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© 1994 by Donald F. Robertson.
This article may be distributed at will, but only if it is not changed in any way, and only if the author's name, the copyright notice, the name of the journal it first appeared in, and this notice remain attached. In addition, this article may not be sold for money, or published for sale in any way, without the author's prior written permission.
This article originally appeared, in very different form, in Astronomy.
Donald F. Robertson
It is twenty-five years since the United States landed the first human beings on another celestial body.
The Apollo project, arguably, was humanity's greatest single achievement. It will be remembered long after most of the other events of our Century are forgotten. With one small step, our species embarked on an adventure without limit or end.
After just nine flights to Earth's moon (including the Apollo-8 and Apollo-10 test flights to lunar orbit, and the Apollo-13 failure which looped around the moon), Apollo was canceled. NASA started the Space Shuttle to try to reduce the cost of getting to low Earth orbit, a requirement for getting anywhere else.
What has happened since? In over two decades, humanity has failed to send anyone to any celestial body. NASA is spending $5 billion each year on just six to eight Shuttle flights, with a vehicle that is perceived to be dangerous and unreliable. Another $1 billion per year -- soon to be $2 billion -- is spent on a Space Station that never flies. The Air Force has wasted billions more failing to duplicate the Shuttle's already-existing capabilities with their giant Titan-IV, and building communications satellites that cost as much as NASA spends each year on the Space Station. Meanwhile, decades of disastrous financial and trade policies have left the United States with little disposable income to spend on perceived luxuries like space exploration.
When President George Bush proposed the Space Exploration Initiative to establish an expensive, permanent base on Earth's moon and land a crew on Mars, he was laughed out of the Congress that had to pay for it. President Bill Clinton is staying closer to home. While not actually canceling the Space Station, he is down-sizing and simplifying the project and bringing in experienced Russians to help. He will use the $200 million saved this year to pay for advanced technology and the Discovery project to send very small automated missions to the inner planets.
So where does that leave the grand dream of sending human beings permanently into the Solar System?
In the terms of that dream, maybe the last quarter century has been wasted. But in another sense, it has not.
Humanity's overall capabilities in space technology are far in advance of what they were in the Apollo project. Everything in Apollo was invented more-or-less from scratch. The Apollo vehicles were literally hand made. Today, much of the technology used in Apollo is readily available in the commercial marketplace, in several different countries, and for far less money.
Nobody really knows exactly how much Apollo cost, but a reasonable guess might be something over $100 billion in today's dollars. Dave Caudle, a design engineer with General Dynamics, told Astronomy that a minimum mission his company has studied to land astronauts on Earth's moon using already-existing launch vehicles might cost well under $10 billion. Even allowing for the vast price increases that seem inevitable in today's space programs, this is a major reduction in the estimated cost of lunar spaceflight.
Look at today's technology. Everything weighs much less. Avionics -- aerospace electronics -- cost less and are far more capable and reliable than Apollo-era counterparts. Modern materials invented in the National Aerospace Plane Single-Stage- to-Orbit project can handle more heat with far less weight.
Today's rocket engines, like the Space Shuttle Main Engines, operate with pressures and power densities fully three times higher than any engine used in the Apollo project. That equates to efficiency, which means that more mass can be lifted by a smaller vehicle. Super-high efficiency electric, or ion, engines are in advanced test and very close to flight on communications satellites. Similar engines might be ideal for deep space propulsion, say to Mars or the asteroids.
The hardware available today has been unfairly criticized. The much maligned Shuttle, for all its admitted faults and extremely high price, in fact has had just one failure in [eighty-one launch attempts, as of early 1997]. No other large rocket anywhere in the world has achieved such a reliability record in its first [eighty-one] flights. Even after hundreds of flights, only the relatively small Delta has equaled that record. If the orbiter were replaced with a cargo module, the Shuttle launch system can orbit the same mass as a Saturn-V at less cost (launching a Saturn-V cost well over $1 billion in today's dollars).
The remaining old expendable rockets -- Commercial Atlas, Commercial Delta -- lift far more weight for less money than they used to. Soon, Europe and Japan will be introducing new, thoroughly modern expendable rockets, while the United States is beginning to test sub-scale Single-Stage-to-Orbit vehicles. Russia's giant Energya probably still could be revived, although that country is rapidly losing the social organization required to maintain large, high-technology projects.
