The Straight Dope - How can I make my own spaceship?

What would it take to make a homemade spaceship?

— Matt B.

Depending on how you define “homemade,” “space” and “ship,” you can get a craft into space, or at least a respectable distance off the ground, for somewhere between $500 and $2.5 billion. I realize that’s not very helpful for budgeting purposes, so let me tell you what you get for your money at the different price points. Rather than begin at one end of the continuum and work my way to the other (my usual practice), I’ll start at the ends and finish in the middle — the better to clarify what you could do, Matt, before explaining why you probably won’t.

First let’s define those terms. By homemade I imagine you mean something you can throw together in your workshop a la the Wright brothers. Where space flight is concerned this seriously limits the possibilities, so let’s include any craft constructed by anyone other than a national government.

Next, what do we mean by space? The commonly accepted threshold is 100 kilometers up, or about 62 miles. That’s the so-called Kármán line, roughly the point at which the air gets so thin that a winged craft would have to exceed orbital velocity to generate enough lift to stay aloft. In the interest of affordability, however, we may want to adopt a more expansive definition. More on this below.

Finally, ship. If we limit ourselves to a capsule with people in it, this is going to be a short column. Instead, we’ll define a ship as a payload — basically anything you can heave aloft.

With that in mind, here’s the menu of spaceship possibilities:

First, orbital human space flight. I throw this in mainly to establish the boundary condition, since it’s never been accomplished by any nongovernment entity, and only three governments — the U.S.S.R., the U.S. and China. It’s not cheap. The space shuttle Endeavour, for example, cost $1.7 billion to build, plus hundreds of millions more per mission.

The private sector offers two cheaper routes into space. One is orbital flight with no people aboard. Space Exploration Technologies Corporation, better known as SpaceX, boasts that it can put a satellite into orbit for $54 million. The other possibility is suborbital human space flight, which so far has been accomplished by one craft: SpaceShipOne, a rocket plane akin to the old X-15, built by aerospace pioneer Burt Rutan and funded by Microsoft co-founder Paul Allen. Cost: $28 million.

Suffering from sticker shock? Let’s jump to the Baltic-and-Mediterranean corner of the board and consider stratospheric flight. OK, the motive power is a weather balloon, not a rocket, and the highest you can get your payload is 20 to 25 miles, well short of space as usually defined. However, the cost is less than $1,000, and the payoff is pretty cool. Last year two amateurs, one from Brooklyn, the other from the U.K., cobbled together ingenious instrument packages on the cheap (the Brooklyn guy used a mini video camera plus an iPhone with a GPS tracking app). The result, easy to find with a little Googling: photos and video showing in haunting detail the curvature of the earth, the thin layer of atmosphere, and beyond it the blackness of space.

Nonetheless you may be thinking: balloons are nice, but I want rockets. Fine. We’ve got one last option: suborbital instrument flight. I spoke with Ky Michaelson, driving force behind the Civilian Space eXploration Team, or CSXT, which he says is the only amateur operation so far to launch a rocket into space. They did it in 2004 using a 21-foot homemade rocket that went 72 miles straight up and then came straight down. Total time for the flight, which was duly witnessed by the Federal Aviation Administration: just more than 14 minutes. Cost, including a couple previous failed attempts: roughly $350,000.

Maybe you could surpass that feat, Matt, but I’m not betting the ranch, for two reasons. First, the 72-year-old Michaelson is one of a vanishing breed of self-taught rocketeers, raised on chemistry sets, hot rods and Sputnik. Today’s whiz kids grow up staring at computer screens, not the stars. Second, the next frontier for amateur rocketry is orbital flight, a steep hill to climb for both technical and regulatory reasons — no way are the authorities letting amateurs shoot flaming bombs over populated areas.

Not to get all heavy on you, but that’s why I’m down on the prospects for space travel in general: It’s too hard. Sure, NASA wants to turn its space transport chores over to private companies, and there’s a decent chance that’ll happen. We’ll have plenty of commercial satellites, the occasional space probe, maybe someday a Mars mission. And there’ll always be bored billionaires willing to bankroll the latest venture into the unknown. But space tourism, popularly priced lunar flybys, that kind of thing ... sorry, I don’t see the business case. Then again, that’s Mr. Practical talking. Mr. Starry-eyed Dreamer says: Prove me wrong.

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