# Space Shuttle SRBs crash land in Disneyland...how long to safely remove them?

Here’s the setup—It’s 1985, and after an exceedingly poorly planned and executed Space Shuttle launch from SLC-6 at Vandenberg AFB, the Shuttle’s Solid Rocket Boosters (also thanks to an exceedingly poor execution of the range safety system), land intact…at Disneyland. One landing in the “Rivers of America”—roughly between Tom Sawyer Island and the Haunted Mansion—the other in the “Mickey” lot of the parking area.

Now, my question is: how long will it take to safely remove the boosters (or what’s left of them, after hitting the surface at roughly 50 mph, according to my notes) from the park?

As you might have guessed, I’m on vacation at the moment, so I’m unwinding by asking one of my patented Weirdo Technical Questions™. Anyone wanna bite?

I’m going to take the under here and say a few days to a week at most.

Landing that way they’re going to come in like a bomb and be flinders. Removing them will be a matter of bringing in accident recreation teams and locating, documenting and removing them to a more secure location for analysis. The odds of finding a large piece is low but there will be a LOT of small pieces.

Looking things up on wiki, a great deal of effort in terms of design and parachutes are expended to make sure the things can be recovered from a deep water landing. Hitting something solid like tarmac or even the shallow water/island out there won’t be good for it. Presuming a catastrophic failure with no parachutes they’ll arrive from a maximum of 220,000 feet and the booster can weigh - approximately - 148,000 kilograms. Force equals mass times acceleration means pow.

I wouldn’t want to be under it - or anywhere near it - when it come in.

Where are you getting the 50mph terminal velocity? I’m showing it at much higher. I bet we’re using very different variables. I calculated it at it’s actual weight with 200 square meters of downfacing surface and the drag coefficient of a car and got ~180 meters per second as it’s terminal velocity. That’s more like 400 mph.

I’m seeing the ~50 mph landing speed quoted online—with the SRB parachutes deployed. I’m generously assuming that, in this scenario, they at least were functioning perfectly. (Although, as you noted, there’s still a notable difference between landing in deep sea, and landing on asphalt/cars or eight feet of water)

OK, I’ll buy that 50mph with the chutes deployed. But we have to note that the boosters are designed to hit the water vertically. Those things, not hitting deep water, are going to compress and shatter in 2 seconds or so. They’re about 150 feet and will be coming at it - I checked - a bit more than 73 feet per second. So 2.1 seconds for full compression and destruction.

It’s going to be a whale of a hit, but coming in that way has a decent shot of limiting the debris field so clean up will be easier. I’ll stand by my 2-7 day estimate. Most of it being fine-tooth comb searching for missing pieces.

And unless I miss my math, it’ll arrive with approximately 3300 newtons worth of energy.

Jonathan, I think you’re missing the environmental contamination issue in your projected clean-up time. I think it would take way more than a week.

When the shuttle broke up over Texas, one of the major concerns was the really nasty stuff that would be scattered amongst the wreckage. There were constant warnings to local people not to touch anything they found.

If it can take weeks to just clean up an empty lot that used to be a filling station with simple oil and gas contaminants, how much longer to clean up the soil contamination from a space shuttle solid burn rocket?

According to Wikipedia:

That, and the APU apparently used hydrazine. Not sure how much nasty crap would be left after burning out and landing via parachute, but if the answer is something other than “none at all”, that’s going to be a mess to clean up.

I don’t disagree on the environmental mitigation. That’s a long process complicated by many factors. I simply chose to focus on the ‘remove the boosters’ part while noting that it won’t be a matter of a crane and some lifting.

Someone is going to have the fun job of separating metal SRB shards from metal car and building shards.

I just think that the solid fuel in the boosters is part of the boosters.

No one is applying the Disney factor.

45 minutes.

Newtons are a measure of force or weight. A Newton is defined in base units as kg*m/s[sup]2[/sup]. A 100g apple weighs about 1N in Earth’s gravitational field (G being ~9.8m/s[sup]2[/sup].

Energy is in Joules - Nm or in base units kgm[sup]2[/sup]/s[sup]2[/sup]

The “inert weight” (empty mass really) of a SRB is ~91000kg per Wiki.
The impact velocity is 23m/s per the same source.