Getting into low Earth orbit is not as inexpensive as it should be; but, contrary to the popular perception, it is cheaper than it used to be. This trend will continue, if not in the United States, than in Europe, China, Russia, or Japan.
America's specialty has always been at the high end of space exploration, sending automated spacecraft far into the Solar System. The ancient Centaur, the world's first upper stage to burn high-energy liquid oxygen and liquid hydrogen propellants, and the vehicle that more than anything else made America's automated space program possible, has undergone constant improvement. Soon, the Centaur may see a major upgrade to the Single-Engine Centaur. This already-existing "space tug" should be relatively easy to rate for human spaceflight, and is ideal for deep space propulsion.
Europe has developed Spacelab, a habitable module that fits into the Space Shuttle's payload bay, and Italy helped a commercial company build a smaller version called Spacehab. These modules, like soon-to-be-available Space Station modules, can be adapted into habitats for interplanetary spacecraft and planetary bases. The Space Station program has advanced closed life support -- which recycles consumables like water, air, and food -- and high-capacity generation of solar energy.
As we will see, the small renaissance that commercial space is enjoying may be the most important development of all. Defense contractors are commercializing their ex-military technology. The communications satellite industry remains the principal market for most commercial space services, and is a major money-maker for the United States. In the next few years, broadcast television, global mobile telephones, portable video telephones, air traffic control satellites, and other new products, will require more satellites, which in turn will require new, more efficient launch vehicles.
And a new trend is developing: many would-be British East India Companies are building small launchers to orbit tiny communications, Earth observation, and scientific spacecraft. These idealist companies hope to use money earned to boot-strap their vehicles into ever larger commercial projects.
What does any of this have to do with sending humans to the planets? Individually, every one of these advances seems, and is, modest, at least compared with our goal sending humans into the Solar System. The important point is their sheer quantity.
In general, more advanced space technology, even if developed for a completely unrelated purpose, makes planetary exploration easier -- and cheaper. Someday, that overall cost may drop below what some organization is willing to pay, and human planetary missions could then become a reality. We will discuss later who some of those organizations may be.
NASA's "space program" may be in serious trouble, but overall, the "space industry" is far healthier than it was during Apollo. Instead of one customer -- the government -- there are many customers. More and more people and organizations have a stake in the space industry's success.
A lot is happening in space. Put it all together, and . . . what? What can we do with what we now have? And who will pay for it?
In 1992 and early 1993, General Dynamics conducted a study on what a near-term mission to place astronauts on Earth's moon might look like. The ground rules were simple. To keep costs low, the project must use hardware already developed for other purposes. The missions must be "meaningful." That is, they must accomplish science that had not already been done by Apollo. And the missions must pre-position supplies and equipment, test technology, and obtain knowledge useful for a later lunar base.
According to Dave Caudle, a design engineer involved in the study, the project started in the marketing department at General Dynamics. They wanted to propose a human lunar project to NASA that could be done cheaply enough to fit within realistic NASA budgets, yet could be done within a decade, like Apollo. "They came to me, as someone who knows the hardware, and said, `This is what we want to do. We want to use the Space Shuttle and the Titan to go to the moon. Come up with a vehicle that will do it.' So I came up with a vehicle that could do it," says Caudle.
The project was to begin in 1994, and culminate in the year 2000. The principle launch vehicles are a slightly uprated Space Shuttle, and a Titan-IV with larger and lighter fuel tanks or a European Ariane-V with two extra solid rocket boosters. The Single-Engine Centaur is used to get to the moon, and a capsule shaped like the Apollo Command Module returns the crew to an ocean splashdown. The capsule would have a modern interior, but the old Apollo shape and size was retained to avoid having to do extensive new wind tunnel tests. The only vehicle that has to be developed from scratch is the lander. To reduce the weight that needs to be sent to the moon, and to avoid having to refuel on the moon, the lander must be a far more efficient vehicle than its Apollo counterpart.
