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Comment by jefftk | Hacker News Reader

> There will never be a "cheap" version of a commercial rocket with an accepted less-than-perfect failure rate. Spaceflight is an all-or-nothing game.

Why? If you're launching people I see why you want near-perfect, but if you're launching something with a low replacement cost (ex: getting fuel to orbit to support other projects) it seems to me that as volumes get large enough eventually "use lower quality and accept a slightly higher probability of failure" starts to be cost effective.

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Because there is no way of building a cheaper rocket with a less reliability. Take aircraft. Does anyone deliberately build cargo aircraft with less reliability than passenger aircraft? Does anyone build a smaller airliner with less reliability than the big airliners because fewer lives are at risk in the smaller aircraft? No. All aircraft are designed and built to amazingly high standards because, in such as complex high-energy environment, there is no money to be saved by building less-than-perfect machines.

I'm with you on spaceflight but people definitely have built small cargo carrying UAVs to a lower standard than passenger aircraft. Such a thing is conceivable anyway.

Ya but smaller UAVs aren't operating in the same energy environment. They are small enough that them randomly dropping on people's houses doesn't matter much. Aerospace is about things large/fast/high enough that all failures put lives at risk.

Okay, so you're not saying it has to be expensive, but almost the opposite? Perfect and slapdash have similar production cost, so properly designed rockets will all be just about perfect?

Most cargo planes are expected to run out of civilian airports where a failure could result in debris launching themselves into populated vehicles or buildings. In contrast a crop duster launching off a dirt runway and expected to go no more faster than highway speeds actually can be built fairly loose, and often are. For example, this duster here [1] won a award in the 70s for innovations like a "pressurized cockpit" and "air conditioning".

[1]https://en.m.wikipedia.org/wiki/Grumman_Ag_Cat

Listen, we don’t need to speculate. Read the History of Falcon9 development.

Your comments in this thread all go against the development approach of that rocket— Falcon9 is a stable platform now as it is used in production. In the development phase there were tons of explosions. This all happened in the past.

This is simply not true. Rockets require significant additional testing to become human flight rated, even if they are already cargo rated.

Is unarguably cheaper to forgo the additional testing and cost required for human flight.

No. All aircraft are designed and built to amazingly high standards because, in such as complex high-energy environment, there is no money to be saved by building less-than-perfect machines.

But this is totally false. There are entirely different standards applied if you want to design an aircraft for commercial airline passenger transport vs for general aviation. There are entirely different requirements for instrumentation reliability if you're building a day-VFR aircraft vs one that is allowed to fly in instrument conditions. And there are entirely different requirements for aircraft that you sell to the public vs ones that you build yourself.

The aviation side is full of examples of exactly the sliding scale you're saying doesn't exist.

> there is no way of building a cheaper rocket with a less reliability

Of course there is. The famous example is radiation hardening. SpaceX opted for redundancy instead. Not only cheaper, but more modern, too.

> in such as complex high-energy environment, there is no money to be saved by building less-than-perfect machines

SpaceX has launched zero humans. (EDIT: Totally wrong!) It aims to, so target reliability is high. (I would argue their track record in production is a product of their willingness to push the envelope in tests.) But there is a large market for cheap, if unreliable, launches. Because there is an emerging market of cheap satellite makers.

SpaceX has launched 9 crew missions with around 30 or so humans.

It is the only US entity with the capability to do so.

> SpaceX has launched 9 crew missions with around 30 or so humans

Sorry, had a brain fart, no idea how I typed that out.

Low quality rocket full of fuel? I don't think anyone wants it on their launch pad.

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