Maglev launcher for suborbital space tourism?

[maglifter]

Hi, I'm not an engineer nor a scientist, but I'm fascinated by maglaunchers and I have a few questions about them which maybe you could answer.

-I read that maglaunchers are being studied to accelerate spacecraft in a first phase, in order to reduce or get rid of the first stage of the rocket.
-Moreover, I read that maglaunchers would be first used to bring microsats into LEO. But there are doubts about the economic feasibility of such a system, since it would require hundreds (even thousands) of launches a year. And the market is simply not there.

Knowing this, I was wondering if a maglauncher would be feasible for suborbital space tourism. Getting a 3 person craft up to only 100km or so, is entirely different from getting it into real LEO orbit. And there's definitely a market for hundreds of launches a year.

-So does anyone have any idea on how long such a maglauncher should be? How many kilometres? And how steep should the launch angle be?
-Would the space tourists survive the high gees? And which are those gees?
-Would it make a considerable difference if you were to build such a system on a mountain slope, so that the track's end would be located at, say, 4.5km altitude, reducing atmospheric drag at launch?
-Likewise, would it make a significant difference if you were to build it right on the equator (say in the Andes mountains)?

I'd love to hear your comments. I know there's a lot of sci-fi about maglaunchers, but one science consortium is studying the feasibility (only: their website is "under construction": http://www.maglifter.com - so it's not very useful).
Moreover, I read that NASA and ESA have been working on maglaunchers, as has the US Navy, for launching intercontinental missiles. (a good review here: http://archives.cnn.com/2002/TECH/space/01/03/maglev.launches/)

Put simply: would such a system make sense if it were only to serve for suborbital space tourism flights, which are, after all, quite less demanding than getting into orbit.

Thx for your input.

 

[drag]

Greetings !

You can use the ussual x = a * t^2 / 2 to calculate
the track lenght. For a manned vehicle the maximum
reasonable a is probably about 3 gs. Say you need
Mach 6 so you get something around 60 miles.

For space tourism, building a 60 mile long maglev launcher
is EXTREMELY expensive - not worth it at all.

Live long and prosper.

 

[maglifter]

Greetings !
For space tourism, building a 60 mile long maglev launcher
is EXTREMELY expensive - not worth it at all.
Live long and prosper.

Thanks! Now I know I don't have to spend my money on building a mega maglauncher.
But this won't stop me from living long or from prospering!

Next!

 

[russ_watters]

Maglev (or possibly air-gun) launchers are, however, feasible for some satellites, which can be hardened to withstand several hundred g's.

 

[maglifter]

Of course, maglaunchers are being built to provide launch assist. So the idea in itself is nothing new.

I was just wondering if you could pop out a small tourist spaceplane with it, for suborbital rides only. The answer is obviously yes.

 

[Invader_tech]

If you think about it, the conventional idea for a track as such would be started at the base of a track angled skyward (obviously) and so you would have to reach a certain velocity in the shortest timeframe possible withought knocking out your passengers. This acceleration shouldn't just be limited to the track alone though. If I had to think up plans of my own for this, I would start the shuttle off on landfixed rails (like a train) maybe using a propulsion other than magnetics. By the time this shuttle has reached a suitable velocity the track would switch into magnetic, and it would start to slop upward. At this point you can accelerate the car to a slighty greater velocity. This way, you can launch the shuttle earlier and the track won't have to be as long.

The benefits from my idea-
--Shorter magnetic track saves on money
--Shorter magnetic track saves on engineering difficulties
--G's exerted on passengers are less strenuous
--Passengers get a slightly longer flight time :)

Hope I helped...

 

[drag]

Even for space tourism, the top speed of 200 mph max which
you could reach upon a normal railway is negligable compared
to the total speed you'd need.

Peace and long life.

 

[Kenneth Mann]

Just a few observations here in reply.

-I read that maglaunchers are being studied to accelerate spacecraft in a first phase, in order to reduce or get rid of the first stage of the rocket.
-Moreover, I read that maglaunchers would be first used to bring microsats into LEO. But there are doubts about the economic feasibility of such a system, since it would require hundreds (even thousands) of launches a year. And the market is simply not there.

