Why is the US building a Lunar Orbital Platform-Gateway (LOP-G)?

Question

An excerpt taken from the Wikipedia page on LOP-G says space-experts have criticized it:

The Deep Space Gateway has received criticisms [...] for lacking a proper scientific goal.

Former NASA Astronaut Terry Virts [wrote] that the Deep Space Gateway would "shackle human exploration, not enable it" [...] and that he cannot envision a new technology that would be developed or validated by building another modular space station.

Mars Society founder Robert Zubrin [...] called the Deep Space Gateway "NASA's worst plan yet" in an article on the National Review. Robert went on to say "We do not need a lunar-orbiting station to go to the Moon. We do not need such a station to go to Mars. We do not need it to go to near-Earth asteroids. We do not need it to go anywhere. Robert also stated that "If the goal is to build a Moon base, it should be built on the surface of the Moon."

Retired aerospace engineer Gerald Black stated that the "LOP-G is useless for supporting human return to the lunar surface and a lunar base." He added that it is not even planned to be used as a rocket fuel depot and that stopping at LOP-G on the way to or from the Moon would serve no useful purpose and it would actually waste rocket fuel.

Pei Zhaoyu, deputy director of the Lunar Exploration and Space Program Center of the China National Space Administration, concludes that, from a cost-benefit standpoint, the gateway would have "lost cost-effectiveness." Also, Pei said the Chinese plan to focus on a research station on the surface.

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My question to the community is, what could a rectilinear halo orbit around the moon potentially gain for us, especially if refueling isn't planned to occur at that location? It's clearly not being used as a Mars staging point if there's no fuel depot, and it seems to not have much utility other than studying Lunar orbit, and possibly studying the lunar surface...

• Does anyone have more in-depth plans on what the actual mission is?
• Why, as the Chinese stated, do we not build something on the surface?
• What, if anything, can we learn that the Apollo programs missed and that the James-Webb Telescope might miss as well?

Answer 1

A zillion years ago I was at a meeting where large projects were discussed and attempted to be justified. A slide was shown listing say five reasons why project such-and-such was absolutely vital and the speaker enthusiastically forwarded each reason in turn.

The one response was "If you had one good reason you wouldn't need five.

Ultimately it wasn't funded.

My other answer reminds me of this story.

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note: I'm presenting the following position while neither advocating nor criticizing it. Until the time that we live in Gene Roddenberry's envisioned future, there's nothing wrong or dirty about economic growth.

The Ars Technica article NASA says it’s building a gateway to the Moon—critics say it’s just a gate is really worth reading.

It contains a similar zinger-like insight in my opinion:

the Gateway will be a place where rockets can go.

This has not left much oxygen in the room for dissenters—publicly, at least. However, a few critics persist, and they raise valid questions about the lunar Gateway. Robert Zubrin, a high-profile aerospace engineer outside of NASA’s policymaking process, has emerged as a chief antagonist.

“It is the next giant leap into quicksand,” Zubrin argued (YouTube link) during a recent meeting of The Mars Society. “If you wanted to send people to the Moon or Mars, would you take some of your money to build a lunar orbit space station on the way? You would not.” (emphasis added)

Zubrin and others argue that the Gateway exists not to smooth NASA’s way to the Moon or Mars, but rather to provide a destination for the agency’s expensive rocket, the Space Launch System, and Orion spacecraft. These vehicles, built for NASA by large aerospace firms with hundreds of subcontractors around the country, cannot presently go to the Moon or Mars. Combined, they’re just not powerful enough. NASA has struggled for the better part of a decade to find something for them to do. And after wandering in the wilderness, agency leaders finally settled on the Gateway concept.

“Let’s be honest about this,” Zubrin said of NASA's human exploration plans. “This is not a purpose-driven program, this is a vendor-driven program. Imagine running your business to please your vendors.”

Answer 2

Let's examine what Jim Bridenstine, current director of NASA and previous member of the Rocket Racing League (1, 2, 3) says.

NASA Administrator Jim Bridenstine Explains the Lunar Gateway is a recording of director Bridenstine in YouTube, described as

Published on Aug 7, 2018

NASA's new administrator spoke with reporters after a two-day trip to Kennedy Space Center about the agency's plans for a lunar gateway.

I don't have a date for the talk yet, presumably it's recent.

A quick summary:

• "Ultimately the gateway, the first gateway is a technology demonstrator, and it’s going to retire risk, that’s what it’s for."

• "The second gateway that’s going to go to the Moon, will be a deep space transport. That will be our capability to get to Mars. That’s the purpose of the gateway."

• "what the Gateway represents is that critical infrastructure to where all of our partners can, in essence, have access to the surface of the moon, and to orbit around the moon and ultimately go back and forth from the Earth to the Moon."

• "what the Gateway gives us (to your question) what the Gateway gives us more access to more parts of the Moon than ever before. And it gives us long-term sustainability at the Moon that we’ve never had before."

This is my own attempt at transcription, starting at about 01:50.

Remember that this is likely an impromptu summary and review of key points to the press, rather than a prepared public speech, so it appears a little choppy when written out as text.

There are more commercial partners than any point in history.

So all of this enables us to do more than ever before, and what the Gateway represents is that critical infrastructure to where all of our partners can, in essence, have access to the surface of the moon, and to orbit around the moon and ultimately go back and forth from the Earth to the Moon.

So the Gateway is that critical piece of infrastructure. We want it to be an open architecture. We want all of the interfaces to be published whether it’s power, whether it’s docking, we want it to be absolutely open so that international and commercial can use it and take advantage of it and we want more access to more parts of the moon than ever before.

