Skunk Works TR-X

originally posted by: Zaphod58
a reply to: darksidius

It's entirely possible. The X-15 proved that. Just like with every other major advancement, such as going supersonic, it's a matter of getting things right. You have to find out what you don't know, and then figure out how to make it work.

didn't the x-15 hit nearly mach 7

a reply to: bigx001

Yup, and it pretty much proved that the easiest (and best) route to hypersonic speeds is rocket propulsion and borderline-exoatmospheric altitudes.

There were a bunch of veery interesting studies for X-15-derivatives and X-15like craft in the mid-60's that all went dark around the time the A-12 was retired. One of which was a study about launching a stretched, delta-winged X-15 derivative using an XB-70 as a carrier plane.

It's funny that you never hear about where that 3rd, uncompleted XB-70 airframe went...

It's also funny that all of those very complicated heat-management technologies like reinforced carbon-carbon and HRSI tiles seemed to pop out of nowhere as completely mature technologies during shuttle development in the mid-1970's...

a reply to: Barnalby

what did the latest scram jet do, mach 8 in short flight? it was air breathing

a reply to: Barnalby

What do you make of the XR-7 & SR-75 combo mentioned Here? I wonder if that anything to do with your missing XB-70

a reply to: Zaphod58

No, youre choice is to make an SR-72.

a reply to: BigTrain

Why not go for Satellites then if you're only interested in one platform to do the job. Or just spend the entire budget of the military to make a hypersonic ISR platform. We don't really need strike platforms, or air to air platforms, or anything else. Just make a really fast ISR platform and be done with it.

a reply to: Zaphod58

That seemed to be the theme with the A-12/SR-71/YF-12. To me it looks like they got to a point where they said, what the hell do we need a really expensive supersonic intercepter when we already have F-15's that do that job almost as well for alot cheaper. Like you said though ISR is another thing all together.

a reply to: Bfirez

The only interceptor in that bunch was the YF-12, which was cancelled, because there were others that could do the job cheaper, and honestly, better. The SR-71 was retired because to fly that fast, for that long is expensive. The operating cost for the aircraft was between $27-38,000 an hour, although some numbers go a lot higher depending on the source. Then there's a LOT of specialized equipment required for it, that only it can use, such as fuel.

originally posted by: Barnalby

It's also funny that all of those very complicated heat-management technologies like reinforced carbon-carbon and HRSI tiles seemed to pop out of nowhere as completely mature technologies during shuttle development in the mid-1970's...

Those could also be coming out of ICBM re-entry vehicle work.

a reply to: Zaphod58

I should have been more specific, I meant that was why out of the three the A-12 and the SR-71 made it to production and the YF-12 did not. As always zaph I appreciate your posts alot. As an aviation enthusiast I aspire to one day be on your knowledge level with aircraft.

What are the merits of Sat Optics vs High altitude High speed Aircraft?

a reply to: Blackfinger

Pros for satellites: Resolution, resolution, and more resolution (a 2.4m primary mirror will do that for you), really hard to shoot down, can fly anywhere without stirring diplomatic tensions.

Cons for satellites: Really expensive, "make the B-2 look cheap" acquisition costs, they (for the most part) fly in fixed, predictable orbits so you can track them and know when to hide the secret stuff.

Pros for aircraft: On-demand flights can mean you can catch the enemy off-guard and see the secret stuff that's hard for the satellites to see. Rapidly deployable and able get relatively instantaneous imagery without having to wait for a satellite pass. Can be cheaper to purchase up-front.

Cons for aircraft: The realitiea of drag means that the biggest camera/mirror setups they can carry will be the size of a Corona or gambit-era spysat, expensive hourly flight costs, high-speed craft are more expensive to research/develop, can be shot down, can start diplomatic incidents when they're caught or shot down, and can leak expensive/sensitive technologies when they're shot down.

TLR: Sats = dem massive optics, Planes = dat speed.

a reply to: Blackfinger

Flexibility. Satellites are predictable and fairly easy to hide from. A high altitude platform, whether it's high speed or not, goes over at random times on random days, and if it's stealthy, is much harder to hide from.

a reply to: Zaphod58

Yet you say something like 'the green flame' destroys all previous speed records.

a reply to: BlackDog10

Which doesn't mean that it's hypersonic. You can shatter every SR-71 record and still not be hypersonic.

The Blackbird was traveling 2455 mph at mach 3.2. If the Lady was capable of Mach 4, that's over 3,000 mph. That's a significant leap, but still below hypersonic.

a reply to: Zaphod58

A key distinction seems to be altitude, and if you've played enough KSP, you should know just how different atmospheric heating at a given speed can and will be at different altitudes.

a reply to: Barnalby

And heating, even at high altitude is what has been killing hypersonic vehicles. The heat actually causes their skin to peel as they fly. Eventually the computer loses the ability to retain control and it crashes.

a reply to: Zaphod58

And I'd imagine that skin designs that are, shall we say, designed to do a little more than resist atmospheric heating, are even less resistant to that heat accumulation...

Friction/drag increases as a square of airspeed, and atmospheric density decreases as a square of altitude, and so a ~25% increase in speed over the SR-71, if combined with a ~25% increase in altitude, should land you at more or less the same rate of heating due to atmospheric friction that the SR-71 experienced, because the increased drag is cancelled out by the decreased air density at that altitude. More or less.

Other thing than the skins are the internal structures and flight and propulsion systems..Materials grow when they heat up and contract when they are cold..Remembering the Sr71,s fuel tanks used to leak like a sieve until flight temperature closed them up.

originally posted by: Barnalby
a reply to: Blackfinger

Pros for satellites: Resolution, resolution, and more resolution (a 2.4m primary mirror will do that for you), really hard to shoot down, can fly anywhere without stirring diplomatic tensions.

Cons for satellites: Really expensive, "make the B-2 look cheap" acquisition costs, they (for the most part) fly in fixed, predictable orbits so you can track them and know when to hide the secret stuff.

Pros for aircraft: On-demand flights can mean you can catch the enemy off-guard and see the secret stuff that's hard for the satellites to see. Rapidly deployable and able get relatively instantaneous imagery without having to wait for a satellite pass. Can be cheaper to purchase up-front.

Cons for aircraft: The realitiea of drag means that the biggest camera/mirror setups they can carry will be the size of a Corona or gambit-era spysat, expensive hourly flight costs, high-speed craft are more expensive to research/develop, can be shot down, can start diplomatic incidents when they're caught or shot down, and can leak expensive/sensitive technologies when they're shot down.

TL

R: Sats = dem massive optics, Planes = dat speed.

Can you get the Pro's for a Satellite inside an X-37 size vehicle?