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shadow boxer
The Finger Painter & Master Ranter
in Zocalo v2.0
Getting into space the easy way.
Whats the biggest problem with Space travel for us right now ?
Getting into bloody orbit ! The Shutte uses something like 90% of it's fuel lifting fuel, irony of all ironies. So, the key is to break Gaia's grasp and acheive orbit much more cheaply.
How do we do that ?
Okay, well I think I've got that covered. How ? read on.
We know Scramjets work, we also know they need a velocity of almost Mach 7 before they will even light up. The Aussies at Woomera (shameless plug), got thiers to go by using a conventional rocket, shooting it up about eight kilometres, turning it and using gravity for an additional booster, they threw it back down again achieving the velocity they needed to fire up the engine.
Okay, if we have Scramjets, then we have escape velocity, provided we can get a Scramjet to operational parameters cheaply. How do we acheive that intial velocity ? Same principile as the above example, except, we use a tethered rigid helium or hydrogen lifting body around what is effectively a 'castle in the air' spaceport... tethered so pressure heights/storms/static discharge etc dont pose a threat, and also offer the opportunity to let the spaceport have a little positive lift while being winched down by the tethering points. LTA's of the 1930's had a lift ratio of 1 cubic metre of gas, to one kilo of mass. Given the advances of material science, ( carbon fibre, better aluminium/steel/titanium etc) that ratio is probably much better by now.
12 Scramjets at 120 tonnes =1440 tonnes, control tower 100 tonnes, launch bays and infrastructure 2500 tonnes, gas cells 2500 tonnes with change = 7000t
Thats 7Mm3 of gas, or a vessel, expressed in linear measurments, 350mx200mx100m
That's not really that huge and quite possible in terms of construction, practical feasibility is of course the real issue.
During the takeoff cycle, a dozen or more Scrams are loaded into basically massive cobra bays. Then up goes the spaceport to the edge of the atmosphere. Then, one by one the Scrams launch, "Express elevator to hell" style. (While a massive compensatory burnoff of hydrogen lift gas is completed when 80/120 tonnes of Scram 'leaves the barrel').
The Scrams go straight down, with the assistance of regular jet or chemcial engines, (perhaps jettisonable boosters like the Shuttle), until the candles lit. Then, with the assistance of extended variable wing geometry, the 'lit' Scram proceeds to pull out of the mother of all dives and climbs into orbit under Scram driven power, until of course it runs out of atmospehere to breathe, then I guess its back to chemical rockets.
There HAS to be some energy/fuel savings here somewhere...
Once its disgorged its payload into a Space station, moonbase, et al, it returns, re-enters the atmosphere and lands on the runaway adjacent to where the Spaceport lands, it taxis up to the Spaceport in 'down mode' and packs and racks for the next ride.
Please tell me whats wrong with this idea.
Whats the biggest problem with Space travel for us right now ?
Getting into bloody orbit ! The Shutte uses something like 90% of it's fuel lifting fuel, irony of all ironies. So, the key is to break Gaia's grasp and acheive orbit much more cheaply.
How do we do that ?
Okay, well I think I've got that covered. How ? read on.
We know Scramjets work, we also know they need a velocity of almost Mach 7 before they will even light up. The Aussies at Woomera (shameless plug), got thiers to go by using a conventional rocket, shooting it up about eight kilometres, turning it and using gravity for an additional booster, they threw it back down again achieving the velocity they needed to fire up the engine.
Okay, if we have Scramjets, then we have escape velocity, provided we can get a Scramjet to operational parameters cheaply. How do we acheive that intial velocity ? Same principile as the above example, except, we use a tethered rigid helium or hydrogen lifting body around what is effectively a 'castle in the air' spaceport... tethered so pressure heights/storms/static discharge etc dont pose a threat, and also offer the opportunity to let the spaceport have a little positive lift while being winched down by the tethering points. LTA's of the 1930's had a lift ratio of 1 cubic metre of gas, to one kilo of mass. Given the advances of material science, ( carbon fibre, better aluminium/steel/titanium etc) that ratio is probably much better by now.
12 Scramjets at 120 tonnes =1440 tonnes, control tower 100 tonnes, launch bays and infrastructure 2500 tonnes, gas cells 2500 tonnes with change = 7000t
Thats 7Mm3 of gas, or a vessel, expressed in linear measurments, 350mx200mx100m
That's not really that huge and quite possible in terms of construction, practical feasibility is of course the real issue.
