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A rocket a day keeps the high costs away (1993)

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Re: A rocket a day keeps the high costs away (1993)

#51

Post by mkl »

flashback2199 wrote: post #14

[flagged]

The article proposes using hydrogen to be carbon-free fuel-wise:

> Environmental Issues. One reason for insisting on LH2/LOX rather than Kerosene/LOX, hypergolics, or solids/hybrids is that it's clean. We could launch one every minute and contribute less to global warming, ozone layer depletion, and other varieties of atmospheric pollution than 747s crossing the Atlantic every day. Also, exhaust and/or fluffy white clouds resulting from the occasional really bad day aren't harmful to anybody who happens to be downwind.

Re: A rocket a day keeps the high costs away (1993)

#52

Post by SCM-Enthusiast »

btilly wrote: post #11
SCM-Enthusiast wrote: post #4

Earlier quoted context omitted.

the novelty is how to handle such scale. Sure, if we build a million rockets it'll be cheaper, but how do we USE those rockets and get funding at "relative peace time". SpaceX's real innovation was starlink in allowing it to "Soak up" excess production. Besides the obvious of reusability, which wasn't that "Obvious" considering the temperatures of reentry.

Actually, reusability was an obvious idea from the start. For example the Space Shuttle and the McDonnell Douglas DC-X are examples of attempts at reusability in the USA, and other countries had their own experiments. It just became non-obvious that it was the right approach after a long history of failed attempts at it.

it was always the "Right approach" and everyone knew that there was nothing in the laws of physics that prohibits this. But you are writing that as if it's still be solved.

No one has ever had a fully reusable orbital rocket.. still to this day. Althought starships got a shot.

Re: A rocket a day keeps the high costs away (1993)

#53

Post by SCM-Enthusiast »

promiseofbeans wrote: post #40
actinium226 wrote: post #6

According to Ashlee Vance's "When The Heavens Went On Sale" this was the inspiration for Astra (the book links to this same article in the relevant chapter). The company hoped to produce and launch >300 rockets a year without re-use. The goal was to get economy of scale in manufacturing. Part of the business plan assumed that people would be using the rocket to launch replacement satellites for constellations, and so…

Isn't Astra developing a reusable launch system now?

they are selling off their assets and focusing on selling engine that could be "Reusable". I won't hold my breath.

Re: A rocket a day keeps the high costs away (1993)

#54

Post by blkhawk »

sitkack wrote: post #46
looofooo wrote: post #35

Earlier quoted context omitted.

What would another James Webb Telescope would have cost? Far far less then the first. Sure it is costly to destroy a prototype, but not as much as you think.

In my ideal universe, we have a JWST assembly line.

...in orbit. Imagine what a device could do you can just take a wrench to if it breaks. and how much cheaper you could build that.

Re: A rocket a day keeps the high costs away (1993)

#55

Post by snewman »

lacksconfidence wrote: post #31
flashback2199 wrote: post #24

Earlier quoted context omitted.

Correct me if I'm wrong but I am under the impression that Starship does not use that, the least expensive fuels for rockets are highly CO2 emitting, and the least expensive fuels are what will get rolled out in mass numbers if SpaceX, Blue Origin, and others succeed in building a rocket transportation industry.

starship uses methalox, a combination of methane and oxygen. I'm far from an expert, but my understanding is the methane comes from refining LNG.

That's generally where methane comes from today, but in time it may come from captured CO₂, e.g. see https://terraformindustries.com/ (disclaimer: I am a minor investor).

Re: A rocket a day keeps the high costs away (1993)

#56

Post by bryanlarsen »

pi-e-sigma wrote: post #50
bryanlarsen wrote: post #41

Earlier quoted context omitted.

Starship has the size to carry about 400 passengers. Both stages together carry about 5,000t of propellant. But over 3/4 of that is liquid oxygen, and most of that is the first stage. The second stage alone with 1200t of propellant can't put humans into orbit, but it does have a range comparable to that of a 787. So 300t of liquid methane will get 400 passengers about as far as a 787 can get 250 passengers with 100t…

It doesn't gain anything back, what are you on. Before landing it has to shed all the speed it gained that was needed for the ballistic trajectory. That energy is lost. Orbital or suborbital flights will never, ever be competitive to flying with regards to required energy expended.

