Javascript bytecode

ixid nuaccount at gmail.com
Wed Dec 19 15:57:25 PST 2012


On Wednesday, 19 December 2012 at 21:00:20 UTC, Walter Bright 
wrote:
> On 12/19/2012 2:05 AM, eles wrote:
>>> Consider the US space shuttle design. It's probably the most 
>>> wrong-headed
>>> engineering design ever, and it persisted because too many 
>>> billions of dollars
>>> and careers were invested into it. Nobody could admit that it 
>>> was an extremely
>>> inefficient and rather crazy design.
>>
>> Hey, this is really OT, but I'm interested in. Why do you 
>> consider it is such a
>> bad design? Because the shuttle is intended to be reentrant 
>> and this is costly?
>> Some other issue?
>>
>> Is about the design or about the entire idea?
>
> It boils down to the overriding expense in spaceflight is 
> weight. There's the notion of "payload", which is the weight of 
> whatever does something useful in space - the whole point of 
> the mission.
>
> Every bit of weight adds a great deal of more weight in terms 
> of cost to push it all into orbit.
>
> To make the shuttle return and land, you've got wings, rudder, 
> landing gear, flight control system, basically a huge amount of 
> weight devoted to that. That weight subtracts from what you can 
> push up as payload. All of the lifting capability for that also 
> must be insanely reliable.
>
> (And never mind needing things like a custom 747 to transport 
> it around because it's too big to go on the roads, all that 
> money spent trying to make a reusable heat shield, etc.)
>
> Now consider the only thing that actually has to return are the 
> astronauts. And all they actually need to return is a 
> heatshield and a parachute - i.e. an Apollo capsule.
>
> Thinking about it from basic principles, you need:
>
> 1. astronauts
> 2. payload
> 3. a way to get the astronauts back
>
> So the idea then is to have two launches.
>
> 1. an insanely reliable rocket to push the astronauts up, and 
> nothing else
> 2. a less reliable (and hence cheap) heavy lift rocket to push 
> the payload up
>
> The two launches dock in space, astronauts do their job, 
> astronauts return via their Apollo-style capsule.
>
> Mission accomplished at far, far less cost.

The shuttle was originally intended to be a lot smaller and sit 
atop the central booster, avoiding the issues that caused the 
Columbia disaster. I believe that design may have been intended 
to operate in the manner you suggest, however the CIA demanded 
that the shuttle be made much larger to accommodate large 
military satellites, distorting the design and making it a lot 
less efficient.


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