SpaceX launches X-37B on eighth mission: USSF-36 lifts off with quantum navigation demo

SpaceX launches X-37B on eighth mission: USSF-36 lifts off with quantum navigation demo
25 August 2025 0 Comments Darius Kingsley

Night launch, tight secrecy: X-37B heads back to orbit

Just before midnight in Florida, a Falcon 9 rose off Launch Complex 39A and sent the U.S. Space Force’s X-37B back to space. Liftoff for the eighth Orbital Test Vehicle mission—USSF-36—came at 11:50 p.m. ET on Thursday, August 21, 2025, after a launch window that stretched into the early hours of Friday. United States Space Force officials confirmed spacecraft separation shortly after ascent, and tracking data indicated a northeast trajectory consistent with low Earth orbit.

This flight marks the third time SpaceX has launched the secretive military spaceplane, following the OTV-5 mission in 2017 and OTV-7 (USSF-52) in late 2023. For USSF-36, the Space Force assigned Falcon 9 as part of its National Security Space Launch (NSSL) Phase 2 work, managed by Space Systems Command. It’s the second of two Order Year 2 (OY2) missions awarded to the company in this cycle; the first, NROL-69, flew on March 24, 2025. Space Systems Command listed the combined value of the two OY2 launches at $179.7 million.

The Boeing-built X-37B—an uncrewed spaceplane about the size of a small bus—has been flying since 2010. It carries experiments in a payload bay, deploys a solar array once in orbit, and returns to Earth for a runway landing after months or even years in space. The service considers it a flexible testbed: get gear to orbit, run it in the real environment, bring it home, and inspect it. For USSF-36, the Space Force says the focus is on next-generation communications and navigation technologies.

The Falcon 9 first stage for this flight, booster B1092-6, notched its sixth mission. It previously supported NROL-69, the CRS-32 space station cargo run, GPS III-7, and two Starlink deployments. After stage separation, the booster reversed course for a return-to-launch-site landing, touching down at Landing Zone 2 on Cape Canaveral Space Force Station. That brought the familiar twin sonic booms across Florida’s Space Coast and added another successful recovery to the reusable fleet.

Public orbital details remain sparse, but the launch profile pointed to a low Earth orbit, likely a roughly 500-kilometer circular path at about 49.5 degrees inclination. Amateur trackers will watch for clues as the vehicle maneuvers, changes altitude, and possibly deploys auxiliary payloads. Early chatter among mission watchers pointed to the deployment of a small satellite known as LIMASAT, likely released soon after launch from the spaceplane’s bay or a service module. The Space Force has not detailed its purpose.

What flew and why it matters: lasers, quantum sensors, and cislunar resilience

The headline experiments on USSF-36 aim at two hard problems: moving data faster in space and navigating precisely without GPS. The mission includes demonstrations of high-bandwidth inter-satellite laser communications. Think of it as fiber-optic speeds without the fiber. Laser links can move large volumes of data between spacecraft without relying on radio frequencies, which are crowded and easier to jam. They can also be more secure and directional, reducing the chance of detection or interception.

Laser crosslinks are becoming standard on commercial constellations, but military requirements add tougher guardrails: anti-jam performance, low probability of intercept, and the ability to connect diverse platforms spread across orbits. A test on a long-lived vehicle like the X-37B lets operators try new terminals, point-in-space handoffs, and encryption schemes over months, not days. If the payload works across changing orbits and thermal loads, it’s a strong signal the tech is ready to leave the lab.

The other standout is a “highest-performing” quantum inertial sensor, according to Space Force officials. That phrase might sound grand, but the goal is simple: know exactly where you are and how you’re moving even when GPS goes dark. Quantum sensors often use ultra-cold atoms and measure how they interfere when accelerated or rotated. The result is a very stable reference to track motion. In plain terms, it’s like having a super-accurate internal compass and speedometer rolled into one—no satellite signals required.

