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I'm glad and sad that that's over

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No computers; high technology of a different sort today.

Shuttle Atlantis has safely returned to earth for the last time; the Space Shuttle Program is over. Which both makes me sad, and makes me breathe a huge sigh of relief. Thank goodness that is finally over.

As you might have gathered, I am highly ambivalent about the Shuttle Program. It is unique in that it just might be the biggest engineering success and the biggest engineering failure of all time, at the same time. What a contradiction!

On the success side: the Shuttle is by any measure a stunning human achievement and everyone who worked on designing, building, maintaining and flying Enterprise, Columbia, Challenger, Discovery, Atlantis and Endeavour has every right to be proud. I mean, we're talking about  a vehicle that:

  • takes off as a rocket, flies as a spaceship and lands as an airplane.
  • has an main engine (those cones on the back of the orbiter) with the highest power-to-weight ratio of any engine, period. Imagine if every pound of your car's engine produced a hundred horsepower!
  • achieves temperatures inside the engine that would not just melt, but actually boil iron.
  • orbits the entire planet in about 90 minutes.

and so on. It is an astonishing vehicle and one of the great achievements of our civilization.

But all that said, as much as it is an amazing engineering success, the Shuttle Program failed to achieve almost all of the important goals originally envisioned. Those goals included:

  • Frequent launches. The original vision was for weekly launches, then that was decreased to twice a month, then once a month. In practice, the average launch rate over the last 30 years was over three months between launches: between a third and a tenth of the originally envisioned launch rate. The launch rate is an order of magnitude lower than envisioned.

  • A cheaply reusable launch vehicle. Reusable? Absolutely, but the whole point of "reusable" was to lower its cost. In practice, the costs of inspecting the tiles, overhauling the engines, and so on mean that launching the Shuttle is actually more expensive than just building a new throwaway rocket. When you consider just the per-launch costs, it cost about $18000 per kilogram to get an object into orbit with the Shuttle. When you consider the total cost of the 30+ year program divided by the number of kilograms it has put in orbit, it was a whopping $60000 per kilogram. The program goal was to achieve costs of $1400 per kilogram in 2011 dollars; the Shuttle cost is orders of magnitude higher than envisioned. (*)

  • A reliable vehicle. I clearly remember that day in eighth grade, heading back to my locker to get my lunch when a girl in my home room class named Christine said in passing "Hey Eric, the Space Shuttle just exploded." I thought she was making an unfunny joke, and was horrified to learn moments later that no, she was absolutely right.

    During the enquiry that followed the Challenger disaster, Richard Feynman estimated that the failure rate would be about 1%, and he was spot on: 135 missions, two total-loss-of-vehicle disasters. Yes, space travel is inherently dangerous, but a ~1% chance of total loss of vehicle and crew is absolutely unacceptable. The safety of the Shuttle is orders of magnitude less than envisioned. (**)

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Ultimately the only truly failed experiment is the one you learned nothing from; we have learned a tremendous amount from the Shuttle Program in both its successes and its failures, and so it was a successful experiment. It is my fervent wish that this knowledge not be lost. I believe that it is within our reach as a species to explore space; it's a big universe waiting out there and we can and should go see what's out there, both in person and with awesome robots.

I am genuinely awed by the engineering achievement that was the Shuttle Program. What's even more amazing than that is: we can and will do better, at lower cost and with greater reliability.

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I'm heading off to Europe for a week to attend a wedding, and then spending a couple of weeks with my family and friends in Ontario. Unlike some previous years I haven't prepared automated postings for my absence, so the blog is going to go dark for a month or so. I hope you all have a pleasant August and we'll pick up with more fabulous adventures in late August or early September.

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(*) Another unfortunate aspect of the Shuttle Program's massive cost is that money has been spent on the Shuttle Program getting people into low earth orbit that could have been spent on getting more awesome robots to other planets. I love having awesome robots on other planets. The scientific knowledge gained per dollar spent is way higher for robots on other planets than for humans in low earth orbit.

