle orbiter. It was initially intended to launch from the cargo bay of a space shuttle. But after the Space Shuttle Columbia crashed and killed all seven astronauts on board in 2003, it was redesigned to launch from a different rocket, making it smaller and more autonomous.

The project cost nearly $192 million, and Boeing was awarded another $301 million contract in 2002 through the Space Launch Initiative, a joint research effort led by NASA and the Defense Department. The X-37 project was transferred to the Defense Advanced Research Projects Agency in 2004 and became classified because of its military applications.

In 2006, the Air Force announced the development of its own variant of the space plane, known as the X-37B, designed to operate with an orbital speed of nearly 17,500 mph for up to 270 days.

The uncrewed test vehicle was nearly 30 feet long and had a wingspan of about 15 feet. Its max takeoff weight was 11,000 pounds, and it could accommodate payloads of up to 500 pounds.

Dubbed the "most advanced re-entry spacecraft," the X-37B program would focus on "risk reduction, experimentation, and operational concept development for reusable space vehicle technologies, in support of long-term developmental space objectives," then-Air Force Secretary Michael Wynne said in 2006.

The X-37B was tasked with multiple orbital missions, ranging from testing materials under the conditions of space to releasing a small satellite with its own experimental payloads.

The first X-37B vehicle was launched into orbit from Cape Canaveral in April 2010. The test vehicle spent 225 days in space and returned in December 2010 after conducting several orbit changes, though the data it collected during its maiden mission was classified.

In 2020, the X-37B's sixth mission involved toting a small service module into space for the first time. The FalconSat-8 was a small satellite developed by the US Air Force Academy carrying five experimental payloads. After a record-breaking 908 days in space, the X-37B completed its mission and landed at the Kennedy Space Center in November 2022.

Because much of the X-37B program is classified, the secrecy fueled speculation about the purpose of its mission sets, with some speculating that the space plane could be a weapons platform or used for intelligence, surveillance, and reconnaissance from space.

The X-37B embarked on its seventh and current mission in December 2023, launching from the Falcon Heavy rocket, manufactured and launched by Elon Musk's SpaceX.

The Falcon Heavy is capable of launching payloads over 22,000 feet above Earth, so the X-37B was launched higher than any other spaceplane and flew in a highly elliptical orbit.

The purpose of its seventh mission was to experiment with "future space domain awareness technologies" and analyze the radiation effects on plant seeds during spaceflight, according to the Space Force.

Another key objective of the X-37B's current mission is to refine and execute novel maneuvers called aerobraking, using the drag of Earth's atmosphere to quickly shift into low orbit and safely dispose of service module components using minimal fuel. Changing orbit is a crucial capability should the spaceplane be used to upgrade US satellites or disable those of its adversaries.

Though the image taken by its onboard camera shows just a small portion of the X-37B, few photos of the vehicle itself are available to the public.

A video montage posted on X in 2023 included a blink-and-you'll-miss-it moment of the X-37B separating from its service module during its sixth mission in 2020. The US military and Boeing also released the first photos from the same mission after it was completed in 2022.

The X-37B is known for conducting tests and scientific experiments in space, but details about its military applications remain highly classified.

Operating space-based technology for decades, including the X-37B, has given the US an edge on the new frontier of orbital warfare. China follows closely behind the US with its own spacecraft known as the Shenlong, named after a dragon god in Chinese mythology.

Like the X-37B, much about the aircraft is still shrouded in mystery. The Shenlong was first announced in 2007, but China has publicly disclosed few details about the top-secret space plane program. There are no known images of the Shenlong, and among the few capabilities that are known about the unmanned vehicle is that it can deploy via a rocket, quickly maneuver in space, and deploy payloads into space, much like the X-37B.

During its first orbital flight in September 2020, the Shenlong remained in space for two days to release an object into orbit before returning to Earth.

Its second launch in August 2022 lasted considerably longer, operating in orbit for nine months. The Chinese spaceplane was reportedly practicing maneuvers to deploy and recover a subsatellite, operations that require similar techniques to capture an enemy satellite.

In December 2023, the Shenlong's third mission, which began just seven months after the second, reportedly had a similar objective, releasing an object from its cargo hold to test proximity operations. It completed its mission after nine months in space, returning to China this past September.