We don't call ourselves anything, because no one has thought of anything more clever than
>/n/iggers

>>301816

Damn. Aren't the blue boards supposed to be halfway intelligent?

Apart from /v/, of course.

Oh, and have an artist's conception of another spaceplane. Another sexy, sexy spaceplane.

We're halfway intelligent enough to not call ourselves anything, because no one has thought of anything more clever than
>/n/iggers

we are all gentlme/n/

I've always been partial to frie/n/ds.

a/n/ons?

X-37B landing video
http://www.youtube.com/watch?v=XTxMbda-j4Q

I was always preferential to /n/IGGERS.

I like an articulating exhaust nozzle on a space plane

>>302039
THRUST VECTORING OWNS THE SKIES!

X-20A Dyna-Soar concept circa 1960

>>301829

No joke, a couple of years ago I saw the carrier plane (The one that carries the actual rocket, its called White Knight if i recall correctly) at Oshkosh Wisconsin.

Lunex lunar lander for a crew of three, concept circa 1958. The lowest stage with feet is the landing stage for descending to the lunar surface. Above that is the launch stage for leaving the lunar surface. On top is the lifting body for flying back to Earth.

The lifting body length "366" is inches (30.5 feet, or 9.3 meters). Engineers may have calculated vehicle dynamics like F=MA in units where a force F of 1 pound causes an acceleration A of 1 inch per second squared for a mass M in units called the slinch.

http://en.wiktionary.org/wiki/slinch

Lunex cutaway figure confirming the general size.

Since this is a bike board you either call us
/n/omads or /n/iggers

Lunex lifting body configuration reappears in the X-33 (~45 years later).

X-20A fuselage rises at the tail to increase stability at transsonic speeds (circa 1960).

X-37B fuselage rises at the tail like the X-20A (50 years later).

OP, I heard you like spaceplanes, so I put spaceplanes in a plane with lots of space

>>302679
The fuck? What is that scale of "Cp"?

>they will never put the X-37 in the next Bond movie

Glorious Soviet space plane

Bike /n/erds

>>302801
Cp is "coefficient of pressure" or "pressure coefficient". It's the dynamic pressure on the body divided by some reference pressure to make Cp dimensionless: http://en.wikipedia.org/wiki/Pressure_coefficient

For incompressible flow (say, below Mach 0.7), we let the reference pressure be the so-called "dynamic pressure" because that conveniently makes Cp = 1 at the stagnation point on the nose of the body: http://en.wikipedia.org/wiki/Dynamic_pressure

For compressible flow (approaching and above Mach 1), Cp > 1 on the nose means the supersonic bow wave makes the pressure higher than the simple formula for subsonic flow would predict.

yeah yeah, but CP on /n/

bamping spaceplanes to fight spam

>>302829
Incompressible flow is below .3 mach.....

HL-10 with the outer fins in the original configuration, recognizable by the bare metal on the leading edges and along the fuselage. Flown in this configuration only once because of flow separation over the outer fins at high angles of attack.

HL-10 with fiberglass leading edge gloves added, recognizable by the white paint on the leading edges and along the fuselage. Downward camber of the leading edges maintained flow attachment at high angles of attack.

Cutaways:
HL-10 (above)
M2-F2 (below)

I sure love me some X-38.

>>301816
Personally, I like /n/injas.
>>302075
F-35s don't have thrust vectoring, save the B-variant which only uses it for hovering.
>>304386
Technically, NO gas-state fluid flow is TRULY incompressible; it's simply a matter of where you decide to pick it based on your standards for when an approximation is no longer "close enough."
So neener.

How do these space planes re-enter? I was under the impression that low drag re entry caused massive overheating due to the low amount of air around the surface as opposed to the blunt surfaces that are used for re-entry currently.

>>305506
AFAIK, the low-drag, nose-down reentry has not yet been utilized. I presume all orbital space planes thus far (of which only the Shuttle, Buran, and X-37 have ACTUALLY performed full-fledged orbital reentries) have only used the nose-high reentry we're familiar with.

