Mach Effect progress

[Skipjack]

I mean to put an experiment in micrograv for long enough and cheap enough.

I am surprised that Musk or others like him have not thought about investing into that. I guess it is too risky, even for Musk (though the cost would small for a proof of concept).

Yeah it's just a drop in the bucket. But that drop is worth the bucket when the goal is such a long shot and is so sacred as it is for believers like Musk. He'd have to research it privately if at all, even if he were coordinating his team with e.g. Woodward & co.

I just can't put my brain around no one putting the "few" 3 digits it'd take to move this within sight of conclusive evidence either way. Given the implications. It boggles my mind every time I read one of those discussions on the net with hardcore debating of how it just can't be real because it doesn't pass sanity check one way or another. So much time spent going round and round theoretically, instead of just building/running experiment and getting actual reality check.

If I had the money, I would finance it, but I don't

[hanelyp]

I think SpaceX is closer to reaching their goal than you might think. But they can only lower it so much with conventional engines and a TSTO launch vehicle.

The figure I've heard for airliners is total costs around 4-5 times the cost of fuel. Chemical fuel rockets have a long ways to drop in cost before they approach that.

As for nuclear rockets, those would be fiscal suicide in the current US regulatory environment. A polywell powering a QED system might work, but that's several years the other side of a demonstrated ground power reactor.

[Skipjack]

I think SpaceX is closer to reaching their goal than you might think. But they can only lower it so much with conventional engines and a TSTO launch vehicle.

The figure I've heard for airliners is total costs around 4-5 times the cost of fuel. Chemical fuel rockets have a long ways to drop in cost before they approach that.

Oh, absolutely. The cost of fuel for an F9 launch is only 200k USD (according to Elon Musk). Even if the cost for a launch goes down to 7 million, 200k is only a small fraction of it.
No, the reason why chemical rockets can not lower the cost much further than 7 million a launch is the rather complex operations, they need.

1. They are huge (and the F9 has rather little payload). Large launch vehicles are more expensive to build and maintain.
2. Their mass fraction for propellant to structure is also huge (30 to 1 for the F9). Because of this, part of the strength of the F9 is due to the pressure in the tanks. If the tanks were not pressurized, they would not be stable enough to withstand the forces of a launch. That means that they are comparably fragile.
3. They contain a lot of flammable fuel. That makes them pretty dangerous.
4. They are very complex, with lots of systems and subsystems. That means that there are long checklists and complex procedures between flights. That means lots of manpower and that drives up cost.

While I do like NTR fission engines, I do not think that they could change the above issues sufficiently to lower the launch cost much below 7 million. They might allow more payload for the same size vehicle, though (which would lower cost per pound).

Aneutronic fusion engines could be nice, but we are still at a very low TRL there.

[AcesHigh]

Musk isn't even interested in fission rockets so I doubt he'd take a real look at any advanced propulsion. It's hard to make predictions though, especially of the future.

Musk is interested in colonizing Mars and the Solar System. I am sure he will be interested in anything that can help achieve that goal. However, I think Musk will only invest in concepts that have been proven.

We must understand that just 6 years ago, SpaceX and Tesla were almost bankrupt. And still now, SpaceX has not proved itself in the eyes of many, or even sometimes legally, which is why ULA did not choose them (when they did the bidding process seems to be the crux of the lawsuit)

Therefore, for now, Elon Musk is not in condition to invest in unproven concepts. (nuclear is proved of course, but you know what I mean... it was not developed enough as a propulsion tech)

My guess is that as SpaceX advances and becomes more solid in all fronts, THEN Musk will start looking at concepts that might help to colonize the solar system.

[Skipjack]

And still now, SpaceX has not proved itself in the eyes of many, or even sometimes legally, which is why ULA did not choose them (when they did the bidding process seems to be the crux of the lawsuit)

Uhm, no. That is not what happened. You should read it up!

