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Crew Dragon Docks with ISS

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Re: Crew Dragon Docks with ISS

#111

Post by avmich »

raverbashing wrote: post #86
calaphos wrote: post #75

Earlier quoted context omitted.

Turns out it is a lot more useful to (potentially) reuse the first stage than to carry a lot of additional weight to reuse the last stage.

Well, but the Shuttle SRBs were reusable. The only non-reusable part was the external fuel tank. But yeah, sending something as big as a bus up and down was probably the bane of it.

> Well, but the Shuttle SRBs were reusable.

But to use them again a lot of efforts had to be spent, comparing to what's possible with first stages of F9. That's why Shuttle boosters are called refurbishable.

Re: Crew Dragon Docks with ISS

#112

Post by justinator »

tnli wrote: post #29
godzillabrennus wrote: post #16

Earlier quoted context omitted.

Elon Musk will have cities on planets names after him for generations to come. The legacy he leaves will be greater than that of Ghengis Kahn, Ceasar, or Alexander the Great.

Elonville, Musktown?

X Æ A-12-ville

Re: Crew Dragon Docks with ISS

#113

Post by jeffdavis »

toshk wrote: post #109
bane wrote: post #15

SpaceX runs basically as a giant R&D program that also happens to accomplish useful things as byproducts of its approach (with the miracle of insurance to cover costs if things get explody). Every flight is data for incremental improvement. If you think of all SpaceX has ever done was try to get to this point, with somewhere around 80 flights on the Falcon 9, but for a variety of mission buyers (NASA, USAF, Commercia…

Incredible. Also Tesla seems to be extremely focused on r&d. How does Elon Musk push and run his organisations so differently that he seems to be one of the only few, if not only one, capable of running big organisations that are able to accomplish this extreme level of innovation paired with tangible results?

You only do new things if you believe you will fail if you don't.

Established companies have an expectation of success if they just keep doing what they are doing, so anything new is an unacceptable risk.

Re: Crew Dragon Docks with ISS

#114

Post by pfdietz »

7thaccount wrote: post #22
bane wrote: post #15

SpaceX runs basically as a giant R&D program that also happens to accomplish useful things as byproducts of its approach (with the miracle of insurance to cover costs if things get explody). Every flight is data for incremental improvement. If you think of all SpaceX has ever done was try to get to this point, with somewhere around 80 flights on the Falcon 9, but for a variety of mission buyers (NASA, USAF, Commercia…

Incredibly impressive, but you have to take into account both more modern technology, as well as the fact that they were able to build off the shoulders of giants. It is still amazing of course, but I doubt they could've done the same thing during the era of the mercury program, so not really apples to apples comparison.

Guidance systems are vastly less expensive now, and can take advantage of things like MEMs, fiber laser gyros, and GPS (and, of course, modern computing power).

The tanks on Falcon are welded using Friction Stir Welding, which was invented in the early 1990s.

The landing algorithm for the first stage uses convex optimization algorithms based on interior point methods, which were not available in the 1960s.

However, something very much like an expendable F9 could probably have been built in the 1980s. Simply evolving the Saturn 1B (which was cheaper, per lb of payload to orbit, than the Saturn V) could have easily beaten the Shuttle's economic performance.

Re: Crew Dragon Docks with ISS

#115

Post by arrrg »

hinkley wrote: post #36

I recall Elon was hoping to get an order of magnitude reduction in cost per launch, but Wikipedia claims it costs $160 million per launch versus the Soyuz price of $76 million per astronaut. That would “only” be a 3x reduction with a crew of seven, but they’ve configured for a crew of four, which is a hair under 2x. I wonder how reuse affects the math, and what they’ll be able to do to lower those prices further. Obv…

I think you might be confusing price and cost.

What NASA pays doesn’t necessarily reflect the cost since we do not know the margins.

However, I do agree that it’s valuable to be skeptical of unproven claims regarding cost reduction, though most of what we say is that we do not know much about the current real cost.

Re: Crew Dragon Docks with ISS

#117

Post by dnautics »

VLM wrote: post #89
bane wrote: post #30

Earlier quoted context omitted.

Sure, there are likely many small advantages that add up. For example, 3 flat panels and a few buttons probably weigh less than a metal panel full of dials, allowing for a better payload ratio. That technology wasn't available during the Mercury/Gemini/Shuttle period for any price.

sensors and wiring always weighed more. Of course now the wiring COULD be CANbus or similar in concept instead of individual (heavy) wires. Or move the analog processing and microcontroller to the sensor itself instead of running wires all over the place to a central computer.

Iirc the computers are connected by commodity cat 6e Ethernet.

Re: Crew Dragon Docks with ISS

#119

Post by toshk »

jeffdavis wrote: post #113
toshk wrote: post #109

Earlier quoted context omitted.

Incredible. Also Tesla seems to be extremely focused on r&d. How does Elon Musk push and run his organisations so differently that he seems to be one of the only few, if not only one, capable of running big organisations that are able to accomplish this extreme level of innovation paired with tangible results?

You only do new things if you believe you will fail if you don't. Established companies have an expectation of success if they just keep doing what they are doing, so anything new is an unacceptable risk.

At the same time "startups" are also not able to reach any of the tangible results musk is producing.

He seems to be able to benefit from the resources of a big company, while at the same time keep the fresh mindset of a relatively small company.

Re: Crew Dragon Docks with ISS

#120

Post by tomp »

toshk wrote: post #109
bane wrote: post #15

SpaceX runs basically as a giant R&D program that also happens to accomplish useful things as byproducts of its approach (with the miracle of insurance to cover costs if things get explody). Every flight is data for incremental improvement. If you think of all SpaceX has ever done was try to get to this point, with somewhere around 80 flights on the Falcon 9, but for a variety of mission buyers (NASA, USAF, Commercia…

Incredible. Also Tesla seems to be extremely focused on r&d. How does Elon Musk push and run his organisations so differently that he seems to be one of the only few, if not only one, capable of running big organisations that are able to accomplish this extreme level of innovation paired with tangible results?

My extremely naive interpretation: he’s at a sweet spot crossroads of a few favourable features:

- he’s technical enough so that he actually understands what he’s doing (unlike a “non-technical cofounder”)

- working on actually inspiring projects (unlike “let’s sell ads” Google, “let’s make rich people richer” finance, “no innovation” Boeing or “Instagram for dogs” bullshit startups)

- he’s rich enough to be able to start his own company with extremely capable people, with less need to please the investors (at least in the short term)

- he’s actually driven, not just money/power-hungry like 99% of billionaires who use their wealth to buy goodwill/influence/art.

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