Now, blunt body theory was conceived during early ICBM nosecone development, where reentries were expected to be fully ballistic and dive balls-first into the thick lower-atmosphere. With lifting reentries, however, you can maintain your altitude and stay in the thin upper atmosphere where heat loading is minimal for a prolonged distance and period of time. This of course would require a (mostly) radiatively-cooled thermal protection system, since an ablative system would NOT ablate in these low-heat conditions and would actually overheat SOONER as a result. Such TPSs were experimented with as part of the Dyna-Soar and X-23 projects project with testbeds such as ASSET and PRIME, proving the viability of such a reentry scheme.

>>305508
Forgot my picture.

>>305506
All the spaceplane reentry concepts I've seen would fly a hypersonic phase nose-high, with the belly acting as a blunt body, and the shock wave helping carry energy away from the body. After the hypersonic phase, they might transition to a more conventional maneuvering phase (slowing from supersonic to subsonic), and a landing flare. No single configuration could be optimal for all those regimes (the X-38 replaces the landing flare with a parachute).

Lifting bodies are optimized more for the hypersonic phase, in particular not needing to worry about hypersonic flow almost perpendicular to the wings (as in pic related, shuttle study NAR A circa 1969).

>>305508
Excellent reminder of different strategies for thermal protection. The Space Shuttle's approach was to fly through the heating phase quickly enough before the heat could penetrate the glued-on foam tiles and melt the aluminum airframe. What could go wrong?

National Weather Service radar KSHV:
http://radar.weather.gov/ridge/radar.php?rid=shv&loop=yes

The scale dBZ measures radar scattering strength per cubic meter for rain. The green around the radar location is measurement noise. In the pic, the red stripe is debris from Columbia raining down over the Texas/Louisiana border.

>>305687
>The Space Shuttle's approach was to fly through the heating phase quickly enough before the heat could penetrate the glued-on foam tiles and melt the aluminum airframe. What could go wrong?
Actually, that more accurately describes Mercury and Apollo reentry schemes than the Shuttle's. Ablative heat shields RELY on a high heat loading to ablate; if they reenter too gently, a la Space Shuttle, they fail to begin chemically decomposing, and instead just soak up all that heat instead, until it reaches the bondline and causes a catastrophic failure. Of course, EVERY reentry scheme will include some level of heat soak, and most ablative heat shields rely on getting reentry over with quickly and then dropping the heat shield to prevent this soaked heat from reaching the payload.

Now the Shuttle, on the other hand, used a ceramic radiatively-cooled TPS, which depended on a LOW-enough heat-loading to permit equilibrium at a sustainable temperature. The surface of the TPS basically simply absorbed all the heat (rather than pumping it away with a chemical reaction), and re-radiated it at an equillibrium black-body temperature. The higher the heat load, the higher the temperature. Thus, an uncontrolled, ballistic reentry simply was not an option for the shuttle, unlike Soyuz which has survived such reentries time and again during partial failures.

>>305687
And one more thing - the nose-high attitude isn't to help increase the bluntness ratio - the rounded nosecone does all of that just fine (just look at any modern ICBM reentry vehicle to see just how little bluntness you can get away with nowadays). No, the post-stall attitude is used simply to increase the drag coefficient (by a factor of ten or so) while in the thin upper atmosphere, since dynamic pressures (achieved by shifting to a lower altitude in 10x thicker air) required to achieve the same drag and deceleration from a nose-low attitude would threaten to crush the ship and its occupants at the slightest attitude perturbance. Thin air is forgiving, even at mach 25.

Now, a gentle, high-altitude, nose-low, drawn-out gliding reentry is technically viable (if the TPS is designed to handle it), and recent hypersonic glider tests such as those of HTV-2 are exploring this, but it does present other issues and doesn't achieve much over a high-alpha stalled reentry (peak G-loads can theoretically be reduced from 3 to just over 1, but 3 Gs is already pretty darned low), and it presents issues like overflight of foreign countries during early reentry and necessary cooling systems to keep internal temperatures down (a radiatively-cooled TPS should be VERY happy with this sort of low heat-load profile, but the equillibrium temperature would still be several hundred degrees C and WILL eventually penetrate any insulation you have during such a drawn-out reentry).