[hanelyp]

Oh, absolutely. The cost of fuel for an F9 launch is only 200k USD (according to Elon Musk). Even if the cost for a launch goes down to 7 million, 200k is only a small fraction of it.
No, the reason why chemical rockets can not lower the cost much further than 7 million a launch is the rather complex operations, they need.

1. They are huge (and the F9 has rather little payload). Large launch vehicles are more expensive to build and maintain.

But are they more expensive out of proportion to their size?

2. Their mass fraction for propellant to structure is also huge (30 to 1 for the F9). Because of this, part of the strength of the F9 is due to the pressure in the tanks. If the tanks were not pressurized, they would not be stable enough to withstand the forces of a launch. That means that they are comparably fragile.

Flipped around, a lot of fuel is used in proportion to the amount of hardware. The reported structural margin for the Falcon-9 is pretty good compared to many other rockets.

3. They contain a lot of flammable fuel. That makes them pretty dangerous.

I understand that RP-1 has combustion properties pretty close to JP-4 or Jet-A used by jets.

4. They are very complex, with lots of systems and subsystems. That means that there are long checklists and complex procedures between flights. That means lots of manpower and that drives up cost.

That is where the shuttle failed utterly, with multiple systems that required painstaking inspection between flights. The required inspection and repair appears related to the bleeding edge margins in some shuttle systems. Reducing the man-hours required for each flight is critical for reducing launch costs. As is reducing the costly facilities supporting the spacecraft.
My impression is that the Merlin engine is markedly less complex than the jet engine on a common airliner.

[Skipjack]

Oh, absolutely. The cost of fuel for an F9 launch is only 200k USD (according to Elon Musk). Even if the cost for a launch goes down to 7 million, 200k is only a small fraction of it.
No, the reason why chemical rockets can not lower the cost much further than 7 million a launch is the rather complex operations, they need.

1. They are huge (and the F9 has rather little payload). Large launch vehicles are more expensive to build and maintain.

But are they more expensive out of proportion to their size?

2. Their mass fraction for propellant to structure is also huge (30 to 1 for the F9). Because of this, part of the strength of the F9 is due to the pressure in the tanks. If the tanks were not pressurized, they would not be stable enough to withstand the forces of a launch. That means that they are comparably fragile.

Flipped around, a lot of fuel is used in proportion to the amount of hardware. The reported structural margin for the Falcon-9 is pretty good compared to many other rockets.

3. They contain a lot of flammable fuel. That makes them pretty dangerous.

I understand that RP-1 has combustion properties pretty close to JP-4 or Jet-A used by jets.

4. They are very complex, with lots of systems and subsystems. That means that there are long checklists and complex procedures between flights. That means lots of manpower and that drives up cost.

That is where the shuttle failed utterly, with multiple systems that required painstaking inspection between flights. The required inspection and repair appears related to the bleeding edge margins in some shuttle systems. Reducing the man-hours required for each flight is critical for reducing launch costs. As is reducing the costly facilities supporting the spacecraft.
My impression is that the Merlin engine is markedly less complex than the jet engine on a common airliner.

Don't misunderstand me. SpaceX is doing an absolutely fantastic job and they are bound to revolutionize the space launch business, if they can do all they set out to do. But at some point, they will hit a wall with their approach, not matter how much they refine it. They say that they can get the cost for a F9 launch down to 7 million with full reuse. That seems to be a lower limit give or take a million or two.
RP1 is essentially kerosene and while that is comparably benign to other rocket fuels, a fully fueled F9 is still a huge safety hazard that requires closure of ranges and surrounding areas. It can not be launched over populated areas and there are a lot of regulations and hurdles that wont just go away with reuse and even with a perfect safety record.
A large chemical rocket with two separate stages, 10 main engines, several maneuvering thrusters and many subsystems still needs a comparably large team for a launch and the launch preparations. Elon Musk wants to reduce the time between launches to 1 hour, but that does not include a lot of the work that goes on around the LV that add man hours on top of that. All these things cost money. At some point your optimizations will hit the point of diminishing returns.
I think that maybe with the new methane engines, they will be able to do a SSTO RLV at some point, way down the road. That might allow them to reduce the overhead for a launch even more. But that too will hit a wall. Plus the vehicle will cost more to begin with.
Either way, with chemical engines, I just don't see the launch cost coming down to a point, where it becomes a consumer product. It will be close, but not close enough.

