Mission to Mars (17 page)

They portray a six-month mission to an asteroid taking astronauts several million miles from Earth—many times farther away than the moon, but closer than Mars. This requires a very capable spacecraft with propulsion, living space, and life-support supplies, as well as safety features to protect the crew in the event of a problem, since they can’t return to Earth quickly.

Frankly, stuffing a crew into the tight quarters of an Orion capsule—even two of them docked together—is not the way to
go. Again, I advocate building off of our International Space Station. We need to use our station experience to prototype both a specialized crewed interplanetary habitat and a specialized crewed interplanetary taxi. That’s the way to get down to business in projecting ourselves outward into deep space.

What’s also urgently required is a much better survey of NEOs, using ground- and space-based assets, to greatly expand the catalog of accessible and meaningful asteroid targets for human exploration. Identification of a sufficient number of accessible and desirable asteroids is critical for future human missions. While the whereabouts of several thousand near-Earth objects
are known, the number and physical makeup of space rocks that are reachable by piloted flight are highly uncertain. There’s a paucity of targets at present to assure maximum mission flexibility. Besides, when it comes to a long-haul, piloted expedition, asteroid size does matter.

Astronauts will grasp tethers to stay close to asteroids
.

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Illustration Credit 5.9
)

Here’s my advice: No crew should travel for months on end and pull up to an NEO that’s smaller than their own spacecraft! In short, we need to know where to go.

In July 2011 the report
Target NEO: Open Global Community NEO Workshop
was issued, based on a meeting held at
George Washington University earlier that year. The document pointed out that programs and planned missions to asteroids may be leveraged for mutual benefit in terms of data exchange. It also recommended coordination with the European Space Agency and other space agencies on a planetary defense demonstration mission.

Piloted space exploration vehicles might approach an asteroid
.

(
Illustration Credit 5.10
)

The report points out that a target NEO will need to be discovered several years in advance to provide adequate lead time to deliver robotic precursor missions to scope out the object, plan the human mission, and then send the crew to the chosen objective.

But operating at an asteroid is not a piece of cake. There are great lags in Earth-to-NEO communication times. This kind of deep space mission calls for true autonomy, as crew members are far from Earth, and their space travel must include a great deal of assurance in backup hardware, space propulsion, life-support gear, and radiation shielding. That being the case, a major report finding is that the body of data required to support flying astronauts outward to an NEO is severely limited.

Then there are the psychological and sociological issues linked with an NEO-bound crew cooped up and confined in tight quarters like those offered by an Orion spacecraft. The 2011 report underscores the fact that deep space missions do not afford the abort opportunities and the psychological comfort provided by rapid return to our home planet—a hallmark of my Apollo 11 mission and the six follow-on flights within cislunar space.

My concern here is that far more work is essential to support human expeditions outside of Earth’s protective
magnetosphere. What still remains as a biological concern is the heightened and long-term physiological effects of space radiation on the human body.

There are arguably many “need-to-knows” about NEOs. That is, just how much data is requisite before a piloted mission departs Earth toward the target space rock? What about the object’s spin rate, size and shape, and makeup—solid rock or rubble pile? Also troubling is the ability to station-keep with an asteroid without placing crew and spacecraft in harm’s way. In this case, a mobile exploration module deployed from the main spacecraft could carry explorers and robotic tools over to the asteroid. That would seem like a wise and safe approach.

Visits by crews to even the largest asteroids must deal with lack of gravity to safely land. It’s more likely to be “docking” to the object in some manner. One idea, proposed by MIT researchers, is tying a lightweight network of tether material entirely around an asteroid. Once in place, astronauts could attach themselves to this set of connections and maneuver or perhaps even walk along the surface. Still, along with the low gravity, asteroids are surely going to be challenging destinations for human and robotic investigation due to the fine, granular topside material spread across the object’s surface.

There are ways to make practice runs at NEOs right here on Earth. One technique, which draws upon my early work in underwater simulation of spacewalking, is NASA’s Extreme Environment Mission Operations, or NEEMO for short. International crews of aquanauts are trying to understand what a mission to an asteroid would be like. Home base for these
evaluations is the National Oceanic and Atmospheric Administration’s Aquarius Reef Base undersea research habitat off the coast of Key Largo, Florida, and some 60 feet below the surface of the Atlantic Ocean.

Underwater maneuvers replicate the challenge of asteroid exploration
.

(
Illustration Credit 5.11
)

Part of the work is to develop tools and techniques for use on lower gravity environments of NEOs. Working on an asteroid presents special obstacles, say for snagging and bagging geologic samples. Again, great care must be taken as loose material can coast away; an astronaut can be propelled off an NEO’s surface just by striking a rock with a hammer.

