11: SPACE: IT'S NOT JUST FOR GOVERNMENTS ANYMORE
Life on Earth was a total waste,
I don't care if I'm lost in space,
I'm on a rocket to nowhere!
-- WEBB WILDER [1]
Webb Wilder wrote these words to describe the drawbacks of a swinging-single lifestyle, but they apply all too well to America's decidedly non-swinging space program. The old government-based approach hasn't done very well, but fortunately some smaller players, empowered by technology and competition, are stepping up to the plate. They may be just in time.
The aerospace industry as a whole is in trouble. Even in the aviation sector, there are too few companies for significant competition, and only one major company -- Boeing -- is really competitive in the civilian market. Today's airliners are modest improvements over the 707s that ruled the skies when I was born, but there's nothing on the drawing boards that will be much better.
Ditto for the space sector, only more so. Oh, it's not all bad: the civilian commercial space industry has been booming in terms of revenue. There's actually more commercial money spent on things like communications satellites and Earth observation than on government space programs, these days. But the technology of getting into space hasn't progressed much since the 1960s, industry concentration is even worse, and there's no prospect of any improvement.
Certainly the International Space Station isn't doing much to promote our future in space. Originally designed as a place that would support extensive experimentation, and the on-orbit construction of bigger-crewed structures and interplanetary spacecraft, it has now been pared down so thoroughly that it's little more than a jobs program -- lots of people on the ground supporting three astronauts in orbit who spend most of their time simply doing maintenance. And the balky, expensive space shuttle may actually be a step backward.
NASA has gotten leaner, but not appreciably meaner. It's like the Space Station writ large: Most of what science and technology development goes on there is an afterthought, with the lion's share of the agency's revenue and energy going instead to supervise NASA bureaucrats who produce nothing.
This isn't entirely NASA's fault. At the White House there has been a policy vacuum regarding space programs for a over decade. NASA successfully used inflated cost estimates to kill President George H. W. Bush's 1991 Mars mission plan for fear it would compete with the Space Station. The Clinton administration -- which abolished the National Space Council that used to oversee space policy -- never provided much new guidance beyond Al Gore's lame plan to launch a satellite that would broadcast pictures of Earth via the Internet.
Quite a depressing litany. I could spend another chapter or twenty dwelling on the sordid details. But instead let's address what to do about the dire situation that the interplay of space development and big government has created.
THE BIG ISSUES IN ORBIT
On the governmental front, the first thing we need is some direction at the top. It's virtually impossible to accomplish anything through bureaucracies without strong White House backing. So I suggest reconstituting the National Space Council (traditionally headed by the vice president), whose abolition was opposed by every major space group at the time. (Full disclosure: I was an advisor to the Space Council in 1991-1992.) Once reconstituted, the Space Council should set out to address several major problems:
1. Concentration. There aren't enough firms in the space industry to foster competition, and competition is what gives us expanded capabilities and lower costs. Whether this calls for the Justice Department to pursue a breakup of some of these companies, or whether the government should attempt to foster the growth of startups is unclear, but these options should be considered closely. Neither of these tactics constitutes unwarranted interference with the free market, since what we have now is in essence a cozy, government-supervised cartel anyway.
2. Caution. People in the established space enterprises are afraid to fail. In fact, they're afraid to even try things that might risk failure. A certain amount of caution, of course, is a good thing. But failure is one of the main ways we learn. For instance, the failure of the X-33 single-stage-to-orbit program yielded some important lessons and -- because of the program's comparatively small scale -- didn't produce a serious political backlash. Those lessons could prove useful, but only if a program is in place to take advantage of them. We need to institutionalize learning from failure, something NASA and the aerospace industry did very well in the 1950s, but not so much today. More thoughts on that later.
3. Civilians. The military has caught on to the importance of space to its mission; civilians in the federal government outside NASA (and a disturbing number within NASA) don't feel a comparable urgency. But space isn't a Cold War public-relations arena now. It's essential to economics, military strength, and cultural warfare. Agencies beyond NASA need to get more involved and more supportive: the FCC, for example. More thoughts on that later too.
4. Counting. It isn't sexy, but having a decent accounting system makes a huge difference. In conversations I've had, experts within the government have called NASA's financial management system "abominable." It's not that they don't know where the money goes, so much as that they don't know what they're getting back for it. (This may not be entirely an accident. Government programs seldom encourage that kind of transparency and accountability.) NASA administrator Sean O'Keefe was well positioned by experience to fix this problem during his term, but didn't make enough progress, and the agency has yet to complete this essential first step toward fixing other problems.