[tokamac]

Musk isn't even interested in fission rockets so I doubt he'd take a real look at any advanced propulsion. It's hard to make predictions though, especially of the future.

Musk is interested in colonizing Mars and the Solar System. I am sure he will be interested in anything that can help achieve that goal. However, I think Musk will only invest in concepts that have been proven.

We must understand that just 6 years ago, SpaceX and Tesla were almost bankrupt. And still now, SpaceX has not proved itself in the eyes of many, or even sometimes legally, which is why ULA did not choose them (when they did the bidding process seems to be the crux of the lawsuit)

Therefore, for now, Elon Musk is not in condition to invest in unproven concepts. (nuclear is proved of course, but you know what I mean... it was not developed enough as a propulsion tech)

My guess is that as SpaceX advances and becomes more solid in all fronts, THEN Musk will start looking at concepts that might help to colonize the solar system.

I agree with you and ask the question the other way:
Is Mars colonization conceivable with chemical rockets only?

I mean, with no nuclear power at all, no plasma thrusters. I though that electric plasma propulsion driven by enough MWe was the only way to go for inhabited interplanetary missions. Am I wrong?

Musk wants to colonize Mars and he wants to see that in his lifetime. Currently I see SpaceX goal to reach ISS for NASA and sell reusable rockets as a way to get enough money to fund what truly follows, i.e. interplanetary spaceships.

Regarding this, shouldn't Musk have another ace in his pocket, other than VTOL chemical rockets? He must have a big plan.

Nuclear fission is very dangerous, armful in case of an accident, adding the needed security for manned missions increases cost and weight, thus cost again… not counting the real proliferation risk.

So, suppose Musk thinks for "next stage" about going from chemical to nuclear fusion directly, skipping nuclear fission. Maybe he just waits for some successful powerful and compact fusion generator to emerge from all current research projects, among Polywell, Focus Fusion, General Fusion, Tri Alpha Energy, Helion Energy, MagPie z-pinch, etc…

Regarding this, the power source is tied to, but remains more important than the kind of thruster that could be attached to. Direct or indirect thrust, electrothermal with electromagnetic confinement like VASIMR or John Slough's fusion driven rocket, electromagnetic plasma thruster with Lorentz force acceleration… and above all that, if scientifically real and technologically practicable, a Mach-Effect thruster.

Maybe the electric fusion generator must be invented first, before Musk could envision putting his money into exotic propulsion like METs. I see the scheme that way.

[AcesHigh]

And still now, SpaceX has not proved itself in the eyes of many, or even sometimes legally, which is why ULA did not choose them (when they did the bidding process seems to be the crux of the lawsuit)

Uhm, no. That is not what happened. You should read it up!

what is not what happened?

I read it up. This is what I understand of the whole thing. (edit: I noticed I accidentaly replaced the USAF with ULA, is that what you were talking about?)

USAF left them out because they had not done all the required launches... SpaceX says USAF should have waited a tiny bit more, specially considering the bid is for rockets to be launched a few years from now.

SpaceX sues USAF saying the bidding should wait so there would be competition, plus saying that ULA uses russian engines that should had been embargoed (and I suppose embargoing those engines could compromise ULAs capacity to deliver those launches, despite they saying it doesn´t)

[AcesHigh]

I agree with you and ask the question the other way:
Is Mars colonization conceivable with chemical rockets only?

