Posted on 03/10/2021 10:11:57 AM PST by CondoleezzaProtege
Well, not quite. Turns out stacked donuts of solid fuel had a more useful performance profile than other designs. The performance of a solid rocket fuel is a function of the combusting area. As solid fuel combusts, it erodes. If the erosion significantly increases or decreases the area combusting, thrust and chamber pressure change and if this reaches an inconvenient balance the booster might not produce enough thrust during a critical phase in the mission profile, or it might shut down or blow up. However as the 3 exposed faces of the cylindrical segment erode the surface area remains relatively constant and/or predictable so performance can be made optimal for the mission profile (in this case roughly constant thrust until burnout near the end of the gravity turn, with the SSME used to compensate).
The political benefit was just gravy...however we should take notice that a gravy train is needed for the successful funding of a federal project. Thus elevating such consideration to an engineering concern, provision of gravy, HHOS.
I worked at Corning Inc at the time, a division, Erwin Ceramics Plant. The material is actually a ceramic tile with a foam like interior. Very lightweight. About the size of a bar of soap. You can hold it in your hand at one end and get the other end red to almost white hot and not fall the heat.
We are referring to the foam insulation on the center fuel tank. i think you are talking about the heat shield tiles on the bottom of the orbiter.
That made me chuckle.
As someone who shouldn't have once told me...
"You like science fiction, right? Take what you think we might have, add 100 years, and you are getting close."
Should’ve had him investigating TWA Flight 800.
Center fuel tank, my ass.
I’m still waiting for flying cars.
If they had them, do you really think they would let us have them?
A people used to liberty blessed with high technology is very hard to control.
We almost didn't get the internet.
Did someone else sign off instead??
Big fan of alternate history fiction as well. Good question. Not really sure. It had direct and personal effects on me and classmates, but not so sure of the long term global changes. Perhaps, we’d have some form of space based SDI as that was the big project going on at the time.
IIRC, he was ‘overruled’ by higher ups....................
Wasn’t the booster fuel material more of a sludge as manufactured, that had to be poured into the casing? They couldn’t pour a 100 foot long tube without cracks or voids with would result in explosive failure, so they had to do smaller segments and stack them.
I don’t know, I read that sometime after the accident.
Original plans had the shuttle with an escape pod like the F-111 aircraft had. But it was determined as too costly.
Yes, that's very common for solid propellant. It was perchlorate, aluminum, HMX (a kind of plastic explosive, heheh), and some kind of binder like butyl rubber cured solid...they could pour it and it would solidify in the case. Way easier. Of course when Feynman visited the factory they were certifying the casings cylindricality by measuring 3 points on the top, a total fail. I think a lot of modern standards for GD&T (geometric dimensioning & tolerance) are a legacy of lessons learned from the investigation.
They couldn’t pour a 100 foot long tube without cracks or voids with would result in explosive failure, so they had to do smaller segments and stack them.
Another plus for using segmented propellant, manufacturability. But the segmented approach was really optimum for the required mission performance.
The shuttle program was just using a standard approach. I've done the same thing in candy rockets, cast segments in a mold and slipped them into a heavy paper tube with a plumbers' putty gasket between each segment to protect the exposed paper. The propellant segments deform a little when you compress the stack and the putty bonds with the paper. Some people use PCB pipe with similar effect. Makes the math easier, that's for sure.
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