16 ms·

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

131 points by joebig 3y ago

mrkstu 3y ago
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-to-build-starships-as-often-as-boeing-builds-737s/ https://arstechnica.com/space/2024/01/elon-musk-spacex-needs...
- philipwhiuk 3y ago
  It's not really that novel.
  - SCM-Enthusiast 3y ago
    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.
    - JumpCrisscross 3y ago
      > SpaceX's real innovation was starlink in allowing it to "Soak up" excess production SpaceX had a lot of real innovations. Starlink is one of them, but it’s not in the top five.
      - gertlex 3y ago
        Might be referring to top "business plan innovations".
        JumpCrisscross 3y ago
        > Might be referring to top "business plan innovations" No. 1 and No. 2 are positing a private space company and mass manufacturing. Those are, hands down, SpaceX's transformational business plan innovations. COTS, No. 3, is a business-engineering hybrid. Using NASA funds as stepping stones, versus treating them as the ends, No. 4. Maybe we can slot Starlink into No. 5, but it wasn’t unpredictable; telecom was always the moneymaker in space. (I’d argue published pricing with online ordering nudges it out.)
        IshKebab 3y ago
        Starlink isn't even a new idea. https://en.wikipedia.org/wiki/Teledesic https://en.wikipedia.org/wiki/Teledesic As always, ideas are cheap. SpaceX is doing well because it's actually managing to successfully implement lots of old fantastical ideas.
    - btilly 3y ago
      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.
      - panick21_ 3y ago
        The Shuttle was the only serious attempt. And even then, they dropped the largest structural part and used solids that can't practically be reused anyway. The DC-X is just a research project, that they would ever develop a reusable launch was basically fantasy. The same in other countries, very little actual large investments. The Soviet Shuttle was even less reusable then the US one. And that was actually pretty smart of them. So I don't think that were that many real failed attempts. There was practically speaking one real attempt.
      - SCM-Enthusiast 3y ago
        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.
        tsimionescu 3y ago
        It should be noted that reusable rockets are fundamentally less cargo per trip than non-reusable ones, since the reusable rockets have to carry extra fuel for re-entry. The sweetspot of having enough mass to orbit so that this reduced capacity is still worth it is not at all easy to reach. In general, if rocket building costs could really be reduced to almost nothing, reusable rockets would be useless. The only case where reusable rockets have a chance is if building rockets is still very expensive.
        Qwertious 3y ago
        Even if building rockets can be cheap, not all rockets/use-cases can be solved cheaply.
    - mlsu 3y ago
      Starlink wasn't really considered for years until SpaceX already was well underway. It was fortuitous but unplanned, not a factor in the original vision of the company when it was founded.
      - twic 3y ago
        Before Starlink, SpaceX assumed/hoped that a mass of new customers would come out of the woodwork when cheap launches became available (the easyJet strategy!). When they didn't, they came up with Starlink to be that customer.
        foobarian 3y ago
        Although, aren't they launching something pretty much daily or weekly, even without accounting for Starlink? It just isn't in the news much.
        twic 3y ago
        I picked September last year [1] more or less at random; SpaceX launches by day of the month: 01 - Starlink 02 - military 04 - Starlink 09 - Starlink 12 - Starlink 16 - Starlink 20 - Starlink 24 - Starlink 25 - Starlink 30 - Starlink A skim through the other months suggests that per month, there is usually one US government launch, zero to two commercial or rideshare launches, and a bunch of Starlink launches. There is an amazing range of stuff on the rideshares! [1] https://en.wikipedia.org/wiki/List_of_spaceflight_launches_in_July%E2%80%93December_2023#September https://en.wikipedia.org/wiki/List_of_spaceflight_launches_i...
        panick21_ 3y ago
        There are lots of new costumers. The thing is just that most of those don't need the huge sats of the past. And also people lose perspective. What we have to remember is how few launches other large rockets used to have. Ariane 5 the commercial success story peaked at 7 launches. So yes, new costumers, but not enough to go from 7 to 100+.
- NortySpock 3y ago
  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
