MM-38 Static Test Attempt #1

A report of the first (failed) attempt to test MM-38
Featuring rain and horses

It must be a Tuesday, I never got the hang of Tuesdays

Arthur Dent, The hitchhikers guide to the galaxy

On this particular Tuesday, no experiment took place
But this is not for a lack of effort

Problems began before we even started
Seemingly, due to either forces beyond our understanding trying to tell us something, or just plain ol’ bad luck, it was raining for the two hours we had allocated to this test, and only those two hours

The gear, pre transport
The gear, now slightly moist
The gear before being transported to location
The gear at the test site

Alright, that’s not so great, but we thought we could get around it with copious amounts of polymer protection and some clever adaptation
Well we didn’t factor in the wind either, so improvising a tent proved harder than anticipated

The improvised field tent
Held together with rope and good hopes

The tent was to be setup to provide a dry staging point, from which to unpack and prepare equipment, and to make MM-38 ready for testing

As such, after setting up the tent, the first step was (supposed to be) loading up the pre-prepared fuel block into MM-38
That’s when disaster struck

Due to a mix of thin cardboard, low tolerances, torque and possibly moisture, the cardboard tore after 80% was already inserted
Since the sacrificial thermal liner is essential to the proper function of MM-38 (by preventing the casing from burning trough), and also isn’t field replaceable, the test was called off

It happens to happen
And it happened to happen too

The one good thing about this is that because it was out literal first step, no extensive setup had already been conducted, simplifying our walk back

On our “walk of shame” back to the car, a number of inquisitive, but not particularly impressed horses stared us down

Mildly Perturbed Horses

Now its not all a lost effort, since by making a lot of mistakes we can learn a lot as well
I restate what I said in my article on STS-XL

No plan survives first contact with the enemy

Helmuth von Moltke the Elder, paraphrased


The difference between theory and practice is often greater in practice than in theory

Both of which are to say, no matter how much you prepare, you need actual experience to show the now obvious leaks

Experience, the thing you acquire right after you needed it

So, some things we have learned

  • Tests in rain are impractical and are to be avoided, and wind is a factor that should be accounted for even during static tests (or attempts thereto)
  • The amount of cable I brought on my spool is not enough by far to power my laptop, which was immediately obvious upon first seeing the test location
    • There was also no backup plan in case the laptop would not have external power, which would further have complicated matters
  • The thermal liner is not strong / easily insert-able enough in its current configuration, and will need to be changed to account for this
    • It should be inserted prior to going to the launch pad, as long as this can be achieved safely, such as by leaving out the bulkhead until systems go

To name a few

So now the plan is to account for these caveats, partly rebuilt the fuel assembly (we have the technology!), and retry on the 28’th

I would also like to thank my fellow rocketeer for helping me plan this test and make arrangements, and a very big thanks to the person who let us use their property to conduct our Science™, I am very grateful to both of you

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