SR-71 continued from lunar hoax forum .

[FP]

On 2002-08-25 02:07, SAMU wrote:
Donnie B.
Interesting, you come up with a number that just happens to be half of what my and the official number is. King Solomon would be proud.

Regardless, we'll use your numbers.So at sea level with 65,000 lbs of thrust at 1000 mph the air

SAMU, are you saying that the SR-71 could travel over 2,000 mph AT sea level? I think the 2,000 mph + figure comes from calculating the distance traveled divided by the time, and has nothing to do with actual sea level velocity. When the Blackbird hit those speeds it was at 80,000 feet (with an indicated air speed of 385 kts -thanks, overrated- due to the decreased air pressure at that altitude.)

I have seen the A-12 at the Boeing Museum and it is truly an awesome experience! If you are in Seattle it is a must see.

One more point. If the SR-71 became orbital, how did it get back? No retro rockets, no ceramic tiles or heat shield for re-entry!



<font size=-1>[ This Message was edited by: FP on 2002-08-25 14:01 ]</font>

[Bozola]

As to the airbraething engines not operating outside the apmosphere. The point is that they operated inside the apmosphere, achieving orbital speed while there is still air to use as oxidizer for its fuel and coasting into orbit. As the X-15 did when it burns its fuel until "burnout" and then coasts well into space (300,000 ft).

You realize that 60 miles up isn't quite in space, it's as they call it "the edge of space", perhaps bit better than half way, nor is 4,500 mph orbital velicity.

For an SR-71 to glide to 100+ miles up from 18 miles is a rather remarkable accomplishment.

[SAMU]

Bozola,

I didn't write "it glided up" I wrote it coasted up. Very different.

RCS thrusters and retro fire thrusters might add one or two thousand lbs to the weight of the vehicle. Fully fueled weight of 140,000 pounds makes such added weight only a little over one percent of the total weight. Certainly not an insurmountable physical obsticle and easily still classified equipment.

[overrated]

Even if it's coasting, the SR-71 just doesn't have enough velocity to get into orbit. Period. The chart in the flight manual shows it, airspeed calculations show it, physics show it. Even the X-15, which hit speeds nearly twice as fast as the SR-71's, still only had about one-fifth the velocity needed to get into orbit. Further, the X-15's ceiling (let's say 60 miles) is only about to the mesopause and maybe halfway to the orbital altitude of the Space Shuttle.

And just drop the RCS engine thing, okay? Nowhere, anywhere, have you showed evidence that the SR-71 has them. We have showed ample documentation that it DOESN'T, ranging from photos to anecdotes to actual flight manuals. Saying there is hidden, classified information is a cop-out--the manual is declassified and it's a public record that falls under FOIA. The only thing in the manual that ISN'T declassfied is the synthetic-aperture radar surveillance system, which has nothing to do with the plane's flight characteristics. If you take the attitude that there's all kinds of juicy data about the SR-71 that shows it can go into orbit but that we can't obtain, well, we can't really debate this, can we, because your "evidence" is un-disprovable conjecture.

And that's not even taking into account the increasingly obvious fact that you've been making facts up about the X-15 program as you went along. Even the project overview document you linked to showed that RCS engines were a part of the X-15's airframe from the beginning.





_________________
PC load letter? What the @%$# does that mean?

<font size=-1>[ This Message was edited by: overrated on 2002-08-25 19:10 ]</font>

[FP]

On 2002-08-25 16:43, SAMU wrote:

RCS thrusters and retro fire thrusters might add one or two thousand lbs to the weight of the vehicle. Fully fueled weight of 140,000 pounds makes such added weight only a little over one percent of the total weight. Certainly not an insurmountable physical obsticle and easily still classified equipment.

Where would you put the retro-rockets that would not upset the aerodynamics of the airframe? I am also interested in the re-entry. How did it keep from burning up?

[Bozola]

coast (kôst)
...
v., coast·ed, coast·ing, coasts.

v.intr.