This, in a way, shows some of the illogic in our nature. We'd rather spend exorbitant amounts for each launch, than to implement a high cost substitute which would greatly lessen these recurrent costs. We spend tens - maybe hundreds of millions per launch, so couldn't we instead put this into some system which would reduce the per-launch costs to negligible amounts? The answer then appears to be - no. Then we'd be putting billions into a system just to put up a few thousand dollar insertions. No one even seems to stop to think that by reducing the cost for each launch, there will be more launches. ("If you build it, they'll come.") The problem appears to be more political than either technical or economic.

The only really suitable approach, it appears, would be to implement a truly cooperative effort, in which business and government; scientific, military and economic interests; and all willing to put up investments, would share a stake - sort of a "super corporation". I'm afraid that this though would degenerate into a cat fight. The industrial nations would squabble over control and prestige, scientific, military and economic interests would squabble over mission priorities and third-world nations would try make it a transfer-payments program.

-Knowing this, I was wondering if a maglauncher would be feasible for suborbital space tourism. Getting a 3 person craft up to only 100km or so, is entirely different from getting it into real LEO orbit. And there's definitely a market for hundreds of launches a year.

In my opinion - No! The tourism trade alone, would never pay enough to cover the up-front costs. First we would need a system, then tourists could take advantage of the ultimate per-launch cost reductions. In essence, the tourist trade could be part of the overall stakeholder pool.

While we're at it, why limit tourist interests to just suborbital flights? It seems to me that this should be an open-ended, develop as you go approach. Who knows? Maybe at some point, we could develop hotels resorts and maybe even cities out there. (I don't venture to guess when.) First though, we need to start the infrastructure upon which all these things can be built. (Why do we even consider going to the Moon, etc. without that infrastructure?)

--So does anyone have any idea on how long such a maglauncher should be? How many kilometres? And how steep should the launch angle be?
-Would the space tourists survive the high gees? And which are those gees?
-Would it make a considerable difference if you were to build such a system on a mountain slope, so that the track's end would be located at, say, 4.5km altitude, reducing atmospheric drag at launch?
-Likewise, would it make a significant difference if you were to build it right on the equator (say in the Andes mountains)?

I'd love to hear your comments. I know there's a lot of sci-fi about maglaunchers, but one science consortium is studying the feasibility (only: their website is "under construction": http://www.maglifter.com - so it's not very useful).
Moreover, I read that NASA and ESA have been working on maglaunchers, as has the US Navy, for launching intercontinental missiles. (a good review here: http://archives.cnn.com/2002/TECH/space/01/03/maglev.launches/)

Why do we need a high 'G' launcher. Do we want a ballistics projectile 'thrower', or are we simply seeking a launch booster which would offload a significant portion of the job from a self-contained spacecraft ? (And enhance safety.) If the latter, then mach one or two is more than significant. This would make a 'high G' boost unnecessary.

A mountain slope appears to be a great approach. It won't be cheap, but then we're talking about something useable here over a very long term.

The Equator would offer only marginal advantage in achieving orbit over say, the latitude of Canaveral. On the other hand, for reaching the Moon or planets (which share a similar inclination to that of Canaveral) the Equator would be a disadvantage.

-Put simply: would such a system make sense if it were only to serve for suborbital space tourism flights, which are, after all, quite less demanding than getting into orbit.

In my opinion - - - No!

KM

 

[maglifter]

Thanks for your informed opinion, Kenneth.

 

[drag]

This, in a way, shows some of the illogic in our nature. We'd rather spend exorbitant amounts for each launch, than to implement a high cost substitute which would greatly lessen these recurrent costs. We spend tens - maybe hundreds of millions per launch, so couldn't we instead put this into some system which would reduce the per-launch costs to negligible amounts? The answer then appears to be - no. Then we'd be putting billions into a system just to put up a few thousand dollar insertions. No one even seems to stop to think that by reducing the cost for each launch, there will be more launches. ("If you build it, they'll come.") The problem appears to be more political than either technical or economic.

