I Love Chemically-Fueled, Vertical Take-Off Rockets But Doesn't Humanity Need a More Elegant Way to Get into Space?

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boomtube-mk2 said:
Well the way things are going now, by the time anybody actually has the capability to build a Beanstalk, the United States might not be much of a factor on the world stage anymore.

We seem to be headed to Hell in a handbasket and recently we've added wheels and a rocket motor to it.
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When you get there, drop me a postcard. I'll probably be enjoying a single malt and watching the sunset.
 
boomtube-mk2 said:
It's too bad we can't do what the "Slavers" did in Larry Niven's "Known Space" stories and grow solid-fuel, rocket propellent grains.
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When all you have is a pen and a piece of paper, you can do anything.

I am also a Niven fan. But he wrote science fiction, which is, not to put too fine a point on it, fiction.

Sure, lots of "science fiction" has become fact. But as a system developer, I have to wait until the technology exists before I can actually use it.
 
There's an outfit in CA working on Gerald Bull's concept using a hydrogen cannon.
 
RICHARD COLARCO said:
Having been in the space business for over 30 years, I hear this all the time. "We need something better than chemical rockets." My comeback is, "So get busy and design and build something." That usually stops the conversation cold.

Wanting a space elevator is one thing. Designing and building one is something else entirely. Before you start dropping a cable from Geo, take a few courses in orbital dynamics.
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Pretty much exactly my attitude upon reading the thread title. Well said.
 
It surprises me no one has discovered a way to harness the Earth natural power sources yet.
With the vast electrical magnetic field around the Earth, and the ability to make static electricity at will, I suppose a way to store and regulate it for use would be the biggest hurtle.
The Cable Elevator Thing will never get off the ground. The scale is too large to be realistically possible or probable.
I think Tesla was on the right track with broadcasting electricity, but instead of broadcasting it, it would be pulled from the vast resources that run around our planet consistently generated my our moving molten atomic core.
I may be wrong in my thinking, but I believe it's there and we just need to learn how to use it.
Just as I believe it runs throughout the Universe. We just need to learn to identify it and learn how to use it.
 
Woody's Workshop said:
It surprises me no one has discovered a way to harness the Earth natural power sources yet.
With the vast electrical magnetic field around the Earth, and the ability to make static electricity at will, I suppose a way to store and regulate it for use would be the biggest hurtle.
The Cable Elevator Thing will never get off the ground. The scale is too large to be realistically possible or probable.
I think Tesla was on the right track with broadcasting electricity, but instead of broadcasting it, it would be pulled from the vast resources that run around our planet consistently generated my our moving molten atomic core.
I may be wrong in my thinking, but I believe it's there and we just need to learn how to use it.
Just as I believe it runs throughout the Universe. We just need to learn to identify it and learn how to use it.
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"It surprises me no one has discovered a way to harness the Earth natural power sources yet."

Ever heard of wind turbines? Hydroelectricity?

We store electricity all the time. Ever heard of batteries, or capacitors?

The cable elevator is only attractive to people who think geostationary satellites are actually stationary.

You can broadcast electricity, as long as you don't mind turning your house into a microwave oven.

Everything is possible to the man who does not have to do it.
 
RICHARD COLARCO said:
"It surprises me no one has discovered a way to harness the Earth natural power sources yet."

Ever heard of wind turbines? Hydroelectricity?

We store electricity all the time. Ever heard of batteries, or capacitors?

The cable elevator is only attractive to people who think geostationary satellites are actually stationary.

You can broadcast electricity, as long as you don't mind turning your house into a microwave oven.

Everything is possible to the man who does not have to do it.
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Totally missed the point.
 
It is my opinion and I think many here might agree, that if we don't come up with a more elegant way to get into orbit, and beyond, we, the human race, are never going to truly be able to fully explore and exploit "Outer Space" and by outer space I mean anything beyond NEO and maybe, JUST MAYBE the Moon.

Yes we can send probes to Mars which takes months, everything else taking years, and that's nice and all if all you desire is information and pretty pictures.
As for sending people to Mars or the asteroid belt or chuckle, chuckle, Jupiter and the other gas giants, we're practically at the stage of the Neanderthal staring out at the Atlantic Ocean and . . .

Now if you happen to believe that UFO's are spacecraft from other solar systems, which I don't, then it becomes obvious that the science is out there and thus the technology, to make incredible voyages across inconceivable distances and it must be easy enough to make it reasonable that a bunch of different alien races would make Earth a tourist destination.

So the question becomes; is Earth science on the right path to discover what these aliens all seem to know or have we gone off the rails somewhere along the way and our science is actually leading us in the wrong direction entirely?
 
boomtube-mk2 said:
It is my opinion and I think many here might agree, that if we don't come up with a more elegant way to get into orbit, and beyond, we, the human race, are never going to truly be able to fully explore and exploit "Outer Space" and by outer space I mean anything beyond NEO and maybe, JUST MAYBE the Moon.
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If you have any idea how to do this, I'm sure NASA would like to hear it.

