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61

The O-rings and the temperature were only the last in the long chain of blunders, and that had little to nothing in common with reusability. The construction of the SRBs wouldn't be much different with no reusability in mind. Indeed, SRBs of very similar design are to be used in SLS, and they are not intended to be reusable. About the most important factor ...


53

No. Compare Space Shuttle Launch Countdown. The SRB fire command and the hold-down fire commands are issued at the exact same time. The delay of about 6 seconds (note: each SSME is started at a different time, all 0.2 seconds apart) is to ensure that each of those engines are up to full throttle without errors prior to launch (which is called a Redundant ...


45

I don't have an immediate citation handy, but the answer is no. The SRBs were powerful enough to overcome the hold-down studs. That said, the same signal was used to blow the nuts on the hold-down studs and ignite the SRBs. Once the SRBs light, the vehicle is going somewhere.


42

Specific impulse is not the only measure of a rocket. For the case of the SRBs, high thrust is much more important than high specific impulse. In this case, you want to look at the heat of formation for carbon dioxide vs aluminum oxide. Carbon dioxide has a heat of formation of roughly -390 kJ/mol, compared with roughly -1670 kJ/mol for aluminum oxide. ...


40

Long March 11 is a cold-launched rocket, based on a concept popular with military rockets. A gas charge is generated by the launch platform (often using a chemical gas generator) to eject the rocket from the launch platform before engine ignition. This saves the launch platform from having to manage hot exhaust gases, and reduces wear and tear on the launch ...


30

Absolutely not. Even if the hold-downs could keep the rocket on the pad, the thermal energy released during the SRB burn would destroy the launch pad, the tower, the entire stack, and many careers.


29

No, a quick calculation yields a $\Delta v$ of about 4.6 km/s and you need about 9 km/s to get to low-Earth orbit. You'll lose a lot of that velocity to aerodynamic drag as well as the vertical portion of the flight, so a rough estimate of the final speed at burnout would be somewhere around 3 km/s -- or about 10,000 km/h. Using the specifications from the ...


26

SRB Ignition SRB ignition can occur only when a manual lock pin from each SRB safe and arm device has been removed. The ground crew removes the pin during prelaunch activities. At T minus five minutes, the SRB safe and arm device is rotated to the arm position. The solid rocket motor ignition commands are issued when the three SSMEs are at or ...


24

Not reusability per se, but design and politics. The competitor to build the SRBs for the Shuttle program was Aerojet, and their design was monolithic. In other words, no segments. Aerojet was actually selected as the winning contractor but the NASA administrator Fletcher overrode this and gave it to Morton Thiokol. Aerojet had already built an awe-...


21

It's a quenching probe. After burnout of the booster was confirmed, a CO2 fire extinguisher was moved into the nozzle area to inject carbon dioxide into the booster to kill any remaining fire in order to preserve the systems in their condition at burnout, allowing for a detailed study of the components of the SRB.  Source: http://www.spaceflight101.net/...


19

You might be interested in the tool called cpropep. This allows us to gain basic performance indications for different fuels by solving the physics behind it: chemical equilibria and expansion/compression. So how does $NH_4ClO_4 + Al$ perform against $NH_4ClO_4 + C$? First we feed it the approximate conditions: Chamber temperature: anything (calculated ...


19

Yes, several of the previous shuttle launches exhibited erosion and/or "blow-by" of the SRB O-rings, starting with the second flight, STS-2. Much has been written about the failure of NASA and Thiokol management to recognize the severity of the problem and respond appropriately. The Rogers Commission report covers a lot more than the O-ring problem, but is ...


18

The SRBs have smaller solid separation motors, 8 on each, which simultaneously fire to push the boosters safely away from the orbiter/ET. Here's a video showing them in action -- they're powerful enough to give the external tank a good scorching. You can see the separation is designed to turn the boosters slightly outward so any remaining SRB thrust takes ...


18

Wings, engines to fly back to the launch site, and landing gear are heavier than parachutes. Using this design on the SRBs could have resulted in a significant payload to orbit reduction (every 10 pounds added to the SRBs resulted in 1 pound less payload that could be carried to orbit). However, this was studied for the case of liquid fueled flyback ...


17

The Ares 1-X used stock Shuttle program SRB thrust vector control (TVC) - hydrazine fueled power units drove hydraulic pumps which powered actuators that could tilt and rock the nozzle, which incorporated a flexible bearing in its design. (Pictures from "Space Shuttle", Jenkins, 1992 edition p.263 and here - p 2.13-48 of linked PDF) However, unlike the ...


