Realistic Forecasts of Humanity’s Spacefaring Future

Response to “Predictions for the End of the Century” by “Kyplanet” YouTube Channel

I am an old man, and I have witnessed most of humanity’s adventures in space during my lifetime. While I don’t recall hearing Sputnik I’s beeping signal on the radio, I do remember how monumental it was to adults at the time. I watched as the U.S. became determined to win the space race in the early 1960s and was among the millions of ebullient Americans who celebrated that triumph. Expectations in those days were sky-high. Scientists like Gerard K. O’Neill were projecting that—with a sufficiently strong commitment to space development--by the early 21^st century we could have orbital habitats with comfortable artificial gravity, housing small, somewhat self-sufficient ecosystems. But, of course, the requisite focus on space development never emerged and such advances never materialized. In many respects, we are no closer to achieving those visions today than we were when Professor O’Neill published The High Frontier: Human Colonies in Space in 1976.

The enormous successes of the 1960s and 1970s were fueled by a unique combination of factors: a national imperative to beat the Communists in the space race, the booming post-war U.S. economy, and social and ethical standards unlikely to ever be replicated. Taking risks came more naturally in those days. The U.S. government wasn’t nearly as fiscally overstretched, and the relative cost of space industries was lower. Today, cost, return on investment, and risks to human well-being are the chief impediments, and the cost factors alone remain staggering.

What humanity needs is someone with the wealth and influence of a Musk or a Putin who is:
(a) neither a sociopath nor a megalomaniac;
(b) sensible enough to learn from others;
(c) genuinely committed to moving humanity in the right direction; and
(d) satisfied if their legacy is simply to get the process started, understanding that the standard sci-fi dream will likely take generations to achieve.

While Musk’s achievements with SpaceX are undeniably impressive and have brought us closer to significant milestones in space exploration, I do not see anyone alive today who fulfills all five conditions described above.

The reality is that there are far too many essential intermediary steps that must be addressed before humanity can make substantial progress toward becoming a true spacefaring species. Yet, a predominant tendency persists to either “place the cart of manned missions to other planets before the horse of orbital infrastructure and long-term habitation” or to explicitly aim at skipping these vital steps entirely, rushing toward manned missions beyond the Moon without adequately laying the groundwork.

Equally concerning is the lack of interest and attention given to the developments that are most critical for sustainable and meaningful progress. Below, I outline the requisite steps humanity must complete—or should prioritize for optimal advancement—along with my best estimates of how long it might realistically take to achieve them:

1. Space Planes
Reusable rockets like Falcon have indeed marked progress by significantly improving cost-efficiency. Their capacity to carry larger payloads ensures they will likely always have a role in space operations. However, relying solely on Single-Stage-to-Orbit (SSTO) reusable rockets for all aspects of a burgeoning space colonization era would be inherently inefficient and costly compared to the combined use of space planes.

Spacecraft that can take off from runways, achieve orbit, deliver payloads, and then return to land on runways have the potential to increase efficiency by an order of magnitude. Moreover, space transit systems that present safety risks to Earth communities only slightly greater than commercial airlines—and are scalable in a manner akin to air travel—would be vastly superior, even if the efficiency margins don’t quite meet initial projections.

Given current progress, achieving this capability is unlikely before 2030, with scaled implementation more likely by 2050 or 2060. Many of the core engineering challenges appear to have been solved and demonstrated in prototypes, such as the Sabre engine developed for the Skylon project. However, a critical barrier remains funding.

Musk, for example, could likely fund such projects to completion, but space exploration has never been—and likely never will be—his primary concern. As with many ambitious individuals who achieve significant wealth, his focus appears to be on accumulating even more.

2. Self-Sustaining and Truly Healthy Orbital Habitats
What we currently have in orbit is best described as primitive outposts. These facilities lack virtually any self-sustaining capacity and have no provisions for long-term, much less permanent communities. For humanity to progress to the next phase of becoming true spacefarers, we must develop the ability to live in space for prolonged periods, with health risks comparable to those of a long assignment at an Antarctic research facility.

Microgravity living does not support this level of livability. Nor does a small microgravity facility like the ISS offer significant self-sustenance, such as onboard biota capable of scrubbing carbon dioxide, replenishing oxygen, or establishing a self-sustaining energy and nutrient loop. Developing the requisite technologies and scientific understanding for such habitats will require millions of person-hours and hundreds of billions of dollars in investment.

