The American people expect big things from our nation’s human spaceflight enterprise.

Tragically, however, for the past 20-plus years, our country’s civil human spaceflight effort hasn’t been able to deliver big things, such as achieving historic exploration milestones at far-away destinations or dramatically advancing the cause of easy human access to near-space locales.

Instead, human spaceflight in the United States has struggled just to keep its sole domestic transportation system — the space shuttle — flying a few times per year, and to complete the assembly of its sole destination — the international space station. And new programs, with names such as the Orient Express, the Space Exploration Initiative, the Orbital Space Plane and now Orion/Ares, in every case became politically or fiscally unsustainable, yielding only hallucinations for space exploration. This is something we must change if the United States is to lead in space.

One longstanding characteristic of human spaceflight efforts in the United States is that they have consistently revolved around a monolithic architecture-destination combination that requires the efforts of tens of thousands of individuals and consumes virtually the entirety of NASA’s human spaceflight development budget. But it’s no secret that if you own only one stock, you probably deserve what you get when it’s in trouble.

By contrast, in NASA’s science program, which I formerly directed, dozens and dozens of concurrent spaceflight projects are always in development, from brief suborbital missions, to small Earth orbiters, to small-, medium- and large-scale planetary missions, to vast multibillion-dollar efforts such as Cassini, Hubble and the James Webb Space Telescope that require thousands of individuals to develop.

The diversity of NASA’s science mission portfolio is one of its great strengths — for no single mission, no individual development, no single charge number, and no single launch, risks the fate of the entire program.

This diversity of science mission efforts, just like the diversity in other forms of aerospace development — from airliners to missiles, to combat aircraft to transports — is a trait that civil human spaceflight could well benefit from.

Fortunately, in President Barack Obama’s vision for NASA, we already see the seeds of a diversified portfolio for human spaceflight. In its 2011 NASA budget request, the Obama administration requests funds to use multiple human-carrying suborbital vehicle designs to conduct research and education missions, and to initiate two or more systems to transport crew to the international space station.

Such multipronged efforts promote competition, drive innovation and design diversity, and give the government valuable cost-control options that monolithic (single-legged) transportation access does not. Multiple efforts also provide a kind of robustness in the event of accidents that domestic human spaceflight has never before enjoyed.

The administration should be commended for this fresh and promising approach, and Congress should endorse it in the authorization and appropriation processes.

But could that same approach be further extended to human exploration of the solar system?

There are no laws of man or physics that require human exploration systems to cost tens of billions of dollars and take multiple decades to field. Indeed, there is now ample empirical evidence that old-style, Apollo-like development practices today produce more commotion than forward motion, and have only stymied the pace and achievement of human space exploration.

What we need now is more than just a flexible path. We need parallel paths.

To be more specific, we need to be funding a diverse suite of individually lean but exciting human space exploration efforts, perhaps fielded by different NASA centers as we do in robotic spaceflight. These efforts should be aimed to put in place simultaneous projects involving lunar and asteroid exploration, high Earth orbit and Lagrange point servicing, and perhaps the first forays to fly by the planets with humans.

Of key importance to successfully exploiting this approach is the recognition that these new systems — developed in most cases via nontraditional “New Space” economic practices — cost pennies to dimes on the dollar compared with the old-style, “so big they always fail” human spaceflight efforts. As just one example, Burt Rutan’s Scaled Composites invented and fielded a fledgling human spaceflight capability for many times less than NASA expended on space shuttle brakes alone. Achieving such lower costs is fundamental, for it is only the combination of a multiplicity of efforts and breakthrough price points that makes a diversified human spaceflight portfolio viable.

So let’s give industry incentive to produce safe systems for human exploration inexpensive enough for NASA to afford multiple parallel efforts. And let’s ask how, more than 40 years after Apollo —as far in Apollo’s future as Charles Lindbergh was in its past — American ingenuity can produce a lunar return by Americans for a $3 billion to $5 billion development, a high-orbit satellite servicing capability for a still lower development cost, and a first mission to a near-Earth asteroid that costs no more than 10 times what a decade-long robotic mission to Pluto does — say, for $7 billion to $8 billion.

Yes, the developments that result may be limited in their capability compared with what $40 billion and $100 billion development efforts might promise, but for decades, expensive, monolithic development efforts have been singularly unproductive in delivering actual exploration.

Of course, because human spaceflight is harder and more expensive than robotic spaceflight, there will likely never be nearly as many projects in NASA’s human spaceflight program as in NASA’s Science Mission Directorate. But perhaps we can imagine the day when at least a few separate human spaceflight exploration missions are simultaneously being fielded, rather than one.

It is time to reinvent human space exploration, to make it simultaneously affordable, sustainable, exciting and robust. It may be hard, but it is time to find a new way forward that can serve the future rather than the past.

So let’s diversify our human spaceflight portfolio in the United States, let’s reinvent how we do things, let’s turn some heads, and let’s make history and lead again — and again — and again.


S. Alan Stern is an aerospace consultant and NASA’s former associate administrator in charge of science. He is chairman of the Commercial Spaceflight Federation’s Suborbital Applications Researchers Group.


Alan Stern is a planetary scientist and the chief executive of Golden Spike. He is a former associate administrator in charge of all of NASA’s science efforts, and he serves as the chairman of the Commercial Spaceflight Federation’s Suborbital Applications...