In 1969, America won the Space Race by landing on the moon. In the half-century since, technology has made just about everything easier except getting back up there. In this two part series, we explore some of the reasons why a modern moon mission is a long shot in its own right. In part one, we covered the unique geopolitical climate of the 1960s that led to an influx of economic support for NASA and the Apollo program in particular. Now, we’ll address some of the engineering and political obstacles standing between mankind and the moon.

You can read “Why can’t we get back to the moon? Part 1: Apollo as a ‘one-off’ enterprise” here.

NASA doesn’t have a rocket that can reach the moon

While rockets that can reach low earth orbit are seemingly a dime a dozen these days, rockets that are capable of traveling the nearly 239,000 miles to the moon and back are exceedingly rare. SpaceX’s Falcon Heavy may, in fact, be the first rocket capable of the feat since the retirement of the legendary Saturn V (which only had 13 total launches before being sent out to pasture). However, even the Falcon Heavy’s 5 million pounds of thrust pales in comparison to the Saturn V’s 7.6  million.

For years now, NASA has been working on developing the Space Launch System (SLS), which will theoretically unseat the Saturn V for the title of most powerful rocket in history — but the SLS has progressed painfully slowly thanks to its design decisions being made largely by political committees rather than engineers and experts. Couple that with a smaller budget and space policy schizophrenia (more on that later) and you have a recipe for failure, not for moon missions.

As a result, the SLS has been dubbed “the rocket to nowhere” by some press outlets, and rumors continue to swirl about its potential cancellation in favor of relying on privately owned rockets from firms like SpaceX. Despite the limitations of time and space, I can still hear you asking aloud, “well, why not just pull the Saturn V out of the mothballs and retrofit some better computers into the crew compartment?”

The thing is… the Saturn V may have been an incredible feat of engineering, but it wasn’t a resoundingly safe one. The first Saturn V launch was actually the first time many of its components were even tested. In fact, some of the catastrophic failures in elements of the Saturn V’s huge F-1 engines and accompanying fuel system were never worked out completely, so much as mitigated until they were statistically less likely to kill everyone on board. At the time, this level of risk was considered acceptable, but that wouldn’t be the case for a modern moon-mission that didn’t involve racing the Russians to the finish line.

Presidents are a big problem (no matter whom you vote for)

At this point, it’s safe to say we all understand how technically difficult it is to reach the moon, but Apollo proved that it’s entirely possible as long as NASA has appropriate funding and consistent goals. The problem is that with each new administration the goals change. Even if we take a look back at just the past three presidents, a disturbing trend comes into focus.

“American leadership is inspiring the world by consistently doing what no other nation is capable of doing. We demonstrated that for a brief time 45 years ago. I do not believe we have done it since,” Buzz Aldrin wrote last year. “I believe it begins with a bipartisan congressional and administration commitment to sustained leadership.”

In 2004, President George W. Bush tasked NASA with the development of a spacefaring platform that could replace the shuttle program. NASA then dreamed up the Constellation program, which would have used Ares rockets to make the trip. The Agency invested $9 billion into the program over five years, but by then, a new president was in the White House.

Once in office, President Obama received a report from Government Accountability Office that highlighted NASA’s inability to estimate just how much the Constellation program would cost in the long run. Concerned about runaway costs, Obama opted to completely scrap the program in favor of the new SLS endeavor with the aim of putting astronauts on a near-earth asteroid, rather than the moon.

“To people who are working on these programs, this is like a death in the family,” an emotional NASA chief Charles Bolden told reporters after the announcement. “Everybody needs to understand that and we need to give them time to grieve and then we need to give them time to recover.”

A few election cycles later, Donald Trump took office and once again moved the goal posts after years of research and development. Under President Trump, NASA was ordered to re-adjust focus for a new moon mission and for a much more ambitious one to Mars, with the unrealistic timeline of accomplishing both before the completion of a potential second term. Why so fast? Because Presidents, like NASA, know that there’s no promise your space-program will continue after you’ve left office.

“Why would you believe what any president said about a prediction of something that was going to happen two administrations in the future?” former astronaut Chris Hadfield said. “That’s just talk.”

The technical challenges of a return to the moon are not insignificant; but they’re also not so daunting that they can’t be overcome. What’s really holding America back from returning to the moon is far simpler than rocket science: in a large way, it’s the politics. At NASA, if a program can’t be completed within a four-year election cycle, it will always run the risk of cancellation — and if we want to make it to the moon in under four years, NASA will need a whole lot more than 0.48% of Uncle Sam’s pocketbook.