One month ago, I wrote a blog about lunar exploration architectures. In it, I listed reasons why the current baseline plan, the Lunar Gateway, is a compelling option given current political realities. The NASA administrator, Jim Bridenstine, had promised that NASA would soon release their own long awaited technical justification for Gateway, a lunar space station that is intended to enable human visits to the moon.
In it, I was hoping to learn something I didn’t already know. Something that could galvanize the many disparate parts of human spaceflight into coherent action. A document with a powerful vision, well communicated, and supported by the laws of physics.
At this point I should probably make crystal clear that the following blog represents aspects of my personal opinion, and I don’t speak for my employer.
Finally, at long last we have the official NASA Gateway justification. It isn’t good. At just under 2000 words, I was so overwhelmed by its mediocrity that I initially confused it for parody. I can’t decide whether I’m more surprised by how half-baked it is, or how little its publishers seem to care. In the era of Trump, laziness is its own way of projecting power.
Now, more than ever, it is plain that Human Space Flight needs a decadal survey.
Why is this important? NASA and the space industry are full of dedicated, smart people. For a generation, they have been waiting for a sufficient alignment between politics and technology in human space flight to give them a cause worth doing the overtime for. A compelling vision. A defensible strategy. Something that makes sense. If this article proves anything, it proves that Gateway is not what we’ve been waiting for.
Before I focus on what this report says, let’s take a second to notice what it doesn’t say. There is no byline – perhaps it’s intended to project an official point of view but not one actually believed by the author? Further, for a technical report there is a distinct lack of any technical content. It seems from the text that the author had access to technical information but opted not to include it – perhaps because they believed the intended audience wouldn’t derive much value from it?
The text of the report is copied below in block quotes, with numerous grammatical errors uncorrected.
NASA is developing a two-phased approach to quickly return humans to the Moon and establish a sustainable presence in orbit and on the surface. The two phases run in parallel, and both have already begun.
Phase 1 is driven exclusively by the administration’s priority to land the next American man and the first American woman on the Moon by 2024. In this phase, NASA and its industry partners will develop and deploy two Gateway components: the Power and Propulsion Element (PPE) that will launch in 2022, and a minimal habitation capability that will launch in 2023. Both will launch on commercial rockets. This initial Gateway configuration represents the beginning of its capability buildup, and the primary components required to support the first human expedition to the lunar South Pole.
Phase 2 is focused on advancing the technologies that will foster a sustainable presence on and around the Moon – a lasting and productive presence enabled by reusable systems, access for a diverse body of contributing partners, and repeatable trips to multiple destinations across the lunar surface.
By commercial rockets, they almost certainly mean Falcon Heavy. Delta IV Heavy is much more expensive, slightly less capable, and has a much longer lead time. New Glenn does not yet exist.
Sustainable and productive mean different things to different people. Here, the author almost certainly means politically sustainable, as opposed to financially or environmentally. It has not been ignored by senior NASA types that every long term human space flight project has been severely damaged by presidential turnover, except the ISS. The ISS’s sunk cost has been too great to throw away, and so while better ideas have withered, it has survived.
While the Gateway is the first of its kind to be funded, the concept has been proposed for decades as a necessary and foundational capability for a sustainable return to the Moon, and a port for vehicles embarking to farther destinations. It supports every tenet of Space Policy Directive 1 and the infrastructure it provides is critical to an accelerated return to the Moon.
A lunar-orbiting space station has indeed been proposed since the 1950s, but has never been adopted for a wide variety of valid reasons. I have to ask: What has changed? During the space race, the Soviets and the US engaged in a fair bit of “me too” program design. When the US achieved the lunar landing, the Soviet designers consolidated their program to what they could achieve – modular space stations, of which they flew several. The US responded by cancelling the last Apollo flights and flying Skylab. When the Shuttle development program (which the Soviets copied with Buran!) blew the schedule and Skylab crashed into Australia, it was clear that there wouldn’t be enough money left over to do everything, so the ISS was born – another modular station that consumed decades and hundreds of billions of dollars to produce, at most, incremental advances in scientific knowledge.
SpaceX’s design philosophy (which is not uniquely theirs) has delivered strong evidence that the “reusability at any cost” Shuttle program was ill-conceived. The ISS has reached the point of diminishing returns. Will we learn from the mistakes of the past or repeat them?
Why is Gateway necessary for Phase I?
