NationStates Jolt Archive

Ok, I know most of you will probably go yeah, excellent; or scream and shout GODMOD or something. Any ideas about making it the littlest bit plausible will be very welcome. So, onto the actual aircraft:


MTA-B01
http://www.globalsecurity.org/intell/systems/images/sr-71-ec95-42883-4.jpg
AOA - Atmosphere-Orbit-Atmosphere. This aircraft was designed to able to enter and leave orbit at will. Using a basic aircraft design, specialised air spikes (similar to those used in conjunction with PDWE) instead of pushing air away, pull it towards the SABRE engines, and around the wing. VTOL capability has been sacrificed for the ability to enter space, and a long runway is needed for it to operate. There are several canisters of liquid oxygen, protected by Triad armour, that provide oxygen for forays into space, plus as an attitude controller once in space. CO2 scrubbers remove excess Carbon Dioxide and prevent loss of consciousness for the pilot.

High heat resistance materials are incorporated into the Triad armour on the outside of the aircraft to deal with the high temperatures of re-entry, also allowing high speed entry and subsequent suprise afforded thus. External mounts are unavailable as this would change the structure of the aircraft and cause damage upon re-entry.

The SABRE engines will gather fuel from the atmosphere (such as oxygen etc), which it can then store for later parts of the flight. This design doesn't allow for prolonged periods of time in space, just a quick breach into space, then back again fairly quickly, thereby preventing the majority of the condensed fuel from evaporating away. Once re-entry has occured, the aircraft will require a moderate amount of time in the atmosphere to gather enough fuel for exit to space, though at the speed the aircraft will be travelling at, at that moment in time there should be enough time before any enemy aircraft reach you.

Designed by: Phoenixius
Function: AOA bomber
Crew: 2
Length: 40m
Width: 20m
Height: 5.5m
Ceiling (normal flight): 30,000m
Thrust: 100,000 lbs
Max Speed (SABRE): Mach 10
Max Speed: Mach 3
Supercruise: Mach 2
Weapons:
6x MTG-03
2x MTM-01
1x MTG-01 A
Systems:
Archangel G-IV
PHBVS G-III
EMPPS
PDCS G-II
APS
PMAS G-II

Cost: $500mil

So nothing really bad, nothing really amazing then hey? So would anyone buy it?

The Republic of Intelligent Neighbors would like to order 4 of these aircraft for research and development purposes. An order for more will be forthcoming if they meet our requirements. The money will arrive shortly after your confirmation.

Marcus Brandt
Head of the IN HSS.


//OOC: Good design Phoenixius, I am researching the possibility of using the natural rotation of the earth to allow the plane to travel very fast. Is it possible to reach outer orbit and let the earth spin below then re-enter at any point?//

ooc: Good idea...

Actually this has been discussed and researched in RL. In the next 15-20 years look for something like this coming into existence or design. Many civilian aircraft makers have thought of this design because it allow them to go really fast at very high altitudes and then go into space and coast and cool...

OOC: It looks at least partially plausible, but I dont really see the point in giving a fighter the ability to enter space. Not only is there nothing in space that requires a $500m fighter to destroy, but it also requires you to give over a lot of space for liquid oxygen, which greatly decreases your operational range.

It could work but the weight has to be under 40,000 lbs. I'm comparing this to the X-15. The X-15 had a maximum take-off weight of 34,000 lbs while it produced 70,400 lbf of thrust. That's a ratio of 2.07:1. I would suggest having a little higher than that for your airplane.


Praetonia: You could always have a surprise attack on the enemy with this fighter ;)

OOC: It looks at least partially plausible, but I dont really see the point in giving a fighter the ability to enter space. Not only is there nothing in space that requires a $500m fighter to destroy, but it also requires you to give over a lot of space for liquid oxygen, which greatly decreases your operational range.

//OOC: Well I was not intending to use it as a fighter, I would pack it with more oxygen tanks/fuel and reconnaisance equipment in place of weapons. This shouldn't be too hard, the plane does bear many similarities to a certain SR-71 Blackbird... ;). The benefits of such a plane are immense, it is one hell of a lot cheaper, not to mention faster, to use one of these rather than position a satellite over the area. Space is also a good hiding place from enemy fighters. I do agree however that the thrust per pound issue needs to be looked at, after all Phoenixius is looking for constructive criticism.

Mach 8 isn't fast enough to reach orbit, and 30,000m isn't even a third of the way to space.

The 30,000m ceiling was for normal flight only - obviously not enough for orbit. This has now been shown on the specs. Thrust has been upped to 100,000lbs - hope it should be enough. As for speed is Mach 10 the right speed? I know you need to be travelling at 11km/s to reach orbit from the ground with only the initial force.

As for it being a fighter, the idea was so that it could strike at enemy aircraft before they realised they were there. Recon and bomber AOA aircraft are o nthe drawing board, but I wanted to see if this would be acceptable before wasting time on something that wouldn't be allowed per say.