To slide down an incline through the effect of gravity.
To move effortlessly and smoothly. See synonyms at slide.
To move without further use of propelling power.
To act or move aimlessly or with little effort: coasted for a few weeks before applying for a job.
Nautical. To sail near or along a coast.
-----------------------------------------


RCS? So where did you say they were, again?



I guess the men in black are going to visit me now, 'cause here's a photo of the super-secret engine...

(dang URL)

<font size=-1>[ This Message was edited by: bozola on 2002-08-25 21:03 ]</font>

[SAMU]

Did you know that for every thousand mph you go your weight is reduced 5%? At 2200 mph (the stated speed of SR-71) its weight can be reduced 11 percent. I mention this as just one more advantageous factor that can contribute to its ability to achieve orbit.

[SAMU]

FP,
Quote
"...no ceramic tiles or heat shield for re-entry!"

Ever heard of heat sink shielding? Or cooling via pumped coolant (fuel) through tubes under the plating of the SR-71. (previously mentioned by the way.)

[Kaptain K]

Did you know that for every thousand mph you go your weight is reduced 5%?

Yikes!!! Where did that come from? [img]/phpBB/images/smiles/icon_confused.gif[/img]

SAMU,
With every post, you make it more and more obvious that you know about as much about air and space vehicles (not to mention basic physics) as Joe the Bartender (see thread in "lunar conspiracies" forum) does about photography, i.e. nothing!

_________________
When all is said and done - sit down and shut up!

<font size=-1>[ This Message was edited by: Kaptain K on 2002-08-26 05:18 ]</font>

[SpacedOut]

From the original thread in the Apollo Hoax forum:

On 2002-08-21 02:10, SAMU wrote:
It is sometimes fun and interesting to speculate, even though "official" sources can and will deny your conclusions. for example

[body of post deleted by SpacedOut]

To further connect the dots one might speculate that the SR-71 was not just a high speed aircraft but actually the first reusable orbital space vehicle. If so, since it has been in operation since the 50s, what might one speculate have they been doing with it for all those years.

Samu – Are you just engaging in speculation or do you really think that the SR71 has achieved orbit? If you really think it has, can you provide any evidence other than idle speculation?

Unless you can provide some real evidence I’m finished with this debate.

Thanks to everyone for their insights, as usual I’ve learned something from this so it wasn’t a total waste of time. BTW, Bozola, you links to (and posts of) the various photos are great!

[GENIUS'02]

correct me if i'm wrong but isn't escape veloctiy, dependant on altitude? i've never studied orbital mechanics but i did have a couple of readings on escape velocity, also isn't escape velocity the minimum velocity required to leave a gravitational field and go to infinity?
if this is so why does this come into play in this topic, samu is not trying to say the bird wants to leave earths gravitational field just to orbit. orbit velocities must be slower than escape velocities. plus wouldn't orbital velocities be dependant on distance from the centre of the earth, not sea level?

this may be wrong, probably is, since they don't touch this in my syllabus but it seems logical to me.
don't bite my head off i'm 16 i have no knowledge on the subject, as much as i'd like to, and have forgotten much physics over the past two months, and am trying desperately to regain that knowledge.
well if its wrong let us know.
cheers
chris

_________________
its amazing how in the space of a few months, the memory can be serverly damaged, and all that you once knew is now hearsay and you know.... notmuch.

<font size=-1>[ This Message was edited by: GENIUS'02 on 2002-08-26 10:48 ]</font>

[Bozola]

Thank you, SO..[img]/phpBB/images/smiles/icon_wink.gif[/img]

------------------------------------------
To orbit (a circular one, not that you have much latitude, pardon the pun) at 30km you need to be moving around 7890 meters/sec and have a period of 85 minutes.