NASA’s position, based on technical and programmatic analysis, is that the Gateway enables the most rapid landing of the next Americans on Moon, the earliest strategic presence around the Moon, while preserving the ability to evolve all lunar systems for a longer-term human presence. In Phase I, Gateway development will be focused exclusively on the components necessary to support human lunar surface operations in 2024.
At this point the welds between the existing Gateway plans, which are an outgrowth of the cancelled ARM mission, and the new Presidential directive to land humans on the Moon ASAP, become obvious. NASA correctly anticipates that Presidential whims are likely to evolve and wants to hedge by preserving their existing programmatic structure. It is worth noting that NASA’s technical and programmatic analysis, which this report claims conclusively prove the Gateway’s merit, have yet to be released or subject to peer review.
Gateway supports the acceleration of landing Americans on the surface of the Moon in 2024 by providing a reusable command module and integration capabilities; the initial configuration of the Gateway acts as a waystation for the lunar surface mission, allowing the docking of Orion and checkout of lunar lander systems, as well as providing a temporary home for the crew who remains in orbit during the surface sortie.
It would be remiss of me not to point out that these claims are controversial. The Gateway wouldn’t have any transfer capability, so astronauts flying from the Earth to the Moon would still have to have some vehicle in which to make the transfer, with all those command module capabilities. That this vehicle, Orion, has taken two decades to develop and is still overweight and underpowered is no reason to erect an even bigger house of cards around it. Orion does not even currently have independent docking capability.
These initial Gateway capabilities have been in study and formulation for years, and critical components built by U.S. industry will be under contract within this calendar year. To move fast and meet the 2024 objective, NASA must leverage what is available now, including Orion and current Gateway acquisition activities.
NASA is happy to exploit the new Presidential urgency to encourage congress to write checks to their contractors for new systems. This is substantially less unusual than it sounds. NASA has always had very close and mutually beneficial relationships with all the major contractors. Arguably the main function of NASA contracts is to ensure continuous industrial capacity in the US for a variety of advanced technologies that would otherwise lack economic support.
Several critical systems for the lunar architecture are beyond the point of redesign if they are to support the lunar architecture.
• The Orion service module design is locked, and flight hardware has been delivered or is in production for the first three Exploration Missions, including the 2024 mission to the Moon. With propulsive capabilities of 1,100 meters per second, which is compatible with NRHO. Increasing its propulsive capabilities by more than 80 percent – from 1,100 to almost 2,000 meters per second to enter into and depart out of low lunar orbit (LLO) – is not possible.
It is probably too late to transform Orion into a modern and mass-efficient spacecraft, but of all things technically challenging or impossible, doubling the size of the fuel tank is not that hard. There are half a dozen major contractors in the US who could execute on this without difficulty in the time frame available. Of course, the Orion service module is a European contribution, but the ESA also has a stable of competent contractors.
For completeness, the issue is probably not the technical difficulty of increasing the size of the fuel tank, but that a beefed up Orion would be too heavy for launch by the SLS, because the systems design margin calculations performed 20 years ago were inadequate.
• The Space Launch System (SLS) is designed to evolve to the highest mass and volume capacity rocket ever built. There is no feasible means to redesign it or any other heavy left rocket to more transport the lunar landing elements on a single launch by 2024.
The SLS is derived from the shuttle core propulsion system, but despite adding a stage and 30% more fuel somehow lost 40% of its lift capacity. If you know how this happened, please let me know. The SLS also has a fixed production rate of one per 2 years, which means that its mass capacity to orbit per year is well below that of nearly every other launch provider. The only thing it excels at is launching big monolithic things to orbit – which is why yet another modular space station makes even less sense. It is also worth noting that “designed to evolve” means, in this case, NASA has a second stage on paper (the Exploration Upper Stage) which is not scheduled to fly until 2023.
• The power and propulsion element at the core of the Gateway as a staging platform, will be on contract in a matter of weeks, with its initial operating orbit (NRHO) one of the few NASA unique requirements levied on the contractor(s).
I have no idea what this means. Perhaps it means NASA is making Lockheed Martin jump through hoops?
• NASA studies revealed that the lander architecture that stages out of Gateway in NRHO is the most technically feasible, although industry is conducting trades through an open BAA. NASA is not aware of a direct landing system via LLO that could be developed by 2024, and leave open opportunities to evolve the system to a reusable architecture by 2028.
