The ultimate goal is Mars. To do what exactly, and for how long, is unknown. The path has varied wildly across the past two U.S. administrations.
The George W. Bush administration would have had us return to the Moon and use it as a springboard for Mars. Funds sufficient to accomplish this were never requested.
Faced with a depressed economy, the Barack Obama administration decided to scrap the Moon plans, and the balloon payment needed, and send astronauts to a near-Earth asteroid in the 2020s. The long-duration spaceflight would support the future Mars goal. Suddenly, the administration changed gears and decided to capture a small asteroid and bring it back to lunar orbit for subsequent exploration by astronauts — or maybe not. The objectives are not clear.
A workshop of experts met recently in Washington to review and discuss the Asteroid Retrieval Mission (ARM). It is apparent that the mission is poorly conceived and lacking in basic planning, and carries huge cost and schedule risk that is more dumb than heroic. NASA may not know it yet, but ARM is dead, and the future of American human spaceflight is again in question.
Perhaps it is time to move away from stunt as policy — a tragic legacy of the Apollo program. If we are going to confront a true frontier like space, we need to ask some basic questions to find out what is possible or at least practical. Then we can define long-term goals with a real plan to achieve them.
Back in the 1960s, the public was inspired by the idea that we were at the dawn of a space age in which we would inevitably (and soon!) find ourselves living and working on other worlds. These would be new self-sustaining economies. This continues to echo in science fiction and the roadmaps of advocacy groups like the National Space Society. It has never been given serious consideration by the government. After half a century, we do not even know whether Earth life can thrive in the lower lunar or martian gravities. We don’t need to go to the Moon or Mars to answer the question. We just need a centrifuge and the international space station (ISS).
Our activities in space will always be limited by the high cost of launching everything we need from the surface of Earth. For more than 30 years scientists have explored the possibility of resources, such as water, from near-Earth asteroids. This could supply fuel for propulsion, water for life support and shielding from radiation.
We are also limited by our clunky spacesuits. Hopping around the lunar surface with a hammer and a bag may make for entertaining videos, but it is extremely limiting when it comes to science or any other activity that can be done.
So, what should be the focus of the American human exploration program today?
Homework.
With the Space Launch System and a scaled-down version of the electric propulsion system contemplated for ARM, let’s launch a small habitat to the L1 Lagrange point between Earth and the Moon. The astronauts in it would conduct investigations of the lunar surface by controlling small landed systems through immersive telepresence (used today in medicine and mines on Earth). The habitat could be also moved to the far side of the Moon, at L2, to conduct further experiments. In the meantime, long-term experience in the habitat and its maintenance would be gained and telepresence skills learned that could be extended to other solar system bodies as well as spacecraft.
In parallel, a version of the planned centrifuge for the ISS that was canceled in 2006 could be sent up to conduct fundamental life-science experiments that will answer the question of whether Earth is the only planetary basket we have in which to keep our eggs.
Studies need to be conducted on ISS to develop the processes to extract water and other materials from asteroid samples in our possession — meteorites. Simulants — materials simulating the expected chemical and mechanical properties of asteroid samples — would also be tested. How would we design an automated resource extraction unit to operate in the nearly zero gravity and uncertain topography of a near-Earth asteroid? Could something like a deployable solar sail be designed to return processed materials to Earth-Moon space?
We cannot assume the resources are there. We need to conduct a space-based survey of near-Earth objects in low delta-velocity orbits (these objects tend to lurk in twilight so surveys using ground-based telescopes are not optimal). Something comparable to the recent and very successful and low-cost Wide-field Infrared Space Explorer would be sufficient to do the job.
If we find the targets and develop the resource extraction processes and the means of returning those resources, if we gain experience in the lunar orbiting habitat and the skills of teleoperation for increasingly sophisticated human tasks, and if we determine that we could expand our space transportation infrastructure at lower cost by using near-Earth asteroid resources, the next step would be simple. Humans would be sent in another habitat with a propulsion system to a reasonably accessible near-Earth object. At the same time, a robotic mission would be heading to the same object with an automated resource recovery test facility. The humans could collect samples and conduct other science experiments, but their No. 1 priority would be to keep an eye on the robotic facility as it deploys and commences operation and do what humans do best — give it a kick if it needs it. They would troubleshoot any problems so that future facilities could be launched to additional targets without being tended. Of course, for this first mission there might also be a precursor robotic mission to characterize the human target.
Asteroidal fuel could be used to send people down to the surface of the Moon. Similarly, lunar resources could provide some of the fuel needed to return astronauts from the surface of the Moon to orbit.
All of this can be done at a pace that financial resources allow. None of it requires a massive, Apollo-like infusion of dollars. It is a step-by-step approach towards an open-ended future with real decision points that require straightforward planning and management.
NASA does not need to compete with the entertainment industry. It can inspire with real questions about a real future in which the public might once again see themselves.
Mark V. Sykes is chief executive officer and director of the Planetary Science Institute.