actinium226 3y ago
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 it wouldn't be such a big deal if a rocket failed every now and then. This would let them use automotive grade parts in some areas as opposed to aerospace grade and reduce costs. However, it turned out that customers were actually using their rocket to launch prototype satellites and other one-off satellites where failure was actually a big deal. Long story short Astra did manage to make it to orbit, but is unlikely to survive into the future.
- looofooo 3y ago
  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.
  - appplication 3y ago
    It would have cost less sure, but it would have delayed the program years. And such a delay could easily shutter the program if political support faltered.
  - sitkack 3y ago
    In my ideal universe, we have a JWST assembly line.
    - blkhawk 3y ago
      ...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.
      - Retric 3y ago
        Not so much. It was a huge publicity boost for NASA, but not actually an efficient use of resources in terms of % shuttle missions * total cost of the shuttle program. That’s arguably unfair because of the sunk cost issue and how the budget was setup, but manned missions are inherently expensive and even more so if you’re trying to match arbitrary orbits.
vl 3y ago
John Walker is also an author of The Hacker's Diet: https://www.fourmilab.ch/hackdiet/ https://www.fourmilab.ch/hackdiet/ While perhaps a bit outdated by modern standards, general principles are sound and it's still a very fun read in itself since he includes some general reflections in the text.
- joebig 3y ago
  The man is also one of the authors of AutoCAD, a mechanical and civil engineering drafting software, which is globally popular (or hated, depending on who you ask!). I personally love the keyboard/commandline integration of AutoCAD, makes for an efficient and 'tactile' workflow (compared to the heavy dependence on mouse for other CAD software out there).
flashback2199 3y ago
[flagged]
- sabareesh 3y ago
  If we can generate Methane for example from CO2 in the atmosphere this could potentially solve this problem
  - joebig 3y ago
    Oxides are incredibly stable chemically. Any further conversion or sequestration process is guaranteed by thermodynamics to be very energy-intensive.
    - wolfram74 3y ago
      we know transitioning to pv/wind is going to lead to some months where we've got megawatt-hours coming out of our ears. If the only problem is energy cost, that won't be a problem long.
      - joebig 3y ago
        If it takes a day worth of solar/wind to offset a minute of rocket emission, then the equivalence is not really sustainable.
  - Ma8ee 3y ago
    The concentration of CO2 is measured in parts per million. Just that simple fact make me believe it is very unlikely there ever is going to be economical to extract CO2 from the atmosphere at any significant scale.
- lkbm 3y ago
  There are thousands of long-haul flights—and something like 100k flights overall—per day. If we're doing 10k+ rocket launches per day, then that's a huge problem. If we're doing 1 per day, it's a rounding error. This is premature optimization. (Either way, the solution, of course, is a carbon tax to price in the emissions.)
orenlindsey 3y ago
Elon Musk probably was inspired by this at some point.
moritzwarhier 3y ago
At first glance, is this about Keynesian economics for space gear? Sorry if this sounds nuts... but it is the best paraphrasing I could come up with.
contrarian1234 3y ago
“then the frontier would open as the great railway to orbit supplanted the first generation wagon trains“ Except the frontier had fertile lands and vast potential. It was not a cold barren emptiness. You could also make access to Antarctica cheap and affordable at scale. It wouldn't suddenly make it economically sensible to go there I'm skeptical there is a huge amount of pent up demand that is just itching for lower launch costs. It's just a bunch of telescopes looking up and look down at every possible wavelength and then a bunch of telecommunications equipment.. There are some serious diminishing returns at play here Tourism.. more telecommunications (ex: starlink).. what else is there to do up there? I don't see it being a huge market. Definitely not enough to fund a colony on Mars or anything like that
- jessriedel 3y ago
  The issue you're point out is real, but keep in mind the global tourism industry is ~$8 trillion, out of a total world GDP of $100 trillion. $1T per year on space tourism is possible.
  - tsimionescu 3y ago