IN, the aircraft are on route now - we hope you enjoy them. These are free of cost, and we would appreciate any information you gather from your tests, to supplement our own.

But I'll have to tell you this, those 100,000 lbs engines will have to be huge! I don't know if they'll fit on the current size aircraft.

OK, I'm not entirely competent on thrust, and the size engines required, so could you give me some details of what you think might work, or should I wait a few days or so before I can get onto GlobalSecruity.org and work around the size and thrust problems?

Hmm.... if I ever finish by orbital bomber (the US is working on one now...) i'll come back and buy some of these.

OK, I'm not entirely competent on thrust, and the size engines required, so could you give me some details of what you think might work, or should I wait a few days or so before I can get onto GlobalSecruity.org and work around the size and thrust problems?

Considering that the space shuttle's engines each produce 400,000 lbf of thrust, I'd say you would have to scale those engine's by 4. ;) That would be small enough though you will have to still significantly inlarge the aircraft to fit those engines in the aircraft.

Orbital velocity is about Mach 25. You might be better off looking at things like HOTOL (http://www.astronautix.com/stages/hotol.htm) or the VentureStar (http://www.astronautix.com/lvs/venestar.htm) if you want a SSTO, rather than trying to scale up the SR-71.

Shildonia, I used the SR-71 pic, because I liked the look of it, as opposed to any other reason. I will look into those links and see if I can do something with them. Thanks for all the help so far, I should update the stats within a few days.

OK, I'm not entirely competent on thrust, and the size engines required, so could you give me some details of what you think might work, or should I wait a few days or so before I can get onto GlobalSecruity.org and work around the size and thrust problems?

The worlds record for jet engines - 127,000 lbs. of thrust - GE's engine for the Boeing 777. Information is here: http://www.geae.com/engines/commercial/ge90/index.html

It's not that you can't build an engine with the right thrust, its that the size on the plane's pic. you show is way to small to deliver that amount of thrust. I like the plane's design as well, but I don't think the engine size is feasible for the thrust you claim to develop. Even if it is a SCRAM jet engine as opposed to a "regular" jet engine.

Ok, so the pic hasn't got the right size engines - is the airframe large enough to hold 100,000lbs engines, or does it need to be larger? I can get someone to make a picture similar to the Blackbird, but with larger engines (I'll get them to put them closer to the fuselarge).

remember the plane isnt going into orbit, its flying around in space, not just hanging there.

i would guess that the picture is just a representation, not EXACTLY what it would look like.

Nice going there, by the way. I would buy some, but my wwii level army can only really do with experimental jets at the moment. and i have just invented the first nuclear weapon for my country. so a little to modern for me.

//OOC: What about a Pulse detonation engine? (http://en.wikipedia.org/wiki/Pulse_detonation_engine) Or even a double pulse detonation engine (as on my VA-3, developed by Azazia) where the dual engines work together to negate any vibrations. Thanks for the free planes Phoenixius!//

Ohia Island Test Facility

The first MTA-F02 fighter laboured into the air, and rose slowly. The engines roared loudly and the plane went higher and higher, picking up speed. Soon the plane was out of sight, and they had to reley on feeds from the computer system and radar. As the pilot neared the limits of space he noticed that the plane was beginning to slow, the resistance proving too much to go into full orbit. The weight of the plane's massive engines was severely affecting the flight, so he decided to end the test, taking the plane down slowly. The first test had failed, but there would be many more tests done on this extraordinary idea.

PDWE are the way to go then? I'm trying to keep this strictly MT, but if PMT is the only way, then so be it. Would everyone agree that PDWE would solve the problems? ANd would 10-15m engines on this 40m aircraft be sufficient?

PDWE are the way to go then? I'm trying to keep this strictly MT, but if PMT is the only way, then so be it. Would everyone agree that PDWE would solve the problems? ANd would 10-15m engines on this 40m aircraft be sufficient?

That wouldn't work. First of all PDWE are jet engines meaning that they require air to work while your fighter will be in space, so you can't use them. Also your only chance as I see is using rocket engines. I suggest you use a turborocket. It works by gathering oxygen from the atmosphere before turning it into liquid, it then is stored in the aircraft for use in space.

http://en.wikipedia.org/wiki/SABRE

This link shows one paticular engine after the concept. You can use it for the basis of your engine.

The PDWE will only be to get it into space - once in space it has compressed air to manouver, and re-enter the atmosphere. The only problem at the moment is actually getting enough speed to get into space in the first place.

And I would rather not use rocket fuel unless it is really necessary - I would like it to be able to enter space at least twice before having to land and refuel or whatever.

Looking at it, that SABRE engine looks perfect. Would anyone have any problems with the thrust and size of the engines as SABRE engines? Would the engines in the pic need to be larger to make them powerful enough?

If this works for everyone, then I'll begin the production of them, and start to desing recon and bomber versions.