17

No, they don't have sufficient thrust when they're jettisoned to catch up with Space Shuttle accelerating away: The SRBs are jettisoned from the space shuttle at high altitude, about 146,000 ft (45 km). SRB separation is initiated when the three solid rocket motor chamber pressure transducers are processed in the redundancy management middle value ...


17

Could the shuttle wait out the whole burn of SRBs on launchpad in case of a problem on launch? No. The question seems based on the assumtion that something (the hold-down bolts perhaps) could hold the stack down while the SRBs burn out, while being immersed in the 3300 degree Celsius exhaust for about 128 seconds. Note that during this time, while the hold-...


16

The Ares I-X was a modified STS SRB with with an upper-stage simulator. So far as I know, this was the only standalone launch of SRB hardware. Even the original SRBs were not flight tested before manned launch. The Ares I-X flight had an apogee of 46 kilometers, less than half the 100 kilometer altitude of the Karman line, which is considered the edge of ...


16

This is referred to as 'kick stage' motor and is commonly used. One example being Star 37. A larger Star 48 is what sent New Horizons on the way to Pluto


16

Meet the Ariane EAP (Étage d'Accélération à Poudre, "Solid Booster Stage"): what are the (presumably eight) circular spots on the external nozzle-like protrusions at the bottom of each of the (presumably solid rocket) boosters on either side of the main engine? They are the business ends of the fusées d'éloignement, or separation motors, which push the ...


15

Technically, it was the O-rings, but that was not the root cause. The root cause was a poor culture at NASA. The technical solution was easy: Don't launch on that cold of a day. In Florida, even in late January, all you have to do is wait a day or two and temperatures will once again be balmy. Technically savvy people knew well of the O-ring problem in cold ...


15

NASA was the most concerned with the thrust oscillation happening near and on depletion of the first stage fuel, roughly 105-115 seconds into the flight after liftoff and just before first stage separation (see Ares I-X Mission Profile below), as it was shown by the computer modeling and early design analyses of the Ares 1 rocket.     This ...


14

SRBs have a very high thrust to weight ratio, even if they have an only modest ISP. That makes it complementary with LH2/LOX systems that have a relatively low thrust. Early on acceleration is almost as important for over all efficiency as exhaust velocity. For the first few hundred m/s of $\Delta v$, a combined metric of ISP and propellant density, called ...


13

There was certainly a risk that the boosters could collide with each other, once they separated they were essentially just big pieces of pipe. The chance of it happening was extremely low though. At separation the boosters were moving at mach 4+, and as they were angled to clear the tank they were angled away from each other. The aerodynamic forces would ...


13

The answer to the question is an ancient philosophical question: Ship of Theseus. As Organic Marble mentioned in his comment which could have been an answer: The SRBs were made up of segments, and the reuse was at the segment level. The obvious lower bound for number of SRB segments produced would be eight: four SRB segments per side per launch. We can ...


13

Yes, the pressure of the first stage exhaust is always at least slightly subatmospheric, because that gives the maximum average ISP over the whole burn time. Rockets with boosters attached (parallel staging) often operate at the lowest possible exhaust pressure that prevents the flow from detaching from the nozzle walls. Historically, the Summerfield ...


11

My reading of the function of the SRB manual separation control is that it would not actually trigger a separation while the boosters were firing (bold mine): SRB separation is normally performed automatically by the onboard GPCs; however, the flight crew can command separation through use of the SRB separation switches on panel C3. The SRB separation ...


10

The shuttle SRBs weren't really cost-effective to reuse. The nozzles and nozzle boots were replaced completely, as were many other components; the segment casings were deformed by the force of splashdown, and had to be reshaped. Designing the booster for reuse, and inspecting each rebuilt booster thoroughly to be assured that it was safe to use — ...


10

I don't know about 1986, but if the systems were like the ones that existed in the 2000s, pad audio recordings will not help your quest. The microphone we put out on the pad, we only use that when the sparklers ignite. Once the engines kick on you have to get off that immediately, or you have nothing but overdriven clipping noise. Loren Mathre, audio ...


9

Solid rocket booster nozzles can gimbal. If you take the SRB of the Space Shuttle: Each SRB had two hydraulic gimbal servoactuators, to move the nozzle up/down and side-to-side. This provided thrust vectoring to help control the vehicle in all three axes (roll, pitch, and yaw). You will find more explanation on this Wikipedia article, where I found this ...


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