Saturday, July 30, 2011

Kerbal Space Program: Rocket (Explosion) Science!

When I was young, I thought the shuttle was the future. It was reusable, you see, and glided back to Earth after a successful mission - not like those blast-apart rockets they showed in old movies and TV shows, which weren't new and thus weren't as good. Today, we're on the cusp of another Rocket Age. With the Space Shuttles at rest after thirty years of flight, the business of boosting crap from Earth into space is once again purely the domain of the rocket. The towering stacks of boosters and fuel that flung men to the moon forty years ago are once again the kings of the spaceways. What better time than this to not only celebrate the new ascendancy of the rocket, but gain a more personal appreciation of what it means to get one of those beasts to lumber off the pad?

Or, alternatively, to find dark humor in how those beasts lumber off the pad, immediately start swooping and diving with all the majesty a drunken eagle while the hapless crew screams in terror and you fight to keep control, only for it to punch a new crater into the land seventeen seconds later?

Kerbal Space Program has that.

Under development by Squad Games of Mexico City, Kerbal Space Program is a free-to-download game centered around the establishment and management of an entire space program so that the small, green, cylinder-headed Kerbals can "fulfill their ultimate mission of conquering space." Right now the game is in a bare-bones alpha stage, and presently functions as a wide-open sandbox focused on the construction and launch of spacecraft out of a variety of parts - some included with the basic game, others created by members of the community and made available for download. There are no challenges yet except what you make for yourself; perhaps you start with building a rocket that doesn't immediately explode when the motors start running, and go up from there.

That's not to say it's necessarily easy, though. There is a steep learning curve here, and it's definitely not for everyone. Kerbal Space Program does not pull its punches as far as physics is concerned, to the extent that the center of mass for your rocket will change as its fuel is expended. It hasn't been described as a "Von Braun blooper reel" for nothing. My current bugbear is making it into orbit of Kearth, a rather salubrious world about an order of magnitude smaller than Earth and home of the Kerbals. Once you've got a fair grasp on how to build non-explosive rockets, it's fairly straightforward to build one capable of reaching orbit; actually reaching orbit is something else again. There's a very good reason that NASA uses computers. Even if you do make it into some kind of orbit, it's easy to be left with too little fuel to execute a deorbit burn and return to the surface - leaving those poor Kerbals stranded up there, until the seals on the command pod start to break.

Which is, incidentally, not that hard to imagine. Kerbal Space Program is based around the idea of a rickety, ramshackle space program on the cheap, where you build rockets out of parts found lying by the side of the road or built in a junkyard. It actually reminds me of The Wings of Honneamise in some respects - a shining representation of that belief that we can get anything we want if we want it badly enough.

Planet Kearth is blue, and there's nothing I can do...

Kerbal Space Program is one of those rare games that, just by playing it, you can't help but learn something. You learn about how rockets are staged, how solid-fuel rockets compare to liquid-fuel ones, what it means to enter into an orbit, how to steer a craft tumbling in three dimensions. I think it's got great promise as an educational game in its own right - twelve-year-olds would love it.

Aside from the fierce learning curve, which is more than understandable for a game that approaches rocketry in a rigorous way, I can't think of any complaints I have about Kerbal Space Program that aren't a result of the extremely early state the game is in. Sure, it's difficult to get into orbit when you have look up velocity and altitude tables to figure out whether or not it's a stable one, but I have confidence that some kind of trajectory indicator will be added in a future update. Considering that the game will eventually include missions, space stations, and voyages to other worlds, it's a bit out there to expect players to entirely eyeball their flights into orbit. The finished game will be a pay product, but this original sandbox version will be free forever - and hell, this is a game that I'm eager to buy.

By the way, once you make it into orbit, here's a tip: don't try landing on the night side of the planet. Something's bugged in the game's collision detection there. Your command module will explode upon landing regardless of whether or not you remembered to install and activate the parachute.

My recommendation? Sit back, put on "Space Oddity," "Rocketman," or "Yakety Sax," depending on the tenor of the mission, and help the Kerbals swim in the cosmic ocean. It can be downloaded from the main Kerbal Space Program website here, from its mirror here, or torrented here.

Get this game. GET IT!


  1. Not sure if you are a Neal Stephenson fan (everyone should be)but he wrote a great piece in Slate about why we are so wedded to rockets,

  2. I would take his argument a lot more seriously if he explained what some of those alternative to rockets were - he doesn't seem to. The fact is that rockets are pretty much the most straightforward way to get to orbit. Building a gigantic railgun to literally shoot payloads into orbit isn't exactly economical; plus, the G-forces produced by any latter-day Verne cannon wouldn't exactly be pleasant for a crew.

    Nor, as someone interested in alternate history, do I necessarily buy his thesis that "we would not have been launching rockets into space so soon if not for Hitler." There are a lot of possible reasons to do something. To focus in on just one is historical tunnel vision.

  3. Agreed, but part of the point is we don't know what technology would have beed developed if one type hadn't been given the head-start for other reasons.

    The shuttle itself is an example of building a "Space Plane" that was an abject failure, partially because it was forced to rely on 50 years of research into ballistic rocket technology. Rather like the electric car had little hope in the 1970s because we were so damn good at building internal combustion gasoline engines.

  4. I have always loved model rocketry. Can't say as much for a simulation, sorry just not interested in things that don't catch fire.

    Head down to your local hobby shop, and pick a few 3 packs of Estes 'D-0' model rocket motors, and a few pieces of straight balsa wood (square or round) and make yourself some home-made bottle rockets that in a single stage will reach 2000+feet.

    Then graduate into multi-staging ! Finally begin arming your model rockets with reports, such as a strobe, stars, or a bear-scare !

    And NEVER EVER follow the safety recommendations - Werner Von Braun never did - spoils the fun.

  5. Anon:

    Sounds like fun, but i have one question first: How many fingers do you have?