Technical feasibility is, again, a controversial subject. I don’t think NASA has asked the major contractors to bid (Apollo style) on a human Lunar landing system to be delivered by 2024, possibly because only one contractor (SpaceX) would be in a position to make a strong bid. In any case, with the human spaceflight budget totally consumed (and then some) by ISS operations, Russian crew transfer price gouging, and the SLS’s blank check development program, it’s clear that NASA is between a rock and a hard place. What I don’t understand is why it’s considered easier to land human lives on the moon with a woefully inadequate architecture than to build a coherent exploration vision that can move hearts in Congress. It can’t be that hard to open the national coffers – just take a look at the F-35 development program.
• Commercial rockets limit the mass allocation for the HLS ascent vehicle, making it difficult for necessary surface logistics to be launched inside the ascent cabin from Earth. 2024 surface logistics need to be launched separately and loaded onto the ascent vehicle via the Gateway
I think this means that commercial rockets are not considered to be powerful enough to launch a fully-stocked lunar ascent vehicle to the Moon. In 1962 NASA realized this favored the LLO-rendezvous architecture, and the math hasn’t changed since. The argument here is that gateway can enable separated launched supplies to be transferred to the ascent module before it is sent down to the moon, but it’s not clear why this could not be done in Low Earth Orbit. It is also not clear why adding a fully functional space station to the critical path is in anyone’s best interests.
In short, the Gateway architecture has a number of compelling strengths in terms of enabling both near-term missions starting in 2024 and long-term reusability and sustainability, with only limited and very manageable technical penalties compared to other architectural concepts like LLO staging (for example, the amount of mass delivered to trans-lunar injection for a lunar landing mission is roughly equal for both).
Roughly equal, here, means that LLO is actually better. That, and it doesn’t require the construction of an otherwise completely redundant space station before doing anything else. In contrast to this paragraph’s stated summary, the only compelling strength of Gateway is that it partially compensates for other previous, and entirely predictable (decades ago!), technical shortcomings of existing hardware. I think the argument here is that while Gateway is worse than LLO-rendezvous, it’s only a little bit worse. I don’t think the argument is well made, I don’t think it can be well made, and I don’t buy it.
On balance, the near- and long-term benefits of pressing forward with the Gateway architecture far outweigh the risks of incurring substantial delays and inefficiencies that would inevitably result from a change to the architecture at this late date.
What is stated tacitly here is that abandoning Gateway, which is the result of some rather tortured logic, will lead to a credibility crisis for the agency’s senior leadership. In practice, this could be addressed by reshuffling some job titles, but again, it is apparently thought easier to cheat the laws of physics. The only other thing worth noting here is that the strongest justification for Gateway seems to be the sunk cost fallacy. If we’re talking about inevitable results, why don’t we mention the 14 deaths in the Shuttle program as the inevitable result of this sort of blithely technically-haphazard non-leadership?
Why is Gateway necessary for Phase 2?
Phase 2 is focused on hardware development and technology advancement to evolve the 2024 Gateway infrastructure and surface systems. Gateway assembly will continue beyond the initial configuration comprising the PPE and minimal habitation capability, to culminate in a full capability deep space laboratory with extended crew stay options.
I think this means that after a decade of investment and construction, the Gateway is intended to be capable of supporting human life, for up to 30 days per year.
This affordable permanent infrastructure would serve as the bedrock for increasing commercial opportunities, affordable long term international partnerships, and a global commitment that makes our overall campaign resilient over the decades to come.
I don’t know if NASA’s partners on the ISS have complained about the expense (I suspect not) but I would be interested to know what is considered “affordable”. I fully appreciate the relative political invulnerability of expensive, laboriously constructed space stations, but I have yet to see a good reason why, for example, our international partners would be unwilling to contribute to a space station laboriously constructed on the surface of the Moon. I very much doubt NASA has the resources to build and operate more than one space station at once, and I fully expect Gateway to consume everything in its path, just as the SLS and the ISS has done, and the Shuttle before that.
NASA, industry, and international partners will provide the Gateway’s additional habitation volume, environmental control and life support (ECLS) systems, airlock, external robotics, and science capabilities. The docking ports provided by additional Gateway modules will allow landing system components and commercial cargo ships to dock with the Gateway for refueling and aggregation.
It is not clear to me how this differs from the ISS, or what this would enable that the ISS does not already support. Are we being softened up for a proposal to reuse the less leaky parts of the ISS after its end-of-mission?
As additional modules are added, the Gateway’s function as a reusable command module will increase. During Phase 1 operations, without a U.S. or international habitat module at the Gateway, the crew is limited to surface expeditions of no more than four days (assuming a 21-day mission that includes a five-day crew transit to Gateway in Orion, 2 days transit from Gateway to the Moon, 3-4 days on the surface, 2 days transit back to Gateway, and five days transit from the Gateway back to Earth).
