
Rocket Launches Are Surprisingly Successful - anthelios
http://blogs.scientificamerican.com/life-unbounded/rocket-launches-are-surprisingly-successful/
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Animats
No, they're not. Failures are around 4% - 5%, and they've been around that
since the 1980s.

Chemical fuels are just barely powerful enough to allow reaching Earth orbit.
They can't get any better; they're already as energy dense as chemistry
permits. NASA's "The Tyranny of the Rocket Equation" explains this clearly.[1]
The payload fraction for the Saturn V was about 1%. The Space Shuttle, 4%. A
747 freighter, about 25%.

The fuel fraction for rockets is so high that the structures have to be weight
reduced too much. If you could build a spacecraft with the weight budget of an
airliner, it could potentially be as reliable as an airliner.

With nuclear engines, one could beat those limits. Early plans for Apollo
included a nuclear upper stage. But nuclear is messy.

That's why rocketry hasn't progressed much since the late 1960s.

[1]
[http://www.nasa.gov/mission_pages/station/expeditions/expedi...](http://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html)

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walkingolof
The basic physics may be the same now and in the 60's, but there is allot that
can be done better in the rocket building industry.

Lutz Kayser (of OTRAG [1]) once said that rocketry currently is like
"transporting potatoes in a Rolls-Royce".

Build inexpensive, modular rockets like OTRAG, that can be clustered (and
possible reused) and you may cut at least some cost out of the equation.

[1] [https://en.wikipedia.org/wiki/OTRAG](https://en.wikipedia.org/wiki/OTRAG)

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amelius
I think it is far more surprising that an IC fab can create a chip with
millions of transistors, without even a single defective one.

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gvb
The number of components in rockets and IC transistors are probably roughly
comparable. ICs have the advantage that they are making a huge number of only
a couple of different things (e.g. transistors, resistors, capacitors).
Rockets are composed of a huge number of different things, many of which are
totally unique, which makes them much more challenging to build successfully.

Their failure rates are similar, but IC die failures are much less public.

Ref: [https://www.quora.com/What-is-a-typical-value-for-good-
yield...](https://www.quora.com/What-is-a-typical-value-for-good-yields-in-a-
semiconductor-fabrication-process)

~~~
marcosdumay
> The number of components in rockets and IC transistors are probably roughly
> comparable.

Unless you are counting the payload, I really doubt it.

ICs are only possible because people create some way to mass manufacture those
features, and people don't even design the features by themselves.

If people created them at the traditional route of "manually
design|manufacture this -> encapsulate into component -> use components to
manually design|manufacture that -> encapsulate again...", it would be
impossible to create chips as complex as we have now. But there still aren't
better way to produce rockets.

All the problem with rockets is that they are created by joining a big number
of things that don't really like to stay together (or, in a few cases, don't
like to stay by themselves either). I doubt they have more bare complexity
than a modern car.

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wmkn
What does 'failure' mean in this statistic. Does failure always mean a
catastrophic failure (i.e. the recent SpaceX launch) or are failures also
rockets not leaving the platform?

I would think that a >5% failure rate is surprisingly high for something we
have been doing more than 70 years.

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Heliosmaster
In the last 70 years we've focused a lot on not having failures, spending all
the money it took.

Now, the focus is somewhere else (namely reducing the cost per launch, in
order to get us a lot more to space).

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kiba
Pretty sure that SpaceX is focused on reliability. One of the analogy that
Elon Musk used is comparing a Honda Civic versus a Ferrari, asking which is
more reliable.

Historically, rockets are focused on performance, not cost.

SpaceX's focus on producing cheaper rocket and launching more of them will
yield more reliability. You make more of them, you make more mistakes, more
opportunities to correct them.

Eventually you'll have a system for making very reliable rockets.

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rimantas
there is Honda Civic, never heard of Toyota Civic :)

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kiba
Fixed.

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bogomipz
For anyone interested in seeing an actual rocket launch(in the US), this
article is a really good resource:

[http://www.space.com/32683-see-a-rocket-launch-in-
person.htm...](http://www.space.com/32683-see-a-rocket-launch-in-person.html)

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pyrale
Sounds like a PR article written just in time to rescue spaceX. The way data
was picked (only half a year, many one-off new players) makes it look like 5%
failure rate across the industry is the norm :

[https://en.wikipedia.org/wiki/List_of_Ariane_launches](https://en.wikipedia.org/wiki/List_of_Ariane_launches)

[https://en.wikipedia.org/wiki/List_of_Atlas_launches_%282010...](https://en.wikipedia.org/wiki/List_of_Atlas_launches_%282010%E2%80%9319%29)

Some rockets can claim years or decades of service without losing a single
satellite.

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api
Sure. I do have to point out though that those systems are not innovative.

I personally expect SpaceX to have more failures and am not surprised that
they have. Back when NASA and the USSR were innovating in the 50s they both
blew up a lot of stuff.

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JabavuAdams
Hairless Ape 1: Ok, we're going to strap you into a tin can on top of huge
tanks of stuff that will freeze you, burn you, and maybe give you cancer. Then
we'll light it. Okay?

Hairless Ape 2: Sign me up. Sounds Awesome.

I love/hate you hairless apes. Give 'er!

