No problem. My survey of nonconventional launch technologies is up at Popular Mechanics.
25 thoughts on “No Rockets?”
No Space Pier mention? Sad. 🙁
Also sad you didn’t have more word count to flesh out the explanations, and pros/cons, of the systems. I think some of those laser launch systems are really clever.
What about Airship To Orbit?
I’ve always wondered about that one. I think it’s feasibility boils down to whether a very high ISP drive can produce enough thrust to overcome the drag incurred by the envelope. I’ve never seen any definitive knockdown of the concept.
I’m bummed that stacking turtles wasn’t picked.
I quibble with your categorization of Orion as an external energy vehicle. The energy source and the reaction mass of Orion is entirely self contained like any other rocket.
It’s a fair quibble, but I wanted to differentiate it from a chemical or thermal rocket, which heats and ejects a working fluid with the heat generated internally. I probably should have just come up with different categories. Also, they dropped a couple examples in the interest of space.
It’s external combustion rather than internal combustion.
I’m a bit surprised you didn’t mentionTsiolkovskii in your static structure section. I’d always heard space elevators attributed to him, but the Wikipedia entry sounds more like a tower. I’m not sure it would have added anything to the article other than some historical notes.
Dani Eder had a proposal quite a while back to combine a non-rotating tether with a light gas gun. Maybe if you had room you might have mentioned that some of these ideas could be combined.
Bennet: That’s because it’s turtles all the way DOWN, not turtles all the way up. Sheesh.
Aha, thanks for clearing that up for me, Ray 🙂
Also, they dropped a couple examples in the interest of space.
ack. punmaster.
Historical note: Turtles went around the moon before Apollo 8! Yes, the soviets (who said they weren’t in a race) did it.
The article illustrates what I think is something we are going to have to learn to live with: there are no promising alternatives to rockets. The most promising alternatives to rockets are something that is still quite closely related to rockets: combined rocket/air breathing propulsion. And even then mostly because of the convenience of cross-range and horizontal takeoff and landing. We should probably be happy if they manage to pay for themselves by improving effective specific impulse by just enough to cancel out the added dead weight of airbreathing machinery. I’m very skeptical you could get much more than that out of it.
“Vaporize the air”?
…there are no promising alternatives to rockets.
If by promising, you mean there’s no alternative that has had trillions poured into it over the past half century and change, then yes.
So what promising alternatives do you see?
there are no promising alternatives to rockets
Too bad the Dean drive was a bust. It seems you do need reaction mass.
Then it becomes a question of power source… Chemical, nuclear, antimatter.
We reached about the limit of chemical and have shown that nuclear can move us beyond. The control of antimatter has a huge potential.
Solar sail also has a lot of potential.
If enough sources for water are available, even solar steam becomes viable. 200 seconds of specific impulse works if you can step from one water source to another.
So what promising alternatives do you see?
Engineering alternative spacelift ain’t anywhere near the point where you can determine whether it offers an economic breakthrough above and beyond what we can reasonably expect out of rocketry. That’s my point.
Well, then the alternatives are hardly promising are they? Maybe we are in for some unexpected surprises, but not expected … eh … surprises.
@Ken:
For in space propulsion there are more promising alternatives, or at least more promising power sources and higher exhaust velocities. For Earth launch it’s hard to see we’ll ever get rid of rockets. I think airbreathing s the most probable addition. Maybe only for things like aerial propellant transfer, flyback boosters (although boost back could work too) and cross-range, maybe for a bit more.
Given that the military is pushing the development of modular high efficiency lasers, I suspect laser launch may be coming.
Idle (and entirely unserious) thought: wouldn’t a saucer shape be good for a laser powered atmospheric vehicle? This explains why UFOs look like that! Now we just need to find the mothership in space with the laser. 🙂
Well, then the alternatives are hardly promising are they? Maybe we are in for some unexpected surprises, but not expected … eh … surprises.
We don’t know if they’re promising or not, and at present rate we won’t know for some time.
ken anthony – Turtles have gone much further than Luna. Don’t forget the Great A’Tuin, the Giant Star Turtle (species: Chelys galactica).