Given these concrete numbers, we can compare Apollo 17 which spent 3 days on the surface on a 13 day mission. It is again not clear to me how the Gateway improves upon this. Same surface duration limitations, almost twice the mission length, and a huge upfront investment in “infrastructure” of marginal utility and huge risk.
During Phase 2, with a U.S. or international habitat module at the Gateway that includes its own substantial ECLS systems, total mission durations in the lunar vicinity can be extended from 21 to beyond 30 days, allowing for longer surface expeditions of up to two weeks (assuming supporting assets on the lunar surface). Longer stays at the Gateway in Phase 2 also will enhance human and robotic missions on the surface and support deep space science activities.
What this means is that provided there’s advanced life support on both the Gateway and the Moon (however it gets there), longer missions might be possible in the 2030s. Given that life support is needed on the Moon anyway, what marginal advantage is there to having to duplicate resources in Lunar orbit?
Deep space research is a common argument in favor of Gateway development, expanded, and commentated, below.
Phase 2 activities build on the capabilities that are ready or near-ready today, and incorporate engineering flexibility for unforeseen changes. The Gateway in a NRHO around the Moon allows:
• Continued use of Orion: As stated above, Orion alone cannot support a direct, Apollo-style approach without significant changes to the current spacecraft design. Using the Gateway as a port, Orion provides the only crew access to the Moon. Orion also is a key enabler for Gateway assembly and operations, as it will deliver some Gateway modules, deliver crew, and supplement Gateway ECLS systems when it is docked.
Given that these activities will not occur for another decade, will the existence of the Gateway disincentivize fixing Orion’s design flaws in later iterations of the vehicle?
Arguably SpaceX’s Dragon could also fly astronauts to the Moon, and I’m sure any other major contractor could provide a solution over that time frame.
It is important to note that Orion’s poor mission suitability are not a surprise to anyone who’s been paying attention since about 2007. Was there ever a better plan to deal with Orion’s problems than to build a string of huge space stations all along the way? Surely a better option is to go back to the drawing board and ensure that the design actually meets programmatic requirements, or better yet – ensure the requirements reflect physical reality!
Orion, like the F-35 and the Shuttle before it, is a victim of requirements growth demanding a “jack of all trades, master of none” vehicle. In general, vehicles that have to overcome gravity can really only afford to do one thing really well. In other words, a turkey is a chicken designed by committee.
Yes, $18b has been spent on Orion development. But is a ten year programmatic delay and another $150b on a Lunar Gateway really the best way to patch this issue?
• Continued use of mixed fleet of launch vehicles: Gateway’s orbit is accessible by an assortment of government and commercial launch vehicles (both those active today and soon-to-be available).
I note only that all these vehicles, and more, can also access any intermediate location, including LEO.
• Reusable Human Landing System: To evolve a 2024 landing system to become reusable, the Gateway will be required as a port to dock landing system components for refueling and refurbishment.
I think this is a stretched metaphor. The argument goes that Lunar landers can refuel either at the Gateway or at the surface, if a Lunar fuel mine is built. But there’s no reason that they couldn’t also refuel anywhere else between LEO and the Moon, depending on where fuel is readily available. Flying from Earth to LEO is by far the hardest leg of the voyage. SpaceX’s Starship design can credibly transport hundreds of tonnes of cargo or humans from LEO to the Moon and back again without refueling at any point. The whole point of landing on the Moon is that it has weak gravity and can be escaped in a single stage.
• Global lunar surface access: Gateway’s orbit and maneuverability provides access to the entire lunar surface, including the South Pole and lunar far-side
Given that the competing architecture offers access to the whole Lunar surface at any time and twice as fast, while Gateway only offers access once per location per year, and later perhaps once per month, this is not a strong argument in favor of Gateway.
• Communications: A high data-rate relay, with constant communication with the Earth by never being in the Moon’s shadow.
Unless the NRHO is precessed using Lunar mascons or copious, unavailable fuel, the Gateway will sometimes be on the other side of the Earth. Furthermore, TDRS, NATO, and other geosynchronous comsats already offer high data-rate relays anywhere in cis-Lunar space. Finally, building a few more comsats or optical relays, if necessary, is hardly on the critical path.
• Longer mission duration: Gateway’s logistics and habitation capabilities support longer total mission time, from launch to landing, maximizing time on the lunar surface.