Doing the straight physics calculation for energy, we get

E = 1/2mv[sup]2[/sup]
(0.5)(91000kg)(23m/s)[sup]2[/sup]
=24,069,500J = ~24MJ (Megajoules)
or about the energy in 24 sticks of dynamite (although not delivered as quickly), or the caloric content of ~11 McDonalds Big Macs (although not delivered as slowly).
or about the kinetic energy of 68 Toyota Priuses impacting at 55mph.

It will make a mess.

-DF

No, they don’t need that long. That’d only be if they needed cranes and forklifts and trucks and so on. All they need to do is to post some things online explaining how they’ve always been there, and announcing the grand opening of their brand-new exhibit, and charging people \$500 apiece to go see them.

But it would take them a bit of time to put up the RocketLand sign and install some animation. Maybe a figure of Neil Armstrong or something. Buzz Lightyear?

Assuming the RSRMs do not detonate on impact (which there is a good chance of for any speed above a few hundred feet per second, even with the relatively insenitive PBAN-bound propellant used in the SRBs, removing boosters with propellant that is potentially fractured and friable is an extremely risky proposition, both due to mechanical friction and the potential for electrostatic discharge. The SRBs can only be handled as a unit by special handling fixtures; you can’t just pick one up with a single crane and sling, and one with case damage that could cause it to buckle is extremely dangerous. Even with the correct handling fixtures, a damaged SRB could pose a massive personnel and property hazard.

In any normal demil/destruct operation, the nozzle is removed and the case strapped down, and then the motor is just ignited in place (in a burn pit), or alterantively detonated using high explosive for HC1.1d (mass detonating) propellants. For the SRBs, this probably isn’t possible, especially if there is a chance of breaching a field joint and the potential for catastrophic failure, as a detonation would pose substantial hazard to Anaheim and nearby occupied areas. Likely the best option would be to completely shut down Disneyland and perform a washout (literally spraying the inside of the motor with high pressure water and detergents designed to break down the binder), collect the runoff, and dispose offsite. Depending on the condition of the motors, this could take many weeks or even months to set up and perform the washout operation.

Stranger

The thing is, not very long at all after the shuttle clears the tower it goes into a pitch and roll maneuver. It puts the shuttle into an eastward trajectory. Anyone who saw tapes of the Challenger saw the SRBs generally maintain their trajectory. I don’t see the SRBs maneuvering to land on Disney World.

Vandenberg could be used for a polar orbit launch (such as for a classified USAF payload, this still being 1985). Or, really, really wonky winds over the Mojave, this being California, who knows…

But I’d hate to be the guy at NASA Legal when they get the call from Disney Legal. Better hope it IS a Defense/NSA mission so it all gets shut down on National Security grounds…

This doesn’t seem physically possible. The SLC-6 launch azimuths were all southward, from 201 to 156 deg. The very purpose of shuttle launches from SLC-6 was to achieve polar orbit which requires a southward launch over the ocean. As the shuttle ascends southward over the ocean, the earth is turning eastward, moving the land further away.

At the equator the earth is rotating 1037 mi/hr, and at the latitude of SLC-6 (34.74 deg. N) the rotational speed is cos (34.74) = 0.82, or 0.82*1037 = 850 mph. So the coast is moving away perpendicular to the shuttle’s ground track. Atmospheric affects would diminish this down low but by the time the SRBs separate, they are essentially in a vacuum.

Under the nominal ascent where the SRBs reach their maximum downrange distance, the impact point is about 120 miles from the launch site. That’s as far as they go after expending 100% of the propellant in a guided trajectory.

Even if the shuttle went haywire, did a hard eastward turn after launch from SLC-6, somehow stayed together, then flew in a straight line toward Anaheim, then jettisoned the SRBs at the most optimum point for maximum range, they wouldn’t reach Disneyland.

OK, so talk to me about propellant. Assuming a normal usage how much propellant can we expect to remain in the SRB on impact at Disney? I’d have thought - but am prepared to be wrong - that most or all of the propellant would be used up over the course of launch. It’s not like it’s used for manuvering once in orbit, it’s discarded and tossed into the ocean.

So do we need to account for it?