Like many youngsters during the heady space race days, I built model rockets. One such pride and joy that emerged from my converted garage, at that time full of half built miniature aircraft, poorly soldered electronics, and polystyrene dioramas, was a high altitude beauty sitting atop three stages of the largest, longest burning Estes "D" engine available at the time. I lugged the rocket and apparatus out to a deserted Texas pasture for its maiden flight, hooked it up to a crusty old battery, and dramatically counted down. Let’s just say, it worked! In a flash it leapt skyward, straight as a laser, and a few seconds later the now tiny speck pierced the sagging white belly of a morning cloud never to be seen again.
But even at that tender preteen age I knew it had eventually fallen back to earth, somewhere, because every young space race kid knew the magic number: 7.7 miles per second or almost 28,000 mph, the escape velocity of planet earth. My rocket was fast, but nowhere near that fast. To impart that kind of velocity, plus put people and tons of machine into orbit, takes something like one of those beautiful babies on the left.
Of course, there’s more than just the one magic number, every planet, star, or galaxy has one too. Besides, here on earth there are several velocities corresponding to how far off the earth one wants to get. And, while they’re all blistering fast, the difference between them is measured in thousands of miles per hour, tons of propellant, and billions of dollars in booster rocket. The most famous booster rocket of all time, the mighty Saturn V, could loft over a quarter million pounds to Low Earth Orbit (LEO), but barely 100,000 pounds all the way to the moon (Trans Lunar Injection or TLI). To understand the headaches the next NASA Director will face, you have to understand the significant differences in LEO and TLI, and the primary elements in NASA’s proposed moon to Mars concept, collectively referred to as Project Constellation.
The most challenging, or perhaps worrisome, component in Constellation is the Ares rocket. It comes in two flavors, Ares I and Ares V (Ares 1 is well underway and looks entirely doable). Ares V, years away at the current rate of progress, is a big bad rocket, bigger than the Sat V. It's intended to put an unmanned Earth Departure Stage (EDS), consisting of a lunar lander (LEM), a TLI rocket motor, and fuel, into LEO. Ares I then transports the crewed Orion Command Module to LEO where they dock with the EDS, and fire up the TLI rocket for the moon (Or, maybe someday, beyond). From there events follow the Apollo sequence. The fragile combo rockets out to TLI and then 'falls' into low lunar orbit. The LEM separates, slows, lands on the lunar service, then returns to the command module. The crew ride home on the remaining rocket to a fiery reentry and parachute assisted touchdown. Just to get a hint of the grand magnitude of accomplishment we're talking about, tell me it wouldn't blow your mind -- and make you just a teensy bit proud -- if NASA pulled this off:
All well and good, right? Well, not so fast. There are a number of interlocking conflicts over Constellation that we’ll explore in later posts. They'll center on development time, cost, design viability and survivability, alternatives, and taxpayer benefit. But briefly, on viability and developmental concerns, it's worth bearing in mind that Apollo did not come out of a box, safe and ready to fly. Two years before the first Apollo flight, the massive Sat V engines were blowing up in ground tests. And I drive down a street everyday named posthumously after one of three astronauts that were incinerated inside a faulty Apollo command capsule that was sitting on earth a scant few feet away from rescue.
On the rest, suffice it to say for now that if NASA is to pursue deep manned spaceflight, still put up and maintain the dazzling interplanetary orbiters and rovers we’ve almost come to take for granted, get every last possible flight out of the space shuttle, maintain the ISS, and on top of all that design, build, and test a new generation of the most advanced, powerful rockets ever flown, they’re underfunded (And that’s saying it mildly). Just for comparison: we spent enough on the AIG bailout alone to fund NASA’s entire budget for almost a decade. Anyone think AIG is going to produce ten times the value of NASA?
Long before Constellation was a gleam in anyone’s eye, hemmed in by budgetary reality and vacillating Presidents, the eternal, classic debate between manned and unmanned missions was well underway. Proponents of unmanned missions point out, correctly, those robotic probes are way faster, and obviously safer, to build and fly. Plus they return more hard science. Exhibit A: Voyager I and II, the Hubble Space Telescope, the Martian Rovers, plus a bunch more, all for the price of a single return to the moon mission. On top of that, with Moore’s Law on their side, using the economies of scale and implementing existing advances in interplanetary plasma propulsion, future unmanned missions could soon offer an almost irresistible bang for the buck.
Manned enthusiasts might respond that 1) Super heavy boosters like Ares V can launch a lot more than manned missions. Imagine a 10 to 14 meter space telescope millions of miles away from earth's glare (20 to 30 times better resolution than Hubble) able to resolve everything from exosolar planets to hypothetical, large scale ET construction projects; 2) Humans can do things machines can’t do; 3) Necessity is the mother of invention – the spinoffs from past manned space projects include everything from the device you are reading this on, to materials and designs found throughout your neighborhood and workplace.
For the more pragmatic among us, those who raise the perfectly fair question of value, consider this: the rapidity and scope of technical advance and subsequent commercial and national security applications that manned and unmanned space flight has already given us, have been purchased at ghastly cost and enormous risk under only one other national program: World War II.
And there's something more, something as intuitive as it is difficult to articulate: there is an inspirational aspect of human exploration that speaks to a powerful, ancient portion of our psyche, the portion that carried anatomically modern humans out of East Africa and around the world over thousands of generations. It propelled Columbus and Magellan to risk their lives on the uncharted ocean, Amundsen and Hillary to the coldest, most inhospitable places on earth, Barton and Beebe to the depths of a completely unsuspected, alien biosphere lurking quietly beneath our ocean. We are a species deeply wired to roam.
We do not have "Higgs Drives," magnetic catapults, or space elevators. We're probably not going to have them anytime soon. The only way available, now and for the foreseeable future, to punch through the viscous atmosphere, break past the magic number, and wallow out of the slippery gravity well of our rocky home planet is the same kind of miniature contraption I started this essay with: chemical rocket. Ergo, in the near future, with and only with the aid of a heavy lift chemical rocket, will it be possible to assemble the first manned interplanetary spacecraft in LEO (Or gigantic computer operated asteroid/comet steering nuke if you prefer the dramatic), fire it up, and head off to a distant world and into the pages of history.
As long as we’re all collectively stuck here on a shrinking, crowded earth, I’d just as soon forgo the World War III option. Let's instead devote a modestly greater fraction of our considerable resources on the peaceful manned and unmanned exploration and footfall on the shores of a frontier so vast, so demanding, and so inspiring, it will keep our species, and far flung descendants, plenty busy with new conquests and new challenges until the stars themselves burn out.