During the takeoff cycle, a dozen or more Scrams are loaded into basically massive cobra bays. Then up goes the spaceport to the edge of the atmosphere. Then, one by one the Scrams launch, "Express elevator to hell" style. (While a massive compensatory burnoff of hydrogen lift gas is completed when 80/120 tonnes of Scram 'leaves the barrel').
The Scrams go straight down, with the assistance of regular jet or chemcial engines, (perhaps jettisonable boosters like the Shuttle), until the candles lit. Then, with the assistance of extended variable wing geometry, the 'lit' Scram proceeds to pull out of the mother of all dives and climbs into orbit under Scram driven power, until of course it runs out of atmospehere to breathe, then I guess its back to chemical rockets.
There HAS to be some energy/fuel savings here somewhere...
Once its disgorged its payload into a Space station, moonbase, et al, it returns, re-enters the atmosphere and lands on the runaway adjacent to where the Spaceport lands, it taxis up to the Spaceport in 'down mode' and packs and racks for the next ride.
Please tell me whats wrong with this idea.
Comments
[url="http://www.she-dc.com/stuff/Scramport.pdf"]http://www.she-dc.com/stuff/Scramport.pdf[/url]
are there no astrophysisists in the building ? aeronautical engineers ? [img]http://216.15.145.59/mainforums/biggrin.gif[/img]
[b]Getting into space the easy way.
Whats the biggest problem with Space travel for us right now ?
Getting into bloody orbit ! [/b][/quote]
What we need, is a REALLY big slingshot...
1. Acceleration for gravity (G) = 9.8 m/sec^2
2. Mach (using bad English to metric conversions of five miles/sec) = 8335 m/sec
3. Scram Velocity = 7 * Mach = 7 * 8335 = 58345 m/sec
4. Guestimated Weight (W) (using a [url="http://www.simviation.com/rinfolocc130.htm"]loaded C-130[/url] for comparison, probably too light) = 18,955 kg
5. Guestimated [url="http://www.grc.nasa.gov/WWW/K-12/airplane/shaped.html"]Cd of 1.14[/url] (a prism)
6. Guestimated [url="http://www.windpower.dk/stat/unitsw.htm"]air density (sea level)[/url] of 1.225 kg/m^3
7. Guestimated frontal area of 9 m^2 (probably small)
5. [url="http://www.grc.nasa.gov/WWW/K-12/airplane/termv.html"]Terminal velocity[/url] is where the Drag (D) = Weight yields 54.92 m/s
I don't see how you can achieve Mach 7 from free fall.
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bobo
<*>
B5:ITF
so, eith these values we end up with:
Mach 7= 7*330 = 2310 m/s
Terminal Velocity = 194,705 m/s
thats not quite mach 1, but its a start. add up some boosters, and it should work (if I calculate this correct (eh, more guesstimating)), at 3g (+1g of earth´s own gravity) booster accelleration it would take some 60 seconds to reach mach 7. on the other hand, if it would launch straight down, the spaceport would have to be at some 133000m altitude (and that´s not counting the altitude needed to pull the plane up again) - nearly in space itself.
Also, I myself would feel rather uncomfortable, sitting in a spaceplane, accelerating [b]downward[/b] at 4g... there´s to much chance something could go wrong, and suddenly I find myself digging a rather big crater below our spaceport - not a very pleasant outlook. but, otherwise a nice new idea - it also could be used as a testbed for technologies needed for the construction of a space elevator.
and thats what pre-paid funeral plans are for.. [img]http://216.15.145.59/mainforums/biggrin.gif[/img]
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[url="http://www.minbari.co.uk/log12.2263/"]Never eat anything bigger than your own head.[/url]
"Nonono...Is not [i]Great[/i] Machine. Is...[i]Not[/i]-so-Great Machine. It make good snow cone though." - Zathras
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Talk is silver, but violence is gold.
[img]http://216.15.145.59/mainforums/biggrin.gif[/img]
Yeah I imagine it would have to be up as high as freakin possible to give the craft some room to move.
I guess that perhaps Scrams would not make fantastic passenger craft, leaving what would be effectively a steam catapult, straight down, or even down at a steepish angle wouldnt be for the faint of heart, the atmosphere also gets thicker as you go down.
I still maintain that we have to find a better way to get stuff into orbit... I think I'm on the right track...
1. Are you doing this over the ocean away from anyone? My thinking is the sonic boom would be large, and given how people hated the Concorde so much… Can you say broken windows?