>>305776
>>305794
Excellent technical info, thanks!

When NASA's shuttle program accepted support from the Department of Defense, the DoD added a cross-range maneuvering requirement with the ultimate point being to support reentry from a *polar* orbit -- but the shuttle was never able to *launch* into a polar orbit, so the DoD requirement for reentry maneuvering only hurt the shuttle design.

The HTV-2 Falcon experiments with long shallow maneuvers may help specialized spaceplanes maneuver from a polar orbit back to a horizontal landing in the United States.

>>305794
About a nose-high hypersonic phase, I say we're both right.

You said the point is to increase drag, while I said:
>All the spaceplane reentry concepts I've seen would fly a hypersonic phase nose-high, with the belly acting as a blunt body, and the shock wave helping carry energy away from the body.

I found my citation needed:
http://en.wikipedia.org/wiki/Atmospheric_entry
>In the United States, H. Julian Allen and A. J. Eggers, Jr. of the National Advisory Committee for Aeronautics (NACA) made the counterintuitive discovery in 1951 that a blunt shape (high drag) made the most effective heat shield. From simple engineering principles, Allen and Eggers showed that the heat load experienced by an entry vehicle was inversely proportional to the drag coefficient, i.e. the greater the drag, the less the heat load. Through making the reentry vehicle blunt, air cannot "get out of the way" quickly enough, and acts as an air cushion to push the shock wave and heated shock layer forward (away from the vehicle). Since most of the hot gases are no longer in direct contact with the vehicle, the heat energy would stay in the shocked gas and simply move around the vehicle to later dissipate into the atmosphere. The Allen and Eggers discovery, though initially treated as a military secret, was eventually published in 1958.

I'm saying this is what lifting body bellies are for:
>the greater the drag, the less the heat load

>>305869
The shuttle was technically able to reach polar orbit for the entire duration of its service, albeit with a reduced payload. However, since the Pacific launch site at Vandenberg was never finished, this would mean dropping SRBs either on North Carolina or Cuba, and NASA wasn't ready to go and do something like that.

>>305871
I already addressed those issues. You can't exactly generalize a study intended for fully-ballistic, axisymmetric blunt-bodies to fully address the considerations of a lifting reentry trajectory such as that used by a spaceplane. As odd as it may seem, the OPPOSITE of what you're suggesting is true in the simplest case - Lowering the nose and reducing drag at a given altitude and airspeed will actually REDUCE heat loading. It's the blunted nosecone which creates the detached shockwave, not the belly. This mechanism is not disrupted by lowering the nose. However, lowering the nose WILL momentarily reduce the magnitude of compression heating, and since (UNLIKE THE BALLISTIC CASE) this does not necessarily entail rapidly dropping into thicker air (since spaceplanes can produce lots of lift at pre-stall AOAs as well), this "momentary" reduction can actually be sustained for the entirety of the (longer) reentry... as you soar past KSC and 2/3s the Atlantic Ocean owing to the reduced amount of drag.

Of course, none of these spaceplanes (X-20, ASSET and HTV-2 aside) have a proper TPS for this sort of profile, so they'd still end up cooking their faces off despite the lower heat loading owing to the simple fact that the spaceplane's windshield (or equivalent) isn't adequately protected.

Bampin' with Pegasus.

>>301816
What happened to "/n/utjobs" and "/n/utcases"?

>>306886
They /n/ever took on.

>>306886
I might add those to my /n/ vernacular for special circumstances.

>>306914
So, in other words, it went /n/owhere?

>>307011
Esse/n/tially, yes.

>>307011
In a /n/utshell.

spaceplane thread must come back to front page

bumping this awesome thread with the next generation spaceplane, the Dream Chaser

...and the first private spaceplane.

>>309116
>OSC Pegasus
Argument invalid.

>>309115
I'm glad that the concept (and all that research and investment) didn't die with the HL-20 program. I really hope they press on and reach operation in some capacity; it's just a good, sensible spacecraft.

This thread needs some X-15.

HAMUHNAHAMUHNAHAMUNA