That's about 17600 mph.

http://hyperphysics.phy-astr.gsu.edu.../orbv3.html#ov

[GENIUS'02]

ok so is this the formular for orbital periods,
T^2= (4pi^2r^2)/(GM)
if so could is
G= gravitatonal constant
M= body (earth) where the gravity originates
iare they correct?

could someone give me an easy, not laymans, not PhD, explanation of gravity, my teachers pretty...... hmmnn..... politically correct word.... useless. either here or email me.
thanks in advance
chris


OHH
also does gravity increse by a factor of four if the the radius is halved?

sorry just trying to beef up my memory

[FP]

On 2002-08-26 03:00, SAMU wrote:
FP,
Quote
"...no ceramic tiles or heat shield for re-entry!"

Ever heard of heat sink shielding? Or cooling via pumped coolant (fuel) through tubes under the plating of the SR-71. (previously mentioned by the way.)

How much fuel would the plane have after acheiving orbital velocity? How will you pump the fuel around if the engines won't work in a vacuum? When the fuel is used for cooling in the atmosphere it goes directly to the engines. During re-entry, where would this super-heated fuel go?

As for heat sink shielding, please label it for me on one of the photos already posted on this thread. Thanks
(edited for spelling)
_________________
Learning without thought is labor lost; thought without learning is perilous.
Confucius, The Confucian Analects

<font size=-1>[ This Message was edited by: FP on 2002-08-26 13:07 ]</font>

[Valiant Dancer]

On 2002-08-26 11:04, GENIUS'02 wrote:
ok so is this the formular for orbital periods,
T^2= (4pi^2r^2)/(GM)
if so could is
G= gravitatonal constant
M= body (earth) where the gravity originates
iare they correct?

could someone give me an easy, not laymans, not PhD, explanation of gravity, my teachers pretty...... hmmnn..... politically correct word.... useless. either here or email me.
thanks in advance
chris


OHH
also does gravity increse by a factor of four if the the radius is halved?

sorry just trying to beef up my memory

http://hyperphysics.phy-astr.gsu.edu/hbase/gpot.html

This site has a few things which might be useful.

Basically, the amount of speed to get to an orbital altitude is dependant on altitude in radiuses of Earth. It just gets easier to get to that speed as altitude grows. (less air friction) This, however, proposes a new set of problems such as the necessity for wholly contained propulsion systems. (Ones not possessed by the SR-71 project as it's primary engines are air breathers)

For Earth, that speed is 11.17 km/s at the surface. To get a lasting orbit of some sort, one must get to the edge of the atmosphere in a place where the craft goes into perpetual freefall. That point is dependent on the mass of the item to be orbited and the mass of the body for that item to orbit.

The amount of gravitational force depends on an inverse square law of gravity. If the gravitational force on the surface is 1 (at r from center), then the gravitational force from a height of r above the surface (2r from the center) is one fourth that from the surface. From a height of 2r above the surface (3r from the center), the force drops to one ninth of the force from the surface.

Source:

http://hyperphysics.phy-astr.gsu.edu.../isq.html#isqg

According to this calculator

http://hyperphysics.phy-astr.gsu.edu.../vesc.html#ves

The escape velocity from 60 miles in the air is 11.16 km/s. Not much difference.

I'm sure if my physics are shaky, someone will call me on it nicely and provide a correction. Hopefully, I'm pretty close.

_________________
Valiant Dancer

<font size=-1>[ This Message was edited by: Valiant Dancer on 2002-08-26 16:31 ]</font>

[Chip]

On 2002-08-26 03:00, SAMU wrote:
"Ever heard of heat sink shielding? Or cooling via pumped coolant (fuel) through tubes under the plating of the SR-71. (previously mentioned by the way.)"

Not in those thin tail rudders.

BTW: Not scientific, but I'd just like to add, the SR-71 is a wicked looking airplane!

If you're going to pretend an aircraft can fly into space, it's a better choice than the elder spy-plane sister the U2. Though both can achieve very high altitudes. I presume so high an altitude in fact, that the sky is considerably darker from the cockpit. I recall reading that modified WWII Spitfires were used to intercept high altitude German aircraft, and that the British pilots could see a very dark daytime sky after struggling to get up there, so if that's the view from a 60 year old prop plane, then it's probably even more pronounced in the much more advanced SR-71 - though not orbital. (On the other hand, and this might be wrong, but could not the older X-15 have gone into a low orbit if NASA wanted it to?)