I mean, with no nuclear power at all, no plasma thrusters. I though that electric plasma propulsion driven by enough MWe was the only way to go for inhabited interplanetary missions. Am I wrong?

are you asking the other way? I am under the impression I was saying exactly the same thing

no, I don´t think you can colonize Mars with chemical rockets. Even simple EXPLORATION missions to Mars are difficult without nuclear propulsion imho.

Musk wants to colonize Mars and he wants to see that in his lifetime. Currently I see SpaceX goal to reach ISS for NASA and sell reusable rockets as a way to get enough money to fund what truly follows, i.e. interplanetary spaceships.

I fully agree. That´s basically what I said.

Musk's interviews say that. Even Paypal seems to have been just a way to make cash so he could go on with his projects to change the world and specially colonize space.

Regarding this, shouldn't Musk have another ace in his pocket, other than VTOL chemical rockets? He must have a big plan.

maybe yes, maybe not. Maybe he wants to have, but still have not decided. Maybe he is waiting for some techs to mature, and while he waits for that, he tries to revolutionize access to LEO.

Nuclear fission is very dangerous, armful in case of an accident, adding the needed security for manned missions increases cost and weight, thus cost again… not counting the real proliferation risk.

well, I don´t fully agree, but other people here who know more about stuff like NERVA, comment on it.

I would think that JUST LIKE Musk betted on good old ROCKETS (and more than that, the old dreams of rockets that could land vertically) instead of going the spaceplane way, maybe his vision for interplanetary travel involves good old almost fully developed tech like NERVA.

So, suppose Musk thinks for "next stage" about going from chemical to nuclear fusion directly, skipping nuclear fission. Maybe he just waits for some successful powerful and compact fusion generator to emerge from all current research projects, among Polywell, Focus Fusion, General Fusion, Tri Alpha Energy, Helion Energy, MagPie z-pinch, etc…

well, fusion powerplant schemes don´t really translate all the time to fusion propulsion schemes. We just have to see the fusion PROPULSION research... some similarities, quite some differences.

Check out the one by Dr Rob Adams (google it), here is only a superficial interview with him https://www.youtube.com/watch?v=8tI9uQ4YJSQ

also the one by John Slough with the metal liners http://nextbigfuture.com/2013/11/john-s ... s-his.html

this, the power source is tied to, but remains more important than the kind of thruster that could be attached to. Direct or indirect thrust, electrothermal with electromagnetic confinement like VASIMR or John Slough's fusion driven rocket, electromagnetic plasma thruster with Lorentz force acceleration… and above all that, if scientifically real and technologically practicable, a Mach-Effect thruster.

well, you know about John Slough propulsion scheme, I am not sure why you think Musk would then wait for development of land based commercial fusion reactors, instead of going directly to fusion techs specifically designed for space propulsion.

[Skipjack]

(edit: I noticed I accidentaly replaced the USAF with ULA, is that what you were talking about?)

Yes that and.
The protest is about the fact that the USAF extended the block buy from ULA to 36 cores without ever opening any of them for competition. Originally, they were going to compete 14 missions and that has been cut down to as little as 1. SpaceX was excluded from launches scheduled way into 2018! That is more than 4 years from now. SpaceX has to demonstrate 3 successful launches of the current configuration of the LV in order to become certified by the USAF (ULA never had to do that). At the time of the USAF signing of the block buy, SpaceX had already had two of those and the 3rd was only days away.
There is no reasonable reason that the USAF could not have waited a few days with the signing of the block buy in order to give SpaceX a chance to fulfill the 3rd launch required (which they subsequently did). So SpaceX is not suing because they were rejected, but because they were never allowed to compete for launches as long as 4 years into the future. This could potentially cost the US taxpayer billions. The whole RD-180 matter is just a second angle that SpaceX is persuing to up the pressure on the USAF and ULA, it is not the actual reason for the lasuit, though.