5. Cost. Cost is the major barrier to doing things in space. The government is lousy at lowering costs. But it can help promote the technological and economic environments that will allow such things to become feasible on a self-sustaining basis. Sadly, while the federal government has the power to help, it has even greater power to screw things up in this department. NASA needs to rethink its core mission and focus on its original role of developing technologies that enable others to do things, rather than feeling that it must do things itself. NASA needs to see the space tourism industry, for example, as one of its offshoot accomplishments, not, as it sometimes does now, a competitor. It's the free market that lowers costs, and empowering a little friendly competition will do more to promote American supremacy in space than any single R&D program.
In addition, the government needs to do other things to smooth the path: streamlining regulation for commercial space (FAA); protecting radio spectrum needed by space enterprises (FCC); making some sense out of export controls (Commerce and State); and so on. Congress has actually made a start at this, but there's room for much more.
The good news, as Holman Jenkins notes in the Wall Street Journal, is that space advocates have used the Internet to end-run the usual interest groups affecting space policy. In 2004, space activists pressured Congress to pass a space tourism bill, and more recently they've been publicly criticizing NASA's new moon-Mars programs. As Jenkin notes, the old "iron triangle" of government contractors, NASA, and congressional delegations now faces "an effective peanut gallery, their voices magnified by the Web, which has sprouted numerous sites devoted to criticizing and kibitzing about NASA." [2] These grassroots supporters aren't just critiquing government policy, though. They're also working to get things going on their own.
REACHING FOR THE STARS VS. REACHING FOR THE PAPER
The year 2001 is now behind us, but we're a long way from the space stations, lunar bases, and missions to Jupiter that Kubrick and Clarke made so plausible way back when. It's time to get our act together, so that we won't find ourselves in the same straits in 2051. The good news is that some people are doing just that. In fact, private foundations, private companies, and even NASA itself are waking up to some new approaches.
The X-Prize Foundation, organized by space supporters who were frustrated by the slow progress of government programs, decided to resurrect an old surefire motivator: a prize. The X-Prize approach is based on the historic role played by privately funded prizes in developing aviation. (Charles Lindbergh crossed the Atlantic to win the $25,000 Orteig Prize.) Its founders and organizers hope that private initiative, and lean budgets coupled with clear goals, will produce more rapid progress than the government-funded programs organized by space bureaucrats over the past five decades or so. (More full disclosure: I was a pro bono legal advisor to the X-Prize Foundation in its early days.) In particular, the founders are interested in bringing down costs and speeding up launch cycles, so that space travel can benefit from aircraft-type cost efficiencies. And so far it looks as if they're having some success.
The X-Prize Foundation began by offering a $10 million private award for the first team that: "Privately finances, builds & launches a spaceship, able to carry three people to 100 kilometers (62.5 miles); Returns safely to Earth; Repeats the launch with the same ship within 2 weeks." The official prize winner was Butt Rutan's Scaled Composites, with its SpaceShipOne spacecraft. But the fact that twenty-seven competitors, from a number of different countries, competed for the prize indicates that the foundation itself is the real winner. The $10 million prize generated a lot more than $10 million worth of investment.
Which is, of course, the point. Ten million dollars in a government program won't get you much; by the time paper is pushed and overhead is allocated, it may not get you anything. A $10 million prize, however, can attract much more -- with competitors driven as much by prestige as by the chance of making a profit.
Another great benefit is that prize-based programs allow for a lot of failure. By definition, if twenty-seven teams go for the prize, at least twenty-six will fail. And that's okay. Government programs, on the other hand, are afraid of failure. So they are either too conservative, playing it safe so as to avoid being blamed for failure, or too drawn out, dragging on so long that, by the time it's clear they're not going anywhere, everyone responsible has died or retired. (In government, or big corporations, it's okay not to succeed, so long as you aren't seen to fail.)
Since we usually learn more by taking chances and failing than by playing it safe and learning nothing, in the right circumstances a prize program is likely to produce more and faster progress. This isn't by accident. As X-Prize cofounder Peter Diamandis noted in recent congressional testimony:
The results of this competition have been miraculous. For the promise of $10 million, over $50 million has been spent in research, development and testing. And where we might normally have expected one or two paper designs resulting from a typical government procurement, we're seeing dozens of real vehicles being built and tested. This is Darwinian evolution applied to spaceships. Rather than paper competition with selection boards, the winner will be determined by ignition of engines and the flight of humans into space. Best of all, we don't pay a single dollar till the result is achieved. [3]
Bureaucracies are good at some things, but doing new things quickly and cheaply isn't one of them. Foundations like X-Prize offer a different approach. I wonder what other government programs could benefit from this kind of thing?