<font size=-1>[ This Message was edited by: Chip on 2002-08-26 16:26 ]</font>

[Andrew]

SAMU, how does the SR-71 survive re-entry if it's an orbital spaceplane?

[Firefox]

Given the current X-15 record of mach 6.7, I doubt it could make it to even low orbit. That, and the fact that it was a fuel hog, doesn't make it very likely.

[EDIT]According to this web page, the X-15 had a flight path range of 250 miles.


-Adam

<font size=-1>[ This Message was edited by: Firefox on 2002-08-26 17:42 ]</font>

[Chip]

Thanks Firefox,
Yes. The website you linked to stated an altitude record of 354,200 ft which though not orbital, would look very space-like to the pilot. They also stated: "It had reaction controls for attitude control in space, and was a major step on the path toward space exploration. Much of what was learned on the X-15 was applied to the Space Shuttle." I don't know if the "reaction controls" were put into use at that altitude. One of the X-15s was lost when it burned up on descent from the upper atmosphere.

I brought up the X-15 because yesterday (08/25/02) my girlfriend and I saw a splendid painting of it described as a "space plane" in the traveling "Art Train" exhibit devoted to Nasa space art on it's stop in Sacramento. The train's final stop will be near the San Francisco bay area in early September. Anybody near that area should see this exhibit. Great space art, realist to abstract, and lots of fun.

<font size=-1>[ This Message was edited by: Chip on 2002-08-26 18:28 ]</font>

[SAMU]

Kaptain K,
Quote:
"Did you know that for every thousand mph you go your weight is reduced 5%?"
"yikes!!! Where did that come from? "
End quote

HA! I knew I'd get someone with that one. With a velocity of 20,000 mph and constant distance from the earth you would be weightless (in orbit). With a velocity of 10,000 mph (half of orbital velocity) and a constant distance from the earth you would be half weightless. With a velocity of 1000 mph and a constant distance from the earth you would have 5% of orbital velocity and be 5% weightless. You would weigh 5% less.

But more look at how you respond even though you are wrong.

Quote:
"With every post, you make it more and more obvious that you know about as much about air and space vehicles (not to mention basic physics)as Joe the Bartender."

Tut, tut. You took the time to write this out, to think up what to write(rather than just saying it before you had a chance to think). Rather than thinking about the problem.

To the rest,

I have no proof that SR-71 has specific (classified) equipment (amounting to 1 or 2 % of its total weight,a few thousand pounds) supporting a flight into space or reentry (except for fuel cooled hull plating in which the fuel was used a s both a coolant and and heat sink and could be burned, dumped or vaporized to dispose of heat.). However I have posted a speculation, based on its revealed power, fuel and acceleration curve that is comparable to (and in some respects greater than) the Atlas manned orbital vehicle, that it may have had a (classified) orbital performance.

All of the above already has supporting links posted.

[Bozola]

[quote]
HA! I knew I'd get someone with that one. With a velocity of 20,000 mph and constant distance from the earth you would be weightless (in orbit). With a velocity of 10,000 mph (half of orbital velocity) and a constant distance from the earth you would be half weightless. With a velocity of 1000 mph and a constant distance from the earth you would have 5% of orbital velocity and be 5% weightless. You would weigh 5% less.
[quote]

Dude....ummm.....do you know why when something is orbit the Earth why it is "weight-less"? Simplely, because it's falling with gravity (free-falling) and missing.

Any falling body is "weight-less". It's just that the bodies that are traveling at sub-orbital speeds have a very rapid negative acceleration phase they go through when they impact the Earth.


But supposing you ment a powered AC flying around the globe. Bzzzt.

Your assumption about centripital force doesn't cut it. Check your math. It's velocity squared over radius.