[tokamac]

well, you know about John Slough propulsion scheme, I am not sure why you think Musk would then wait for development of land based commercial fusion reactors, instead of going directly to fusion techs specifically designed for space propulsion.

Is John Slough fusion engine intended to achieve breakeven? It could produce thrust without reaching it as I understand, but in this case it would need a power supply to feed it.

[Skipjack]

well, you know about John Slough propulsion scheme, I am not sure why you think Musk would then wait for development of land based commercial fusion reactors, instead of going directly to fusion techs specifically designed for space propulsion.

Is John Slough fusion engine intended to achieve breakeven? It could produce thrust without reaching it as I understand, but in this case it would need a power supply to feed it.

If you are talking about the "fusion driven rocket" is supposed to have a gain of up to 500. 500 would reduce the trip time to mars to 30 days.
The "fusion engine" is actually the (maybe a bit confusing) name of their terrestrial fusion reactor for electricity generation. It has a lower gain, but is more economic to run, which is what is relevant for power.

[tokamac]

If you are talking about the "fusion driven rocket" is supposed to have a gain of up to 500. 500 would reduce the trip time to mars to 30 days.
The "fusion engine" is actually the (maybe a bit confusing) name of their terrestrial fusion reactor for electricity generation. It has a lower gain, but is more economic to run, which is what is relevant for power.

John Slough has indeed two fusion projects. His fusion power plant involves two colliding supersonic FRC plasmoids. See Helion Energy.
It reminds me a bit of Clint Seward who says he can create fusion from two self-stable plasma toroids colliding (Electron Power Systems).

John Slough's second fusion project is the rocket, and it's very different. There's only one FRC plasmoid, and it doesn't collide with another. It is compressed by a metal liner then expelled from the thruster into space.

I can believe he could achieve fusion reactions (with breakeven) and a good gain in his collider, but I don't understand from where he gets this "gain of 500" with a plasma compressed by a metal liner, whereas all other researchers all over the world failed to generate fusion at all with all sorts of liners for decades (except maybe Sandia labs using wire-array z-pinches with tens of millions of amperes).

But we digress from Mach Effects. This discussion underlines the fact that a high power source is preferable for deep space exploration.

[Skipjack]

If you are talking about the "fusion driven rocket" is supposed to have a gain of up to 500. 500 would reduce the trip time to mars to 30 days.
The "fusion engine" is actually the (maybe a bit confusing) name of their terrestrial fusion reactor for electricity generation. It has a lower gain, but is more economic to run, which is what is relevant for power.

John Slough has indeed two fusion projects. His fusion power plant involves two colliding supersonic FRC plasmoids. See Helion Energy.
It reminds me a bit of Clint Seward who says he can create fusion from two self-stable plasma toroids colliding (Electron Power Systems).

John Slough's second fusion project is the rocket, and it's very different. There's only one FRC plasmoid, and it doesn't collide with another. It is compressed by a metal liner then expelled from the thruster into space.

I can believe he could achieve fusion reactions (with breakeven) and a good gain in his collider, but I don't understand from where he gets this "gain of 500" with a plasma compressed by a metal liner, whereas all other researchers all over the world failed to generate fusion at all with all sorts of liners for decades (except maybe Sandia labs using wire-array z-pinches with tens of millions of amperes).

But we digress from Mach Effects. This discussion underlines the fact that a high power source is preferable for deep space exploration.

I know
John Sloughs Fusion Engine (Helion) is rather similar to the work Tri Alpha is doing. John, David and the others at MSNW/Helion are a lot less ambitious though and settle for the low hanging fruit with TD instead of PB11. It is a shame that they don't get more funding. They are among my personal front runners for practical and economic reactors within the next few years.

Their fusion driven rocket differs from other approaches, because they use a FRC plasmoid as the target. It is not the metal liner itself that does the compression, but the several megagauss strong magnetic field that is created by the liner and the plasmoid.