SpaceX caught a rocket: what's next?

TLDR: The company has a long way to go to reach the moon.

The capture of the Starship rocket by two massive mechanical arms earlier this month marked a significant step in SpaceX's efforts to change the way humanity approaches space exploration. However, despite the grandeur of the event, this is just another stage on a long path. SpaceX strives to make launches cheap, frequent and reliable, and dreams of a future where rockets quickly return to the launch pad, refuel and take off again within hours. The company says this will lead to regular Starship landings on the Moon and Mars.

Critics say Starship's low-orbit refueling architecture is inefficient. For example, to fully refuel a ship capable of taking people to the Moon and back, at least a dozen flights of refueling ships will be required. But this turns out to be impractical only within the old paradigm, where launches are expensive and rare. This approach makes much more sense if SpaceX can launch Starship dozens of times a week.

The capture of the Super Heavy booster on October 13 at Starbase in Texas brought SpaceX closer to its dream of radically increasing the frequency of flights. This event confirmed the viability of the concept of a launch tower, which not only supports the rocket at launch, but can also catch it upon landing. Two years ago, this idea seemed impossible, but SpaceX has proven that their stage does not need landing legs and does not require complex procedures to move the rocket back to the launch pad. Reduced weight and reduced preparation time are significant advantages of Starship.

What will happen next?

Let's try to evaluate the next stages of the Starship program that must be achieved so that the ship is ready to land people on the Moon as part of NASA's Artemis program and perform demonstration flights to Mars. We've also included approximate dates, although these are just estimates and are likely to change.

Raptor in-flight re-ignition (late 2024 – early 2025)

To date, Starship's upper stage has never completed a full orbital flight. After the first three flights lost the second stage, SpaceX was able to achieve a controlled re-entry over the Indian Ocean in its final two tests. The main reason Starship has not yet entered orbit is the need to rehearse the vehicle's safe return to Earth to ensure there is not much risk of its parts falling onto land. To do this, SpaceX must demonstrate the ability to re-ignite the Raptor engines for a deorbit maneuver.

Last week, the booster for the sixth test flight was delivered to the launch pad for testing. If one or more Raptor engines can fire during this flight, it will allow SpaceX to begin orbital testing and possibly the first launches of Starlink satellites using Starship as early as the first half of next year.

Return of Starship to land (mid-late 2025)

During the fifth test flight, SpaceX proved the ability to accurately land Starship in the ocean, now the company will have to work out the return of the ship to land. Elon Musk has talked about “capturing” Starship on the launch tower by the first half of 2025, but this requires many legal issues to be resolved.

Unlike the Super Heavy booster, which flies over the Gulf of Mexico, Starship will have to fly over Mexico and Texas when landing. So before landing the ship, SpaceX may conduct landing tests in other locations, such as Johnston Atoll in the Pacific Ocean. In the future, SpaceX will likely develop several modifications of Starship for different purposes, including ships with landing legs for landing on the Moon or Mars.

Whether SpaceX will focus on developing landing legs or try to achieve the capture of Starship in Texas is an open question.

HLS refueling demonstration (late 2025)

The next major milestone for NASA in the development of the Starship-based Human Landing System (HLS) required for Artemis missions is the demonstration of in-orbit fuel transfer. NASA officially expects the Artemis crew to land on the Moon in September 2026, and agency officials told Ars that SpaceX should conduct orbital fuel transfer tests as early as early 2025. However, before this, a significant amount of preparatory work remains.

For the demonstration, SpaceX will send a “target” Starship into low Earth orbit, then it will be joined by a “catching up” Starship. These ships will dock in orbit, and for the first time in the history of astronautics, the “catch-up” will transfer a significant amount of cryogenic fuel to the “target”. Having completed the procedure, they will undock and perform deorbit maneuvers.

