NationStates Jolt Archive

Hey OOCly do you guys think an air craft would be able of going mach 12 by 2039?

Well ok on MSN I have these persons *cough wont mention names* being idiots to me yelling flaming bating the sorts , they claim OMFG an air craft going mach 12 IN 2039 GOD MOD !!@!#!$!@$! Any who I wanted to take this question to you .

It is; it just isn't possible aerodynamically. Unless you have some form of ship that doesn't use chemical engines but some other form of propulsion, any form of airplane, jet, or what have you cannot obtain Mach Twelve. At all.

If it is unmanned and unarmed it is not too much a stretch of the imagination assuming that you have some kind of technology that doesn't yet exist. If this is a fighter however then not a chance, and of course surely not for a bomber.

Just for the record people, there was only one person repeatedly using expletives in the aforementioned MSN conversation, and it was The author of this thread.

Now Rob, as I was trying to say before, the design you showed us:

http://img.photobucket.com/albums/v374/TheFedUnion/MACH12F-75.jpg

Is not capable of Mach 12 flight. Mach 12 flight in itself will be extremely difficult to accomplish in atmosphere, unless you aim for some kind of radical design, which would in turn negate the usefulness of that design as a combat aircraft.

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Rob i will ask you to edit you initial post to make it more accurate or i will post the chat logs.

Now as to mach 12... by that time it may be possible for craft to reach that speed, but ONLY as the scram jet do now, as novelty research peices, not on craft built either by the military or comercially.

the asnwer is, for all intents and purposes no.

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(pushes secret "productive post alert" button.)

The X-43 (http://en.wikipedia.org/wiki/Boeing_X-43#Tests) quite happily did Mach 9.8 in November of last year. A vehicle capable of reaching Mach 12 is easily possible, certainly given a further 34 years of research. It would need some kind of heat shield, but given that the technology already exists to produce lightweight reusuable heatshields (to an extent) it will easily be possible.
Mach 12 is an extremely conservative estimate, and could be easily exceeded by 2039.

Hey OOCly do you guys think an air craft would be able of going mach 12 by 2039?

Not really, no

The X-43 (http://en.wikipedia.org/wiki/Boeing_X-43#Tests) quite happily did Mach 9.8 in November of last year. A vehicle capable of reaching Mach 12 is easily possible, certainly given a further 34 years of research. It would need some kind of heat shield, but given that the technology already exists to produce lightweight reusuable heatshields (to an extent) it will easily be possible.
Mach 12 is an extremely conservative estimate, and could be easily exceeded by 2039.

Wasn't that dropped from a B-52?

I dont think it would be able to...

Indeed it was.

rocket powered, unmanned bomber maybe....
air-breathing manned tactical, no.

The question is not /if/ but /where/.

Spaceplanes (the RL NASA type) regularly go Mach 12...in orbit. Within the earth's atmosphere (that is, beneath the point where one is considered to be "in space" or above 90% of the earth's atmosphere) it is extremely difficult to maintain such a speed. The main reason for this is that the materials that aircraft is made out of conventionally cannot stand up to the temperatures that are generated by the passage through the atmosphere at such speeds for extended periods of time.

The S^3 Concept

The top speed designated by the USAF (in Hypersonic Attack; S^3 Concept) for an aircraft operating at 100,000 feet is Mach 12 (but the report also indicates that the materials used would not be conventional aircraft maneuvers, that the aircraft itself would be extremely expensive, and that non-standard materials would be required).

The fuel would have to be slush hydrogen as hydrocarbon fuels would not burn correctly (an expensive proposition estimated to be at a tech level of 2020+ with only 50% efficiency (50:50, slush:solid)) and the payload would at most be 10, 4,000lb cruise missiles (4/7ths the payload capacity of a modern B-52). The engines would be a ramjet/scramjet.

The design would be a very large "waverider" form body (190 feet long (30ft longer than a B-52), 60 feet wingspan (almost as wide as a B-2 is long) at the rear/base of the form). The required hydrogen fuel is ~875,000lbs of slush hydrogen (at about 4K, or -269°C or -452°F. This mass is significantly more than the Max Wartime Takeoff Weight of a loaded C-5 Galaxy)...and all of this to complete a 10,000mi journey. The mathematics prove a 25,000mi range, but more than half of the fuel is required for launch and acceleration to Mach 12, which only happens @ 100,000ft up (until then the speed is ~Mach 3.5).

Additionally, the aircraft would have to slow to Mach 8 to launch its hypersonic missiles as it is turning (with a turn radius of somewhere under 480 miles at 2G's of force). As the report states "The unique mission and design of the SHAAFT will require facilities that are currently very rare or nonexistent."

With all of these complications, the SHAAFT design is most efficient for launching space plane type payloads and is still vulnerable to the 2025 enemy with Mach 5+ SAM systems [[A NOTE: which might be able to strike the SHAAFT if the enemy nation knew of its approach...ABM missiles such as a modified Israeli Black Sparrow (http://www.israeli-weapons.com/weapons/missile_systems/air_missiles/black_sparrow/black_sparrow.htm) missile (that could be set to be an interceptor rather than a target) or an upgraded version of the Israeli Arrow ABM (http://www.israeli-weapons.com/weapons/missile_systems/surface_missiles/arrow/Arrow.html) could also anticipate the strike and, from forward sea bases or launch sites, be used to strike the SHAAFT while it is engaging in the low-speed (Mach 8 turn) phase of its flight.]]. The SHAAFT would still be very hard to hit...but with only a handful (at most, due to cost) of these costly, limited-purpose, low-availability units on hand...would you want to risk it? And this design, even, depends upon special materials (for superlow weight heat-dispersion and superlight extremely strong structural elements) that do not yet (and which may never) exist.

