X-15 In SPACE!

Now I know the X-15 did reach space twice, however i am not here to talk about those flights. I am here to talk about the proposed concept to launch an "Advanced X-15" on a Saturn I rocket. I also wonder if this proposal is a cheaper alternative to the X-20 dyna soar.
A stock X-15 could not survive reentry.
It is hard to imaging a way to add workable thermal protection to the existing x-15 design. The dyna-soar was intended to take crews to and from a manned orbiting reconnaissance satellite to spy on the USSR- remember -- remeber the bomber gap? The dyna-soar was cancelled for several reasons, out of control costs, technical difficulties designing a manned photo-reconnaissance sat ( ie vibration for crew movement and life support equipment), and unmanned reconnaissance sat technology developing to a point that there was no reason to developed a manned capability and also the determination that there was no bomber gap and had never been a bomber gap.

With this in mind, what would the mission of an advanced x-15 be?
They proposed that as Man as soonest in space X-15B.
That imply major modifications, this was a 'stripped' down X-15A, until it got a empty mass of 4500 kg and install a heat shield of beryllium oxide and Rene 41 alloy.
But since the X-15 is a Hypersonic research Airplane, it not have the option for Orbital bombardment or reconnaissance, planned for X-20/Dyna Soar.
As the X-15B was propose to USAF, General Curtis LeMay, main comment was, "Where's the bomb bay?"
NASA not like it either because the X-15 not made one Orbit but almost one around earth
then the X-15B would ditch in the Gulf of Mexico, while the Astronaut had to eject and land by parachute, with the aircraft being lost.
And the X-15 pilots were not happy about that idea....

Illustration only, but it give a view on problem the X-15B Pilots face after landing...
IIRC, they nearly lost an X-15 because, despite 'heat shielding', it caught a nasty case of 'heat soak' on a 'speed run' and suffered a lot of internal damage. Pilot was lucky to get it down safely, but it never flew again...

That may be the one that, um, bent like a 'nana upon landing.

You could not 'grow' the basic X-15 design much beyond strap-on tanks. Back to the drawing board, ~ 50% bigger to carry the weight of spaced heat-shield, probably with boil-off coolant, and you've just got a bigger, heavier X-15 with much the same issues due higher loading. Rinse & repeat, gets further from the X-15's sub-orbital sweet-spot...

IIRC, the math gets better again when you reach something the size of the XB71, as area rises as the square, but volume as the cube...

Happily, Neil Armstrong made 'Astronaut' in an X-15, put his test-pilot skills to taming the Lunar Module and the rest is history.
In 2014, Michel Van wrote
the Irony: NNA proposed a Orbital version of X-15 launch on rocket
after one orbit, this X-15 reenters into atmosphere direction gulf of mexico were the pilot ejected from the plane, land with parachute were he is recovered by US navy...

Earlier this year, I wrote

Any orbital variant of an X15 wouldn't have been launched from an airplane.


actual planes involved various kludged together missile boosters.

Note, too, that it would have needed an aeroshell for protection on reentry, and some plans involved having the astronaut bail out and not even attempt to land the plane.

So it was a very, VERY strange plan. Far more expensive and harder to do than simple capsules.

So. You take an X-15, whose whole purpose is being a reusable, landable plane - and turn it into a disposable 'worse than a capsule' design, where the poor pilot has to parachute out.
Number 1 Sorry for not responding in time however on to the show!
Now the idea of a X-15 derived spaceplane is crazy in its self and that is why I brought it up. The first time I saw a orbital X-15 was on the astronautix page about the Saturn I http://www.astronautix.com/s/saturni.html
However thanks to this thread I have learned about the X-15B that would be launched on a Navaho derived launch vehicle http://www.astronautix.com/x/x-15b.html and the idea of a X-15 spaceplane is crazy in its self and really impractical as Dathi THorfinnsson pointed out here.
So. You take an X-15, whose whole purpose is being a reusable, landable plane - and turn it into a disposable 'worse than a capsule' design, where the poor pilot has to parachute out.
The original proposal of the X-15B was made by Harrison Storms of North American Aviation, in a attempt to beat the Soviets in getting a man to space. He clearly didn't think it through.