Posted on 02/07/2003 4:30:37 AM PST by The Magical Mischief Tour
Bingo! NASA "Award Fees" determine whether the contractor makes a profit that year or not.
I'm not sure we're talking about the same video frame. I took another look at it and it appears to be in sharp focus. You can clearly see defined edges, as well as shadows in the right places on the belly of the orbiter.
The image on the frame is not symetrical, as it would be if it were an iris artifact.
At 400,000 feet altitude, the orbiter is maneuvered to zero degrees roll and yaw (wings level) and at a predetermined angle of attack for entry. The angle of attack is 40 degrees. The flight control system issues the commands to roll, pitch and yaw reaction control system jets for rate damping.
The orbiter's speed brake is used below Mach 10 to induce a more positive downward elevator trim deflection. At approximately Mach 3.5, the rudder becomes activated, and the aft reaction control system yaw engines are deactivated at 45,000 feet.
Entry guidance must dissipate the tremendous amount of energy the orbiter possesses when it enters the Earth's atmosphere to assure that the orbiter does not either burn up (entry angle too steep) or skip out of the atmosphere (entry angle too shallow) and that the orbiter is properly positioned to reach the desired touchdown point.
During entry, energy is dissipated by the atmospheric drag on the orbiter's surface. Thus, descent rate and down ranging are controlled by bank angle. The steeper the bank angle, the greater the descent rate and the greater the drag. Conversely, the minimum drag attitude is wings level. Cross range is controlled by bank reversals.
The entry thermal control phase is designed to keep the backface temperatures within the design limits. A constant heating rate is established until below 19,000 feet per second.
The equilibrium glide phase shifts the orbiter from the rapidly increasing drag levels of the temperature control phase to the constant drag level of the constant drag phase. The equilibrium glide flight is defined as flight in which the flight path angle, the angle between the local horizontal and the local velocity vector, remains constant. Equilibrium glide flight provides the maximum downrange capability. It lasts until the drag acceleration reaches 33 feet per second squared.
In the transition phase, the angle of attack continues to ramp down, reaching the approximately 14-degree angle of attack at the entry Terminal Area Energy Management (TAEM) interface, at approximately 83,000 feet altitude, 2,500 feet per second, Mach 2.5 and 52 nautical miles (59 statute miles) from the landing runway. Control is then transferred to TAEM guidance.
During the entry phases described, the orbiter's roll commands keep the orbiter on the drag profile and control cross range.
Who's kidding who, anyway???
Stand up, get some oxygen to your brain...
Then try again.
I raised this line of reasoning in another thread. I assume it is part of the reason why NASA did not expect trouble, and why they are still looking for alternative explanations. It's pretty hard to make an effective bullet out of styrofoam, unless it's attached to ice.
We now know factually that the rear starboard yaw thrusters activated before the mystery piece broke off, and that there was some sort of problem with them as reported by Dittemore. That possibly could have turned the orbiter sideways.
What sort of force do you figure broke off the vertical stab if it wasn't caused by a yawing force?
Only if you don't understand the physics involved. That NASA estimates the delta-V at ~500 MPH would seem to indicate that they, too, grasp the physics I've already described better than you appear to...
The distance from release point to impact point being 50 feet is a limiting factor. You really believe that the foam decelerated several hundred miles per hour in 50 feet??? In less than 1/6th of a second?
The distance is not the "limiting" factor... There are several involved- surface area exposed to the full force of the air flow, the relatively low density of the material, the hardness of it, etc.
It's way too simplistic to ignore these things...
ONLY when you ignore the physics involved, does damage from the foam insulation appear remote (if not impossible). To anyone who does understand these issues, the chances go from "slim-to-none" to "quite possible" or even "probable," depending on who you ask...
My money has been- since I heard about the insulation hitting the wing- that this is the primary reason the Columbia was lost.
I get the same response from enviro-Nazi's from time to time, when they get on their soap-box about the long-lived radioactive isotopes associated with nuclear power... (My specialty happens to be nuclear power and robotics, not astrophysics...) Common misconceptions or a fundamantel ignorance of certain facts are far more interesting, than reality- which is why enviro-nuts are strictly anti-nuke... They simply fear (and therefore protest) something they obviously don't understand...
When you look at the big picture with regard to the shuttle... this is the only that makes sense... Everything points to this...
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