    If you were to limit tourism to those fit enough to be allowed anywhere near a space launch, do you still think you'd reach that number? Not to mention, space tourism being an eighth of the total tourism market is obviously insane. The total tourism market is gigantic, space tourism would do wonderfully if it it were 0.01% of it (so, 8 billion or so? Probably not enough to warrant an assembly-line approach).
    - jessriedel 3y ago
      > If you were to limit tourism to those fit enough to be allowed anywhere near a space launch, do you still think you'd reach that number? Yes. The majority of the population can handle 3Gs. John Glenn was 77. > Not to mention, space tourism being an eighth of the total tourism market is obviously insane. I don't think space tourism becoming an eighth of total tourism is insane. I'd guess the fraction of tourism dollars that are spent on travel reached by plane is a lot higher, maybe about a third or half.
entropicgravity 3y ago
The risks of space flight are just so much actuarial work until real humans become involved. At that point three nine's is no longer acceptable and everything takes way longer and is way more expensive.
paulus_magnus2 3y ago
Unfortunately this was published a few revisions too early IMHO. And a couple of peer reviews but the exploration itself is a nice try. Due to nonlinearity of the rocket equation some assumptions are really really really off [a] [b]. V2 only has 2500m/s deltaV [5] and the launch vehicle's delta-v needed to achieve low Earth orbit starts around 9.4 km/s [6] (the actual delta-v is typically 1.5–2.0 km/s more for atmospheric drag and gravity drag). [7] Therefore V2 only deliveres (2500/9400)^2 (7% or 1/14 of the needed kinetic energy) Trouble is we only get to convert 1-4% of the launch mass into payload in LEO with chemical engines. And that's for large rockets with economies of scale. Sputnik (rocket) Mass: 267,000 kg Payload to LEO 500kg [3] The smallest orbital rocket is the Japanese SS-520 with the following characteristics: It can launch 3 kg to orbit in 4.4 minutes. It's a modified sounding rocket with three solid-propellant steps. It's only 9.54 m long, 0.52 m dia., and has a mass of 2.6T @ liftoff [google]. The SS-520 rocket cost less than $5 million [google] Bolting a 2nd stage on top of V2 was tried in [2] programme and with both stages at ~0.7 reliability things only work half the time. Not commercially viable. Is there a market for small & cheap rockets? [8] What about dual purpose ? W54 "Davy Crockett" Atomic Projectile was the smallest nuke designed to maintain fission and could be carried around in a backpack! The final weapon was 10.862 inches (275.9 mm) in diameter, 15.716 inches (399.2 mm) in length and 50.9 pounds (23.1 kg). I guess this could be worked with. With the current risk of global war everyone should be mass producing a small launcher. However this way we still only get 1cubesat into orbit per $1m, not what the autor aimed at. To get below $1000/kg into orbit we will need a bigger boat. And that's what SpaceX is doing. (sorry to not have these in the nice order) [8] https://space.stackexchange.com/questions/36261/why-isnt-there-a-rocket-to-launch-a-single-cubesat https://space.stackexchange.com/questions/36261/why-isnt-the... [a] assume that our bigger, more complicated (two-stage), and higher tech (LH2/LOX instead of Ethanol/LOX), launcher costs ten times as much as the V2 [b] If our mass produced LH2/LOX launcher equals the performance of the Delta 6925 by placing 3900 kg in LEO, the cost to LEO is US$333/kg; if we achieve better throw-weight, this figure goes down accordingly. If we build the thing so cheap, dumb, and heavy that its payload is only 1000 kg--one metric ton--the cost rises to US$1300/kg, which is still a factor of ten lower than the comparable cost to LEO for Ariane, Atlas, Delta, and Titan. [1] So yes, a stripped-down stretch-tank engine-augmented two-stage V2-derived rocket, massing 351 tons as opposed to the 12.5 tons in the original, would be able to reach orbit*. :) [2] https://en.m.wikipedia.org/wiki/RTV-G-4_Bumper https://en.m.wikipedia.org/wiki/RTV-G-4_Bumper [3] https://en.wikipedia.org/wiki/Sputnik_(rocket) https://en.wikipedia.org/wiki/Sputnik_(rocket) [1] https://www.quora.com/If-boosters-were-strapped-on-the-V2-rocket-will-it-get-into-orbit https://www.quora.com/If-boosters-were-strapped-on-the-V2-ro... [5] https://space.stackexchange.com/questions/59879/how-much-delta-v-did-the-v2-have https://space.stackexchange.com/questions/59879/how-much-del... [6] https://en.wikipedia.org/wiki/Low_Earth_orbit https://en.wikipedia.org/wiki/Low_Earth_orbit [7] https://en.wikipedia.org/wiki/Specific_orbital_energy https://en.wikipedia.org/wiki/Specific_orbital_energy