The truth is that a hypersonic missile launched from an F-15 (which can be based anywhere in the world, and which which could also be replaced by the F-18 or an F-14, which are sea-based...or from the trusted B-52) or from a surface naval vessel or land platform has almost as great a range as one launched from the SHAAFT. These resources are also readily available and while they would require that US forces be in-theatre...even this missile will face extreme speeds (and hence temperatures) at Mach 8, 100,000ft altitude (again, as-yet cutting edge or undeveloped materials are required). Good news: some of the materials actually exist (although they are damn expensive) and have been tested to the temperature range expected for the hypersonic missile (ie, it's possible) but they're beyond easy purchase prices yet and are still quite experimental in 2005...


Summary
Possible? yes. For a bomber with minimal maneuvering and a massive support base/aircraft (think: "the B-2 was easy")...for a fighter? for a tactical aircraft? not nearly...unless it's all up in space.

Mach 12...Nope. It's not going to be usable, even by 2039. Not for fighters in any case. It may have some value for specially built spyplanes, but I have great doubts that you'll get a plane to go that fast on earth. Not without some heavy wanking combined with heavy future tech...

You can use the tiles off of the space shuttle for heat shielding, or you could use Starlite (http://icnewcastle.icnetwork.co.uk/sundaysun/news/page.cfm?objectid=13902509&method=full&siteid=50081), which would do the job just as well.
Plus you can do suborbital hops, Dyna-soar style which gets rid of most of the friction problem.

Depends on what you refer to as "aircraft" ;) Western Asia does provide an excellent overview, and with future spaceplanes or other suborbital designs such as the proposed HyperSoar concept, it is indeed possible, although with that kind of air/spacecraft you'd go well beyond modern/post-modern tech. However, it is nice to know that the USAF is already looking into the possibility of such, and they are currently also proposing another spaceplane that will carry a "Common Aero Vehicle" - basically a X-43 shaped vehicle carrying conventional payloads that will be able to be either carried by the aircraft mentioned or converted Minuteman III or Peacekeeper ICBMs.

If you are talking about conventional aircraft, at Mach 12 the only way are scramjet designs. I'm not an expert on such matters, but I can assure you with coventional aircraft at Mach 12 if you want it to operate at standard combat altitudes, you'd need a lot of heat shieldings if you do not want your aircraft to burn up because of friction (IIRC when they did the test flights of the XB-70 Mach 3+ designs at Mach 2 speeds, the temperature at the front of the aircraft was already reaching 400 C). Ramjet and pulse-detonation can get the aircraft up to speeds below that of the Mach 12 depending on various designs. Keep in mind however, if you want an actual and functioning tactical military manned aircraft, the latter would be the only way to go. Ramjet and scramjet are largely suited for unmanned missile systems really, not manned aircraft.
Even the SR-71 uses special turbojet designs, and as much as its fame, the interceptor variants you've been hearing about are interceptors, not some Mach 2-4 tactical fighter that can dogfight others in the sky.
Aerodynamic also counts, and this goes to the MiG-25 and -31 interceptors: they are not dogfighters, but they can go beyond Mach 2.5 for a reason.
However, it is important to note that if you are using turbofans, then Mach 3-4 is typically the edge. It has been observed on aircraft such as the MiG-25 that when it start to go Mach 2.6+, the turbojet engines actually start to function as some form of ramjet because of the air flow, and that's not accounting that often they had to replace the engines after the pilot decides to go Mach 3 on the aircraft (another case was when they tried to go beyond 120,000ft, but the engines at that point didn't work too well either). Improved engines could give the speeds and the engine reliability a boost, but still not mcuh when you consider the actual limitations of turbofans and turbojets at high speeds - no, you are not going to see a turbofan-equipped tactical fighter going Mach 6.

Good luck finding a material that won't melt due to air resistance at that temperature.

At Mach 3, the SR-71's metal expands and turns blue. It can't go much faster without melting.

The Space Shuttle's heatshield can withstand the temperatures of reentry, which is more like Mach 25. Therefore the technology already exists to protect vehicles at these speeds, and will certainly exist in 34 years time.

Okay a question here. What about hypersonic engine? Both US and Russia have designs for it. At what mach does Hypersonic speed begin?

You can use the tiles off of the space shuttle for heat shielding, or you could use Starlite (http://icnewcastle.icnetwork.co.uk/sundaysun/news/page.cfm?objectid=13902509&method=full&siteid=50081), which would do the job just as well.
Plus you can do suborbital hops, Dyna-soar style which gets rid of most of the friction problem.

"Starlite" appears to have both appeared and disappeared in 1993 aside from that one news article from 2004 and a single 1997 mention. The result for Starlite is unknown. As for the shuttle tiles, they're considered in the AF's hypersonic study mentioned above but newer, cheaper, and more effective tiles are mentioned for the hypersonic missile and aircraft.

http://www.guardian.co.uk/life/farout/story/0,13028,1187576,00.html
http://www.starlitetechnologies.com/


The Space Shuttle's heatshield can withstand the temperatures of reentry, which is more like Mach 25. Therefore the technology already exists to protect vehicles at these speeds, and will certainly exist in 34 years time.
The reentry speed is normally more like Mach 19 at its peak (the Shuttle turns around and applies a short retrothrust to slow down first)...and that's at well over 200,000ft...its profile is designed to optimally slow down and the tiles are not meant to be strong against much of anything else (vis: a chunk of foam broke open the section of wing covered by such tiles).

As I said in my post, it's all a matter of altitude. 300,000 ft? Okay. 200,000ft? Maybe. 100,000 ft? Look to stuff that doesn't yet exist or which is just now being made...and even that is not definitely capable of the described flight profile.

*Takes notes* bump