【By Observer Net Columnist Flow Rock】

Recently, well-known space journalist Eric Berger published an article on the U.S. tech blog media Ars Technica, and we will discuss specific parts of the article later.

It is well known that NASA has selected SpaceX's Starship-Super Heavy system to develop a Human Landing System (HLS) for crewed lunar landings. However, in the first half of 2025, the Starship system encountered significant difficulties, making it likely that the Starship-based HLS system may not be ready until 2028 or even 2029. Granting any simple two-stage landing contract or urging SpX to speed up seems to be of little use. The NASA Aerospace Safety Advisory Panel stated that if the Starship test flight in the first half of 2026 does not go well, the Starship HLS will not be able to start the HLS contract in 2027.

The successful completion of IFT-10 finally washed away the shame of Starship v2 in the first half of 2025

Eric Berger's article pointed out another possible mode of crewed lunar landing being studied: the HLS supporting Americans' return to the Moon will be Blue Origin's "Blue Moon Mk1" (Blue Moon), rather than the originally planned Starship HLS or the fully developed Blue Moon Mk2 lander.

Regardless, the U.S. crewed lunar landing plan has indeed been delayed, and the main obstacle is the crewed lunar lander. So why is this problem happening?

One

NASA Acting Administrator Sean Duffy recently claimed that the United States wants to beat China in the lunar plan, which is aiming to conduct its first crewed lunar mission in the 2030s.

From 1961, when the Apollo program was launched to achieve crewed lunar landing, and the United States currently has the strongest aerospace technology and the strongest space access capability, it should have had no difficulty with the issue of landing on the Moon. In the early 21st century, the United States also frequently mentioned plans to return to the Moon.

This includes the "Exploration Program" proposed by President Bush in 2005, also known as the Constellation Program, which aimed to build the Altair "Centaur" cryogenic lunar lander, the Orion "Orion" crewed spacecraft, and the Ares V and Ares I rockets used to launch such payloads. The program involved launching the Centaur spacecraft to low Earth orbit with one heavy Ares V rocket, then launching the crewed spacecraft into low Earth orbit with one Ares I rocket, followed by rendezvous and docking before heading to the Moon.

As a lander focused on landing at the lunar poles, Centaur did not use the same type of warm engine as the Apollo lunar lander, but instead developed a "Deep Throttling Universal Expandable Cryogenic Engine" (CECE) based on the RL-10 engine, capable of 10%-100% depth throttling ability, and achieved a throttling ratio of 10%-100% in experiments. Although the Centaur landing module was still single-use, it had expandability and could transport cargo, etc.

Concept drawing of the Centaur LSAM

The grand vision of the Constellation Program was very tempting, but the completely new plan brought huge financial and economic pressure. The brand-new 10-meter rocket body and the overheating problem of the six RS-68B engines were never fully resolved until the end of the project. In 2010, the Constellation Program was canceled. The DIRECT 2.0 Plan proposed in the late 2000s directly used the legacy of the Space Shuttle to transform it into the Jupiter 232 rocket, using the Earth orbit collection model for crewed lunar landing. In the DIRECT 3.0 Plan of 2009, the idea of using the Space Shuttle main engine SSME to replace the ablative cooled RS-68 engine was studied.

Ultimately, these concepts evolved into a rocket similar to the Space Shuttle but not entirely inheriting the Space Shuttle - the Space Launch System (SLS). SLS uses an 8.4-meter diameter similar to the Space Shuttle external tank and installs four SSME engines. However, its contractors, manufacturing/assembly methods, and structural materials have changed, so it cannot be said that the SLS rocket is a legacy of the Space Shuttle. However, the SSME engines and five-segment solid rocket boosters (RSRMV) used by the SLS are directly derived from the Space Shuttle legacy. Although the production is slow, preparation is slow, and the cost is high, the SLS rocket and Orion spacecraft completed their successful first flight in 2021. Although there were some minor issues, they have been resolved.

However, at present, the lunar module, or the "Human Landing System," is facing problems.

