Reusing a Shuttle/ SLS SRB by making a parachuted landing on land.

[fredinno]

Would landing a SLS SRB on land be possible with parachutes? If so, then would it save money doing so (compared to the water landing + recovery, which was proven to not save any money.)

Note: If land is not available, land on a landing boat (like Spacex)

Edited June 5, 2015 by fredinno

[Kryten]

What land? Unless you want to boost them across the entire Atlantic there's nothing there.

[Camacha]

What land? Unless you want to boost them across the entire Atlantic there's nothing there.

That rather depends on where you launch what vehicle from, does it not?

[fredinno]

What land? Unless you want to boost them across the entire Atlantic there's nothing there.

Whoops. Updated to what I meant.

[G'th]

One, it'd probably require bigger chutes to insure the SRB's aren't going to be too damaged once they hit the ground.

Two, there's no way to necessarily predict where they'll land, so without a virtual desert the size of Texas to land in, its too likely that you'll land the booster in a populated area.

Three, a powered landing would likely require designing the entire SRB and would be ABSURDLY complicated. A powered landing using a liquid booster is one thing. Using a solid booster on the other hand is a whole other ballpark. (and its not even built for the same game)

And as far as the whole saving money thing goes, the SRB's were the least of the worries as far as STS went. The Orbiter was more of a money sink than the SRB's were.

[Camacha]

One' date=' it'd probably require bigger chutes to insure the SRB's aren't going to be [i']too damaged once they hit the ground.

Two, there's no way to necessarily predict where they'll land, so without a virtual desert the size of Texas to land in, its too likely that you'll land the booster in a populated area.

Both could be mitigated or fixed by using controlled chutes. It should not be impossible to make software that controls parachutes and a soft landing.

Then again, predicting where chutes will end up its actually fairly straight forward. You know where they are going to be dropped and you know maximum wind speeds. The area is not going to be Texas sized, not at all.

[Jonboy]

That rather depends on where you launch what vehicle from, does it not?

But OP is asking about Shuttle/SLS boosters, which we know will be launched from KSP.

The only option for launches at KSP would be on a barge, which would be VERY difficult using only parachutes. Powered landing is out of the question, because there's NO way a solid motor could provide the fine control needed for a soft landing.

And even if it were possible, developing this sort of capability would likely cost far more than would be gained by recovery on land instead of water.

[Requia]

Both could be mitigated or fixed by using controlled chutes. It should not be impossible to make software that controls parachutes and a soft landing.

Then again, predicting where chutes will end up its actually fairly straight forward. You know where they are going to be dropped and you know maximum wind speeds. The area is not going to be Texas sized, not at all.

This. We landed the moon missions of all things within 5 miles of target. But i still see a problem with land in that you now have to design your boosters to drop at a specific point instead of what's best for the rocket, because there are relatively few mile radius patches to aim for on land, we can warn ships away from the drop point easily.

[sojourner]

You are seriously under estimating how difficult it would be to hit a target with an srb using a parachute.

Besides, SRB's are cheap because they are simple. The minute you start adding requirements you might as well stop using an SRB and move to something more versatile like a liquid booster.

[Camacha]

But OP is asking about Shuttle/SLS boosters, which we know will be launched from KSP.

That assumption makes no sense. There are currently no shuttle or SLS boosters being launched, and nothing forbids them from being launched elsewhere. If you want it to be part of the answer, it should be part of the question.

You are seriously under estimating how difficult it would be to hit a target with an srb using a parachute.

I am not saying it will not be hard, I am saying that it is not impossible to get a reasonable amount of control. Especially feathering before touchdown should be very possible, though mattress style controlled parachutes should be viable too. Our understanding of the aerodynamics involved and computational power have both increased since the days of STS.

Edited June 5, 2015 by Camacha

[Newt]

Besides, SRB's are cheap because they are simple. The minute you start adding requirements you might as well stop using an SRB and move to something more versatile like a liquid booster.

Indeed. The value of the SRB is derived in large part from the fact that, basically, you can get it ready, and leave it with minimal maintainance (for a massive explosive) for long durations. Trying carefully to land it would be a challenge, and would certainly add many parts that need to be maintained (in the STS scenario, adding complexity to an already exceedingly complex vehicle). But I agree with Camcha. Difficult? Yes, it would be a huge challenge, but certainly possible.

@Requia, we landed on the Moon very well, indeed. But that is very different. There is no wind, so courses can be plotted very accuratley, and there is a throttle and an engine. The SRB will be falling unpowered, perhaps a few motors holding fins and chutes, or jets to direct itself. The bulk of the energy from falling will be absorbed not by directly controlled rockets, but by not always that predictable wind. Launch days are good weather days, but that does not mean things will be at all comprable.

[Rune]

The problem with reusing SRBs is that you are only reusing steel casings, in the end. The really complicated part of a solid motor is the engine casting (think firecracker, but with a very precise shape and composition in the propellant to control thrust and burn rate). Casting those things takes time, expertise, and expensive tooling, that's why reusing a SRB costs pretty much the same as building another one, high strength steel is pretty cheap to buy and machine into the casing.

Rune. Yeah, that was an oversimplification, but I won't get into things like quality assurance, which is also an expensive factor in SRB casting.

