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NASA Space Science

Another Leak Delays Final Discovery Launch 104

vsolepr writes "Today's scheduled launch was scrubbed because of a gaseous hydrogen leak near the spacecraft's external tank. This is the fourth time in the past week that Discovery's launch was delayed due to various leaks and electrical issues. NASA now is aiming for a launch date no earlier than Nov. 30."
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Another Leak Delays Final Discovery Launch

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  • Re:Ugh (Score:4, Informative)

    by trout007 ( 975317 ) on Friday November 05, 2010 @07:14PM (#34143034)
    It's the 2010 External tank that is leaking not the 1970's Orbiter.
  • Re:Ugh (Score:3, Informative)

    by qmaqdk ( 522323 ) on Friday November 05, 2010 @07:21PM (#34143064)
    About $1.3 billion per launch, counting total program cost divided by number of launches. Good news is an extra flight will lower the costs per flight to a bargain $1.288 billion.
  • Re:Ugh (Score:3, Informative)

    by jd ( 1658 ) <> on Friday November 05, 2010 @07:50PM (#34143272) Homepage Journal

    HOTOL might have been more cost-effective. The Russian space shuttle almost certainly would have been. The problem with the space shuttle was that false economies were made. Sometimes to save money you have to spend it. The shuttle was under-sized, under-powered and was forced to have dangerous piecemeal boosters for political reasons. By spending the money up-front, you'd have a cheaper, safer, more reliable shuttle which would doubtless still be in production, not scrapped.

    It'll be interesting to see how first-stage alternatives go. One option is to use turbine-assisted ramjets, another is to use a ski-jump-assisted ramjet. These would replace some, but not all, of the current first rocket stage. The idea is the same in both cases - provided you can break 400 mph, the ramjet is capable of self-sustained acceleration. Break the sound barrier and it becomes a highly efficient device. Hydrogen-powered ramjets are good up to about mach 6. Not great, sure, but not bad either. Since the weight should be about 1/5th that required by a rocket to reach the same speed, that's a lot more payload you can suddenly carry. Ideally, you'd use a mix of a ramjet and a scramjet to completely replace the first rocket stage, again reducing weight and increasing the payload you can push into orbit.

  • Re:Ugh (Score:2, Informative)

    by THE anonymus coward ( 92468 ) on Friday November 05, 2010 @10:06PM (#34144602) Homepage

    At least this time... earlier it was a hydrazine leak.

  • by tftp ( 111690 ) on Saturday November 06, 2010 @12:25AM (#34145240) Homepage

    Frankly, I think the astronauts taking this tank into orbit have to be nuts.

    Right you are. That's why they will not take the tank to the orbit. It separates at T + 8 minutes 50 seconds, which is about 69 miles [].

  • Re:Ugh (Score:3, Informative)

    by Jeremi ( 14640 ) on Saturday November 06, 2010 @12:29AM (#34145260) Homepage

    So, how much is this costing us to duct tape this 1970's clunker back together for 1 last hoo-ra and for what scientific gain?

    Average cost of a Shuttle Launch: $450,000,000.
    Population of the United States: 307,006,550

    Therefore, it's costing us an average of $1.47 per person.

  • Re:Silly assumption (Score:3, Informative)

    by bertok ( 226922 ) on Saturday November 06, 2010 @12:30AM (#34145264)

    That's a very valid point, most people don't realize that there never will be any "magic" improvements in rocketry to bring the cost down to the point that we'll all be taking holidays on Mars. It's still a high-energy problem, and new technology doesn't necessarily make the hard problems much easier.

    The ultimate limit on the cost of getting into orbit is the cost of rocket fuel, which is not a lot. What is needed is reliable, reusable launchers which don't require months of maintenance by thousands of people between flights, and that's perfectly possibly with enough engineering effort... the idea that it will 'never' happen is just silly.

    If there are no people, nothing needs to be reused.

    So we should build single-use container ships and sink them after they've crossed the ocean once?

    Reusability is _the_ biggest cost-saver possible, so long as it doesn't require the massive maintenance that a shuttle does between flights (not to mention the cost and complexity of the external tank and boosters).

    You can't re-use the rocket fuel, and it makes up the bulk of all rockets, by both mass and volume. It is also necessarily much heavier than the payload. (think: rocket equation)

    In contrast, a container ship is mostly metal, with only a small fuel fraction, and a high payload fraction.

    The cost computations wildly are different, by several orders of magnitude.

    None of this will change, ever, with chemical rockets for fundamental reasons. We'd need to invent entirely different propulsion systems (nuclear, fusion, etc...) before we can start designing rockets like container ships!

    Your kind of logic created the shuttle, the least cost effective of all commonly used space launch system in use today.

    Returning to my original point about the shuttle, I did mention that re-using the engines might be worthwhile. They're usually complex pieces of turbomachinery made from high-tech alloys. In contrast, the bulk of most rockets is basically just a tube with some internal struts for strength. Compared to the total cost of a typical launch (including payload), the cost of a metal tube is irrelevant.

  • Re:Silly assumption (Score:3, Informative)

    by strack ( 1051390 ) on Saturday November 06, 2010 @03:12AM (#34145766)
    well actully, the high maintainence costs of the shuttle were due to everything *needing* to be quadruple checked because there wasnt a effective crew escape system, like you had on the saturn rockets. and the engines that were machined to such fine tolerances that they needed to be pretty much pulled apart and inspected for cracks after every mission. and the enormous shuttle heat shield, with tens of thousands of tiles that had to be individually inspected.

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