After two cargo missions to pre-position supplies on the Lunar surface, the third mission starts with a Space Shuttle orbiter in a low parking orbit around Earth. The orbiter's payload consists of the lunar lander, the return capsule to take the crew back to Earth, and a lunar crew of two.
The lander and return capsule are prepared for flight in the Shuttle's payload bay. Once they are ready, the lander with attached return capsule is deployed from the Shuttle's payload bay, and the crew transfers from the Shuttle to the lander's crew cabin.
Meanwhile, a Titan-IV or a Ariane-V has been launched from Earth with a fueled Single-Engine Centaur. The Centaur approaches the waiting lunar lander, and docks to become a complete lunar spacecraft, which is checked out by the Shuttle's crew.
The Centaur's engine begins the long burn to send the vehicle toward the moon, then the Centaur falls away. A little over two days later, the lander's rockets fire and the spacecraft lands directly on the lunar surface, without first orbiting the moon. After three weeks of surface operations, the crew blasts off, again aiming directly for Earth. Their capsule reenters and splashes down in the ocean.
But before the crew can be sent, the two 8.5 metric ton cargo flights were used to test the entire system. To provide early science, an optical telescope is mounted on the automated lander. With the moon as a stable platform, and no atmosphere to see through, such a telescope could provide major scientific advances. Other cargo consists of automated scientific equipment, a habitat and supplies, an unpressurized rover, and lunar mining experiments.
A second cargo flight sends more hardware and supplies, including a closed life support system.
After the third mission demonstrates sending a crew, this lunar transportation system would be declared operational. A fourth mission could then send equipment for extended science and the beginnings of a lunar base. All for far less money than has been assumed in the past, according to General Dynamics.
Unfortunately, the company's initial proposal underestimated the project's weight. Wendell Mendell, A NASA planetary scientist who has spent years studying lunar bases, said, "When General Dynamics came [to NASA Johnson] with their presentation, [NASA engineers] were going crazy, because they had worked the problem every which way and had not been able to do it. So they wanted to find out what in the world the secret was."
Caudle admitted that there was a problem, but said, "So we re-did the calculations and said, we can still do it. But you would have to make a lot of modifications. You would have to have the new [Advanced Solid Rocket Motor] boosters for the Shuttle and the new solid boosters for the Titan." The Titan's fuel tanks would need a somewhat larger volume and would be made out of a light alloy called Aluminum-Lithium. The Shuttle's external tank also would be made out of Aluminum-Lithium. Caudle emphasized that all of these changes either are in development or are being considered for other missions.
Coincidentally, when Astronomy interviewed him, Wendell Mendell had just completed a study with International Space University students on establishing a relatively low-cost interferometric observatory on the lunar farside. They reached conclusions very similar to General Dynamics', and their method of getting to the moon was almost identical. The only real difference was use of a very large launch vehicle, like Russia's Energya, rather than the Titan-IV. "If you are not going to do a lot of assembly in low Earth orbit, or if you are not going to obtain fuel on the moon, you need a very large launch vehicle. That," said Mendell, "is where the General Dynamics study is most likely to be unrealistic.
General Dynamics' scenario "does not use existing launch vehicles," says Mendell. "It uses upgraded versions of existing launch vehicles. And once you talk about upgrading, upgrading always sounds very simple. Quite often the word `upgrading' is applied to something that" would cost almost as much as a new vehicle. Mendell maintains that to return to the moon, a new, much cheaper way of getting to orbit is almost essential.
General Dynamics thinks otherwise. Using their plan, how long would it take to return to the moon? "That depends on how badly you wanted to go," said Caudle. "If it was an Apollo level of effort . . . if it were a race with Japan or something . . . we could get there in five years. If it was a normal process with some Skunk Works [management] and they kept the politics out of it, probably seven to eight years."
How much will it cost? "All of these new things [needed for the company's lunar mission] are not trivial," admitted Caudle. They will cost millions to do, and you combine them and they become billions. But they are all much cheaper than building a new rocket, far cheaper." How cheap? $7 billion to $8 billion, according to Caudle, including the required up-grades to the Shuttle and Titan-IV.