[Nibb31]

As Rune said, there isn't much point in reusing SRBs. They are basically just tubes of sheet metal which are quite inexpensive to make. Recovering them out in the ocean simply isn't worth it.

- - - Updated - - -

But OP is asking about Shuttle/SLS boosters, which we know will be launched from KSP.

Surely you mean KSC.

[Camacha]

As Rune said, there isn't much point in reusing SRBs. They are basically just tubes of sheet metal which are quite inexpensive to make. Recovering them out in the ocean simply isn't worth it.

You cannot say that without also explaining why they bothered to rebuild them for the STS.

[Nibb31]

Politics. STS was sold as a reusable launcher, so they made the SRBs "reusable". Maintaining two recovery ships, packing the largest parachutes ever made, and refurbishing the steel casings never made any economical sense.

[Camacha]

Politics. STS was sold as a reusable launcher, so they made the SRBs "reusable". Maintaining two recovery ships, packing the largest parachutes ever made, and refurbishing the steel casings never made any economical sense.

Can you substantiate that with numbers?

[Nibb31]

No numbers... I don't know if any are available, but it's pretty much common knowledge in the industry. The two ships were acquired at the beginning of the STS program. A huge investment was made in terms of infrastructure and training, and reuse was the major selling point of the STS to Congress and the general public, so it wasn't something that they could afford to turn around on.

Recovery was a rather involved process, which involved sending recovery ships, helicopters and divers to safe and secure the SRB. They were then towed back to KSC and dismantled on site.

Most of the SRBs components were scrapped, including the fustrum and the aft skirt with the thrust vector control systems, which were the most expensive parts. Parachutes and pyros were expendable of course. The steel casings, which are the cheapest parts of the SRB had to be sent back to Utah, inspected, cleaned, rinsed, repainted, and reassembled. Many of them ended up buckled or corroded by seawater, so assembly lines had to keep making replacements throughout the program. At the peak of the program, they had 1500 people working on the SRBs.

There is no way that whole malarkey could have been cheaper than manufacturing new steel casings for each flight.

[radonek]

Then why not to detach expendable steel tube and land just expensive parts?

BTW original idea was based on much bigger traffic which would make refurbishment process reasonable. Also, higher attrition rate was expected from the begining, precisely on the grounds of SRBs being cheap.

[Kryten]

It should probably be noted that the steel casings, while the cheapest part of the SRB, were by no means actually cheap. They used many specialised processes to reach the required levels of hardening and the precise shape, most of which was shut down shortly after casing production stopped because nothing else needed it.

[Camacha]

There is no way that whole malarkey could have been cheaper than manufacturing new steel casings for each flight.

A guesstimation really is shaky ground for a good discussion Though it is not unlikely that some politician tried to retain jobs locally, your guess is as good as any other. Intuition quickly goes out the window when dealing with massive and very unusual projects.

[fredinno]

No numbers... I don't know if any are available, but it's pretty much common knowledge in the industry. The two ships were acquired at the beginning of the STS program. A huge investment was made in terms of infrastructure and training, and reuse was the major selling point of the STS to Congress and the general public, so it wasn't something that they could afford to turn around on.

Recovery was a rather involved process, which involved sending recovery ships, helicopters and divers to safe and secure the SRB. They were then towed back to KSC and dismantled on site.

Most of the SRBs components were scrapped, including the fustrum and the aft skirt with the thrust vector control systems, which were the most expensive parts. Parachutes and pyros were expendable of course. The steel casings, which are the cheapest parts of the SRB had to be sent back to Utah, inspected, cleaned, rinsed, repainted, and reassembled. Many of them ended up buckled or corroded by seawater, so assembly lines had to keep making replacements throughout the program. At the peak of the program, they had 1500 people working on the SRBs.

There is no way that whole malarkey could have been cheaper than manufacturing new steel casings for each flight.

Would landing on land (or a landing boat) make the entire SRB reusable, rather than just the steel casing, like it was like when landed on water?

[SciMan]

Probably not. The best idea I've seen here so far is recovering the most expensive parts of the SRB at sea (thrust vectoring, etc.), and letting the rest of it splash down uncontrolled.

Even then, I don't know if the cost of the recovery systems is greater than the cost saved by recovering SRB components. If it's not, then it makes more sense to make the SRBs an expendable item.

The Shuttle and STS programs are mired in politics, which usually results in decisions that aren't fully rational from a purely engineering point of view.

[11of10]

A bit off topic but, I read some place once that the shuttle used solid rockets engines only because it had an already set infrastructure for manufacturing the same thing for ICBMs, and that it was some senator's gimmick to keep his people working or something like that.

Now at topic:

If I'm not mistaking, SpaceX went with powered recovery vs chutes because they calculated they'd lose less deltaV this way.

[sojourner]

If I'm not mistaking, SpaceX went with powered recovery vs chutes because they calculated they'd lose less deltaV this way.

Pretty much. The weight of the chutes outweighed the weight of adding legs and reserving enough fuel for powered landing.

[Capt. Hunt]

Would landing on land (or a landing boat) make the entire SRB reusable, rather than just the steel casing, like it was like when landed on water?

Probably not. While saltwater corrosion was certainly not good for the boosters, the main contributing factor to wear on the components would have been the heat from the rocket motor, and that's not something you can avoid, regardless of where you drop it.