NASA Study Summary: "Summary of 260 inch Solid Rocket Launch Studies"

[luke strawwalker]

Here's a fairly short study from June 1968 entitled "Summary of 260 inch Solid Rocket Launch Studies from June 1965 to May 1968" by Bellcomm. It has a lot of interesting stuff on the 260 inch SRM proposed for a first stage replacement for Saturn IB, and some VERY novel launch facilities! Who'd have ever thought of launching a Saturn IB from a MISSILE SILO!

At any rate, this should go hand-in-hand with the Saturn IB studies related to SRMs both singularly and in clusters to replace or augment the Saturn IB first stage.

Enjoy! OL JR

[luke strawwalker]

Ok... the first group of pics are from the McDonnel Douglas studies of launching the 260 inch SRM first stage Saturn IB. They are a flowchart showing the ground handling, transport, raising, and setup on the launch pad of the over 2 million pound 260 inch monolithic SRM.

The first pic is showing several different approaches that were considered for each step in the chain from factory to launch pad... from different means to pick up and handle the fully fuelled SRM to how to float it to the launch area, to how to stand it upright, how to move it over land to the launch pad, etc.

The second pic is various approaches to standing the SRM upright, and different ideas for launch platforms, blast deflectors, hoisting cranes and support structures, and even some silo launch proposals.

The third pic is the "officially" adopted procedure from the Douglas study, step by step. The SRM is offloaded from the barge and hauled to a crane and motor erection pit, which then lifts the motor upright, and then transports it to the launch pad. It's then emplaced on the pad and the service structure is moved in to attach the upper stage and payload.

More to come! OL JR

[luke strawwalker]

Ok, the first pic is from the followup study done on silo launching, suggested by Bellcomm. The first pic shows the launch silo totally enclosing the SRM, installed below grade in a waterproof caisson. The actual launch tube, 280 inches in diameter, is lowered ring by ring over the installed SRM by the crane before the upper stage and payload is attached. The launch tube is removed after launch to a storage position.

The second pic is the same basic silo launch scenario, but with the silo launch tube being above ground, and only a 20 foot deep blast section of the silo below grade.

The third pic is a proposal to use an underground silo, but with a large sabot to 'piston launch' the 260 inch SRM Saturn IB. This would use engine exhaust gasses from SRM startup, trapped beneath the sabot, to lift the entire vehicle and accelerate it up the silo. Upon reaching the top of the silo, exhaust vents would be uncovered (more likely a series of progressively larger vents would be uncovered as the vehicle rose out of the silo in actual practice, to help with the deceleration of the sabot) which would allow the gases to escape, and the sabot would be stopped at the top of the silo. The SRM's equatorial seal would then allow the SRM to slide up and out of the sabot as it lifted off, leaving the sabot behind. This use of 'waste gases' from the SRM resulted in a significant performance increase, but results in high G loads from the rapid acceleration at liftoff. Also, the main problem was how to slow down and stop the 50 ton sabot before it slammed into the stops at the top of the silo without demolishing it or the silo. Now THAT would get some mission points at a future/fantasy scale event! LOL

The fourth pic is the below grade method as it would be applied to a new site other than LC-34 or LC-37B. It differs slightly from the below grade silo method mentioned earlier.

Later! OL JR