We all know that the focus of the Artemis plan is the lunar south pole, and the accompanying Gateway "Portal" space station also uses the Near Rectilinear Halo Orbit (NRHO), which is more convenient for reaching the south pole. To be honest, NRHO is indeed suitable for deploying a lunar orbital space station because the large elliptical orbit under the three-body gravitational control allows the lunar module to adjust the orbital plane with a small ignition at the far point, which almost allows spacecraft launched from any region on the lunar surface to enter an orbit similar to NRHO and eventually dock with the space station. The return window is more than that of a low lunar orbit. In fact, the total velocity increment needed to enter and exit NRHO from the Earth-Moon transfer orbit is only 1000m/s, which means that the Orion doesn't need a lot of velocity increment.

In order to give Europe a share, NASA handed over the propulsion module of the Orion spacecraft to the European development. The European Space Agency used the propulsion system of the ATV low-orbit cargo spacecraft for improvement, resulting in the Orion spacecraft now having only 1250m/s of velocity increment, which can only enter and exit NRHO and dock with the Gateway. Compared to the Apollo's lunar orbit rendezvous scheme, where the command module-service module spacecraft had more than 2300m/s of velocity increment, responsible for directly entering the low lunar orbit with the lunar orbit module.

This is not necessarily a bad thing, but the biggest problem is that it increases the complexity of the HLS. Compared to the Apollo lunar lander, which only needs to descend from LLO and then take off, the HLS needs to first reach NRHO, dock with the Gateway, then carry astronauts from NRHO down to the low lunar orbit, and then descend from the low lunar orbit to the lunar surface. After takeoff, it also needs to push a bit more from the low lunar orbit to enter NRHO and then dock with the Gateway. This undoubtedly increases the burden on the HLS.

But for the United States, isn't this just a matter of a bit more fuel and launch mass? The United States has Falcon 9, Heavy Falcon, New Glenn, Vulcan, and even if it's costly, there's SLS Block 1B and SLS Block 2. What's the problem with launching a heavier landing vehicle?

Under the influence of various commercialization trends, NASA did not choose to procure the landing vehicle itself, but instead adopted a commercial procurement model for the HLS. NASA believed that commercial procurement could reduce the required funds, as well as lower political costs. Commercial companies could use more innovative technologies without being held accountable by NASA.

On October 25, 2019, NASA released the bid for the HLS system. Before the deadline on November 5, five companies submitted bids. After excluding Boeing's two-stage landing vehicle relying on SLS Block 1B and Vivace's two-stage landing vehicle, the three finalists were the "National Team" led by Blue Origin, Lockheed Martin, Northrop Grumman, and Draper; the "Small Business Team" led by Dynetics; and SpX's three landing vehicles developed based on "Starship-Super Heavy."

Boeing HLS

Vivace's landing vehicle concept, similar to Centaur

The "National Team" integrated landing vehicle (ILV) includes Blue Origin's landing segment, Northrop Grumman's transfer segment, and Lockheed Martin's ascent segment. ILV will be launched to the lunar orbit using three Blue Origin New Glenn rockets or United Launch Alliance Vulcan-Centaur rockets and then rendezvous and dock. Of course, ILV can also be launched using the SLS Block 1B rocket. NASA believes that the National Team's development of ILV has no major time management issues, and the technical risks are acceptable. Dynetics' proposal is a low-lying landing vehicle that requires two launches and has the capability to be modified into a large cargo landing vehicle. NASA gave very good evaluations of Dynetics' proposal regarding time management and technical risks.

The "Integrated Landing Vehicle" is a landing vehicle that requires three commercial rocket launches

Dynetics' landing vehicle is quite low and has cargo capabilities, but it is overweight

Compared to those that looked relatively normal, requiring only a trip from NRHO to the lunar surface and back, SpX's Starship-Super Heavy HLS proposal is extremely radical: it requires one Super Heavy to send the HLS into low Earth orbit, followed by four launches (remember this number) of supply ships to dock with the HLS, then the HLS climbs into the Earth-Moon transfer orbit, brakes into NRHO, docks directly with the Gateway or the Orion spacecraft, and lands on the lunar surface from NRHO. After completing the lunar surface mission, it takes off and docks with the Gateway. Because the Starship spacecraft is a massive object 9 meters in diameter and 50 meters long, its restrictions on the landing area and the complexity of the system exceed the other two. Before the bidding, SpX's HLS had not received very high expectations.