No rational entity will commit that level of time and resources to a project spanning decades without a clear understanding of financial and safety risks and the potential return on investment at every stage. This implies that achieving this "next phase" after highly optimized orbital transport requires extensive preliminary planning to ensure that risks are mitigated and ROI is sufficient in the short, medium, and long term. These challenges are not about "high-tech wizardry" or "boldly going where no one has gone before,” they are fundamentally questions of business, management, engineering, and organization.

Despite being the second most critical factor after cost-effective travel to orbit, this challenge receives little attention today, even though it was a primary focus in the 1970s. Flashy figures like Musk rarely, if ever, address these intricate and complex problems.

Once serious efforts begin, I estimate it could take approximately 100 years to develop orbital habitats that are at least 50% self-sustaining and capable of supporting human health over long periods. This timeline suggests that we might reach the real beginnings of a self-sustaining habitation infrastructure in low Earth orbit (LEO) around 2150. Such infrastructure could then serve as a vital springboard for further advancements.

3. True Space Colonies: Habitats for Families to Live and Grow Indefinitely
The principles outlined in point 2 lay the groundwork for this next step: creating habitats where families can live, grow, and thrive indefinitely. Because of the scale, complexity and costs inherent to the achievement of this stage in the future of human spacefaring, one of the primary challenges, even after basic self-sustaining principles are established, will be addressing the economic, human resource, and risk factors involved.

Early prototypes of space colonies may achieve moderate degrees of self-sustainability, but true space colonies will need to be sprawling, complex, and resource intensive. This is due to the inherent challenges of the physics of centrifugation (to create artificial gravity) and the biology of sustaining interconnected human and natural ecologies.

Projecting how long this phase will take is difficult, but even 100 years seems ambitious. Achieving a fully self-sufficient space colony capable of supporting a sufficiently large, balanced ecology—analogous to a well-designed terrarium—will require tremendous advancements in various fields. While I estimate 2250 as a generous target for reaching this milestone, 2300 seems more realistic.

At that point, humanity might finally achieve habitats capable of indefinite, self-sustaining existence in space—a critical step toward becoming a true spacefaring civilization.

4. Orbital Manufacturing
Once cost-effective methods for transiting Earth’s gravity well are achieved and significant progress is made toward creating truly healthy habitats where human communities can thrive, humanity will be on its way to realizing its full potential as a spacefaring species. However, this will, in many respects, mark only the beginning.

An analogy can be drawn to the early seafaring efforts of humans. Our current capabilities to travel to and from space and sustain limited activity there are comparable to the first primitive canoes and rafts used to traverse water. Achieving routine, low-cost access to orbit, coupled with the development of sanctuary-like space habitats, would bring us to a stage similar to that which enabled the creation of oceangoing sailing vessels. At this point, progress may accelerate, but until the foundational steps of efficient transportation and sustainable living in space are addressed, advancements in orbital manufacturing will remain token and largely demonstrative, rather than substantial and transformative.

Initial orbital manufacturing will likely rely heavily on materials transported from Earth. Even with optimal efficiency in getting resources to orbit, costs will remain high, returns on investment will be modest, and the potential for scaling up operations will be limited. Small-scale, ad hoc orbital manufacturing may begin in the latter half of the 21st century, but its scope will remain constrained until the challenges outlined in steps 1 and 2 above are resolved.

It is plausible that by the early to mid-22nd century, orbital manufacturing could begin to expand as space habitats become safer, more secure, and more self-sufficient. This would mark a pivotal turning point, laying the groundwork for the extraction and utilization of extraterrestrial resources, as well as more ambitious projects that would transform humanity’s presence in space.

5. Extraction of Resources from the Moon and 6. Extraction of Resources from Asteroids
Predicting the emergence and progression of resource extraction from the Moon and asteroids is fraught with uncertainty due to the myriad factors at play. However, as with earlier steps, the key obstacles will revolve around cost, risk, human resources, and return on investment. With the right visionary—be it a billionaire, trillionaire, or a sufficiently focused national regime—significant progress could unfold within decades, likely starting in the mid-22nd century and continuing into the early 23rd. Without such leadership and funding, these advancements could be delayed by decades or even centuries.

The Moon, while critical for research and mining outposts, will never be "colonized" in the traditional sense. No celestial body in our solar system will likely host permanent, self-sustaining communities comprising families. The environmental challenges are simply too severe: low gravity, abrasive dust, and harsh weather conditions make prolonged human habitation risky and unhealthy. Even for small short-term purpose-focused outposts (e.g., mining, research, military, manufacturing, logistics), addressing these challenges will require immense ingenuity and resources.