Actually, NASA is starting some prizes of its own, devoting $400,000 over two years toward competitions aimed at developing some pretty cool technology: wireless power transmission (power-beaming) and high-strength space tethers or "elevators." More competitions are expected to follow. [4] It's not a lot of money, but -- as the X-Prize demonstrated -- you don't need a lot of money to accomplish a lot if you spend it well, something that NASA hasn't done historically. That's the real news here.
Both the tether technology and the power-beaming are important on their own, of course. Space "elevator" technology is rapidly moving out of the realm of science fiction, as progress in material science makes cables strong enough to reach from Earth's surface to a point beyond geosynchronous orbit feasible. At geosynchronous orbit, it takes a satellite twenty-four hours to circle Earth, meaning that a point in geosynchronous orbit remains above the same spot at Earth's equator. A cable (suitably counterweighted) from the surface can thus go straight up to geosynchronous orbit, which conveniently enough is also the most useful orbit for satellites. With such a cable, it becomes possible to reach orbit via electric motors (which themselves can be solar powered by solar cells in space, above earthbound clouds, smog, and atmospheric haze) instead of rockets, making the prospect of cheap spaceflight look much more attainable. And if you can get to space cheaply, you can build big things there cheaply -- instead of expensively and badly, as we do now -- and if you can do that, among the things you can build are solar power satellites that convert the unfiltered twenty-four-hour sunlight of space into electricity to send back to Earth. [5]
So how do you get the power to Earth? Well, you could send it down a cable, if your satellite's at geosynchronous orbit, but you can also beam it, which lets you send power to a much wider variety of terrestrial locations, from a much wider variety of orbits. Hence the relevance of the power-beaming work.
Solar power satellites offer one answer to a question raised by the current wave of enthusiasm for hydrogen-fueled cars: Where will the hydrogen come from? You need electricity to produce hydrogen, and lots of it -- hydrogen is really more like a power-storage system than a fuel -- and if you get that electricity from burning coal or oil you pretty much vitiate the environmental benefits of hydrogen. That's just substituting smokestacks for tailpipes, which is no great improvement. Big nuclear plants are another option, of course, but some people have a problem with those.
What's really revolutionary today aren't these ideas -- people have been talking and thinking about solar power satellites for pretty much my entire lifetime -- but the means by which they are being achieved. Instead of going for a massive Apollo (or worse, space shuttle) sort of program, NASA is attacking these problems incrementally, and it's getting other minds involved. The way the prize program is structured (contestants get to keep their own intellectual property) encourages people to participate, and the goals get more ambitious over time.
What's more, NASA seems to have identified a suite of technologies to be developed by prize-winning competitions that, taken together, look pretty promising where more ambitious projects are concerned:
• aerocapture demonstrations
• micro reentry vehicles
• robotic lunar soft landers
• station-keeping solar sails
• robotic triathlon
• human-robotic analog research campaigns
• autonomous drills
• lunar all-terrain vehicles
• precision landers
• telerobotic construction
• power-storage breakthroughs
• radiation-shield breakthroughs
Put all this stuff together, and you've got the makings of an ambitious space program, with the R&D done on the cheap. Maybe there's hope for NASA yet. Or at least for our future in space.
MORE EGGS IN MORE BASKETS
There had better be, because our future may depend on getting a sizable chunk of humanity into outer space. I attended a conference on terrorism, war, and advanced technology a few years ago, and after hearing about everything from genetically engineered smallpox to military nanoplagues, one of the participants remarked, "This makes space colonization look a lot more urgent than I had thought."
He's not the only one to feel that way. Stephen Hawking says that humanity won't survive the next thousand years unless we colonize space. I think that Hawking is an optimist.
We've seen a certain amount of worry about smallpox, anthrax, and various other bioweapons since 9/11. At the moment, and over the next five or ten years, these worries, while not without basis, are probably exaggerated. At present there aren't any really satisfactory biological weapons. Anthrax is scary, but not capable of wiping out large (that is, crippling) numbers of people. Smallpox, though a very dangerous threat, is hard to come by and easy to vaccinate against, and the populations whose members are the most likely to employ it as a weapon (say, impoverished Islamic countries) are also those most vulnerable to it if, as is almost inevitable, it gets out of hand once used.