Recent Air Force studies argue that developing a new launch vehicle from scratch would take at least a decade, and cost over $10 billion. Some companies, like Boeing, think it could be done for half that, but if General Dynamics is right -- the big `if' -- returning to the moon with existing launchers could cost much less than developing new vehicles.
After the political collapse of President Bush's Space Exploration Initiative, NASA did not completely abandoned the dream of deep space exploration. The agency still maintains a small study office, called the Mission From Planet Earth. The Director, Carl Pilcher, told Astronomy, "Our responsibility really is to develop NASA's long-term planning for space exploration and development, writ large," over several decades.
Pilcher admitted that, after the heady days of the Space Exploration Initiative, NASA is not exactly showering his new office with money: "Our budget is very small. . . . It is basically just me and my deputy and a secretary, and we will have [several] people joining us. One is in education and outreach."
But Pilcher argued that lots of money is not what Mission From Planet Earth needs. "The key issues are not how we are going to get back to the moon. The key issues are why is this nation going to return to the moon and what are we going to do when we get there. . . . Those questions can't be answered by NASA itself. Those are questions that have to be addressed by our society as a whole." NASA wants to "begin to develop a consensus through having a national and international dialog about the entire rational for returning" to the moon.
That sounds ominously lot like the dreaded words: "more studies." Asked about people who had hoped humanity might return to the moon in their lifetimes, Pilcher said, "I understand the frustration. I understand the feeling. We are trying to change the program in a way that would help address some of that frustration." If society as a whole is behind a lunar mission, it will happen.
While not endorsing the General Dynamics project, Pilcher said, "Our office acts as an advocate for those kinds of [company-proposed] activities and that kind of innovated thinking within NASA. I think what General Dynamics did is extremely interesting." However, "A human return to the moon I don't think is anything you could ever describe as `cheap', no matter how you do it." said Pilcher. "Even with the General Dynamics approach you are still talking about a commitment of billions of dollars, even if it is only a few billions of dollars as opposed to a few tens of billions of dollars." Pilcher said NASA is unlikely seriously to consider a return to the moon until the Space Station is completed.
One goal of the Mission From Planet Earth office is to make sure that NASA's near term automated planetary projects take into account the long-term goals of developing the Solar System; to use existing projects undertaken for pure science to further the longer-term goal.
Asked if he feels it makes more sense to go to the moon quickly with current vehicles, or to wait while technology and humanity's spacefaring skills continue their onward march, Pilcher said, "That is a judgment I am not ready to make yet. I don't think that's a judgment we have to make in the near term. Right now, this nation is not on a path to commit itself in the near term to a return of humans to the moon."
So if the government is not going to return to the moon anytime soon, who will?
The short answer is, Nobody. But that is a cop out. It admits defeat, and over-simplifies the true situation. A more accurate answer would be, We won't return easily, and not soon, but it may well happen.
One key advantage is the new world order. While the end of the Cold War removed much of the drive behind the space program, it also removed the most immanent threat to human survival. In today's world, there is simply more time for our civilizations to expand into the Solar System.
Recall the long list of cumulative advances at the beginning of this article. The majority are small improvements to old technologies that over time accumulate into major changes. Of the new technologies, a few are military, but most arose in support of NASA's scientific requirements, or they are commercial, or they were implemented by the government in support of commercial activities and essential services like weather satellites.
This is the long road into the Solar System. It is a painfully slow road, but it is also the healthy road. Since there is a specific reason for every advance, there is less danger of changing politics canceling the program. No matter who is in power, the United States, Russia, the Europeans, Asian countries, and several developing countries are all likely to continue launching ever improved communications, Landsat, and weather satellites. These require ever improved launchers and upper stages. Better vehicles mean you can do more in space.
Will the space industry's expansion remain as slow as it has in the past? Almost certainly not. Commercial space earns the United States over $5 billion per year and rising fast. That money is just beginning to attract more money.
Would-be space industrialists have to be idealists, since it takes years to make money, but they do exist. Over a decade ago, one now-successful company was started from scratch by three young business majors just out of college. Orbital Sciences Corporation developed the innovative Pegasus air-launched rocket that proved there was a market for small, inexpensive launches. They did it without direct government money. The Advanced Research Projects Agency promised to fly a small number of science and technology missions, which allowed the company to raise money in the commercial marketplace. [The author is a small shareholder in Orbital Sciences Corporation.]