An image from NASA shows a diagram of a planned demonstration of cryogenic fuel transfer between SpaceX ships in 2025. Source: NASA/Amit Kshatriya

This will require completion of the second launch tower in Texas, launch of the catch-up, and development and testing of docking mechanisms, fast transfer connections, navigation sensors and hot gas engines. SpaceX is actively working on these elements in the background, but the exact date for this test has not yet been determined. Optimistically, we can expect it next year, and even if the test is successful, SpaceX will likely conduct several repeated tests to work out all the processes.

Re-launch of Super Heavy first stage (early 2026)

SpaceX recently successfully returned the Super Heavy booster and gained valuable data on its post-flight condition. While this booster certainly won't fly again, one of the future examples may make a second flight.

After successfully capturing the rocket, Elon Musk noted that Starship could achieve full reusability as early as 2025, which, according to him, would be a critical step towards a multiplanetary future for humanity. Musk envisions reusing both the booster and upper stage as early as next year, but that timeline is highly optimistic, especially for the upper stage.

Considering that 15 months passed between the first Falcon 9 landing in December 2015 and the reuse of the first stage in March 2017, you can expect SpaceX to take at least a year to relaunch Super Heavy, especially given the size and complexity of that rocket. Additionally, SpaceX may opt for upgraded versions of the booster to improve efficiency.

Testing of ground infrastructure and production of liquid oxygen

To support the Artemis program and frequent refueling flights, SpaceX plans to build two launch towers each in South Texas and Florida. These towers will require approvals from the U.S. Space Force and FAA environmental reviews to increase launch frequency. The production of liquid oxygen is also a significant problem. Launching just four Starships per day uses up its entire daily production in the US, i.e. scaling production and logistics will be critical.

Long-term test flight (end of 2026)

NASA included this goal in the HLS program schedule back in 2021. This long-duration flight will demonstrate Starship's ability to remain in lunar orbit while awaiting rendezvous with the Orion crew. Starship must autonomously maintain conditions for the crew and prevent too much evaporation of cryogenic fuel for up to 100 days while it waits for the astronauts to arrive.

Unmanned Moon landing (early to mid 2027)

This is a key test that will confirm Starship's readiness for a manned lunar landing. The fully fueled Starship will head towards the Moon and attempt to land near the South Pole. The main objective of the mission is to test the stability of the ship on the lunar surface. The mission could include delivering cargo to test an “elevator” that would take astronauts down to the lunar surface. A successful takeoff from the Moon will finally confirm the readiness of Starship as a landing module.

Manned landing (September 2028)

If all goes according to plan, NASA will be able to achieve its original goal of the Artemis program and land two astronauts on the lunar surface in 2028. Although this is two years later than NASA's current date of September 2026, achieving this goal will be a significant engineering and logistical challenge for SpaceX and NASA. If major setbacks occur, such as problems locking the rocket onto the launch tower or failures during on-orbit refueling, the project will inevitably face additional delays.

It's logical to wonder why NASA and SpaceX are putting so much resources into developing a complex lunar module, given that the module for the Apollo missions in the 1960s was much simpler. The main reason is that, like the rest of the Apollo program hardware, the lunar module, Saturn V rocket, and Apollo command module were disposable, and the cost of multiple launches of such systems became too high for the United States after winning the Moon Race.

This old rendering from SpaceX shows how Starship's transportation capabilities will allow it to create infrastructure on the Moon that was not available during the Apollo era. NASA's main goal is to ensure a sustainable presence on the Moon. This requires reusing key elements of the architecture. In addition, the Apollo program could not deliver large pieces of equipment to the lunar surface. The maximum payload of the lunar module, even in the cargo delivery modification, was about 5 tons, while the disposable cargo Starship will be able to deliver an impressive 200 tons to the lunar surface.

If the project is successful, the United States will have a unique opportunity to create a long-term lunar program. But this will require significant effort at the initial stage. Musk has dedicated all of SpaceX's resources to this task, and the company is no longer limited by a lack of finances. The road to realizing Starship's full potential is a long one, but the SpaceX team is working on this project at top speed.