131 points by joebig 3y ago

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-to-build-starships-as-often-as-boeing-builds-737s/ https://arstechnica.com/space/2024/01/elon-musk-spacex-needs...

philipwhiuk 3y ago
It's not really that novel.
- SCM-Enthusiast 3y ago
  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.
  - JumpCrisscross 3y ago
    > SpaceX's real innovation was starlink in allowing it to "Soak up" excess production SpaceX had a lot of real innovations. Starlink is one of them, but it’s not in the top five.
    - gertlex 3y ago
      Might be referring to top "business plan innovations".
      - JumpCrisscross 3y ago
        > Might be referring to top "business plan innovations" No. 1 and No. 2 are positing a private space company and mass manufacturing. Those are, hands down, SpaceX's transformational business plan innovations. COTS, No. 3, is a business-engineering hybrid. Using NASA funds as stepping stones, versus treating them as the ends, No. 4. Maybe we can slot Starlink into No. 5, but it wasn’t unpredictable; telecom was always the moneymaker in space. (I’d argue published pricing with online ordering nudges it out.)
      - IshKebab 3y ago
        Starlink isn't even a new idea. https://en.wikipedia.org/wiki/Teledesic https://en.wikipedia.org/wiki/Teledesic As always, ideas are cheap. SpaceX is doing well because it's actually managing to successfully implement lots of old fantastical ideas.
  - btilly 3y ago
    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.
    - panick21_ 3y ago
      The Shuttle was the only serious attempt. And even then, they dropped the largest structural part and used solids that can't practically be reused anyway. The DC-X is just a research project, that they would ever develop a reusable launch was basically fantasy. The same in other countries, very little actual large investments. The Soviet Shuttle was even less reusable then the US one. And that was actually pretty smart of them. So I don't think that were that many real failed attempts. There was practically speaking one real attempt.
    - SCM-Enthusiast 3y ago
      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.
      - tsimionescu 3y ago
        It should be noted that reusable rockets are fundamentally less cargo per trip than non-reusable ones, since the reusable rockets have to carry extra fuel for re-entry. The sweetspot of having enough mass to orbit so that this reduced capacity is still worth it is not at all easy to reach. In general, if rocket building costs could really be reduced to almost nothing, reusable rockets would be useless. The only case where reusable rockets have a chance is if building rockets is still very expensive.
        Qwertious 3y ago
        Even if building rockets can be cheap, not all rockets/use-cases can be solved cheaply.
  - mlsu 3y ago
    Starlink wasn't really considered for years until SpaceX already was well underway. It was fortuitous but unplanned, not a factor in the original vision of the company when it was founded.
    - twic 3y ago
      Before Starlink, SpaceX assumed/hoped that a mass of new customers would come out of the woodwork when cheap launches became available (the easyJet strategy!). When they didn't, they came up with Starlink to be that customer.
      - foobarian 3y ago
        Although, aren't they launching something pretty much daily or weekly, even without accounting for Starlink? It just isn't in the news much.
        twic 3y ago
        I picked September last year [1] more or less at random; SpaceX launches by day of the month: 01 - Starlink 02 - military 04 - Starlink 09 - Starlink 12 - Starlink 16 - Starlink 20 - Starlink 24 - Starlink 25 - Starlink 30 - Starlink A skim through the other months suggests that per month, there is usually one US government launch, zero to two commercial or rideshare launches, and a bunch of Starlink launches. There is an amazing range of stuff on the rideshares! [1] https://en.wikipedia.org/wiki/List_of_spaceflight_launches_in_July%E2%80%93December_2023#September https://en.wikipedia.org/wiki/List_of_spaceflight_launches_i...
        panick21_ 3y ago
        There are lots of new costumers. The thing is just that most of those don't need the huge sats of the past. And also people lose perspective. What we have to remember is how few launches other large rockets used to have. Ariane 5 the commercial success story peaked at 7 launches. So yes, new costumers, but not enough to go from 7 to 100+.
NortySpock 3y ago
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

actinium226 3y ago

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 it wouldn't be such a big deal if a rocket failed every now and then. This would let them use automotive grade parts in some areas as opposed to aerospace grade and reduce costs. However, it turned out that customers were actually using their rocket to launch prototype satellites and other one-off satellites where failure was actually a big deal. Long story short Astra did manage to make it to orbit, but is unlikely to survive into the future.