(**) The fundamental problem here is not so much technical as it is cultural. NASA management seems to have the curious and obviously false belief that the fact you didn't fall off a cliff yesterday is proof that it is safe to walk even closer to the edge tomorrow, even if you're not precisely clear on where the edge is. That is actually an algorithm for ensuring that you always walk off a cliff. The truly awful thing is that they walked off the same cliff in the same way twice.

Comments

  • Anonymous
    July 21, 2011
    Great post. I feel mostly the same way. I saw the Challenger disaster in person although I was in ninth grade at the time. The only thing I would add is that although robotic exploration is indeed awesome. Those who would completely eschew human exploration in the name of reduced cost or safety are missing the big picture. It is about more than exploration, although that is great. It is about the long term survival of our species which can not happen without the very specialized knowledge gained exclusively by complicated, expensive, and risky human missions to space.

  • Anonymous
    July 21, 2011
    I eat each of your posts with my eyes as soon as they see light, and this is particularly true for those like this one: not strictly about computers and where you let your personal opinion out. Have a nice trip and I'll be waiting for more fabulous adventures. P.S: How many weddings this year??? hahaha

  • Anonymous
    July 21, 2011
    My wife, a Canadian, believes that Americans live by the motto, "why do it when you can over-do it?"  This may be very true when it comes to the shuttle program.  Nonetheless, I am always awestruck by these magnificent vehicles and am amazed at what we can accomplish.

  • Anonymous
    July 21, 2011
    It's weird tho, 40 years after the wright brothers we went to the moon. 40 years after the moon we're scrapping the space shuttle without a replacement. Guess this one says it all: http://xkcd.com/893/

  • Anonymous
    July 21, 2011
    It's a astonishing engineering effort. And it must continue. The shuttles must be improved. These problems must and can be worked out. There are enough materials to create shuttles, there is time to research cheaper new fuels and safety measures and backup plans, there are very smart people who can do that. But wait... there is no money. I am pretty sure there is something terribly wrong with this.

  • Anonymous
    July 21, 2011
    The comment has been removed

  • Anonymous
    July 24, 2011
    The comment has been removed

  • Anonymous
    August 01, 2011
    "I love having awesome robots on other planets." That's fine and all, but I want people mining the asteroid belt.  Heck, I want to be one of them.  Robots aren't going to do much toward that goal. I want robots mining the asteroid belt: robots that use the metal to build copies of themselves! And then after there are a few trillion of them they can rocket themselves back to earth orbit and melt themselves down, and hey, now we've got huge piles of rebar right there orbiting the earth to build spaceships out of. That would be awesome. -- Eric

  • Anonymous
    August 07, 2011
    The comment has been removed

  • Anonymous
    August 09, 2011
    To paraphrase: On the upside, the shuttle is a hugely sophisticated, complex piece of equipment and getting it into orbit time after time is a huge achievement. On the downside, the shuttle is a hugely sophisticated, complex piece of equipment and getting it into orbit time after time is a huge achievement.

  • Anonymous
    August 11, 2011
    One interesting comparison I heard from a NASA engineer is that the Shuttle was a harder problem to solve than getting people to the Moon and back. The public relations angle of space flight seems to be the trickiest problem of all. The Apollo challenge seemed impossible in 1961. But after two moon landings, the TV viewers were bored! The incredible become commonplace. And then a generation later a scary number of people think the whole thing was impossible and didn't happen, so reversing back again. It seems difficult to achieve the desired point in the middle where people understand how hard it is, and are thus impressed that it was achieved. It reminds me very much of Houdini's advice about escaping from a steel constraint and a straitjacket inside a bag - if you know what you're doing it takes about two seconds to free yourself. So you need to stay in the bag and wriggle around for another 28 seconds, or else people aren't going to be impressed when you climb out.

  • Anonymous
    August 11, 2011
    "the fact you didn't fall off a cliff yesterday is proof that it is safe to walk even closer to the edge tomorrow, even if you're not precisely clear on where the edge is" <-- bravo!