It’s been a busy year so far here at Purdue’s School of Aeronautics and Astronautics, as 2019 marks not only the 150th anniversary of our university but also the 50th anniversary of the Apollo 11 moon landing (and the Apollo 12 moon landing, for that matter, though nobody seems to be mentioning that…). Yesterday, my friend and fellow Ph.D. student Justin and I had the opportunity to participate in an informal “Future of Aerospace” symposium, where we were challenged to showcase our visions for what the world of human spaceflight would look like fifty years from now, on the 100th anniversary of the first crewed moon landing (!) in 2069. The audience included NASA’s Associate Administrator for Human Exploration and Operations, Bill Gerstenmaier, and Dan Dumbacher, former Deputy Administrator for the same directorate and current Executive Director of AIAA, as well as several professors and students.
This was a really fun opportunity to think freely and creatively (i.e. to speculate wildly and without consequences) about the future and I thought that I would share the ideas which Justin and I came up with. We structured our presentation around five key technologies and five specific visions. Our technological themes were:
- Air-breathing rockets – A personal interest of mine, air-breathing rocket propulsion is a technology which seems to offer huge potential and yet has remained tantalizingly just out of reach for perhaps twenty or thirty years. Whether the best technology pathway is a rocket-based combined cycle design such as that proposed for the National Aerospace Plane (NASP) or NASA’s GTX single stage to orbit spaceraft or something even more exotic, like Reaction Engine’s SABRE liquid air cycle engine, the ability to utilize atmospheric oxygen as a primary or secondary oxidizer promises to revolutionize the way that we access space; it may also prove to be a viable propulsion system for hypersonic point-to-point transport.
- Disaggregated satellite systems – The ability to launch and control vast arrays of low-cost satellites (as opposed to the singular, monolithic architectures which have thus far dominated satellite design) will allow redistribution and democratization of on-orbit capabilities. Satellite owners will be able to rent out excess capacity on their constellations, and users on the ground will enjoy seamless, unfettered access to worldwide data services such as internet and GPS.
- Intelligent habitats & exploration systems – Increased autonomy of habitation modules and rovers will allow greater capabilities for deep space exploration which may not always sustain a human presence. The planned Lunar Orbital Platform-Gateway, for example, will likely be uncrewed for relatively long stretches of time (certainly during its early stages); the same will almost certainly be true for infrastructure needed for Mars exploration. It will thus be crucial that future space systems can self-monitor and ideally even self-maintain to ensure safety for astronauts and security for the investments we will make in these pieces of hardware.
- In-situ resource utilization – Establishing a human presence off-Earth will require some degree of self-sufficiency. The moon may be relatively accessible, but the same certainly can’t be said of Mars, meaning that astronauts will have to learn to use the resources they find on-planet to spend any significant length of time on the surface. This will likely take several forms – extracting breathable oxygen and combustible fuel from the atmosphere (for example, by the Sabatier process), harvesting water ice for human consumption, or even mining frozen helium isotopes to power nuclear reactors. More than just consumables, astronauts will likely have to use local materials to construct habitats (though I imagine the actual construction will be left to robots to complete).
- Nuclear rockets – While traditional chemical rockets are technically capable of accomplishing our immediate exploration goals on the Moon and Mars, they nonetheless leave much to be desired; the many months required for transit to Mars, for example, all but require a higher-performanc method of propulsion. Nuclear thermal rocket engines would enable astronauts to make the journey in a fraction of the time, minimizing exposure to cosmic and solar radiation as well as the risks of crew and equipment failure.
Our five “visions” represented different scenes that we felt would exist in 2069:
- Terra Firma – a world made more connected, more self-aware, and more efficient by the development of improved satellite services, hypersonic flight, space tourism, and Earth applications for advanced life-support systems and intelligent habitat technology.
- Low Earth Orbit – a dynamic and multifaceted domain of private and public space stations, running operations ranging from orbital pharmeutical manufacturing to space tourism, serviced by single-stage spacecraft providing regular crew and cargo transport.
- Cis-Lunar Space – a permanent human research facility analogous to the remote Earth-based facilities we currently operate on Antarctica, where scicentists regularly visit to carry out important research; an improved orbital gateway will simplify access to the lunar surface and commercial ventures may be starting to make inroads to moon operations.
- Mars – a more recent human triumph, where the architecture required for long-term human presence is still taking shape in the form of 3D printed habitats on the surface; crews of astronauts presently inhabit a rotating orbital station and make short excursions to the surface and the two moons of the Mars system.
