Starship’s Path to Lunar Landings

The race to return humans to the Moon hangs on the success of the largest rocket ever built. NASA has selected SpaceX’s Starship as the Human Landing System (HLS) for the Artemis III mission, which aims to put astronauts near the lunar south pole no earlier than September 2026. This partnership marks a massive shift in spaceflight strategy, moving from government-owned hardware to commercial service contracts. The success of the Artemis program now relies heavily on SpaceX’s ability to iterate, test, and certify their massive stainless-steel vehicle.

The Role of Starship in Artemis III

NASA’s Artemis program utilizes a complex architecture involving multiple vehicles. The Space Launch System (SLS) rocket will launch four astronauts inside the Orion capsule from Florida. Meanwhile, SpaceX must launch its Starship HLS separately.

The plan dictates that the Orion capsule and Starship will meet in a specific path around the Moon called a Near-Rectilinear Halo Orbit (NRHO). Two astronauts will transfer from Orion into Starship, descend to the lunar surface for about a week, and then launch back up to reunite with Orion for the trip home.

For this to happen, SpaceX has to deliver a specialized version of Starship. Unlike the version designed for Earth return, the HLS variant lacks heat shields and steering flaps needed for atmospheric reentry. Instead, it features:

  • High-Mounted Thrusters: Specific landing engines placed high on the ship to avoid kicking up dangerous lunar dust and rocks during touchdown.
  • Solar Arrays: A band of solar panels around the circumference of the ship to generate power during the lunar stay.
  • Crew Quarters: An elevator and airlock system to allow astronauts to exit the vehicle 100 feet above the surface.

Rapid Iteration and Flight Testing

SpaceX uses an iterative development philosophy often summarized as “build, fly, break, fix.” This contrasts sharply with traditional aerospace methods that spend years in design to ensure the first flight is perfect. The Starship system consists of the Super Heavy booster (first stage) and the Starship spacecraft (upper stage).

Recent Integrated Flight Tests (IFT) from the Starbase facility in Boca Chica, Texas, have shown rapid progress:

  • IFT-1 (April 2023): Cleared the tower but failed to separate stages, resulting in a controlled destruction.
  • IFT-2 (November 2023): Achieved “hot staging” where the upper stage engines ignite while still attached to the booster.
  • IFT-3 (March 2024): Reached orbit and demonstrated propellant transfer capabilities internally, though the ship was lost during reentry.
  • IFT-4 (June 2024): Achieved a soft splashdown for both the booster and the ship, marking a major milestone in reusability.

These tests are not just about reaching orbit. They are data-gathering exercises required to meet NASA’s strict safety standards for human flight.

The Critical Challenge: Orbital Refueling

The most technically difficult part of the Artemis III architecture is not the landing itself, but the fuel required to get there. Starship runs on methalox (liquid methane and liquid oxygen). Because the ship is so heavy, it arrives in Earth’s orbit with nearly empty tanks. It cannot go to the Moon without filling up first.

To solve this, SpaceX must master cryogenic propellant transfer. The mission profile is complex:

  1. Depot Launch: SpaceX launches a “target” Starship intended to serve as a fuel depot in low Earth orbit.
  2. Tanker Flights: Multiple “tanker” Starships launch rapidly to transfer fuel into the depot. Estimates for the number of tanker flights range from 10 to nearly 20 launches for a single moon landing.
  3. HLS Fill-Up: The HLS Starship docks with the fully loaded depot, takes on the fuel, and then departs for the Moon.

NASA officials, including Associate Administrator Jim Free, have highlighted this as a primary risk factor. The technology to transfer super-cold fluids in zero gravity at this scale has never been demonstrated operationally. SpaceX demonstrated an internal fluid transfer during IFT-3, but ship-to-ship transfer remains a hurdle they must clear well before 2026.

Uncrewed Demo Mission

Before any astronaut steps foot on a Starship, SpaceX must prove the vehicle is safe through an uncrewed demonstration. The contract with NASA requires SpaceX to fly an empty Starship HLS to the Moon, land successfully, and demonstrate it can lift off again.

This “dress rehearsal” verifies the guidance software, the landing legs (which must handle uneven terrain), and the life support systems. If the uncrewed demo fails, the timeline for Artemis III will slide further. NASA requires this verification to minimize the risk to the crew, as the HLS has no emergency escape system during the lunar descent phase.

Why Stainless Steel Matters

SpaceX chose 304L stainless steel for Starship rather than the carbon fiber composites or aluminum-lithium alloys used in other rockets like the Falcon 9 or SLS. This choice impacts the timeline and cost significantly.

  • Cost: Steel costs roughly \(2,500 per ton, compared to over \)100,000 per ton for carbon fiber. This allows SpaceX to build many prototypes simultaneously.
  • Temperature Tolerance: Steel handles the extreme cold of cryogenic fuel and the extreme heat of atmospheric friction better than aluminum, reducing the need for heavy heat shielding on the booster.
  • Durability: A steel ship is more robust against micrometeoroid impacts in space, a necessary feature for a vehicle intended to stay in lunar orbit for extended periods.

The Path Ahead

The schedule is tight. With Artemis III targeted for September 2026, SpaceX has roughly two years to finalize the HLS design, master orbital refueling, and complete the uncrewed landing. While the SLS rocket and Orion capsule are largely ready, having flown successfully on Artemis I in 2022, the Starship element remains the pacing item.

The success of this approach will determine not just the date of the next moon landing, but the viability of a permanent lunar presence. If Starship works as advertised, it offers payload capabilities dwarfing anything else in history, potentially carrying 100+ tons to the lunar surface in a single trip.

Frequently Asked Questions

When will Starship land on the Moon? The current target for the Artemis III crewed landing is September 2026. However, an uncrewed test landing must occur before that date, likely in late 2025 or early 2026.

How many launches does one moon landing require? It is estimated that SpaceX will need to launch one propellant depot, one HLS ship, and between 10 to 15 tanker flights to fuel the mission. This means a rapid cadence of launches from Earth is required.

Is Starship safer than the Apollo Lunar Module? Starship is significantly larger and includes modern avionics, redundant engines, and advanced automated docking systems. However, unlike Apollo, it relies on complex orbital refueling. NASA creates strict “human-rating” certification standards that SpaceX must meet to ensure the vehicle is as safe as possible.

What happens if Starship is not ready by 2026? If the HLS is not ready, NASA may delay Artemis III or change the mission profile to a different objective (such as an orbital mission) that does not involve landing, pushing the actual moon landing to a later flight.