So what the Gateway gives us (to your question) what the Gateway gives us more access to more parts of the Moon than ever before. And it gives us long-term sustainability at the Moon that we’ve never had before.

It’s also true, because it’s solar-electric propulsion it’s not as big as the international space station. But with solar-electric propulsion, it’s not just going to be in an orbit around the moon, it’s going to actually go to L2 and L1, and give more access to more parts of the moon than ever before.

So you think about from 1969 when we first went to the Moon, all the way up until 2008. We believe that the Moon, at least a lot of people believe at the moon, was bone dry, because our access to the Moon, we have six missions, it was all in the equatorial region, and in all those years we believed that the Moon was bone dry.

Well in 2008 the Indian Space Agency made a discovery. In 2009 NASA doubled-down on that discovery, and now we know that there are hundreds of billions of tons of water ice on the surface of the Moon at the poles. Well that water ice represents a number of things, chief among them is life support. It’s water to drink, it’s air to breathe, hydrogen and oxygen, even more importantly, or at least as importantly, it represents fuel.

When you crack water into its component parts hydrogen and oxygen and you put it in cryogenic form, that’s the same propulsion as the space shuttles.

So water discovered on the surface of the Moon should transform how we think about our activities in space. And so in my view, the gateway represents our ability to learn more about the Moon than we’ve ever known, and we need to go to more parts of the Moon than we’ve been able to get to before. We do that with gateway as critical infrastructure, then we have commercial and international partners and our own landers back and forth between the gateway and the Moon all in a reusable way for a sustainable architecture.

Ultimately the gateway, the first gateway is a technology demonstrator, and it’s going to retire risk, that’s what it’s for. The second gateway that’s going to go to the Moon, will be a deep space transport. That will be our capability to get to Mars. That’s the purpose of the gateway. So we’re going to be able to get to more parts of the Moon than we’ve ever been able to get to before; ultimately everything is going to be reusable; gateway is the critical piece of infrastructure to make that possible, and it will ultimately be our deep space transport.

So the gateway is important. And of course it’s going to be important for Kennedy as much as NASA.

I would look for the power propulsion to launch sometime around 2022. And that would be the first piece, habitation shortly thereafter, maybe 2023, (or 2024).

Answer 3

I can maybe answer these questions, as someone that has worked on NextSTEP studies (HAB, PPE) and HLS Architecture and Lander Studies. In general, I thought a lot of the news articles were mostly shlock posted by people that have little clue about the architecture or Space in general (Yes, this comment is directed at you, Gerald Black - Let me know when working for GE Aviation qualifies you to speak on Spacecraft. I won't start talking airplane engines to you.)

• Does anyone have more in-depth plans on what the actual mission is?

There is no "actual mission". There are various architectures and plans that involve assembling a Gateway at a location in NRHO using U.S. Commercial and International partnership. The primary one involves a couple key modules (PPE, HAB, Cargo/Logistics, and ESA/JAXA/Roscosmos contributions). The purpose of the Gateway is to serve as a long-term proving ground for technology required for living in Deep Space. The environment is far, far different from the ISS, and there is much more to learn and that needs to be proven before we can send humans beyond the moon safely. People that say otherwise either have an agenda (Zubrin, Musk) or are ill-informed (sometimes Musk). There is also Refueling in HLS architectures for lunar landers, and nobody with brains is proposing that people refuel at the moon to go to Mars (and people saying that this is the plan are simply liars).

• Why, as the Chinese stated, do we not build something on the surface?

Manned lunar surface bases are considerably more difficult than orbital ones. We have proven orbital stations on Earth, now we can prove them around the moon, then we can prove lunar surface bases. Skipping the middle progression abandons a lot of what we learned on the ISS, and could have less value, when you consider the surface access /constant comms positives of the NRHO (I'm personally not a massive fan of the orbit) and the possibility of a reusable lunar lander. A good example might be that at the last Apollo mission, we spent <1 week total on the surface of the moon. Any Mars mission would need to last for at least a 26 month period on top of travel times.

• What, if anything, can we learn that the Apollo programs missed and that the James-Webb Telescope might miss as well?

I don't really get what this question is... What we missed in terms of science? A lot! Apollo never went to polar regions, had all their samples contaminated upon return, and really spent an unsignifigant amount of time on the surface. JWST is totally, totally unrelated.

I can add more, but this should be enough thoughts to get started. Now, why are we cancelling/stopping the Gateway? Because it doesn't get us on the moon in 2024, and it was never supposed to get us on the moon by 2024 (2028 at the earliest in many plans). If we want to accelerate boots on the moon, then the gateway needs to scaled back (from a critical path, but more critically from a budget perspective, as NASA can't fund the ISS, Gateway, and Lander at the same time). We can fly Orion to the moon and have it meet a lander there, there's the mission. Now we can argue about whether or not that is a sustainable, long-term plan for permanent human habitation of deep space, or a political move.

Answer 4

Because the Lunar gateway develops technologies for a Mars gateway; it's easier to build them in space than to construct them on the ground; teleoperating robotics (which reduces contamination) is easier from orbit than from Earth.

Building in orbit around the moon is much cheaper than doing so around Mars, and allows for frequent resupply while the technologies to allow a far more self-sustaining environment are developed. It also allows for a return to Earth in days in the event of a catastrophic system failure while lessons are learned.

While this work could be done in earth orbit, it is arguable a new orbital facility would be needed as systems designed in the 70s just can't be upgraded to the standard needed. Even if the ISS can be handed off to commercial entities, running two space stations around the same planet gains nothing compared to the research opportunities running a space lab around the Moon.