It's all well and good to say, "We need a better way," but it's something else again to develop that better way.
 
boomtube-mk2 said:
It is my opinion and I think many here might agree, that if we don't come up with a more elegant way to get into orbit, and beyond, we, the human race, are never going to truly be able to fully explore and exploit "Outer Space" and by outer space I mean anything beyond NEO and maybe, JUST MAYBE the Moon.

Yes we can send probes to Mars which takes months, everything else taking years, and that's nice and all if all you desire is information and pretty pictures.
As for sending people to Mars or the asteroid belt or chuckle, chuckle, Jupiter and the other gas giants, we're practically at the stage of the Neanderthal staring out at the Atlantic Ocean and . . .

Now if you happen to believe that UFO's are spacecraft from other solar systems, which I don't, then it becomes obvious that the science is out there and thus the technology, to make incredible voyages across inconceivable distances and it must be easy enough to make it reasonable that a bunch of different alien races would make Earth a tourist destination.

So the question becomes; is Earth science on the right path to discover what these aliens all seem to know or have we gone off the rails somewhere along the way and our science is actually leading us in the wrong direction entirely?
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I’m confused (a perpetual state, it seems).
You say that you don’t believe that UFOs are spacecraft from other solar systems, but then in the next paragraph you talk about “what these aliens all seem to know.”

What do you think the UFOs are?
Do you believe they are operated by aliens from other solar systems?
What technologies do you think they have?
What path do you think we need to take to learn about those technologies?
What’s your idea for getting to low earth orbit?

Understand that it has been just a little more than a hundred years since airplanes were developed and much less than a century since a human rode the first rocket into space. Within the past thirty years the advancement of technology has been absolutely staggering, almost beyond imagination. I don’t know what will happen with human space travel, but undoubtedly there will be disruptive technologies there also. But at least right now our understanding of physics informs us that chemical rockets are still the most survivable means of getting to LEO. Once in LEO we can switch to a high impulse technology like ion drives, but they are very low thrust. It would be ideal to be able to accelerate at one fee to the halfway point and then decelerate at one gee for the second half of the trip.
 
Look at Ad Astra, astronaut Franklin Chang-Diaz's company. They are trying to develop an ion drive for interplanetary missions. They are making progress, but not there yet.

If you want to see where the future of realizable propulsion and launch lies, you need look no further than SpaceX.
 
Steve Shannon said:
What do you think the UFOs are? Read Operation Trojan Horse by John Keel.
Do you believe they are operated by aliens from other solar systems? No
What technologies do you think they have? I don't think they have any technologies.
What path do you think we need to take to learn about those technologies? Haven't a clue
What’s your idea for getting to low earth orbit? Here's the way I see it. Earth has not been visited by Aliens because the technology to get here from there doesn't exist. Reality gets in the way. I'm convinced that the reason for "The Great Silence" is that no technological civilization ever gets much beyond where we are today with regards to "Space Travel", again, because there is no technology available that will allow for it.
IF there is something swanning around out there in the Milky Way it is IMO some form of machine intelligence and it is getting around at 10 to 20 percent of the speed of light and has about as much interest in and use for biological life as a fish does for a pair of gloves.
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RICHARD COLARCO said:
If you have any idea how to do this, I'm sure NASA would like to hear it.

It's all well and good to say, "We need a better way," but it's something else again to develop that better way.
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Boy do I wish I had a better idea and frankly I don't think one exists. My point is that if nothing better can be found that we are hooped with regards to manned exploration and exploration of our solar system.
The distances are too great, that travel times too long and the energy expenditures too massive to make manned missing beyond the Moon reasonable.
 
boomtube-mk2 said:
Boy do I wish I had a better idea and frankly I don't think one exists. My point is that if nothing better can be found that we are hooped with regards to manned exploration and exploration of our solar system.
The distances are too great, that travel times too long and the energy expenditures too massive to make manned missing beyond the Moon reasonable.
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Not necessarily. We still need chemical rockets to get to low Earth orbit. Getting to LEO is the big energy bill. Saturn V burned 2.6 million kg of propellant to get 140,000 kg of payload to LEO.

However, transfers to other planets can be accomplished with nuclear thermal rockets. NTR is in the NASA Mars Reference Architecture. Ion propulsion is coming along, only (only!) engineering in the way. If you look at Ad Astra's estimates, it's Earth to Mars in 39 days, and launch any time, once they get the ISP up to where they want it. Not there yet.

You can't build a NTR with enough thrust to get an appreciable payload off Earth to LEO. The reactor would be too heavy. However, NTR looks very attractive for Mars injection, a fact NASA understood in the 1950s.

It's not an energy problem. You are stuck with the energy required to change orbits, there is nothing you can do about that. The problem is ISP. Chemical rockets can get us anywhere in the solar system. However, chemical ISP is so low (relative to NTR and ion) that you have to boost an enormous amount of propellant into LEO. This is the real limfac for manned Mars missions.

Hohmann transfers are a very slow, inefficient path to Mars, but we are stuck with them (and with the 2 1/2 year gap between transfer "opportunities") if we want to use chemicals for the transfer. There are actually lower energy transfers, but they take forever even in comparison to Hohmann.

