With the 50th anniversary of Apollo 11 landing on the moon there has been a lot of talk about NASA’s plans to return. Each new dribble of news can be exciting, but a coherent plan remains elusive. Somewhat of a plan is starting to take shape, however.

In a recent commentary for the Washington Post, Astronomer Phil Plait made an interesting point – that the Apollo mission was designed to be self-limited and not a sustained effort. The point was to beat the Soviets to the moon, and so it was baked into the design of the program to do everything to get their quickly not slowly and sustainably. Further, once we did beat the Soviets to the moon, and it was clear they abandoned their own efforts to do so, support for the program faded.

I think this is correct, but it is in contrast to the naive impression I formed as a child during the Apollo program and nurtured throughout most of my life. It always seemed to me that once we became a spacefaring race, progress was inevitable. Certainly every science fiction movie reinforced this impression. Apollo was followed by the space shuttle, then the ISS. OK, that makes sense. But then progress in sending people into space seemed to wane. We now have to hitch rides to the ISS on Russian craft. NASA’s plans seem to change with each administration. Multiple conflicting visions compete for dominance, while we seem to chase our tail.

I have to now acknowledge that it’s possible the massive effort necessary to safely send people to the moon and return them to Earth may only be feasible with the political and public support generated by the cold war and an immediate space race. Without that, we don’t seem to be able to sustain the political will – which in practical purposes means money. NASA and the White House need to be on the same page, and Congress needs to provide the funding.

It is also true that there are perfectly reasonable arguments for spending our space budget on robotic missions. Keeping people alive in space is hard and expensive. Robots thrive in the vacuum of space, and shrug off the radiation. They don’t need water, oxygen, or food. For this reason I am all for robotic missions. Our mechanical brethren should lead the way into space, do all the heavy lifting, and explore the outer reaches inaccessible to people.

But I still maintain there is a vital role for people in space. For the foreseeable future, people are still more capable than robots. The same technology that advances robotic capability, will also augment human capability. Having a human mind on location for exploration, science, and trouble-shooting is still an advantage. I also believe that it is beneficial for the human psyche. We are explorers. Further, human space exploration can unite the world, and help our perspective as one global species. I know that’s a soft argument, but I think it’s worth the investment.

To be clear I do not argue, so please do not assign this straw man to me, that we need to colonize the solar system because we are ruining the Earth. We need to do everything to preserve and sustain our own planet, and no other place in the universe is likely to be as hospitable. But at the same time, our long term survival will be enhanced if we have spacefaring capability, and are able to colonize other worlds. Things beyond our control can threaten our home. Space also gives us access to incredible resources.

So what are NASA’s plans for sustainable human space exploration? For now it seems their focus is on returning sustainably to the moon. This vision is supported by the current administration, but frustratingly they want NASA to accelerate their plans to 2024, and the only conceivable reason for this seems to be the vanity of the current POTUS. They should not repeat what I think are the mistakes of Apollo – take your time, do it right, go back for good.

The current program is called Artemis, after Apollo’s sister. The plan is to use the Orion capsule and the Space Launch System (SLS) rockets, which are powerful enough to get to the moon. The first mission of the entire system, Artemis 1, will take place after June 2020 (exact date not yet set), and will send an uncrewed Orion capsule into lunar orbit for 6 days and return to Earth. The mission will have biological samples to test the effects of prolonged radiation.

But there are still major components of the system not yet even designed. NASA plans to build a gateway, a permanent orbiting lunar platform that can be used as a waystation for getting astronauts to the moon. Orion will dock with the gateway, and then a lunar lander will take them down to the surface. This lander, however, has not yet even been designed.

NASA has just sent their “presolicitation notice” to private space companies to submit proposals for a lunar lander design. They want a preliminary system that can take two astronauts to the surface, but that can be expanded to later take four astronauts. NASA now wants a quick small version of both the gateway and lander, to later be expanded. It seems this approach is necessary to meet the arbitrary deadline of 2024, rather than their original plan of getting back to the moon by 2028.

For decades some space enthusiasts, most recently joined by Buzz Aldrin, argue that a space infrastructure should contain an Earth platform. This might be even more useful than a lunar platform – although both can work together. The idea is that you have a station in Earth orbit from which you can send shuttles to the moon and back. This way you only have to lift astronauts up to this orbiting platform. You then shuttle them from one platform to the next. There is then a lunar lander to get to and from the lunar surface. This system just adds one component to the current plan, but it makes sense.

Most of the energy spent going to the moon, and most places in the solar system, is spent getting into Earth orbit. Breaking the bonds of Earth’s gravity is the most energy intensive. Shuttling back and forth from the moon is nothing by comparison. Why lift into orbit every time everything you need to get to the moon? Send the smallest craft possible up and down from the Earth platform. Then you can send a larger deep space craft to the moon, or to Mars, or the asteroid belt, or anywhere we want to go.

With this system we can design a craft that never has to land. It can even be assembled in space. It also doesn’t have to be aerodynamic. It can be optimized to provide space and protection for the astronauts. It may even contain a rotating section for artificial gravity. It can have heavy shielding to minimize radiation exposure.

I think it’s pretty clear this is where any permanent space infrastructure will head – minimalist systems for getting up and down from any significant gravity well, orbiting platforms as waystations, and space shuttles that forever remain in space and never land themselves. This is what we should be designing and building. NASA is part way there with the lunar gateway.

But even more important – NASA needs a sustainable long term budget dedicated to designing and implementing such an infrastructure. This cannot be at the whim of every administration and congress. I don’t think that will work. It should also be in collaboration with private industry, and other democracies around the world. This should be a human project.

Ideally we will cross a threshold where space travel will pay for itself. It can do this through space tourism, research funding, and also mining the resources of space. One platinum-group asteroid will do the trick.

But first we need a clarifying and unifying vision.