Well, I read about those SABRE engines, and they seem to be good. But I have one issue, whether flight in and out of space could be repeated in a short period of time. This is because the engines need to store rocket fuel, build it up enough to use to get into orbit. But if you wanted to come back down and up again quickly, you wouldn't have enough liquid oxygen/hydrogen without building some up first. Perhaps you could add some storage tanks to be filled before the flight? I don't think the thrust of those engines is an issue, but it takes a while to get up to speed.

I wuld like 10, because my country is resonably vulnerable. :)

I would like 10, because my country is reasonably vulnerable. :)

They are still being developed I believe, I aquired a few because I was helping to evaluate his design and IN is listed as a 'prefered customer' of Miertech. I guess after he has redesigned them with the SABRE engines he will agree to export them to countries such as yourself.

Well, I read about those SABRE engines, and they seem to be good. But I have one issue, whether flight in and out of space could be repeated in a short period of time. This is because the engines need to store rocket fuel, build it up enough to use to get into orbit. But if you wanted to come back down and up again quickly, you wouldn't have enough liquid oxygen/hydrogen without building some up first. Perhaps you could add some storage tanks to be filled before the flight? I don't think the thrust of those engines is an issue, but it takes a while to get up to speed.

Presumably one would have to have sufficient propellant to carry out the re-entry burn left over after orbital insertion, because once in space there's no atmosphere to extract additional propellant from.
You've got to bear in mind that LOX and Hydrogen are both cyrogenic, and it will boil off once in space, which will limit the amount of time the vehicle can spend on-orbit.

sorry to be old fashioned but how about ramjets

sorry to be old fashioned but how about ramjets

That is air-breathing, meaning that it won't be able to operate in space. Also it can't produce anything near enough thrust to get out of space.

As for the problem. I would say that you wouldn't be able to dash back into space. You will have to lengthen your period in the atmosphere to get enough oxygen and then go back. Maybe you could collect oxygen while coming out of orbit and entering the atmosphere though the hot plasma will surely damage the engine parts no matter the material if allowed inside the engine. So I'm thinking that you'll have to get rid of that if you want to have a moderately low-weight aircraft.

Presumably one would have to have sufficient propellant to carry out the re-entry burn left over after orbital insertion, because once in space there's no atmosphere to extract additional propellant from.
You've got to bear in mind that LOX and Hydrogen are both cyrogenic, and it will boil off once in space, which will limit the amount of time the vehicle can spend on-orbit.

I might be wrong but I'm sure he could keep the hydrogen compressed the entire flight. That's not a big problem.

Compressing it won't help keep the temperature down. Liquid Hydrogen needs to be stored at -235 degrees Celsius (LOX can be stored at the comparitively balmy temperature of -183 degrees celsius). Even during the night side of an orbit, the temperature is -121 degrees celsius. It's going to boil without some kind of coolant system, which will add additional mass. SSTO has a pretty low payload fraction as it is, and cooling systems are going to eat into that even more.
Storable propellants are an alternative, but they tend to be highly toxic, so the ground crew will have to either wait for the propellant to be drained (time consuming) or wear HazMat suits (performance degrading). Either way it's going to increase turn around time, so it's not going to spend as much time in the air as a normal fighter.

Compressing it won't help keep the temperature down. Liquid Hydrogen needs to be stored at -235 degrees Celsius (LOX can be stored at the comparitively balmy temperature of -183 degrees celsius). Even during the night side of an orbit, the temperature is -121 degrees celsius. It's going to boil without some kind of coolant system, which will add additional mass. SSTO has a pretty low payload fraction as it is, and cooling systems are going to eat into that even more.
Storable propellants are an alternative, but they tend to be highly toxic, so the ground crew will have to either wait for the propellant to be drained (time consuming) or wear HazMat suits (performance degrading). Either way it's going to increase turn around time, so it's not going to spend as much time in the air as a normal fighter.

From what I know, compressing something bring's it's temperature down.

They usually do, but the increased heat would affect the temperature of the liquid, heating it and causing high levels of stress on the container. This may be a problem during re-entry.

Perhaps stored liquid fuel could be placed in tankers in space? Lots of room and the crafty would just re-fuel and drop back down again. Expensive though, a space station purely for that, there would be much cheaper methods. I agree, quick dashes into space would be hard to acheive, but I would say you could get up there then come down and probably go back up after some more fuel has been stored. But you would be going at over Mach 5.5 in the atmospheric flight section, so not many fighters could catch you... Besides I think this is too big for a fighter, more a medium bomber, reconnaisance plane.

OK then. This was giong to be more short dashes into space, rather than prolonged space flights like the space shuttles, so there should be enough fuel left in the tanks for re-entry. Gathering more fuel for the return flight could be a problem, but at the speeds your going at after the first re-entry should mean that you can out-fly most things for long enough to get enough fuel to enter space again. Even better when co-ordinated with a more conventional airstrike. As for it being a fighter, yeah, I think a recon/bomber would more suit the size of this thing.

I'll update the stats, and some of the description.

So unless anyone else has any problems with the latest design, this is going to be put into production.

I have no problems, and look forward to purchasing some.

Excellent. If there are no objections, then SAturday or so should see the release of this.