Starship HLS docking with the Orion spacecraft in NRHO, note that the Artemis III mission does not involve the Gateway

However, unexpectedly, on April 16, 2021, NASA only selected SpX to develop the HLS lander based on the "Starship-Super Heavy" two-stage reusable heavy-lift rocket, and awarded a contract worth 2.89 billion dollars, including one unmanned landing and one manned landing (Artemis III). NASA stated that although the Starship proposal carried higher risks, SpX could solve the risks through rapid iteration. It seems that the possibility of choosing SpX was probably money - Dynetics' proposal cost the most, between 8.5 to 9 billion dollars, while the "National Team" proposal cost 6 billion dollars, and SpX only 2.9 billion dollars.

Another possible factor that impressed NASA was that SpX's Starship HLS could deliver 20 tons of cargo to the lunar surface, but compared to the original selection of three out of two, selecting only SpX seemed to be somewhat biased. Dynetics' proposal had problems at the time, only able to deliver negative mass to the lunar surface, and the "National Team" that seemed to have won was rejected, which made Blue Origin very angry, and they sued NASA for favoritism, eventually losing the case.

Two

Now we know that the Starship-Super Heavy system, although it has a very advanced concept, has not been smooth in development in recent years. Apart from the series of problems mentioned in our previous article about the SN-36 explosion of Starship, a bigger part comes from the serious overweight of the system.

Compared to the claimed 150-ton two-stage full recovery capacity, the current Starship-Super Heavy v1 version has only a meager 15 tons of carrying capacity, and even the v2 version that has already been completed has only 35 tons. Musk claims that replacing the Raptor-3 in the v2 (which is the v3) can reach a carrying capacity of 100 tons, and the ultimate upgraded version of v4 can reach over 200 tons, but this number is likely to be exaggerated. Due to insufficient carrying capacity, more Starship-Super Heavy launches are needed, and the increasingly complex in-orbit assembly and refueling put higher demands on management and technology, further delaying the time point when this system can establish the capability to reach the moon.

Currently, due to the overweight of the Starship HLS system, in addition to the near-Earth orbit assembly and refueling, it is also planned to perform another refueling in a large elliptical Earth orbit. Eric Berger's article points out that currently, one HLS mission requires 20-40 Starship-Super Heavy rockets, indicating that the problem of overweight is very severe. If a large number of supply ships need to be launched, it will put higher demands on the rapid turnover and in-orbit refueling of the Starship. Although SpX is currently building a second launchpad in "Star City" that can support full-thrust takeoffs, and planning to build a bunch of launchpads at Cape Canaveral, including Kennedy Space Center LC-39A and Cape Canaveral Space Force Station SLC-37B. But considering the current demand of 20-40 launches to support one HLS, it is really too absurd.

Starship HLS in-orbit propellant refueling

If the Starship HLS aims for a crewed landing in 2028, the Starship HLS must complete an unmanned lunar landing by the end of 2027, and by early 2027, it must have a high level of maturity, capable of quickly transferring tens of tons of propellant in orbit, operating in a "flight-like" manner, recycling and reusing, which would require that by mid-to-late 2026, the initial propellant ship-to-ship in-orbit transfer verification and a relatively objective carrying capacity must be achieved, at least achieving secondary reuse launch.

So what is SpX doing now? They seem not to have gathered the first set of Raptor-3 engines for the v3 version of Starship-Super Heavy yet...

Anyway, the maturity node of the Starship HLS has been pushed to at least the end of 2028. Considering SpX's clumsy performance on the v2 version this year, unless Murphy's Law completely fails, everything goes smoothly and enters a fast track, the possibility of achieving a crewed "return to the Moon" in 2028 is not very big. However, it's okay, there are rumors that the launch of Artemis III has also been moved to mid-2028, or even directly abandon the landing mission of Artemis III and switch to Gateway docking, but it's not yet certain.