Why does that matter? Space operations now stretch beyond familiar low Earth orbits. Forces want to maneuver in geostationary orbit, visit the high elliptical orbits used by some communications and early-warning platforms, and keep an eye on the growing cislunar neighborhood near the Moon. Colonel Ramsey Horn, commander of Space Delta 9, underscored that a quantum-grade inertial sensor could harden navigation against jamming and help ships operate far from Earth’s beacons, where GPS is weak or absent. If the demo meets expectations, it could become a cornerstone for resilient spaceflight.

The X-37B is well-suited for this kind of work. It can fly for a long time, run experiments in different orbital regimes, and then land so engineers can tear down hardware to see what survived and what degraded. The program has quietly racked up endurance records: OTV-1 flew 224 days in 2010, OTV-2 lasted 468 days, OTV-3 reached 674 days, OTV-4 hit 718 days, OTV-5 stretched to 780 days, and OTV-6 set the current mark with 908 days in orbit before landing in 2022. OTV-7 launched in December 2023 and remained active well into 2025. With that track record, it’s no surprise the Space Force isn’t putting a clock on USSF-36.

The vehicle itself blends shuttle-like reentry with small-satellite agility. It’s roughly 8.9 meters long with a wingspan of about 4.5 meters, and it flies autonomously from orbit to a runway. It has previously landed both at Vandenberg Space Force Base in California and at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. Recent missions have added a detachable service module to carry extra experiments and power, which is typically discarded before reentry. The Space Force does not comment on configuration for ongoing flights.

On the propulsion side, Falcon 9’s quick reusability keeps the cadence high for national security missions. A return-to-launch-site recovery is a demanding profile—there’s less margin than a droneship landing—but it simplifies logistics and speeds refurbishment. The kind of payloads that ride with the X-37B often need late cargo access and tight security. LC-39A offers both, along with a track record of human and national-security launches. Space Systems Command shapes those decisions under the NSSL program, matching payload needs with vehicle performance and schedule.

Cost matters too. The combined $179.7 million figure for the two OY2 missions assigned here won’t map cleanly to any one launch, but it hints at the value prop: reusable rockets, frequent flights, and a mature ground system. When the first stage comes home, the operator keeps most of the hardware that costs the most to build. Over time, that reduces the price of putting classified payloads in the right orbit on the right night.

The mission specifics will unfold slowly. If USSF-36 mirrors past flights, expect a series of orbit changes, possible payload deployments, and long quiet stretches where the vehicle simply works. Ground-based observers will track passes and note any shifts that suggest new experiments starting up. The Space Force will say little in real time. That opacity is deliberate: the less an adversary knows about timing and capability, the harder it is to counter.

What can we watch for? Laser comms tests may show up indirectly, for example if satellites known to carry compatible terminals adjust to form crosslink geometry. Navigation demos are trickier to spot, but notable changes in altitude or inclination can stress-test a sensor and the navigation software around it. If a service module is on this flight, it may be jettisoned late in the mission, and observers could see that hardware as a new object in tracking catalogs.

The broader context is clear: the military is leaning more on commercial launch providers for speed and scale. SpaceX shares NSSL Phase 2 duties with ULA, and both have added national security flights to their calendars while juggling commercial work. For the Space Force, that means more rides to orbit and more chances to try new tech like quantum sensors without waiting years for a custom satellite bus. For industry, it’s steady demand that supports upgrades to pads, recovery assets, and refurbishment lines.

As for the X-37B’s return? That date stays classified. History suggests months at a minimum and years at the high end. When the flight wraps, the spaceplane will aim for a runway—most likely the Kennedy Space Center’s Shuttle Landing Facility, though Vandenberg remains an option—close its payload bay doors, and glide to a stop. Engineers will pull the experiments, compare the data to what they expected, and decide what’s ready to field and what needs another lap in orbit. Until then, USSF-36 will do what the X-37B does best: disappear into the night and get to work.