No Space Pier mention? Sad. 🙁
Also sad you didn’t have more word count to flesh out the explanations, and pros/cons, of the systems. I think some of those laser launch systems are really clever.
What about Airship To Orbit?
I’ve always wondered about that one. I think it’s feasibility boils down to whether a very high ISP drive can produce enough thrust to overcome the drag incurred by the envelope. I’ve never seen any definitive knockdown of the concept.
I’m bummed that stacking turtles wasn’t picked.
I quibble with your categorization of Orion as an external energy vehicle. The energy source and the reaction mass of Orion is entirely self contained like any other rocket.
It’s a fair quibble, but I wanted to differentiate it from a chemical or thermal rocket, which heats and ejects a working fluid with the heat generated internally. I probably should have just come up with different categories. Also, they dropped a couple examples in the interest of space.
It’s external combustion rather than internal combustion.
I’m a bit surprised you didn’t mentionTsiolkovskii in your static structure section. I’d always heard space elevators attributed to him, but the Wikipedia entry sounds more like a tower. I’m not sure it would have added anything to the article other than some historical notes.
Dani Eder had a proposal quite a while back to combine a non-rotating tether with a light gas gun. Maybe if you had room you might have mentioned that some of these ideas could be combined.
Bennet: That’s because it’s turtles all the way DOWN, not turtles all the way up. Sheesh.
Aha, thanks for clearing that up for me, Ray 🙂
Also, they dropped a couple examples in the interest of space.
ack. punmaster.
Historical note: Turtles went around the moon before Apollo 8! Yes, the soviets (who said they weren’t in a race) did it.
The article illustrates what I think is something we are going to have to learn to live with: there are no promising alternatives to rockets. The most promising alternatives to rockets are something that is still quite closely related to rockets: combined rocket/air breathing propulsion. And even then mostly because of the convenience of cross-range and horizontal takeoff and landing. We should probably be happy if they manage to pay for themselves by improving effective specific impulse by just enough to cancel out the added dead weight of airbreathing machinery. I’m very skeptical you could get much more than that out of it.
“Vaporize the air”?
If by promising, you mean there’s no alternative that has had trillions poured into it over the past half century and change, then yes.
So what promising alternatives do you see?
there are no promising alternatives to rockets
Too bad the Dean drive was a bust. It seems you do need reaction mass.
Then it becomes a question of power source… Chemical, nuclear, antimatter.
We reached about the limit of chemical and have shown that nuclear can move us beyond. The control of antimatter has a huge potential.
Solar sail also has a lot of potential.
If enough sources for water are available, even solar steam becomes viable. 200 seconds of specific impulse works if you can step from one water source to another.
Engineering alternative spacelift ain’t anywhere near the point where you can determine whether it offers an economic breakthrough above and beyond what we can reasonably expect out of rocketry. That’s my point.
Well, then the alternatives are hardly promising are they? Maybe we are in for some unexpected surprises, but not expected … eh … surprises.
@Ken:
For in space propulsion there are more promising alternatives, or at least more promising power sources and higher exhaust velocities. For Earth launch it’s hard to see we’ll ever get rid of rockets. I think airbreathing s the most probable addition. Maybe only for things like aerial propellant transfer, flyback boosters (although boost back could work too) and cross-range, maybe for a bit more.
Given that the military is pushing the development of modular high efficiency lasers, I suspect laser launch may be coming.
Idle (and entirely unserious) thought: wouldn’t a saucer shape be good for a laser powered atmospheric vehicle? This explains why UFOs look like that! Now we just need to find the mothership in space with the laser. 🙂
We don’t know if they’re promising or not, and at present rate we won’t know for some time.
ken anthony – Turtles have gone much further than Luna. Don’t forget the Great A’Tuin, the Giant Star Turtle (species: Chelys galactica).
Rand provided the Quicklaunch link that solves most of the Launch-Cost problem: http://quicklaunchinc.com/home
That would cut the $16k (thumbrule guess) in half.
Forgot to add the Honeymooners qualifier – $16k/kg “to the moon”!
Uh IcePilot, Pokemon is a card game. Zond was a real spacecraft.
Ralph wasn’t really a bus driver… nor was he Ralph.
…and yes, it is turtles all the way down. 🙂