looofooo 3y ago
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.
- appplication 3y ago
  It would have cost less sure, but it would have delayed the program years. And such a delay could easily shutter the program if political support faltered.
- sitkack 3y ago
  In my ideal universe, we have a JWST assembly line.
  - blkhawk 3y ago
    ...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.
    - Retric 3y ago
      Not so much. It was a huge publicity boost for NASA, but not actually an efficient use of resources in terms of % shuttle missions * total cost of the shuttle program. That’s arguably unfair because of the sunk cost issue and how the budget was setup, but manned missions are inherently expensive and even more so if you’re trying to match arbitrary orbits.

vl 3y ago

John Walker is also an author of The Hacker's Diet: https://www.fourmilab.ch/hackdiet/ https://www.fourmilab.ch/hackdiet/ While perhaps a bit outdated by modern standards, general principles are sound and it's still a very fun read in itself since he includes some general reflections in the text.

joebig 3y ago
The man is also one of the authors of AutoCAD, a mechanical and civil engineering drafting software, which is globally popular (or hated, depending on who you ask!). I personally love the keyboard/commandline integration of AutoCAD, makes for an efficient and 'tactile' workflow (compared to the heavy dependence on mouse for other CAD software out there).

flashback2199 3y ago

[flagged]

sabareesh 3y ago
If we can generate Methane for example from CO2 in the atmosphere this could potentially solve this problem
- joebig 3y ago
  Oxides are incredibly stable chemically. Any further conversion or sequestration process is guaranteed by thermodynamics to be very energy-intensive.
  - wolfram74 3y ago
    we know transitioning to pv/wind is going to lead to some months where we've got megawatt-hours coming out of our ears. If the only problem is energy cost, that won't be a problem long.
    - joebig 3y ago
      If it takes a day worth of solar/wind to offset a minute of rocket emission, then the equivalence is not really sustainable.
- Ma8ee 3y ago
  The concentration of CO2 is measured in parts per million. Just that simple fact make me believe it is very unlikely there ever is going to be economical to extract CO2 from the atmosphere at any significant scale.
lkbm 3y ago
There are thousands of long-haul flights—and something like 100k flights overall—per day. If we're doing 10k+ rocket launches per day, then that's a huge problem. If we're doing 1 per day, it's a rounding error. This is premature optimization. (Either way, the solution, of course, is a carbon tax to price in the emissions.)

orenlindsey 3y ago

Elon Musk probably was inspired by this at some point.

moritzwarhier 3y ago

At first glance, is this about Keynesian economics for space gear? Sorry if this sounds nuts... but it is the best paraphrasing I could come up with.

contrarian1234 3y ago

“then the frontier would open as the great railway to orbit supplanted the first generation wagon trains“ Except the frontier had fertile lands and vast potential. It was not a cold barren emptiness. You could also make access to Antarctica cheap and affordable at scale. It wouldn't suddenly make it economically sensible to go there I'm skeptical there is a huge amount of pent up demand that is just itching for lower launch costs. It's just a bunch of telescopes looking up and look down at every possible wavelength and then a bunch of telecommunications equipment.. There are some serious diminishing returns at play here Tourism.. more telecommunications (ex: starlink).. what else is there to do up there? I don't see it being a huge market. Definitely not enough to fund a colony on Mars or anything like that

jessriedel 3y ago
The issue you're point out is real, but keep in mind the global tourism industry is ~$8 trillion, out of a total world GDP of $100 trillion. $1T per year on space tourism is possible.
- tsimionescu 3y ago
  If you were to limit tourism to those fit enough to be allowed anywhere near a space launch, do you still think you'd reach that number? Not to mention, space tourism being an eighth of the total tourism market is obviously insane. The total tourism market is gigantic, space tourism would do wonderfully if it it were 0.01% of it (so, 8 billion or so? Probably not enough to warrant an assembly-line approach).
  - jessriedel 3y ago
    > If you were to limit tourism to those fit enough to be allowed anywhere near a space launch, do you still think you'd reach that number? Yes. The majority of the population can handle 3Gs. John Glenn was 77. > Not to mention, space tourism being an eighth of the total tourism market is obviously insane. I don't think space tourism becoming an eighth of total tourism is insane. I'd guess the fraction of tourism dollars that are spent on travel reached by plane is a lot higher, maybe about a third or half.

