Things to Do Before Space Flight: An Astronaut's Checklist

Space flight. Its been more than 40 years since the Apollo 11 mission, where humans successfully landed on the moon--and made it back to tell the tale. And a small capsule got the 350,000 miles from here to our satellite with the equivalent computing power of a graphic calculator (link). Think about building a metal tin can, placing yourself inside it, blasting off from the top of a rocket, and then calculating how to get to the moon and back with only a TI-83 from Algebra class to guide you. The Apollo missions are one of the best examples of human ingenuity and drive.

And yet, that drive is gone, now. We stopped visiting the moon in 1972, and the space program today is essentially crippled--the grand International Space Station is planned on being retired in a decade or less (link). The Space Shuttle is going to be retired, and with it technology has essentially stagnated--we're back to shooting rockets up with capsules, the same as we were more than 20 years ago.

Some of this is economical. Some is social--we don't have to beat the Russians in the Space Race, so why bother? But either way it is worrisome. Old astronauts and scientists have continual exhorted people to turn their eyes skyward and bring the space program up to full strength again. But so far, support hasn't materialized.

With the current trend, even if we don't have a World War impeding our progress in the future it's doubtful that the universe depicted in Star Trek will come to fruition; we'd have to develop faster-than-light travel by 2063 in order to keep up. But in that vein, let's examine the three biggest problems concerning the expansion of spaceflight into the realm of the science fiction that many of us watch.

*Faster than light travel. Einstein's special theory of relativity basically rules this out; in order for most matter to reach light speed, it would take an infinite amount of energy (link). This is certainly a hurdle in our progress towards warp speed and hyperdrives, no? However, it should be pointed out that people thought that Newton's laws of physics were, well, laws until Einstein poked holes in them. Einstein could just as well be wrong. But how would we accomplish light speed?

While many proposed theories haven't found a way to pin down relativity and refute it (rather, just ignoring it), there might be another way. Theoretical physicist Miguel Alcubierre, for instance, has proposed that a device known as the Alcubierre drive could create field around a vessel. The space the vessel occupies would not move; rather, space is warped in front and behind the craft, contracting the space in front while expanding space behind. The problem, however, is that some material is going to be needed to create the space-time distortions, like the dilithium crystals of Star Trek, and so far, we don't have it (link).

There's another issue here as well. Supposing we are able to exceed the speed of light by whatever method, for such a method of travel to be feasible for space exploration we'd need to go faster than light. A lot faster. There are 33 solar systems within 12.5 light years of us (link). But remember, that's light-years. Ships making this trip would have to sustain their crew and equipment for years or even decades. Even the closest system, Alpha Centauri, is roughly 4.4 light years away. Thus, some sort of cryonic preservation such as seen in science fiction would be necessary for long-term deep space exploration (assuming we wanted the astronauts to survive!) This is why the ships in Star Trek are traveling at warp factors of 2, 3, 4, and so on. For us to follow in their footsteps, we'd have to do similar.

*Deflectors. As the destruction of the Space Shuttle Columbia shows, even small debris can be dangerous to spacecraft. Now take that piece of foam insulation and speed it up to orbital velocity, (up to 8400 kmph in low Earth orbit), and you have a recipe for disaster. Look at it this way. Say there's a small meteor weighing one-fourth of a kilogram (roughly 8 ounces). If that's zooming towards you at 2.33 kilometers per second (the equivalent to the low Earth orbit just mentioned), that meteor has the kinetic energy of about 1,357,000 joules. But a .25 kg meteor is huge compared to micrometeors, which as their name suggests are tiny. But a meteor just .0003 grams in mass can punch a hole .5 cm in size going at 20km per second, an average velocity (link). Even such a small hole is enough to cripple spaceships of today, and there's a frighteningly high probability that you're going to get hit. The Hubble has to be constantly repaired due to such impacts.

But a bunch of joules doesn't mean that much. Let's scale this up, beyond tiny meteors. The fictional Starship Enterprise weighs 172,368,000 kg. Assuming it hits something going at just half light speed (299,792,458 m/s) the kinetic energy produced is 1.93 X 10²⁴ joules. Put to a recognizable comparison, when the Starship Enterprise hits something going that speed, the energy produced is more than 900,000 times the energy produced by all the nuclear weapons detonated on Earth.

But meteors, big and small, are only one issue. Another is radiation and harmful particle bombardment--in space, to the tune of 5000 protons per second. Since humans have only sublight engines, the time astronauts would be exposed to harmful particles that cause DNA damage and even death is fairly long (link), and even in deep space exploration with a faster-than-light drive there would still be a significant risk. Shielding in the form of armor is one method of protection, but it's not the best solution. The reason we aren't cooked mutants on Earth is because all those harmful space rays are deflected by Earth's magnetic field, and it's not surprising that scientists are working on replicating that field. The current model is akin the the deflector dishes found on most ships in Star Trek--a field that repels all manner of harmful space junk and particles (link). For interstellar travel, a similar function is a necessity.

*No gravity. A lack of gravity is a bummer. Travel around in space without gravity, and even exercising isn't enough to stop you from atrophying. Because your skeleton doesn't have to support itself, it begins to lose its bone density, and the problems only get worse with time. If an astronaut spent 30 months in space going to Mars and back, the result would be a healthy young male returning as a bed-ridden spinal-cord patient with bone density to match (link). Drinking milk and running won't be enough to turn that around, and neither will current drugs.

The solution requires artificial or induced gravity. Many are familiar with the 2001: A Space Odyssey-style rotation solution, in which a rotating spacecraft produces the feeling of gravity in its inner hull. But that means we'd be running around with disc or cylindrical-shaped craft; hardly the sleek ships of Star Trek and Star Wars, let alone most sci-fi. Magnetism can produce a similar gravitational effect, but the danger to humans in such a powerful magnetic field are unclear. Attempts at producing artificial gravity have met with little corroborated success so far; associates of the European Space Agency said they produced a successful method of producing artificial gravity, but only to the tune of 1/1,000,000th of a g (link). We're still far away from the "gravity nets" embedded in the floors or similar of futuristic craft.

These are just three concerns that will have to be addressed. But assuming that artificial gravity generators, deflector dishes and warp drives become a reality, each will probably require some significant energy to run. Right now, there's no sort of power source that would be capable of such an output. So while our interstellar space travel plans are put on hold, there's no reason not to keep exploring and learning about the tiny portion of our solar system we can visit. In the mean time, sci-fi writers will keep us exploring strange new worlds and seeking out new life in the boundless depths of our imaginations.