2. You say it would pull out of the dive... is anything alive going to be on this thing? Talk about G forces. That and I also think materials have come a long way but I don't know if they would have the strength to deal with what you are proposing even today or ten years from now.
It's an interesting idea, but wouldn't it be better to just do the 'fly into space idea' or even building an 'aircraft carrier in the sky' or floating runway instead of your big balloon?
[This message has been edited by Konrad (edited 11-25-2002).]
Lower tech Ballon bouyancy or air foil assist can cut the cost down considerably, you are trading off time for power.
Just my thoughts anyway...
[img]http://216.15.145.59/mainforums/wink.gif[/img]
At Mach 7 you would exsert over 27 1/2 tons of Pressure per square inch over your control surfaces on a 5 ton ship. As ship size increases so does weight transfer along surfaces by mulitples of 3.55
In truth the ship or whatever it is would be torn apart by the manouver!
Then there is the human factor, moving at that speed human reactions are not fast enough to react to any mistakes.
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[b]4 Thousand Throats can be cut in one night by a running Warrior[/b]
[This message has been edited by Argone (edited 11-25-2002).]
or throw Scrams out in a shallow climb ???
anyways, the point is getting the launch site up 16km or whathaveyou to lower fuel usage.
Anyways, "they" are working on Scramjets, but they're nowhere near ready for actual use yet. Systems like this are decades away, but they HAVE been considered, so I don't think we're coming up with anything new here.
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[url="http://www.alecm.com/"]Alec McClymont[/url]
"Something is only impossible until it's not."
this is a raw concept... one pushes a raw concept till it absolutely falls over, when one finds a law of physics broken or something else which makes the project unworkable.
Do you know how much juice the shuttle uses in the first few kilometres of its journey ? Trust me, reducing a trip into space for the shuttle by 16 km is LOTS in real terms.
As to the floating platform idea, it would be tough. Balloon technology has only recently allowed people to fly around the world in one (a very high-tech balloon as well), and they only managed to do it because they didn't hit any bad weather or have any technical problems. Balloons are fragile by nature, and using them to suspend a spaceport seems like an overly hazardous proposition.
Realistically, by the time something of this nature were technologically possible, a vehicle using jet/scramjet/rocket engines will be able to take off from a runway and fly into orbit no problem.
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[url="http://www.alecm.com/"]Alec McClymont[/url]
"Something is only impossible until it's not."
Mach equals a mile in five seconds, not five miles per sec!
Mach equals a mile in five seconds, not five miles per sec!
SB (and others), you appear to be making a mistake I often make. The object of any space vehicle is not altitude, but velocity. Escape velocity is 11.2 km/s; anything less and you're in orbit (either stable or ground-intersecting :eek [img]http://216.15.145.59/mainforums/smile.gif[/img].
You do get some payback by being at the equator. If you could tether a launch platform at the equator, you would increase the angular velocity. I'll see what I can figure out.
Who was our resident astrophysicist? Cary or John somebody? I haven't seen him in awhile.
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bobo
<*>
B5:ITF
(Hope I haven't usurped your thread)
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bobo
<*>
B5:ITF
He was good at this kind of stuff indeed. Too bad he's not here now.
- PJH
Then build an elevator to the asteroid using "Special Material" with magnetic rails for drive on special elevaters to take you to the asteroid.
From there take off is easy in 0G
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[b]4 Thousand Throats can be cut in one night by a running Warrior[/b]
interesting reading, with implications for this idea...
it shows that modern blimps are perhaps making a big comback...
using a really large one for an equatorial launch platform has to be good...
using a gunsling to transport materials sounds ok too
if I thought I wouldn't do myself an injury I'd think about building a crude gunsling myself, just to tool about with the idea, certainly not to aerospace standards, but the principile seems pretty good...
come to think of it.. what a nasty hypervelocity gun this would make...
a gunsling, gyrostabilized like a conventional turret, you would have instant 360 deg engagement The actual projectile may be a problem because as disk may not have the penetrative power a spike would, then again whats wrong with a 'ninja star chucker' [img]http://216.15.145.59/mainforums/biggrin.gif[/img] A depleted Uranium Shiruken.
He was on conan a few weeks ago.
They made fun of him, but those of us that understood the principle found it interesting....
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[i]"...Never start a fight...but [b]always[/b] finish it."[/i]
[This message has been edited by Rick (edited 12-13-2002).]