Let’s face facts. We live in a cosmic shooting gallery. Ways to defend ourselves from NEOs need careful study. If there is adequate warning time, we have the means to guard Earth from asteroid impacts—a luxury that the dinosaurs were not afforded. But what deflection method to use is still to be determined. There are brute-force concepts, like using a nuclear bomb to blow an NEO to smithereens. Another less harsh option is the “gravity tractor”—a way to alter an NEO’s course with a slight nudge over time, using the gravity tug of a spacecraft that has sidled up near the object. Lasers or sunlight-focusing mirrors could also be used to heat up a spot on an asteroid, vaporizing surface material to create a propulsive force that alters the object’s path.

There’s even been talk of capturing and transporting a small asteroid to near-Earth orbit. A 500-ton asteroid could be fetched
and then deposited into a gravitationally stable point in the sun-Earth or moon-Earth system. This NEO moving plan uses a container-like robotic spacecraft powered by a solar electric propulsion system. Once the asteroid is on location, it would be subject to human study, perhaps even a popular tourist stop, as well as exploited as a resource.

Outreach to the asteroids yields a number of benefits. Scientifically, we can find out more about the formation and history of our solar system. From a security standpoint, understanding the structure and composition of asteroids, and learning how to operate spacecraft around NEOs, empowers us to deflect a hazardous intruder from afar. Then there’s appraising the feasibility of utilizing asteroid resources for human expansion in space.

Now under way is development of a unique asteroid sample-return mission. This spacecraft is to speed toward 1999 RQ36, a space rock that has the highest Earth-impact probability in the next few centuries of any known asteroid.

NASA’s OSIRIS-REx mission is being led by the University of Arizona and is slated to launch in 2016, rendezvous with the asteroid in 2019–2021, then return specimens of the object to Earth in 2023.

OSIRIS-REx is an acronym drawn from the work of the mission: Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer. The mission will identify carbonaceous asteroid resources that can be used in human exploration. Another spacecraft duty is to take measurements to quantify the Yarkovsky effect—the daily heating of an object rotating in space can exert a small force on the object.

According to OSIRIS-REx researchers, when the heated surface of 1999 RQ36 points its hot afternoon side in the direction of its motion around the sun, the escaping radiation acts like a small rocket thruster. That propulsive push slows it down and sends it closer to the inner solar system. While that thrust is minuscule, a little push day after day, year after year, for hundreds of years, can alter an asteroid’s orbit significantly. More important, the Yarkovsky effect can turn an NEO headed for Earth into an impactor—or a clean miss.

The OSIRIS-REx mission is expected to provide important data, a tool to aid in securing Earth from future asteroid impacts. With time on our side, policymakers can settle on what—if any—steps should be taken to mitigate the odds of 1999 RQ36 banging into Earth.

Extraterrestrial mining in the years to come is one way to spread Earth’s economic sphere of influence. Drawing upon the resources of the moon, Mars, asteroids, comets, and other bodies of the solar system can fuel the economic fires of an expanding, outbound civilization.

There are private efforts under way to scope out the job of quarrying space. While the business plans, dollars required, and the technology needed may be jelling, there are thorny questions ahead, issues that organizations are likely to bend their private-sector pick on: property and mineral rights, ownership and possession, international treaties.

The Space Resources Roundtable, often held at the Colorado School of Mines in Golden, Colorado, has increasingly become a hotbed of discussion on these topics. At a roundtable meeting last year, Jim Keravala, Chief Operating Officer of the Shackleton Energy Company, detailed a plan to “fuel the space frontier”—one that would traffic rocket fuel, oxygen, water, and other items into low Earth orbit and on the moon, making this service available to all spacefarers. A mix of industrial astronauts and robotic systems would service customers with a steady stream of propellants and other materials. The business plan calls for liberation of icy resources bound within permanently shadowed craters at the south pole of the moon, processing that material. The company wants to establish a network of refueling service stations in low Earth orbit and on the moon to process and churn out fuel and consumables for commercial and government customers.

But what’s ahead is the prospect of legal-beagle debate and court cases concerning mining claims, surface rights, even possession by a squatter. During the School of Mines roundtable, some voiced the point that possession is nine-tenths of ownership. Even the view that it’s easier to receive forgiveness than obtain permission circulated among participants.

For a large mining group to get involved in exploiting space resources there must be surety they can make a profit, cautions Dale Boucher, Director of Innovation at the Northern Centre for Advanced Technology, Inc., in Sudbury, Ontario, Canada. He feels that governments should get together and create the regime in which space resource mining can take place.