Three

In May 2023, Blue Origin received the second HLS contract awarded by NASA, worth 3.4 billion dollars. The plan is to develop the "Blue Moon Mk2" lander for the Artemis V mission, which is the second lunar surface mission of the entire Artemis program. NASA claims that introducing a second company can "enhance competition, reduce the cost to taxpayers, support regular lunar landings, further invest in the lunar economy, and help NASA achieve its goals in the Moon and its surrounding areas, preparing for future Mars astronaut missions". Since the Artemis V mission is scheduled for 2032, the first unmanned landing of the Blue Moon Mk2 will not be earlier than 2030.

The Blue Moon Mk2 includes a lander body using three BE-7 hydrogen-oxygen engines and a cryogenic lander tug. In the initial CG效果图, it seemed that only three launches would be needed. Thanks to the powerful BE-7 engine with a specific impulse of 460 seconds, the efficiency of the Blue Moon Mk2 seems not bad. However, Blue Origin equipped the Blue Moon Mk2 with a riskier choice of gaseous hydrogen and oxygen attitude control system, so the technical risks are naturally present.

Old concept of the Blue Moon Mk2 and its cryogenic tug

Newer concept

Perhaps due to a series of reasons such as the insufficient payload capacity of Blue Origin's New Glenn, the number of launches required to propel the Blue Moon Mk2 and the tug to NRHO may reach more than 10 times. Given Blue Origin's current slow production of the New Glenn, even if LC-11 is put into use, more than 10 launches would take nearly a year.

The bigger problem is that the Blue Moon Mk2 is aimed at completion in the 2030s, and it definitely cannot have the capability to carry people by 2027-2028. However, its predecessor, the Blue Moon Mk1 lander, will make its first flight in 2026 and transport the VIPER rover that has won the revival competition to the lunar south pole in 2027. The Blue Moon Mk1 is a lander weighing 21.3 tons, planned to be launched into low Earth orbit by the New Glenn rocket. The New Glenn can carry up to 3 tons of payload to the lunar surface.

Blue Moon Mk1 lander

According to reports from Ars Technica, Blue Origin has already started preliminary research on the human adaptation of the Blue Moon Mk1. Although NASA has not officially requested Blue Origin to develop this technology, according to one NASA official, the company recognized the urgency of this demand.

According to current statements, the Blue Moon Mk1 landing only requires launching three landing modules head-to-tail to send astronauts to the lunar surface and return to orbit. After going around for several years, it has returned to a replica of the "National Team" integrated landing vehicle. This approach does not involve the biggest uncertainty - in-orbit refueling, so Blue Origin engineers are confident that this method will work, although it may not look very elegant. Of course, as an unmanned lander, the changes and certification required to quickly convert it into a manned lander within a few years is likely to be a bottomless pit, but compared to the current problems of HLS, this seems like not much of a shortcoming.

Four

Why did NASA choose SpX? The fundamental problem is that NASA, under instructions from Congress, has allocated all its exploration funds to developing the Orion spacecraft, the SLS rocket, and the ground systems for future missions. This made large contractors very happy, but their cost-plus contracts devoured so much money that NASA had no money left to purchase payloads or other devices that could actually fly with these hardware. Due to the lack of a landing system, the SLS was suspected by skeptics to be a rocket with nowhere to go. Now it has proven that they were probably right.

Due to a lack of funding, NASA had to choose the cheapest SpX "Starship" HLS proposal, while compared to the expensive funding support and long-term development of the SLS rocket, the HLS system has only passed four years, and its funding is far less than that of the SLS, and its complexity is far greater than that of the SLS. Musk reduced his management of the project from the end of 2024, which made the problem worse. Therefore, the Starship HLS naturally failed. However, if everything went perfectly in 2026, the Starship HLS might still be able to maintain its reputation, but the need for optimization is very urgent.

Even without looking at the difficulties brought by the commercial procurement of HLS, its smaller version CLPS commercial lunar cargo service has also resulted in the near destruction of the first batch of several landers under NASA's relentless "commercialization." NASA obviously tasted the benefits of commercialization in the COTS service of the ISS, but a mere "commercialization" is not a panacea. Sometimes, emphasizing cost reduction leads to only "cost reduction" as the goal. Especially in deep space exploration, the environment is much harsher than that of low Earth orbit, the telemetry and control is more difficult, and the maneuvering operations are more complex. CLPS is already like this, and the more complex HLS is therefore understandable.

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Original: https://www.toutiao.com/article/7561623570607931939/

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