It gains efficiency compared with an airplane by spending most its trajectory outside of atmosphere with no air resistance.

Re: A rocket a day keeps the high costs away (1993)

#57

Post by pi-e-sigma »

bryanlarsen wrote: post #56
pi-e-sigma wrote: post #50

Earlier quoted context omitted.

It doesn't gain anything back, what are you on. Before landing it has to shed all the speed it gained that was needed for the ballistic trajectory. That energy is lost. Orbital or suborbital flights will never, ever be competitive to flying with regards to required energy expended.

It gains efficiency compared with an airplane by spending most its trajectory outside of atmosphere with no air resistance.

No it does not, because thanks to atmosphere wings on an airplane generate lift. And they do it more efficient than any kind of engine known to the mankind

Re: A rocket a day keeps the high costs away (1993)

#58

Post by NortySpock »

mrkstu wrote: post #2

Remarkably prescient. Any public knowledge whether Musk has cited this as an inspiration? This arstechnica article feels like a direct descendent: https://arstechnica.com/space/2024/01/elon-musk-spacex-needs...

The fictional book The Rocket Company, by Patrick J. G. Stiennon and David M. Hoerr, is a basic narrative about creating a space launch services company designed around a two-stage rocket, with both booster and second stage manned by a single pilot each, and able to launch and land fully reusable.

The book has paper-thin characters whose whole purpose is to explain and counter-point a long list of technical explanations for why the company, vehicle, and manufacturing processes were designed the way they were. The book has a copyright date of 2005.

I really enjoyed reading the book.

The book, in the front, has a section called "Blurbs for The Rocket Company", which has some comments left by John Carmack of Armadillo Aerospace, Jeff Foust of The Space Review, Gary C Hudson of HMX, Inc, Eric Laursen of International Launch Services, and Elon Musk.

To quote the blurb directly: "This is an interesting approach to the greatest problem in space exploration: the cost of getting there" -- Elon Musk CEO, Founder Space-X

Re: A rocket a day keeps the high costs away (1993)

#59

Post by bryanlarsen »

pi-e-sigma wrote: post #57
bryanlarsen wrote: post #56

Earlier quoted context omitted.

It gains efficiency compared with an airplane by spending most its trajectory outside of atmosphere with no air resistance.

No it does not, because thanks to atmosphere wings on an airplane generate lift. And they do it more efficient than any kind of engine known to the mankind

Yes, an airplane can climb much more efficiently than a rocket. So on a 300km flight where all it is doing is climbing and descending it's way more efficient than a rocket.

But for a 10,000km flight the airplane expends almost all of its fuel coasting rather than climbing.

Luckily we don't have to rely on assertions. If I'm wrong, there should be an obvious error in my math (which is trivial) or facts (which is on Wikipedia). Please point it out.

Re: A rocket a day keeps the high costs away (1993)

#60

Post by m4rtink »

btilly wrote: post #11
SCM-Enthusiast wrote: post #4

Earlier quoted context omitted.

the novelty is how to handle such scale. Sure, if we build a million rockets it'll be cheaper, but how do we USE those rockets and get funding at "relative peace time". SpaceX's real innovation was starlink in allowing it to "Soak up" excess production. Besides the obvious of reusability, which wasn't that "Obvious" considering the temperatures of reentry.

Actually, reusability was an obvious idea from the start. For example the Space Shuttle and the McDonnell Douglas DC-X are examples of attempts at reusability in the USA, and other countries had their own experiments. It just became non-obvious that it was the right approach after a long history of failed attempts at it.

I would argue there were far too few actual previous attempts at reusability. :P

All the while many early concepts from the dawn of the space age often had some sort of partial or even full reusability as part of the design.

Did it not pan out as other things suggested back then as it was not realistic with the technology of the time ?

Or was it perhaps due to usable space rockets mainly developing from ICBMs, which were single use munitions ? The military was also not that cost sensitive, especially at the top of the Cold War + possibly pushing on putting stuff to space sooner than the other side, instead of experimenting with some newfangled reusability concepts.

Well, in any case good thing this is over & things are finally at the right track. :)

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