That will change, though. Already there are troubling indications that far more dangerous biological weapons are on the horizon, and the technology needed to develop them is steadily becoming cheaper and more available.
That's not all bad -- the spread of such technology will make defenses and antidotes easier to come up with too. But over the long term, by which I mean the next century, not the next millennium, disaster may hold the edge over prevention: a nasty biological agent only has to get out once to devastate humanity, no matter how many times other such agents were contained previously.
Nor is biological warfare the only thing we have to fear. Nuclear weapons are spreading, and there are a number of ways to modify nuclear weapons so as to produce lethal levels of fallout around the globe with surprisingly few of the devices. That's not yet a serious threat, but it will become so within a couple of decades.
More talked about, though probably less of a threat in coming decades, is nanotechnology. Biological weapons are likely to exceed nanotech as a threat for some time, but not forever. Again, within this century misuse of nanotech will be a danger.
Want farther-out scenarios? Private companies are already launching asteroid rendezvous missions. Perhaps in the not-too-distant future, a mission to divert a substantial asteroid from its orbit to strike Earth may be on the to-do list of small, disgruntled nations and death-obsessed terror groups (or perhaps Luddites who believe that smashing humanity back to the Neolithic would be a wonderful thing). Imagine the Unabomber with a space suit and better resources.
No matter. Readers of this book are no doubt sophisticated enough to come up with their own apocalyptic scenarios. The real question is, what are we going to do about it?
In the short term, prevention and defense strategies make sense. But such strategies take you only so far. As Robert Heinlein once said, Earth is too fragile a basket to hold all of our eggs. We need to diversify, to create more baskets. Colonies on the moon, on Mars, in orbit, perhaps on asteroids and beyond would disperse humanity beyond the risk of most catastrophes short of a solar explosion.
Interestingly, spreading human settlement to outer space is already official United States policy. Congress declared it such in the 1988 Space Settlements Act. Congress declared as a national goal "the extension of human life beyond Earth's atmosphere, leading ultimately to the establishment of space settlements," and required periodic reports from NASA on achieving those goals, though NASA has dropped the ball on them. [6] The policy was endorsed again by Presidents Reagan and Bush (the Clinton administration didn't exactly renounce this goal, but didn't emphasize it either). But talk is cheap; not much has been done.
What would a space policy aimed at settling humanity throughout the solar system look like? Not much like the one we've got, unfortunately.
The most important goal of such a policy has to be to lower costs. Doing things in space is expensive -- horribly so. In fact, in many ways it's more expensive than it was in the 1960s. This is no surprise: it's the tendency of government programs to drive up costs over time, and human spaceflight has up to now been an exclusively government-run program.
That's why promoting the commercialization of outer space is so important. Market forces lower costs; government bureaucracies drive them up. Among the cost-lowering programs likely to make the biggest difference is space tourism, which is beginning to look like a viable industry in the short term. Oust ask Dennis Tito, Greg Olsen, or Mark Shuttleworth, all of whom have already bought rides into space on Russian rockets, at a cost of many millions of dollars each). We should be promoting such commercialization any way we can, but especially through regulatory relief and liability protections.
Government programs should be aimed at research and development that will produce breakthroughs in lowering costs: cheaper, more reliable engines; new technologies like laser launch, solid-liquid hybrid rocket engines, space elevators. Once this technology is produced, it should be released to the private sector as quickly as possible.
Other research should aim at long-term problems: fully closed life support systems capable of supporting humans for extended periods (you might think that the International Space Station would provide a platform for this kind of research, but it doesn't); exploration of asteroids, the moon, and Mars with an eye toward discovering resources that are essential for colonization; and so on.
Putting these policies into place would require drastic change at NASA, which is now primarily a trucking-and-hotel company, putting most of its resources into the Space Station and the space shuttle, which now exists mostly to take people to and from the Space Station. But we've been stuck in that particular loop for nearly twenty years. President Bush has pushed a return to the moon and a mission to Mars as top goals, and Congress has recently endorsed them. But so far, actual movement seems small.
It's time for that to change. Like a chick that has grown too big for its egg, we must emerge or die. I prefer the former. Apparently, judging from the new proposals to return to the Moon and send humans to Mars, Congress and the Bush administration feel the same way. But there are some issues to be resolved before we go to Mars.
