Fire Took Us out of the Caves. Elon Is Taking Us to the Stars.
published during a waxing crescent moon.

“We might as well just slide back to the caves, cause that’s where we’re headed.” – Neil deGrasse Tyson, on the Daily Show, in 2012.

SpaceX made history with the first successful re-flight—and landing—of an orbital-class rocket on Thursday. News organizations are breaking down the anatomy of these firsts, stacked on-top of SpaceX’s other many accomplishments (and a few fireballs). The handicapping is going a bit like this: Is this really the first reusable rocket? What about the Space Shuttle? How much will Falcon 9 rocket costs drop? Is China going to try and get in front of SpaceX?

These cosmetic questions miss the deeper accomplishment SpaceX has achieved. When SpaceX landed its first rocket successfully in December 2015, I wrote for NOW.SPACE that it was possibly the most important innovation since fire. Today, now that they’ve closed the loop by re-flying and re-landing a booster, I’m ready to close the book: this is the most important innovation since fire.


Credit: SpaceX

Sounds absurd? Let’s back up. When Neil deGrasse Tyson quipped that we should “just slide back to the caves,” he was talking about the need for a human frontier in space exploration—not for exploration’s sake, but because that frontier would drive general investment in science and technology. That frontier leads young people to choose careers in science, even if they become cancer biologists out the other side, rather than astronauts. Without this drive—Tyson was arguing—we belong in the caves, shielded from the dangers and wonders of the universe.

Tyson’s oratory belies Musk’s rationalism: we must make life multiplanetary. Without expansion beyond Earth, Musk argues, human civilization will inevitably end. Depending on how worried you are about neutron stars, asteroids, and our own sun exploding in five billion years, you may take issue with Musk’s urgency. But it doesn’t change the weighty thing that Musk and his team have accomplished on behalf of our species. SpaceX now has the ability to take people and cargo outside Earth’s gravity well at a tiny fraction of the cost of any previous approach. And, they have the talent and momentum to execute their plans to colonize Mars. These ingredients to a frontier outside Earth simply haven’t existed before. The closest analog in history is the peak of the Apollo Program, which had similar talent and momentum, but unsustainable costs.

To truly understand what SpaceX has accomplished, however, we need a wider contextual view. Simply comparing to the Apollo program doesn’t cut it. Consider the Drake Equation, which was devised to contextualize all of the parameters that may affect the frequency of intelligent life in our galaxy. A key term in the Drake Equation is longevity—the amount of time a civilization would be capable of communicating with other species. This term has often been used reflexively, to consider how the threat of nuclear war or some exogenous event might limit the longevity of the human species. Thursday, SpaceX materially reduced a constraint on our longevity: we are no longer constrained to Earth’s gravity well.


Credit: SpaceX/Mika McKinnon

Similarly, the Fermi Paradox was postulated to contextualize limits on the likelihood of our encountering other species of intelligent life. The idea was this: even assuming a modest rate of growth, any space-faring civilization would relatively quickly colonize our galaxy, which is only about one hundred thousand light-years across. So, why aren’t they here? Solutions to the Fermi Paradox include things like: maybe it is too difficult to develop space-faring technology, and so other species have failed to do it. Again, thinking reflexively about the accomplishments of our own species, SpaceX materially reduced this constraint as well.

Thinking abstractly about the future of humanity, one could construct various hypothetical trajectories. But these could be condensed into three general pathways: population decline, stabilization, and growth. We might live out our days on Earth, failing to meet the moral crises of our time, such as hunger and climate change, ultimately sliding back to the caves in a massive population collapse. We might wrest these challenges and coast to a quasi-utopian carrying capacity of some 11 billion people, all the while remaining vulnerable to planet killing events like asteroid impacts. Or we might break the rules on carrying capacity entirely, expanding our resource base and our population outside of Earth’s gravity well. First to Mars and then beyond, inoculating our species against single-planet killers.

An estimated 100 billion individuals are believed to have lived on Earth throughout all of human history. They each owe their existence to those first humans that stepped out of the caves. If humanity is able to inhabit other worlds beyond Earth, hundreds of billions of people yet to be born will owe their existence to reusable rockets, and to the leader and the people that built them, when almost everyone else said it was impossible.

Joe Mascaro is Program Manager for Impact Initiatives at Planet, a satellite Earth imaging corporation headquartered in San Francisco, CA. The views expressed in this article are the author’s own, and do not reflect the views of Planet.