May 1, 2025
For Justin B. Hollander, PhD, FAICP, planning considerations extend far past Earth's atmosphere. A professor of urban and environmental policy and planning at Tufts University, he has authored 10 books, including The First City on Mars: An Urban Planner's Guide to Settling the Red Planet, published by Springer Praxis Books in 2023. As part of the Trend Talks series, Hollander thinks through the possibility — and indeed, probability — of settlements on Mars and the moon, as well as the pivotal role planners could play.
This conversation with Joseph DeAngelis, AICP, research manager at the American Planning Association (APA), was originally published in the 2025 Trend Report for Planners, and has been edited for clarity and length. You can listen to it in its entirety at planning.org/podcast.
JOSEPH DEANGELIS: What does the space industry look like today, and what do you see happening over the next couple of decades?
The First City on Mars book author Justin B. Hollander is a professor at Tufts University, editor in chief of the Journal of Planning Education & Research, and host of the Cognitive Urbanism podcast. Illustration by Rebecca Clarke.
JUSTIN HOLLANDER: First, you have the government agencies that we're all familiar with: NASA and the European Space Agency. Countries in Asia are also building their own space programs and actively developing technology to go into space. Additionally, there's been a real explosion of interest in the private sector, like SpaceX and Virgin Galactic. So, this is a big area of growth and investment. And, as the cost has gone down pretty quickly, I think we can expect further investment.
In many ways, humans have already colonized Low Earth orbit, having had a presence in the International Space Station for over two decades. There will be new space stations. The Chinese are about to launch one, and NASA, with other partners, is building another one.
In the coming decades, I think we will see a permanent or semi-permanent presence of humans on the moon. Before we know it, I think parts of the moon will resemble Antarctica, which is remote and very uninviting for human occupation and settlement yet still settled through different missions and scientific enterprises. And both NASA and SpaceX have been very explicit about their hope through the Project Artemis initiative to build a launch facility on the moon that would then bring humans to potentially settle Mars.
DEANGELIS: It's rare for a planner to think about planning a city from scratch, let alone somewhere other than on Earth. What do you see as the planner's role in helping to design and plan a city on Mars or another planet?
HOLLANDER: Today, plans for space colonization are being led by engineers and scientists, but planners are not part of this conversation. Leaders aren't considering what planning brings to the table. In my book, I've tried to take the most salient pieces of our knowledge base related to outer space planning and put them in one place to show that planners and planning can play a role in helping to shape these cities and settlements in space and on other planets.
For example, science fiction has taught us that cities on Mars will be under futuristic-looking domes. But it's important to understand how important building underground is when you're thinking about a place like Mars. Radiation is a serious problem for sustaining human populations, and being underground can offer protection from that. In addition, it's really cold on Mars in the winter, especially on the poles. Humans have been building and living in underground sunken courtyards and cliff dwellings for thousands of years. If planners are part of this work, they can help to bring some of that knowledge to the table.
DEANGELIS: Going to Mars will likely raise a host of interesting ethical issues. What considerations might planners of the future need to account for when designing or planning a new settlement in an alien environment?
HOLLANDER: Life in space or on Mars is just so dangerous to humans. Even if it's possible to colonize Mars and to have people live there for long periods, it's certainly not going to be a healthy place. I think we need to be aware of those risks and those hazards. I told a student of mine about just how dangerous it will be, and he said, "I don't care if I die there. I just want to be there." I think that's another dimension to consider regarding the ethics of the situation.
There's a famous trilogy of books on Mars by the author Kim Stanley Robinson, where he does such a great job of grappling with this question of what he calls "planetary preservation." As planners, we're used to concepts like historic preservation or environmental preservation. To have a long-term presence on Mars, humans would have to manipulate the climate and the atmosphere. And there's a real destructive component to doing such a thing. The ethical question is: should we just leave Mars alone? Or do we have some sort of manifest destiny to conquer it and make it suitable for human life?
DEANGELIS: Are there any lessons you think can be drawn from studying the settlement of space and other planets that are useful for planners today on Earth?
HOLLANDER: I cannot tell you how terrified I am of the idea of living on Mars. I mean, it's such an awful place — there's no water to drink or air to breathe, and there's no food to eat. We are so lucky that we have Earth. We have something really good right here under our feet. It shouldn't get in the way of us continuing to explore what outer-space planning might look like and prepare for what might happen. But let's be grateful for what we have and continue to love and cherish this planet.
This content is part of the APA Trend Talks series, created in collaboration with the 2025 Trend Report for Planners. The report features more than 100 trends identified by the APA Foresight team, while the monthly Trend Talks series provides additional insights to help planners navigate and shape the future of the profession.
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