40,000 lbs = U2
1,500 lbs = Perlan II
I provided evidence that a “plane” has flown to 76,000 feet. The U2 is another matter.
{Besides, why keep it a secret? 70,000 altitude - 75,000 altitude, tomato - tomaato.}
Besides, why keep it a secret?Conventional jet engines don't do well in thin air. It is not about the altitude so much as it is about the engine design. Modern radar can see the altitude.
The U-2 is powered by a lightweight , fuel efficient General Electric F118-101 engine, which negates the need for air refueling on long duration missions.
Seems like a fairly conventional jet engine.
Now if it had ramjet engines . . . Of course, I doubt that could work with those wings on the U2.
Of course, how to get the U2 up to the necessary mach 3, for the Ramjet to function, is another technical issue to be solved.
What do you mean it’s not about altitude? You have a curious way of looking at physical reality.
U.S. Standard Atmosphere Air Properties - SI Units0 altitude = …Density 1.225(kg/m3)
30,000 altitude = Density 0.01841(kg/m3)
70000 altitude = Density 0.00008283(kg/m3)
source - https: //www. engineeringtoolbox. com/standard-atmosphere-d_604. html (spaces added to disable)
Bringing it back to the Challenger, YouTube just shoved an interesting NASA video onto my suggested viewing, I tried ignoring it, but this morning my finger wasn’t following my brain’s direction.
Warning, very detailed deconstruction of the explosion. If you are an empathetic person and especially if you’re old enough to remember the event, it’s a very depressing video, but if you want authoritative details of what the recovered debris told experts, this is the video for you.
TheConquestofSpace. |. Mar 27, 2011
On January 28, 1986, the Space Shuttle Challenger became NASA’s first in-flight accident causing the loss of seven crew members. The accident would be blamed on a faulty o-ring seal that failed to prevent hot rocket motor gases from escaping and eventually leading to the destruction of the external tank and the orbiter and its crew. Many things had to go wrong on that day and they did. Cold temperatures, upper level wind shear, organizational failure and complacency all contributed to the tragic loss of life. Another accident would follow and while different had in common a human failure to detect and prevent the conditions under which catastrophic events could endanger a crew. The second accident, Columbia, would begin a long goodbye of the Space Shuttle era and raise questions of humankind purpose and next steps in space. This Final Segment Concludes the Technical Analysis of the Accident by the Data and Design Task Force. This NASA film provides one of the most comprehensive views of the photos and video taken of the accident. For even the most knowledgeable and seasoned space pro, this analysis provides a close-up look at the in-flight events that led to the destruction of the vehicle and the crew.
What do you mean it’s not about altitude?Interesting that dynamic viscosity and temperature at 150 - 200,000 ft are about the same as at 10 - 25,000 ft. If I understand it correctly (I may not) with adequate power it should be easier to get lift at 150 - 200,000 ft than at 30 - 60,000 ft. As I posted, I think it is all about the power, the engine. That can be kept secret, altitude can't.
Thanks for the reference, I did not remember about the temperature. I do remember the C-141 had a hole in its flight envelope. It would experience flutter at certain speed/altitude points, but was OK at higher speeds at those altitudes or higher altitudes at those speeds. That airframe configuration responded to the atmosphere in some unexpected ways. I don’t remember the numbers, but they worked it out for the C-5 design.
an interesting NASA videoThe SRB had a steel case and insulating material inside the case to keep hot gas from impinging the case. The solid fuel had a hollow core and it burned inside that core from the top down and inside to outside. It was designed so that there was no way for hot gas to get out except through the nozzle.
Interesting that dynamic viscosity and temperature at 150 – 200,000 ft are about the same as at 10 – 25,000 ft.That sounds profoundly counter-intuitive. Can you offer any sources explaining that.
Can you offer any sources explaining that.Data from your reference in post #342145.