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Does is possible to launch object into space using only SRB


Pawelk198604
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Except scout didn't, athena didn't, and on most launches pegasus doesn't. Not to mention most ICBMs, which while not orbital do require very precise trajectory adjustment.

FWIW - Minuteman has a liquid fuel PBCS (Post Boost Control System) that's used for trajectory optimization. Polaris A-1 and A-2 used blowout ports. (Polaris A-3 just dumped the warheads 'over the side' and let the 2nd stage power on to exhaustion, I'm not certain how the post boost vehicle of the UK's Chevaline variant was powered.) Poseidon used blowout ports and a solid fueled gas generator powered PBCS. Trident -I used and -II uses trajectory shaping (I.E. pointing the thrust vector off-nominal) along with a solid fueled gas generator powered PBCS. In fairness, this isn't really an indictment of the booster as the PBCS is needed for MIRV deployment, so since they have to carry it anyhow it just makes sense to use it for final (highly accurate) velocity trim before they deploying warheads.

SUBROC and ASROC used blowout ports too.

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Without staging? Yes, but you'll need a (very) big SRB. Something you should take a look at is the SASSTO, an SSTO That would have used an S-IVB with a Space Shuttle Main engine that could have delivered a Gemini Capsule into orbit. While SRBs are useful, they do require a lot of quality control, so hopefully your proposed SSTO would have one nozzle for engineering convenience.

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  • 5 months later...
You don't neccessarily need to use a hybrid rocket, you can get throttle control with a pure SRB rocket by altering the fuel density of the solid rocket fuel, allowing you to predefine a thrust profile for your rocket. It doesn't give you the ability to control your throttle on the fly but it does allow you to vary your throttle throughout your ascent profile as part of a predefined flight plan. Similarly you can make an SRB restartable by altering the design parametres of the solid fuel within the booster such that it burns in two or more sections.

HOW?! please tell me, I need this for my shuttle srb's in RSS

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I am quite sure that a 100% solid rocket could reach orbit, but only if you didn't care which actual orbit it reached. However, most rocket launches are aiming for specific orbits because the customer wants their payload to go "there and not anywhere else, thank you very much!"

It is, in theory, possible to reach a specified orbit with just solid rockets, but only if your theory ignores atmospheric disruption and fuel irregularities. In reality, any and all variations of atmospheric conditions can affect the amount of fuel needed to get to orbit. Humidity increases drag, Increased pressure increases drag. Lower temperature increases drag. Winds can push a rocket off the optimal trajectory, forcing the guidance systems to compensate, causing more fuel to be burnt. Tiny variations in fuel manufacture can affect the ISP of a rocket.

As a result, all launches go up with a few percent of excess fuel, and almost never burn the optimal, intended amount - they either end up with more or less than the predicted fuel excess, and either shut off the engines early or late. Pure SRBs can't safely shut down: there are designs that could open an SRB to vacuum and thus drop internal pressure to below that needed to maintain combustion, but they are dangerous as they are liable to create an uncontrolled failure resulting in shrapnel capable of destroying a payload.

As a result, it is almost certain that any "SRB launch" will in fact have at least an upper stage that is either hybrid SRB or liquid fuel.

I work for a US commercial launch company and we uses solid upper stages all the time for precises orbital insertions. We have very accurate models of the thrust profiles/energy content of the motors. We measure loads of parameters that affect the burn rate / thrust profile that all feed into the control system. Weather balloons, etc. are used to measure upper atmosphere conditions, wind profiles, etc. to ensure we have sufficient delta-v to meet the mission profile. At all times knowing the remain dV based on the models, the current orbital position (via inertial guidance & GPS) and desired orbit allows the system to either start scrubbing additional energy or continue to burn in an optimal direction.

So besides lots of math it isn't really that difficult in the real world.

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Well, since this HAS been necro'd...

FWIW - Minuteman has a liquid fuel PBCS (Post Boost Control System) that's used for trajectory optimization. Polaris A-1 and A-2 used blowout ports. (Polaris A-3 just dumped the warheads 'over the side' and let the 2nd stage power on to exhaustion, I'm not certain how the post boost vehicle of the UK's Chevaline variant was powered.) Poseidon used blowout ports and a solid fueled gas generator powered PBCS. Trident -I used and -II uses trajectory shaping (I.E. pointing the thrust vector off-nominal) along with a solid fueled gas generator powered PBCS. In fairness, this isn't really an indictment of the booster as the PBCS is needed for MIRV deployment, so since they have to carry it anyhow it just makes sense to use it for final (highly accurate) velocity trim before they deploying warheads.

Minuteman also uses blowout ports on the third stage (they treat the PBCS as a fourth stage, at least in text). That's largely because the first three stages of Minuteman III (the only version remaining in service) are pretty much identical to the stages used on Minuteman I and Minuteman II, which were single-warhead missiles and used the thrust-termination to provide a lower, faster trajectory while having sufficient accuracy. The liquid-fuel PBCS was added on Minuteman III to both provide final fine correction of the warhead trajectory for greater accuracy, and then to provide MIRV capability. I'm not sure if the now-retired Peacekeeper (MX) used trajectory shaping or final boost stage blowout ports along with the PBCS.

The Space Shuttle's SRBs nearly had a Thrust Termination System (blowout panels) based on that of the Minuteman, but NASA cancelled it to save money on the theory that spaceflight was now safe enough that they didn't need backup systems or intact abort capability all the way from the pad to orbit... but that's a rant for another time.

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Blast something into space on a single stage solid-fuelled rocket? No problem whatsoever. Some sounding rockets are basically that.

Send something into orbit on a single, non-stages solidfuelled rocket? Not possible with current technology. If it was, it was being done already because solid fuelled rockets are cheaper than liquid fuelled ones because of the lack of complex plumbing.

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I'm not sure if the now-retired Peacekeeper (MX) used trajectory shaping or final boost stage blowout ports along with the PBCS.

ISTR seeing reports of the development blowout systems for Peacekeeper back in the day, but have no idea whether they were implemented in the final design. I'm more of an (US) SLBM expert anyhow.

The Space Shuttle's SRBs nearly had a Thrust Termination System (blowout panels) based on that of the Minuteman, but NASA cancelled it to save money on the theory that spaceflight was now safe enough that they didn't need backup systems or intact abort capability all the way from the pad to orbit... but that's a rant for another time.

No, that's not why they cancelled the thrust termination system. (Short version: they didn't actually work as hoped/planned because of the Shuttle's piggyback design.)

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