I just realized I have not talked at all about safety, so let’s remedy that today. Safety is very important in testing rockets and if you aren’t safe, there is always the chance that you won’t be able to keep testing, either through destruction of property, people, or yourself. So lets talk about how to make safety happen.
First things first: think, then act. Most problems are caused by acting too quickly or not thinking through the problems first. Frankly, most safety precautions are to protect you from a bonehead maneuver so step one is go at a decent pace and think your actions through.
Second: general shop safety. This has nothing to do with rockets, but most accidents, even in aerospace, happen in production. So always follow general good shop safety. Here are some of the most important points:
– No loose clothing, gloves, or long hair with power tools, especially lathes.
– Properly clamp down part before machining. And your hand is not any part of a proper clamp.
– Wear safety glasses and hearing protection.
– Learn how to use your tools before using them.
– Keep the shop clean and tidy.
Third: Proper personal protective equipment. With pressurized components, this is a minimum of safety glasses and hearing protection. For most chemicals, you want to wear nitrile gloves. With cryogenic propellants, you want some good cryo or thick leather gloves. I would say just don’t use anything toxic unless you are a professional, and then S.C.A.P.E. With Peroxide, make sure you wear an extra visor as it can blind you quick. And, in general, natural fibers, nothing synthetic as most of it it burns and melts so stick with cotton or wool.
Fourth: Test remotely. There should either be sufficient distance between you and the test or a thick wall – and sheet metal doesn’t count as a wall. A rough rule of thumb from the FAA is that you should be at least 240 ft away from anything in line of site, and further if you have a large quantity of propellant. So maybe you should think about some walls, as 70 meters is a long way. Also, remote testing means the stand must be safe when you approach it even if you lose power. This means normally open vent valves and physical safe/arm switchs.
Fifth: Learn from your mistakes or, better yet, learn from others. You can either find an old timer to help you out for the first couple of runs or see if anyone else needs help. If all else fails, you can read Ignition! and some old accident reports.
This is obviously just an overview and we could go over safety all day and still have things to cover. Finally, listen to the safety guys and gals. They get a fair bit of shit in the NewSpace community, and while it is possible to be over safe and slow down development, it is easier to be cavalier and kill someone.