The first question is, how?
MARS OR BUST!
One well-known proposal that NASA has shown some interest in features Bob Zubrin's Mars Direct mission architecture, which uses mostly proven technology and which promises to be much, much cheaper than earlier plans. Mars Direct involves flying automated fuel factories to Mars in advance of astronauts; the astronauts land to find a fully fueled return vehicle waiting for them. The factories remain behind to make more fuel for future operations.
Zubrin thinks that we could do a Mars mission using this architecture for $30-40 billion -- which, even if you double it, is still manageable. Back when I worked for AI Gore's presidential campaign in 1988, I did a paper on Mars missions that concluded that $80-90 billion (in 1988 dollars, about the cost of the Apollo program) was the maximum feasible expenditure on a Mars mission. This estimate would fall well below that figure. True, we have the war on terrorism to fight now, but in 1988 (and for that matter, during Apollo's development) we had the Cold War.
A more cogent criticism than cost is what we have to show for it when we're done. I'm a fan of Zubrin's approach. But I agree with other critics that the real key to successful space settlement over the long term is to take the work away from governments and turn it over to profit-making businesses -- ordinary people working in market structures that maximize creativity and willingness to take risks. The government has an important early role to play in exploring new territories before they're settled -- it wasn't private enterprise that financed Lewis and Clark, after all -- but government programs aren't much good once the trail-breaking phase has passed. And the earlier commercial participation comes in, the better.
If you want settlement and development, you need to give people an incentive. One possibility, discussed by space enthusiasts for some time, is a property-rights regime modeled on the American West, with land grants for those who actually establish a presence on the moon or Mars. Some have, of course, derided the idea of a "Wild West" approach to space development, but other people like the idea of a "Moon Rush," which I suppose could be expanded in time to a "Mars Rush."
Could our "cowboy" president get behind a Wild West approach to space settlement? He'd be accused of unilateralism, disrespect for other nations, and, of course, of taking a "cowboy approach" to outer space that's sure to infuriate other nations who want to be players but who can't compete along those lines -- like, say, the French. Hmm. When you look at it that way, there doesn't seem to be much doubt about what he'll do, does there?
One reason for optimism is that this time around, cost and technology are getting a lot more thought than when NASA was looking at Mars missions in the 1980s. Nuclear propulsion is at the forefront this time -- back then, it was a political nonstarter. It's possible to go to Mars using chemical rockets alone, but just barely. Using nuclear space propulsion -- where a reactor heats gases to form high-speed exhaust rather than using chemical explosions to do so -- cuts travel times from six months to two, and, because of better specific impulse (efficiency), allows for higher payloads. (There are no plans, as far as I know, to use Orion-style nuclear-explosive propulsion. Should I turn out to be wrong about this, it will probably be a sign that somebody somewhere is very worried about something.)
The United States experimented with nuclear propulsion as part of the Kiwi and Nerva projects in the 1960s and early 1970s. The results were extraordinarily promising, but the projects died because, with the United States already abandoning the moon and giving up on Mars, there was no plausible application for the technology. Nuclear propulsion is mostly useful beyond low-earth orbit, and we were in the process of abandoning everything beyond low-earth orbit.
That appears to be changing, and it's a good thing. I think that the "settlement" part is as important as the "exploration" part. And while exploration is possible based on chemical rockets alone, settlement without using nuclear power will be much more difficult.
Nuclear space propulsion has had its critics and opponents for years, though weirdly their opposition stems largely from fears that it will lead to "nuclear-powered space battle stations." This isn't quite as weird as Rep. Dennis Kucinich's legislation to ban satellite-based "mind control devices," [7] but it seems pretty far down the list of things we should be concerned about. With worries about earthbound nuclear weapons in the hands of Iran, North Korea, and perhaps assorted terrorist groups, it's hard to take seriously claims that possible American military activity in space, spun off from civilian Mars missions, might be our biggest problem. Indeed, the whole concern about "space battle stations" has a faintly musty air about it, redolent of circa-1984 "nuclear freeze" propaganda. Who would we fight in space today? Aliens? And if we needed to do that, wouldn't nuclear-powered space battle stations be a good thing?
Nor are environmental concerns significant. Space nuclear reactors would be launched in a "cold" (and thus safe) state and not powered up until they were safely in orbit. And again, compared with the environmental threat caused by rogue nuclear weapons, their dangers seem minuscule.