entropicgravity 3y ago

The risks of space flight are just so much actuarial work until real humans become involved. At that point three nine's is no longer acceptable and everything takes way longer and is way more expensive.

paulus_magnus2 3y ago

Unfortunately this was published a few revisions too early IMHO. And a couple of peer reviews but the exploration itself is a nice try. Due to nonlinearity of the rocket equation some assumptions are really really really off [a] [b]. V2 only has 2500m/s deltaV [5] and the launch vehicle's delta-v needed to achieve low Earth orbit starts around 9.4 km/s [6] (the actual delta-v is typically 1.5–2.0 km/s more for atmospheric drag and gravity drag). [7] Therefore V2 only deliveres (2500/9400)^2 (7% or 1/14 of the needed kinetic energy) Trouble is we only get to convert 1-4% of the launch mass into payload in LEO with chemical engines. And that's for large rockets with economies of scale. Sputnik (rocket) Mass: 267,000 kg Payload to LEO 500kg [3] The smallest orbital rocket is the Japanese SS-520 with the following characteristics: It can launch 3 kg to orbit in 4.4 minutes. It's a modified sounding rocket with three solid-propellant steps. It's only 9.54 m long, 0.52 m dia., and has a mass of 2.6T @ liftoff [google]. The SS-520 rocket cost less than $5 million [google] Bolting a 2nd stage on top of V2 was tried in [2] programme and with both stages at ~0.7 reliability things only work half the time. Not commercially viable. Is there a market for small & cheap rockets? [8] What about dual purpose ? W54 "Davy Crockett" Atomic Projectile was the smallest nuke designed to maintain fission and could be carried around in a backpack! The final weapon was 10.862 inches (275.9 mm) in diameter, 15.716 inches (399.2 mm) in length and 50.9 pounds (23.1 kg). I guess this could be worked with. With the current risk of global war everyone should be mass producing a small launcher. However this way we still only get 1cubesat into orbit per $1m, not what the autor aimed at. To get below $1000/kg into orbit we will need a bigger boat. And that's what SpaceX is doing. (sorry to not have these in the nice order) [8] https://space.stackexchange.com/questions/36261/why-isnt-there-a-rocket-to-launch-a-single-cubesat https://space.stackexchange.com/questions/36261/why-isnt-the... [a] assume that our bigger, more complicated (two-stage), and higher tech (LH2/LOX instead of Ethanol/LOX), launcher costs ten times as much as the V2 [b] If our mass produced LH2/LOX launcher equals the performance of the Delta 6925 by placing 3900 kg in LEO, the cost to LEO is US$333/kg; if we achieve better throw-weight, this figure goes down accordingly. If we build the thing so cheap, dumb, and heavy that its payload is only 1000 kg--one metric ton--the cost rises to US$1300/kg, which is still a factor of ten lower than the comparable cost to LEO for Ariane, Atlas, Delta, and Titan. [1] So yes, a stripped-down stretch-tank engine-augmented two-stage V2-derived rocket, massing 351 tons as opposed to the 12.5 tons in the original, would be able to reach orbit*. :) [2] https://en.m.wikipedia.org/wiki/RTV-G-4_Bumper https://en.m.wikipedia.org/wiki/RTV-G-4_Bumper [3] https://en.wikipedia.org/wiki/Sputnik_(rocket) https://en.wikipedia.org/wiki/Sputnik_(rocket) [1] https://www.quora.com/If-boosters-were-strapped-on-the-V2-rocket-will-it-get-into-orbit https://www.quora.com/If-boosters-were-strapped-on-the-V2-ro... [5] https://space.stackexchange.com/questions/59879/how-much-delta-v-did-the-v2-have https://space.stackexchange.com/questions/59879/how-much-del... [6] https://en.wikipedia.org/wiki/Low_Earth_orbit https://en.wikipedia.org/wiki/Low_Earth_orbit [7] https://en.wikipedia.org/wiki/Specific_orbital_energy https://en.wikipedia.org/wiki/Specific_orbital_energy