This is simply not true. Gateway’s developmental peculiarities demand longer total mission times, at the cost of time on the Lunar surface. This is due to the unavoidable inefficiencies of extra rendezvous steps.
• Partnerships and economic development: The Gateway’s open architecture invites meaningful contributions from international and industry partners, and standardized interfaces will make it possible for non-traditional contributors to develop Gateway-compatible spacecraft or payload.
If the Commercial Crew Development program is any guide, interfacing requirements will be pathologically overdetermined by multiple infighting NASA factions, resulting in years of delays, mandatory poor engineering, and safety compromises. In practice, only the desperate or extremely powerful contractors will stay on board. The architecture of NASA’s incredibly expensive space station is not, and by definition, cannot be open.
• Significant collaboration for new science: Gateway offers an opportunity to begin a new era of space science, providing unique options for Earth science, heliophysics, lunar and planetary sciences, life sciences, astrophysics and fundamental physics investigations by allowing extended views of the Earth, Sun, Moon, and deep space that are not possible from the Earth’s surface or from Earth orbit.
A cursory review of the astrophysics or planetary science decadal surveys will find that no-one is asking for a crewed space station to study these problems. Indeed, the organization set up specifically to find ways to use the ISS in this way, CASIS, was largely unsuccessful. Also, one former executive is currently being prosecuted for expensing prostitutes.
• Sustainability and extensibility: Gateway is a platform for sustainable, reusable architecture which can be built up in a modular fashion. The Gateway is a valuable destination for proving science, exploration and technological capabilities for destinations farther, and makes a repeatable cadence of lunar surface expeditions possible.
If the ISS hasn’t yet proven that modular space stations are incredibly expensive and time consuming, perhaps the Gateway will? For comparison, Skylab, which had much larger internal spaces than the ISS, was launched in an afternoon. The main problem with modular construction is interfaces and capability flow-down. Every time a new module is added, it complicates the system, reduces its future versatility, and adds dozens of new holes through which stuff can leak out. An enormous fraction of the ISS’s total mass is dedicated to mating adapters – doors that are used only once and function as stress concentrators every time the ISS is moved. Even astronauts using the treadmill shake it enough to fatigue the joints.
I have addressed the Lunar surface mission cadence point earlier. By inserting Gateway into any Lunar surface capability, cadence is actually restricted by the orbital and logistical limitations of the space station. The competing architecture, which does not involve the Gateway, has no such limitations. If NASA wanted to fly two missions at once, or perform crew changes at a surface base, or fly missions at a different time of the year, it could only do this without a Gateway.
How do Phase 1 and Phase 2 support future missions to Mars?
To get to Mars, we will need a transit vehicle capable of conducting complex orbital maneuvers and sustaining human life for up to three years (roundtrip). The gateway is NASA’s first opportunity to test and operate a long-duration crewed vehicle in the deep space environment.
As a sop to the Mars faction, the defense of Gateway will now explain why it’s necessary to getting to Mars. What is the difference between research to be performed on Gateway and research already performed on the ISS, which has a very similar design philosophy? Gateway is to be in “deep space”, which means a bit further from the Earth. It’s still 1AU from the sun, and still relatively close to a large body (the Moon), so it’s not super deep, but I don’t want to get bogged down in semantics. What difference does deep space make? Slightly higher levels of solar radiation – an effect that is well studied and well understood. What difference will this make for the Gateway? Will the Gateway have advanced radiation shielding enabling permanent human habitation? No. So, basically no difference at all.
The habitation volume, functional distribution, and ECLS systems are at the crux of deep space human exploration – particularly when the travel time is 2-3 years roundtrip, as it is for Mars. The Phase 2 Gateway will comprise at least three different habitation volumes, informing form, fit, and function of different approaches and allowing NASA and its partners years of testing in deep space before embarking on missions to Mars or other destinations.
This paragraph contains another interesting tidbit. It implies that according to current baseline design, the Gateway will require not one but three different habs over the lifetime of the station. While this is pitched as an opportunity to try out different approaches, it’s not like failure is an option, so each of the habs will have to be given the full treatment. In practice, this is just a huge cost and schedule multiplier.
It is not clear to me how testing 3 year life support systems in Lunar orbit will be any more useful than testing the same systems on the ISS, or indeed in a lab on Earth.