Low-gravity environments like the Moon and Mars are particularly problematic for human health, especially for conceiving, bearing, and raising children. These locales will never be "healthy" for long-term human habitation. For Mars, the disruptive weather and relatively high gravity well will add further complications. My strong suspicion is that any so-called “colonies” on these celestial bodies will more likely exist as orbital habitats. These would offer artificial gravity, freedom from intrusive dust, and a level of safety and sustainability unmatched by surface-based installations.

Thus, while miners, researchers, and probably even military personnel may live and work on the Moon or Mars temporarily, true permanent communities will almost certainly be space-based. Only orbital habitats can provide the necessary conditions for safe, long-term human habitation beyond Earth, allowing families to thrive and humanity to take its next great leap into the cosmos.

If I’m honest about Mars, I don’t see much real reason for people to go there other than to simply say, “we did it.” Given the immense risks and costs, such a goal seems more symbolic than practical. The Moon, by contrast, offers greater promise due to its proximity and potential as a source of vital materials for developing space habitats.

That said, the real treasure trove of raw materials that could unlock humanity’s full potential as a spacefaring species lies in the asteroids. Certain large asteroids are estimated to contain more precious and rare Earth minerals than all the resources ever extracted from our planet—resources that might even prove easier to extract than those on Earth. However, the technologies required to exploit these resources remain entirely hypothetical at this stage. As always, cost, risk, human resources, and return on investment will be the primary hurdles to scaling such operations. Perhaps by 2400, humans will have developed the capability for asteroid mining on a meaningful scale.

My estimate of asteroid mining by 2400 may seem pessimistic to some, but my intention is not to discourage. I sincerely hope my conservative timelines are proven wrong and that humanity progresses toward its spacefaring potential far sooner. My aim is to provide a balanced perspective by highlighting the often-overlooked realities behind these ambitions. While exponential advances in autonomous systems, robotics, and materials science could accelerate breakthroughs in many areas, other challenges—such as ensuring human safety and health in space—will require solving a vast array of problems across diverse fields, including molecular biology, physiology, ecology, materials science, engineering, psychology, and behavioral sciences. Achieving “truly healthy” space habitats within 100 years strikes me as optimistic, though I welcome the possibility of being proven wrong.

I hope my perspective is not taken as discouraging or dismissive. Rather, I aim to challenge today’s youth to confront these realities head-on and rise to meet them. If there is one message I’d impart to aspiring space enthusiasts, it is this: focusing solely on space-related technologies is not enough. The opportunities and constraints shaping humanity’s future in space are deeply influenced by external factors—politics, culture, economics, and society. These domains have always been, and will continue to be, the primary determinants of how humanity’s spacefaring ambitions unfold.

I understand the allure of dreaming about humanity’s future in space, and I would never seek to extinguish that spark in anyone. However, fundamentally, our future as a spacefaring species depends on addressing the pedestrian, mundane, and often frustrating realities here on Earth. As space enthusiasts, we must devote as much—if not more—focus to these societal factors as we do to the exciting possibilities of science fiction and futurism. The obstacles are immense, but so too is the promise of a future where humanity thrives beyond Earth.

While there remains an abundance of time before our beloved home world is inevitably destroyed as the Sun ages, the brutal realities of the cosmos are inescapable. One day—whether 30 million or 300 million years from now—the Sun will expand to a point where life on Earth is extinguished. Furthermore, various more immediate perils, from asteroid impacts to unforeseen cosmic events, could threaten life on Earth at any moment. As a species, we are woefully unprepared for such eventualities and should place far greater focus on safeguarding the future of life on this planet.

The long-term fate of our blue-green jewel is ultimately death. Yet humanity—and Earth’s diverse lifeforms—need not perish alongside it. The memories and legacy of our home world could live on, preserved within massive, glittering, and unimaginably complex habitats and starships, spreading Earth’s essence throughout the Milky Way.

Perhaps one day, humanity will find another planet suitable for habitation, allowing us to become a truly interstellar species—or, as Musk puts it, “a multi-planet species.” But we should not assume this is inevitable. Until incontrovertible proof emerges, we should operate under the assumption that Earth and space habitats are all we will ever have. Earth, for now, is certain; space habitats could sustain us indefinitely. However, confirmation of a habitable exoplanet—let alone the means to settle it—is likely to take 500 to 1,000 years. Remote sensing and robotic probes will never be sufficient. Only human explorers aboard generation ships, designed for the indefinite survival of large populations, can realistically assess and inhabit distant worlds.

We should orient our thinking appropriately and contribute however we can to this long-term outcome. Though none of us alive today will see the dream fulfilled—and indeed, we will be “ancient history” by the time it comes to pass—our individual contributions can still make a difference. That is the legacy we leave behind.