Other Orbital Sciences projects include upgrading the Pegasus, a medium launch vehicle based on Pegasus called Taurus, an upper stage for the Shuttle, a tiny scientific platform cheap enough for some Colleges and Universities to afford ($10 million per flight), and a global mobile E-mail and fax network. An entire, privately funded space program, independent of NASA and the military except as customers.
Most of Pegasus' payloads to date have been small scientific satellites that were developed specifically for the new launcher. Science is and will remain one of the principal drivers behind even a commercial space program.
Once Pegasus proved the market, a number of other companies -- including giant Lockheed with their small, commercial Lockheed Launch Vehicle -- followed in Orbital Science's steps.
Likewise, an entrepreneurial company called Spacehab used a promise from NASA and money raised by Chase Manhattan bank to develop and fly a commercial scientific laboratory in the Shuttle.
Ironically, Pegasus' very success demonstrates that launch vehicles remain the bottleneck. Reduce costs, and payloads beat a path to your door. General Dynamic's Dave Caudle: "It's the chicken and the egg. No [company] is going to build a payload until they have a launcher that can lift it, and no one is going to build a launcher until they have a payload that can pay for it."
The key to breaking out of this whole chicken-and-egg problem may be the Space Station. The Space Station, if it ever gets built, will be the first permanent facility in Earth orbit. It will absolutely require that a large quantity of supplies and equipment be delivered day-in and day-out. Nobody outside of NASA seriously believes the Space Shuttle is capable of fulfilling this need. The Space Station thus becomes the first large market for commercial launch vehicles.
Call this the San Francisco model of space development. San Francisco was established as a military base, by the Spanish, in what was then an extremely remote area. (During the Civil War, the U.S. Army considered its San Francisco fortress, now literally under the Golden Gate Bridge, a hardship duty because of its remoteness and extreme climate.) This small frontier town became one of the world's great cities by supplying logistical support to the Gold Rush.
Once the city was established -- for whatever reason -- it became a market. A large and ever-growing quantity of supplies had to be delivered from the more established East Coast cities. The existence of San Francisco encouraged the government to provide the subsidies that helped private companies build the rail roads, which in turn built the vast interior of the country.
Likewise, once the Space Station is built -- for whatever reason -- the first large, permanent market will exist for delivering cargo to orbit. This will give companies a reason to invest money in duplicating Orbital Science's feat on a larger scale. It will also mean that they can make a profit in a reasonable period of time, which means more people and organizations may be willing to invest their money.
Then, and only then, will the rail road to orbit truly be open. Once you are in orbit, it is easy to get to the moon: the existing Single-Engine Centaur will do nicely.
A long time ago, says NASA's Mendell, "I figured that political support for the space program is inflexible, limited, and highly changeable -- undependable. The only things I could think of that are dependable were either religion or economics. In trying to pursue economics, I came to the conclusion pretty quickly that there was nothing out there so incredibly valuable that you would import it back to Earth. That meant that you need to put together an economic scenario that was essentially contained in space."
The key point is that you do not need to find resources out there to deliver back here. All you need is a sufficiently valuable reason to be out there. While not entirely subscribing to the "San Francisco" model, Mendell agreed that early colonies in the American west provided a need for infrastructure. Unlike what NASA has been trying to do in space, "We did not build rail roads into the mist," says Mendell.
NASA and most of America's largest aerospace companies recently began the Commercial Space Transportation Study. According to Dave Caudle, these companies "are going around and interviewing a number of different industries and asking them, `How cheap would you have to get a launcher before you would start using them?'"
Some of the likely near-term markets for commercial space projects are surprising. "One of my specialties in this study is space burial, putting ashes in space," says Caudle. "And there's a market for that, believe it or not." Others believe that tourism will be the second big industry in space after comsats. Today, tourism is the world's largest industry and is hugely profitable; it is an industry with imagination and a lot of money to spend. The price of sending an astronaut to orbit would only have to come down by a factor of ten or so to be competitive with today's cruise ship tours of Antarctica. That kind of cost reduction should be well within reach.
Maybe the next person on the moon will be you, or me.