A Mars transit vehicle cannot be launched on a single rocket, nor can it travel direct from Earth to Mars. The transit vehicle needs a location outside of Earth’s gravity well to aggregate, perform operational checkout procedures, and refuel before leveraging a lunar gravity assist to begin its journey to the Red Planet. The Gateway can serve as an aggregation and refueling depot.
This paragraph is probably the single biggest lie in the whole paper. Every robotic mission to Mars has launched on a single rocket and traveled directly from Earth to Mars. There are numerous orbits that are nearly beyond Earth’s gravity, but still orbit the Earth and are readily accessible to nearly any launch provider. SpaceX, among others, have provided compelling exploration architectures that do not involve aggregation or assembly. Finally, anyone who knows the first thing about orbital mechanics knows that a Lunar gravity assist is basically non-existent. The Oberth effect is proportional to the escape velocity of the body in question, so the Moon is pretty useless compared to the Earth. There is no technically valid reason to use the Lunar gateway for anything involving launching Mars missions.
Operations in lunar orbit and on the surface will help us hone our skills for Mars, while relatively close to home. Of utmost importance is astronaut safety. Aboard the Gateway and on the Moon, astronauts will validate the capability to execute both nominal and contingency physical and behavioral health operations autonomously and with time delay. The Gateway also has the potential to conduct complex orbital maneuvers in the Earth-Moon system to maximize science return, and to practice the operational procedures required for transits deeper into the solar system.
NASA, like all mature space agencies, has lost astronauts in flight. NASA has conducted extensive reviews of these tragedies, and even gone so far as to publish them, so their lessons can be learned by those in other industries and other countries. But, when it comes to planning for the future, it’s clear that the authors of this document missed the memo. Human space exploration will never be perfectly safe. But it is in the planning stage that most of the outcomes are determined. Fundamental design flaws doomed the Shuttle – and the consensus is that NASA was lucky to lose only two. The Gateway exhibits serious design flaws born of identical organizational process failures. That this document, the long-awaited official defense of Gateway, fails to even acknowledge these concerns is a real worry.
On and around the Moon, we will learn how to efficiently and safely investigate extraterrestrial bodies, synergistically using automation and robotics to maximize science return, employing dust mitigation strategies, advancing space suit designs, and using in-space, on-demand manufacturing and in-situ resource utilization, or ISRU, to reduce dependence on tools and supplies sourced from Earth.
The same could be said of any Lunar exploration architecture, not just Gateway. Regarding space suit design, there was a recent rumor that astronauts on the planned 2024 landing would be unable to leave their capsule because the budget for space suit development was diverted to, you guessed it, the SLS.
History has proven we can go to the Moon without the Gateway, but Space Policy Directive 1 is not asking us to repeat history. We’re charged with a bolder mission that requires us to build on what we’ve already achieved. We’ve already planted flags on the Moon, and left our footprints. Now we’re going to establish a foundation for exploration to and from the lunar surface, where we can establish an enduring human presence and set our sights on destinations farther into the solar system, including Mars.
The Apollo landings are sometimes mocked, due to their relatively short duration, as being about “only flags and footsteps”. It is important to note here that data and samples from the 6 landings are still being studied today, and literally wrote the book on Lunar science. The rest of this summary reflects the language of Space Policy Directive 1, but could equally apply to any other architecture. It is important to note that SPD1 doesn’t provide funding, which is appropriated by Congress. From NASA’s perspective, it may be more important to build an architecture which can be shown to be adaptable and hard to cancel.
Our newest charge – to land the next man and the first woman on the Moon by 2024 – only amplifies the Gateway’s value. A stable structure orbiting the Moon is critical in astronaut safety and uninterrupted communications with Earth. The phased approach allows NASA to leverage all deep space investments to date, and focus the lunar technology advancement portfolio on those technologies that benefit a long-term presence in orbit and a repeatable cadence of human expeditions to the surface.
This is the end of the document. I know, somehow you want more, and yet it’s already too much.
Where does this leave us? We are now in a position to comment exactly why this document is so disappointing. The arguments provided in favor of Gateway are either fundamentally technically wrong, or not specific to Gateway. That is, what few arguments stand up actually more strongly support other architectures. None of the major concerns about Gateway are even mentioned, let alone addressed. This document magnifies a perception that Gateway proponents either do not understand its shortcomings or simply do not care what anyone else thinks.
For someone who spent most of their life striving to get inside this industry, to build wonderful machines and help other humans do the stuff we can now see only in historical documentaries recorded on obsolete media, it is heartbreaking. Space is only 100km away from anyone – why should it only be getting harder to travel there?