The administration's Mars proposal is at least a step in the right direction, and its adoption of nuclear space propulsion indicates more realism than the flags-and-footprints approach favored by the previous Bush administrations. What's more, the use of nuclear propulsion, which makes interplanetary travel both cheaper and faster, greatly increases the likelihood of going beyond flags and footprints to true space settlement. It's about time.
But there are still questions. Imagine that you've got a lot of money. No, more than that. A lot of money. Now imagine that you want to go to Mars. Oh, you already do? Me too. Then imagine that with your money you've built a spaceship -- perhaps along the lines of Zubrin's Mars Direct mission architecture, though for our purposes the details don't matter. If you prefer, you may substitute antigravity or the Mannschenn Drive as your mechanism of choice.
Regardless of technology, you've got a craft that will take you to Mars and back, in one piece, along with sufficient supplies on the outbound leg and some samples when you come back. You're going to find out firsthand what Viking couldn't settle: whether there's life on Mars. You'll also do some research aimed at laying the groundwork for Martian colonization. Are you ready to go?
Not quite. You see, there might be life on Mars.
Well, duh. That's what you're going to find out, isn't it?
Yes. But if you find it's there, then what? You see, the 1967 Outer Space Treaty requires its signatories to conduct explorations of celestial bodies "so as to avoid their harmful contamination and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter." [8] When you get to Mars you may create the first kind of contamination, and if there's life on Mars, you may create the second-assuming that you plan to return to Earth.
That human explorers will "contaminate" Mars is inevitable -- humans contain oceans of bacteria, and a human presence on Mars is sure to leave some behind. Even if all wastes are bagged and returned to Earth (unlikely because of the expense involved), some germs are bound to escape via air leaks and transport on surfaces of Mars suits and other objects that exit the spacecraft.
NASA now takes extensive steps to sterilize unmanned spacecraft so as to keep Earth germs from reaching other planets, something known in the trade as "forward contamination." Such precautions may be adequate for robotic missions, but it is simply impossible to ensure that missions involving people won't result in contamination. They will.
Given the impossibility of avoiding some sort of "contamination," the treaty obviously and sensibly does not forbid mere "contamination." It prohibits harmful contamination. What does that mean? Well, if Mars is lifeless, harmful contamination can only be contamination that interferes with human purposes. To scientists at the moment, any contamination seems harmful, since it may make it harder for them to determine if Mars has native life when it might have come from Earth. ("Hey, look, Mars has E. Coli! -- er, or some space-probe-manufacturing guy on Earth has poor personal hygiene.") But once humans go to Mars, the framework is likely to change.
If Mars has life of its own (unlikely, but not impossible, especially in light of some intriguing new evidence), the situation gets harder. First, we may have to consider whether Martian bacteria or lichens or whatever may be harmed by any organisms humans bring. Then we have to decide whether we care about that. Is harm to bacteria the sort of harm the Outer Space Treaty was meant to prevent? Almost certainly not, but no doubt bacteria-rights advocates will do their best to get a debate fermenting here on Earth.
Martian bacteria raise another question: the question of "back contamination," as it's called -- contamination of Earth by Martian organisms. That, too, will be difficult to rule out in the event of a manned mission. Oh, it's unlikely that bacteria that can survive in the Martian environment will flourish on Earth, and even less likely that they would prove harmful to Earth life. But unlikely isn't the same as impossible, and people are likely to worry. In fact, they already have worried about it in the context of robotic sample-return missions.
Mars colonization fans -- of whom I am certainly one -- need to ensure that the same questions have been addressed long before any humans set out for Mars. As we've learned in many other contexts, sometimes the environmental impact statement takes longer than the underlying project.
Of course, this may all be much ado about nothing -- as the National Research Council has noted, nontrivial quantities of Martian material have been deposited on Earth as meteorites, blasted loose from Mars by asteroidal impacts, and it is entirely possible that bacteria could have survived the journey. [9] Smaller quantities (because of Earth's greater gravity) of Earth material have presumably gone to Mars in the same fashion. And in the early days of the solar system, when life was new, the greater degree of celestial bombardment on both planets would have made such exchanges far more frequent. So if we find life on Mars, it may simply be Earth life that has beaten us there. Or perhaps it will be our ancestral Mars life welcoming us home. In neither case will we have to worry much about harmful contamination.
But what about beneficial contamination?