- The Frontier – the next steps for space exploration after 2069, whether they take our crews to moons in the outer reaches of the solar system (Titan, Enceladus, Europa) or to the upper atmosphere of Venus (where airships could comfortably cruise), and whether they take swarms of robotic probes throughout the solar system, or take an uncrewed payload on our first true interstellar mission.
Overall, the opportunity to think daring thoughts about the future was thoroughly enjoyable, and the chance to present our ideas to two of the biggest names in human spaceflight was quite a privilege. The illustrations I did for our five “visions”, can be found below along with my slightly fanciful brainstorming; our full presentation can be viewed here.
For added amusement, here are the descriptions I wrote of each scene while brainstorming what to draw:
Terra Firma: The proliferation of spaceflight technologies has had significant impacts on surface life. Swarms of disaggregated satellites have enabled low-cost internet access in even the most remote corners of the globe and seamless telecommunications from anywhere on the planet. Agricultural research intended to help humans grow food on other planets has made farming on Earth more efficient and sustainable, and knowledge gleaned from developing advanced closed-loop environmental control systems for space habitats has helped Earthbound engineers develop more efficient buildings and structures. Development of combined-cycle engines has spurred the first flights of hypersonic passenger aircraft; those with more money than time whiz around the planet near the edge of space, sipping champagne at the top of the atmosphere as the world roars by at Mach 6. Even higher up, the booming business of space tourism has helped remind some of the world’s leading cultural figures what a precious and fragile planet we live on.
Earth Orbit: Low Earth Orbit, the proving ground for so many of humanity’s first ventures off-planet, is now a veritable hive of activity. Air-breathing rocket engines have finally made the dream of single-stage space access a reality and ever-plummeting launch costs have allowed commercial stations to proliferate. Low-cost inflatable habitation modules make development easy, and commercial shuttles offer semi-regular service between surface spaceports and a variety of orbital destinations. Facility owners rent space on orbit to anyone who can pay – denizens of LEO range from the conventional (pharmaceutical manufacturers, Earth scientists, research biologists) to the eccentric (reclusive space tourists and avant-garde artists) to the unbelievable (would-be resource prospectors and space junk collectors). Although the vastness of space and the scale of Earth’s grandeur are inescapable facts of life here, LEO nonetheless evokes the essence of a frontier boom town.
Cis-Lunar Space: In the four decades since the return of crewed missions to the moon, humankind’s presence on our nearest neighbor has steadily grown. Several of the early outposts still exist – some focused on lunar research, others focused on mining water ice for commodity use – but a new generation of lunar outpost is under construction. Soon, the familiar sight of geodesic domes connected by webs of sealed tunnels will be a thing of the past, as the lunar research community migrates underground. Large inflatable modules placed inside ancient magma tunnels make it possible for researchers to live and work underground in a shirt-sleeve environment, protected from harmful surface radiation and temperature variations. An orbiting gateway simplifies logistics, allowing relatively easy and regular access to the lunar surface – scientists come and go, working diligently for months at a time in the pursuit of science in this most isolated bastion of humanity.
Mars: Astronauts first set foot on the red planet in the 2040s. Now, over a decade later, several crews have visited the Martian surface – nuclear thermal propulsion allows relatively fast travel to our planetary neighbor, minimizing the crew’s exposure to radiation, while a space station in Mars orbit allows for easier access to the surface and exploration of Phobos and Deimos. Astronauts in orbit act as an auxiliary mission control center, allowing daily operations on Mars independent from Earth-based control and the resulting communication lag, while virtual reality allows explorers to maximize their limited footprint by sending highly capable rovers into the field under virtual human control. The first Martian structures are taking shape, 3D printed using surface basalt, and slowly but surely, humanity is gaining a tenuous exploratory foothold on this alien planet.
The Frontier: In fifty years, humanity has built settlements on the Moon and is establishing its presence on Mars. Where will the next fifty years take us? With the exploration capabilities we’ve developed, can we leverage our technologies to send crews to the outer solar system? Will we explore our nearest planetary neighbor, cruising far above the surface of Venus in space-age airships? Will ever-smaller satellites allow us to probe the mysteries of our Solar System more deeply than ever before? Will nuclear propulsion allow us to send robotic emissaries on interstellar journeys? Ambitious proposals such as these are working their way through the space industry – they will require ingenuity, leadership, and an otherworldly level of moxie… yet isn’t that what we humans do best?