The only really suitable approach, it appears, would be to implement a truly cooperative effort, in which business and government; scientific, military and economic interests; and all willing to put up investments, would share a stake - sort of a "super corporation". I'm afraid that this though would degenerate into a cat fight. The industrial nations would squabble over control and prestige, scientific, military and economic interests would squabble over mission priorities and third-world nations would try make it a transfer-payments program.

I'm sorry, but I disagree. I believe the problem is purely economic.
If you come to any investor today and ask for money for such
a project what will you tell him when he asks about future profits ?
A simple: "If we build it - they'll come." will not suffice for any bussiness
man. It may seem simple and abvious to us the engineers, scientists
and futurists, but to them things are very different.

Same goes for politicians who need public opinion on their side.
They'll find it difficult to explain to the general public such a huge
economic investment. The only real way for the public to agree with
this is some spirit motivating campain - like in the case of JFK.

Besides, if modern advanced rockets were mass produced for
multiple space launches we'd be able to bring the costs down
10 times at least, as well. But, you need a constant massive
grow in demand for that. And that won't happen until the
prices are lowered at least a few times and many new possibilities
will occur to people - science and mainly bussiness.
So, it's kin'na like a magic circle for now, I guess.

Live long and prosper.

 

[maglifter]

Drag,
I think economically a maglauncher makes sense.
As you know, there has been some serious scenario writing on commercial suborbital space tourism (with Space Ship One as the prototypical launch situation), and in virtually *all* scenario's, the "rocket" stage is seen as very high risk.
We've seen the SSI launches, and in all three of them, there were anomalies, one even showed a serious anomaly.

I think if you tell investors that with a maglauncher, you can get rid of this high-risk stage, and you basically provide a hassle free, ballistic launch, they might be interested.

Let's not forget that you need only *one* crash of a space tourism vehicle, and the entire industry would collapse. Consumers are highly risk averse. A maglev launch would be much safer. And hence be an alternative to risky rocket launches.

People would be willing to put up the extra money, I think.

 

[drag]

I agree that this is an important factor, indeed. But we're
talking a LOT more money, so it's certainly not enough.
Perhaps, though, the 11,000 who signed in with that British
investor for sub-orbital flights on space-ship-one type rockets
with a 190,000$ price tag will start making an impact on
other potential major investors, as well.

Peace and long life.

 

[Kenneth Mann]

I'm sorry, but I disagree. I believe the problem is purely economic.
If you come to any investor today and ask for money for such
a project what will you tell him when he asks about future profits ?
A simple: "If we build it - they'll come." will not suffice for any bussiness
man. It may seem simple and abvious to us the engineers, scientists
and futurists, but to them things are very different.

Same goes for politicians who need public opinion on their side.
They'll find it difficult to explain to the general public such a huge
economic investment. The only real way for the public to agree with
this is some spirit motivating campain - like in the case of JFK.

Besides, if modern advanced rockets were mass produced for
multiple space launches we'd be able to bring the costs down
10 times at least, as well. But, you need a constant massive
grow in demand for that. And that won't happen until the
prices are lowered at least a few times and many new possibilities
will occur to people - science and mainly bussiness.
So, it's kin'na like a magic circle for now, I guess.

Live long and prosper.

You are right, and at the same time you've made my point. No commercial interest will at this time see any profit - if working alone, or if expected to put up a large part of the investment. Governments, on the other hand won't see any substantial return in the short term, and in the political and economic realms, short-term seems to be more and more, the dominant thinking mode. Somehow, we've got to start thinking long-term and working more together.

Yes, it is economic, but mostly in the minds of the would-be actors. There will be great pay-back if we pull together, but this won't come until:
a) We all see the potential.
b) We resolve to work together and share the effort.
c) We realize that the pay-back will not come soon.
The real drawback in this is the fact that the greatest pay-back probably won't accrue necessarily to those who made the greatest investments. Columbus got little profit from his effort. Spain did for a while, mostly through plunder, subjugation and exploitation, but the greatest benefit came years (centuries) later to the nations (and their millions) that came from the venture. (Some, notably those who came to the Americas before Columbus could argue the benefits derived, but even these people stand to profit in future years, if we don't regress badly.)