NTR will get us to Mars. And staging from the Moon is a very good idea to explore, especially if we can manufacture propellant on the Moon.
 
If the chemical propellants are liquid oxygen and hydrogen from water (i.e. electrolysed or recycled from oceans, or “green”), I see no down side to chemical propellants.

Use of all other kinds of chemical propellants should be restricted to model rocketry 😁 (because I wouldn’t know the effects of mass usage).

Once in orbit. I don’t think it really matters anymore.

According to Elon in his latest interview, rocket reusability is the most pressing issue for wider access to space. No one is sure yet if it’s possible. Consider the difference between buying a new car for each trip, vs having one car able to make many trips. It’s that big a deal.
 
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Big downside to hydrogen is it is not long term storable. Hydrogen is a great fuel for initial boost, but the tanks are immense (Shuttle). H2 gives great ISP for a chemical propellant. The combination of H2 and the SSME was a winner, but it's unlikely anyone will use H2 at large scale in the future.

SpaceX is looking at methane. Easy to make, and storable. Lower ISP than H2, but everything is a tradeoff.

I'm not sure reusability is the most pressing issue, but it certainly offers significant economies. NASA Mars reference architecture uses expendables, but the architecture was initiated before reusability was anything more than a pipe dream. I have not seen where NASA is considering reusability for Mars, but they are going to SpaceX for return to the Moon. So I suppose reusability is a default for Mars.
 
Like so many “why don’t we do this different/better” topics this one is about two things - materials science/engineering and computing power. Even if we had the political will (and some kind of incentive beyond “just doing it because it’s there”) to build a space elevator we don’t have the materials to do it with - though we probably have the computing power. SSTO space planes look like elegant solutions but again, what do we build them out of and how do you get enough energy on board to make them viable while ensuring they haul enough people and cargo to be useful? Chemical powered rockets are the answer for getting out of planetary gravity wells and will be for the foreseeable future…until they aren’t, which will only happen when some kind of fundamental “new thing” comes along that works better. Sail powered ships dominated both military and commercial water travel for hundreds of years - until steam replaced wind almost (relatively) overnight. So we’re stuck with our current version of the clipper ship - until the next Alexander Carnegie Kirk ( ! ) designs space travel’s version of the triple expansion steam engine and builds the 21+st century version of the SS Aberdeen 😎
 
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I don't know of a better way to put objects in LEO. There are certainly other ways...

But more importantly. I have a huge crush on Sarah Knights. It's almost embarrassing. She's like the modern day Majel Barrett.
 
Air Force Space Command (RIP) spent many years looking at aerospike engines and SSTO. They concluded we could not do it with any reasonable payload. Maybe someday............
 
Funkworks said:
If the chemical propellants are liquid oxygen and hydrogen from water (i.e. electrolysed or recycled from oceans, or “green”), I see no down side to chemical propellants.
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Another big issue to consider is that it takes a lot of energy to electrolyse that much water, and you won't get it all back when you burn the hydrogen due to the second law of thermodynamics.

Because of this, hydrogen fuel really isn't as green as people think it is.
 
Antares JS said:
Another big issue to consider is that it takes a lot of energy to electrolyse that much water, and you won't get it all back when you burn the hydrogen due to the second law of thermodynamics.

Because of this, hydrogen fuel really isn't as green as people think it is.
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But if you use unreliable green sources such as wind or solar it’s a great way to store energy.
 
RICHARD COLARCO said:
Big downside to hydrogen is it is not long term storable. Hydrogen is a great fuel for initial boost, but the tanks are immense (Shuttle). H2 gives great ISP for a chemical propellant. The combination of H2 and the SSME was a winner, but it's unlikely anyone will use H2 at large scale in the future.
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To expand here a little, H2 doesn't just have "great Isp," it's literally the best possible for a chemical rocket. Specific impulse is total impulse divided by propellant weight, and because hydrogen is the lightest substance in the universe, you're dividing that total impulse by the lowest possible propellant mass and getting the highest result.

There is one other major disadvantage to using hydrogen as a rocket propellant: along with being very light, liquid hydrogen is also very "fluffy" as opposed to dense, meaning you need to add more inert mass to your rocket in tankage to hold the volume of hydrogen you need. You can see this in the stages of the Saturn V - on the first stage, the lower tank (with the black and white stripes and USA's) is the RP-1 tank, and the oxygen tank is above it, with the flags. You can see how much more volume of oxygen is needed than RP-1 to burn all the propellant. Now look at the other two stages, which were hydrogen-powered. All you can see on the outside is the hydrogen tank walls. The oxygen tanks are relatively small ellipsoid-shaped tanks nestled in the aft ends of the stages, separated from the hydrogen by a common bulkhead, that you can only see in cutaways. You can imagine what the first stage would have looked like if it was hydrogen-powered as well.

RICHARD COLARCO said:
SpaceX is looking at methane. Easy to make, and storable. Lower ISP than H2, but everything is a tradeoff.
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Methane is a fossil fuel. I'm not sure what you mean when you say that it's easy to make.
 

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