Whoops, you’re right. I thought the gimbaling was just on the SSMEs (attached to the orbiter) but in retrospect it’s obvious that the SRBs had to have some control of their flight path. I’m now actually rather curious about the range safety stuff for the SRBs—one of the dangers of an SRB is that there’s basically no way to shut it down, and indeed they kept going for some time after Challenger blew up—but the gimbaling is indeed an obvious sign that I should have checked my memory/assumptions. Thanks.
I’m now actually rather curious about the range safety stuff for the SRBs—one of the dangers of an SRB is that there’s basically no way to shut it down, and indeed they kept going for some time after Challenger blew up
What I’ve heard (no research) is that thrust termination for a solid rocket works by charges opening the top end, so that the exhaust exits from both ends and the thrust mostly cancels itself out, or perhaps by splitting along the length of the side (destroying all integrity). In any case, the fuel still burns, but you can stop it from accelerating further.
Hm. A solid rocket burns from one end, opening up the nose will do nothing to the thrust. Splitting a side, I would guess, will lead to uncontrolled acceleration with chaotic flight path, but not zero acceleration.
Apparently that’s true of some model rocket motors, but the SRBs have a hollow through the entire length of the propellant, so that it burns from the center out to the casing along the entire length at the same time.
That exposes the maximum surface area for combustion, I guess (the surface area actually increases as the propellant is burned, interestingly) so blowing the top would work, yeah.
Whoops, you’re right. I thought the gimbaling was just on the SSMEs (attached to the orbiter) but in retrospect it’s obvious that the SRBs had to have some control of their flight path. I’m now actually rather curious about the range safety stuff for the SRBs—one of the dangers of an SRB is that there’s basically no way to shut it down, and indeed they kept going for some time after Challenger blew up—but the gimbaling is indeed an obvious sign that I should have checked my memory/assumptions. Thanks.
What I’ve heard (no research) is that thrust termination for a solid rocket works by charges opening the top end, so that the exhaust exits from both ends and the thrust mostly cancels itself out, or perhaps by splitting along the length of the side (destroying all integrity). In any case, the fuel still burns, but you can stop it from accelerating further.
Hm. A solid rocket burns from one end, opening up the nose will do nothing to the thrust. Splitting a side, I would guess, will lead to uncontrolled acceleration with chaotic flight path, but not zero acceleration.
Apparently that’s true of some model rocket motors, but the SRBs have a hollow through the entire length of the propellant, so that it burns from the center out to the casing along the entire length at the same time.
That exposes the maximum surface area for combustion, I guess (the surface area actually increases as the propellant is burned, interestingly) so blowing the top would work, yeah.