In any case, I believe that an aggressive development of the near-Earth region of space offers us the best (long-term) opportunity, and we shouldn't blow it, but I'm not at all certain that we won't. (For one thing, the demand will never come first.)

KM

 

[Kenneth Mann]

Drag,
I think economically a maglauncher makes sense.
As you know, there has been some serious scenario writing on commercial suborbital space tourism (with Space Ship One as the prototypical launch situation), and in virtually *all* scenario's, the "rocket" stage is seen as very high risk.
We've seen the SSI launches, and in all three of them, there were anomalies, one even showed a serious anomaly.

I think if you tell investors that with a maglauncher, you can get rid of this high-risk stage, and you basically provide a hassle free, ballistic launch, they might be interested.

Let's not forget that you need only *one* crash of a space tourism vehicle, and the entire industry would collapse. Consumers are highly risk averse. A maglev launch would be much safer. And hence be an alternative to risky rocket launches.

People would be willing to put up the extra money, I think.

You've hit on probably the main advantage of the "maglauncher", and that is its capability for ameliorating much of the presently very high risk in spacecraft launches.

The Shuttle has demonstrated to us that there are two periods of very high risk involved in spacecraft launching, and especially where human crews/passengers are concerned. These are:
a) At initial lift-off and during the early boost phases.
b) During the upper re-entry period.

During the first of these, the lift-off and boost phases, our present launch mode is extremely unstable. We have, in essence, an extremely volatile substance dependency carried in very fragile structure, moving initially at very low, difficult to control speed, using fragile and short-life propulsion hardware, and having virtually no abort and glide-back capability. The result is that we must exert an exorbitant effort into our quality control processes, with the resultant orders of magnitude increases of cost and time.

Right off - the maglauncher approach relieves of one of these (probably the most serious) problems - in that it gives us an abort-glide back capability. First, as with an aircraft during take-off, if critical 'launch speed' isn't achieved at a predermined point during the maglev run-up, the launch can be aborted on the track, and the maglev vehicle removed and repaired. Next, if the maglev achieves its launch speed, and the boost vehicle does not ignite, it simply becomes a ballistics glider, and can be taken to designated 'abort landing facilities' (it is assumed that the boost vehicle has wings of some sort). Then, if the boost vehicle ignites but lacks sufficient impulse to achieve orbit, it simply becomes a suborbital vehicle, and can be directed to other designated landing facilities. Finally the chances of a launch-phase explosion are greatly reduced by the simple fact that the boost vehicle structure and propulsion engines can be made more substantial and thus more reliable (use of such intermediate boost methods as the Scramjet would also help in this direction - and the Maglev could bring the Scramjet up to its ignition velocity). Actual use of rockets and rocket propellants could be minimized.

In similar manner, the second "high-risk" element can also be reduced by allowing us 'beef-up' our re-entry shielding, and to add other aids to re-entry, or even to employ more powered braking during re-entry (if that is found preferable).

Finally, by obviating much of the checking and re-checking and re-re-checking required in Today's very fragile launch systems, we significantly reduce the per-launch costs. An interesting discussion of launch cost factors is given in the following opinion article:

http://www.ghg.net/redflame/launch.htm

Still, I believe that to make maglev launch a reality, government (more than one) must join with industry, in a combined approach.

KM

 

[Kenneth Mann]

I agree that this is an important factor, indeed. But we're
talking a LOT more money, so it's certainly not enough.
Perhaps, though, the 11,000 who signed in with that British
investor for sub-orbital flights on space-ship-one type rockets
with a 190,000$ price tag will start making an impact on
other potential major investors, as well.

Peace and long life.

A huge amount of money! We need not only those interested in the ride, but also everyone else with some interest in space.

KM