4 ms·

I think the problem is not the technological advancement, it’s the limits of physics which are the same as in today as it was back in 1960s. We have immense co

I think the problem is not the technological advancement, it’s the limits of physics which are the same as in today as it was back in 1960s. We have immense computing power now compared to 50 years ago. But that doesn’t help to escape the gravity well of earth. We’re still using the same chemical rockets to go to space, haven’t invented any new type of rocket drives

ashika 1mo ago
cough https://en.wikipedia.org/wiki/Liquid_rocket_propellant#Methane https://en.wikipedia.org/wiki/Liquid_rocket_propellant#Metha... cough
- sajithdilshan 1mo ago
  It’s still a chemical reaction
  - pfdietz 1mo ago
    Now estimate how much that propellant will cost per kg of payload to orbit. The problem with expensive launch in the past wasn't due to propellant cost.
- m4rtink 1mo ago
  Bah, this is the way: https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls... (Unfortunately if you do launch from Earth, neighbors will likely by a bit annoyed).
pfdietz 1mo ago
That's a very bad take. Rocket costs are not driven by physics, they're driven by more mundane issues, like single-use hardware. The cost floor dictated by cost of propellant is remarkably low.
- m4rtink 1mo ago
  Yeah, the moment propellant drives your launch costs, you have effectively won the chemical rocket launch game. And can then transition to more advanced stuff, like space resource extraction (so you can only launch important bits), launch loops/skyhooks/tether shenanigans in general, etc.
  - pfdietz 1mo ago
    People think rockets use tremendous amounts of fuel, but a Falcon 9's fuel is only slightly more than half the weight of the fuel in a fully fueled 747. There's also a lot of oxidizer (about 2.5x as much as the fuel) but LOX is very cheap, the second cheapest industrial liquid after water.
WalterBright 1mo ago
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ashika 1mo ago

cough https://en.wikipedia.org/wiki/Liquid_rocket_propellant#Methane https://en.wikipedia.org/wiki/Liquid_rocket_propellant#Metha... cough

sajithdilshan 1mo ago
It’s still a chemical reaction
- pfdietz 1mo ago
  Now estimate how much that propellant will cost per kg of payload to orbit. The problem with expensive launch in the past wasn't due to propellant cost.
m4rtink 1mo ago
Bah, this is the way: https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls... (Unfortunately if you do launch from Earth, neighbors will likely by a bit annoyed).

pfdietz 1mo ago

That's a very bad take. Rocket costs are not driven by physics, they're driven by more mundane issues, like single-use hardware. The cost floor dictated by cost of propellant is remarkably low.

m4rtink 1mo ago
Yeah, the moment propellant drives your launch costs, you have effectively won the chemical rocket launch game. And can then transition to more advanced stuff, like space resource extraction (so you can only launch important bits), launch loops/skyhooks/tether shenanigans in general, etc.
- pfdietz 1mo ago
  People think rockets use tremendous amounts of fuel, but a Falcon 9's fuel is only slightly more than half the weight of the fuel in a fully fueled 747. There's also a lot of oxidizer (about 2.5x as much as the fuel) but LOX is very cheap, the second cheapest industrial liquid after water.

WalterBright 1mo ago

[dead]