SpaceX has recently provided a detailed update on the progress of its Starship Human Landing System (HLS) variant, addressing questions about whether it will be ready in time for NASA’s Artemis 3 mission. The Artemis program aims to return humans to the Moon and establish a sustainable presence there, and Starship HLS is a key component of this effort.
The Starship HLS is a specialized version of SpaceX’s Starship, based on the Block 3 design currently under development. This Block 3 Starship is expected to fly for the first time in the first quarter of 2026. The HLS variant will work in conjunction with tankers and depots to refuel in space, allowing it to transport both astronauts and roughly 100 tons of cargo to the lunar surface.
Since winning the HLS contract in April 2021, SpaceX has made significant progress in developing this lander variant. The company has been working on interior systems and other critical subsystems, moving closer to finalizing the design and beginning construction of flight hardware. The HLS will feature two airlocks, each with a volume of 13 cubic meters, which is twice the internal volume of the Apollo Lunar Excursion Module (LEM). The total internal volume of the HLS is planned to be about 600 cubic meters, compared to the International Space Station’s roughly 1,000 cubic meters. This space will accommodate supplies, sleeping quarters, a command and control area, and more. Because the HLS will land vertically on the Moon, astronauts will use an elevator to travel from the airlock down to the lunar surface.
In addition to the six main Raptor engines, the HLS will have multiple smaller landing thrusters positioned higher on the ship’s structure. These thrusters are designed to minimize the disturbance of lunar regolith during landing.
SpaceX has completed 49 development milestones for the HLS so far. One key achievement is the qualification of a docking adapter developed with NASA and Lockheed Martin. This androgynous docking system, based on the flight-proven Dragon 2 design, will allow the HLS to dock with the Orion capsule and the Lunar Gateway in lunar orbit. Life support and environmental control systems have been tested in a full-scale cabin with multiple people aboard. The elevator system has been demonstrated using Axiom Extra Vehicular Activity (EVA) suits, which astronauts will wear during Artemis missions. Landing leg testing has also been conducted, including dropping a full-scale article onto simulated lunar regolith to study the interaction between the landing legs and the Moon’s surface.
While many milestones have been reached, SpaceX still faces numerous challenges before the HLS becomes operational.
The HLS is just one part of the broader Starship program, which includes several variants and objectives. To support the Artemis mission, the Block 3 Starship and its core systems must be fully developed and tested. SpaceX has conducted 11 full-stack flight tests so far, with mixed results, but ended the Block 2 era on a positive note.
So far, SpaceX has demonstrated the ability to recover boosters at the launch site and reuse them, send a Starship into space, relight a Raptor 2 engine in orbit, transfer propellant in space, control the ship in orbit, and safely reenter Earth’s atmosphere. These achievements lay the groundwork for future reuse and more complex operations.
The next critical steps include testing the new Block 3 ship and booster designs, as well as a new launch pad. SpaceX aims to launch a Block 3 Starship into orbit and maintain that orbit for an extended period. Key milestones will include catching a returning ship, reusing it, and performing ship-to-ship docking and cryogenic propellant transfer. These capabilities are essential for rapid turnaround and deep space missions.
SpaceX also plans to test tanker, depot, cargo, and eventually the HLS variants. Once these vehicles and operations are proven, SpaceX will have the infrastructure to transport humans and large amounts of cargo to the Moon, supporting the construction of a lunar base. This framework will also support future missions to Mars, SpaceX’s ultimate goal of making life multiplanetary.
Regarding the Block 3 upgrades, SpaceX has conducted over 40,000 seconds of Raptor 3 engine firings and continues daily testing. The Raptor 3 engine offers increased thrust and requires less shielding, reducing the dry mass of the vehicle.
For boosters, SpaceX has two test tanks at its Masseys test area: B18.1 and B18.3. B18.1 tests the redesigned booster aft section and part of the new landing tank, while B18.3 focuses on the integrated hotstage truss and grid fin sockets. B18.1 has undergone 10 cryogenic proof tests since May 10 and has been subjected to 13,400 tons of thrust in testing, exceeding the 10,000 tons expected in future boosters with 33 Raptor 3 engines. B18.3 has been at Masseys since September 20 and has completed a few cryogenic proof tests. SpaceX is building a second can crusher cap to further test the new truss design on B18.3. Additionally, the company is testing a new, larger transfer tube design with multiple test tanks. This transfer tube will improve booster flipping and other operations.
SpaceX does not yet have a completed Block 3 ship test tank. A partially stacked test tank was previously in Mega Bay 2 but has since been moved to the Starfactory, possibly awaiting a Block 3 ship aft section for testing.
Alongside vehicle and engine testing, SpaceX is nearing completion of a new launch pad design at Pad 2(B) in Starbase. This pad features a flame trench, a water-cooled steel deck, a redesigned tank farm, and a more robust overall structure. Similar pad designs are being built at LC-39A, with plans for two more at SLC-37 pending approval. Pad 1(A) at Starbase is also undergoing conversion.
The first full flight test of Block 3 will involve Booster 18 and Ship 39, expected to launch in the first quarter of 2026. Neither vehicle is currently complete, and cryogenic proof testing is unlikely to begin before December. Booster 18 will conduct engine testing on the new launch pad, while Ship 39 will commission the Masseys static fire tank farm and repaired stand, following the loss of Ship 36 due to a Composite Overwrapped Pressure Vessel (COPV) failure. After individual testing, a full stack wet dress rehearsal will likely be required to test the new countdown and pad systems.
Booster 18 features extensive redesigns, with both the aft and forward sections completely reworked. The aft section now has high-pressure piping, engine controls, and gas distribution mounted externally rather than inside heavy shielding. The reduction in shielding around the Raptor 3 engines has allowed SpaceX to add metallic tiles to protect the booster’s aft plate during reentry, reducing weight and improving performance.
The forward section includes the integrated hot stage truss, with grid fins mounted inside cavities within the liquid methane tank. There are now three larger fins instead of four, reflecting the higher angle of attack expected during the glide phase. The top grid fin was removed because it would be ineffective due to low airflow.
Ship 39, currently only partially stacked, already shows design changes. The ship catch pins have been refined and relocated to the nosecone. The positions of the four Starlink antennas have changed again. The common dome has been moved down slightly, allowing more liquid methane to be loaded into the tank. The aft dome will likely move down as well to maintain the proper liquid oxygen to methane ratio.
The heat shield has been improved by relocating smaller tile strips over dome welds to enhance gap closure between tiles on the tank wall. Ramps over the chopstick pin sockets and stabilizer sockets have been removed by integrating the stabilizer socket more effectively and eliminating the lifting pin socket, as the catch pins now serve as the primary lifting points.
A significant new feature is the probe-and-drogue docking system, which will enable Starships to dock with each other in orbit. This system has passive and active components. Ship 39 currently has the passive drogue system installed in its payload bay.
Flight 12, involving Booster 18 and Ship 39, is expected to mark a new phase in the Starship program. However, given the many milestones still to be achieved, it remains uncertain whether the HLS variant will be ready by mid-2027 for the Artemis 3 mission, assuming all other Artemis elements are prepared on schedule.
Nevertheless, a series of successful flight tests could accelerate the Starship program and help meet the Artemis 3 timeline. Regardless, SpaceX has a substantial amount of work ahead to reach the Moon with the HLS and ultimately to send humans to Mars.