Just to be picky, I don't think you've been working on this since 1012.
Mines the pedantic coat.
The grand finale of the Low Orbit Helium Assisted Navigator (LOHAN) saga is approaching, and is now so tantalisingly close you could almost reach out and stick a match to it. It's been a long, winding road, to be sure, but we still have a few things to wrap before we can finally see what happens when you stick a rocket motor …
Bravo for these tests. I think they are pretty crucial.
I do still worry that the motor will have problems at altitude, simply because there is so little air pressure that it may not be able to get motor up to operating pressure in time with what small amount of combusting material you have.
The problem is that the rate of burn of the motor is linearly dependant upon the pressure. The nozzle provides a restriction that causes the motor pressure to rise - reaching a steady state when the motor is a at full thrust. But if there is almost no pressure to start with, the initial rate of of burn may be too low to climb onto the rising pressure curve, and instead simply peter out. Ignition with one atmosphere pressure is a big step onto this curve. This is why suggestions about some form of rupturing or pop-off cover for the nozzle are suggested. Such a cover can hold the pressure of the combustion products of the igniter inside the motor and you get a nice high pressure startup of the motor. Of course you then have the issue of designing a suitable cover.
The point? Well if the test succeeds, you are fine. If it fails, this is almost certainly the solution. What you could consider is a dual trial. Think seriously about the design of a suitable cover, and maybe fly two motors. If the initial test fizzles, set it up to try igniting the second one.
Funny. I saw those names and thought something else entirely: an anime involving outer space bounty hunters.
So it begs the question, which came first: Cowboy Bebop or Girl Genius?
On third thought, perhaps something prior to both used those names in the past, and each independently took them on.
I'm surprised the Spanish are confused about Punch & Judy, don't they also have the tradition of "Guiñol", based on the French Guignol?
Good luck on Saturday 5th. I'll be on a 747 heading into Heathrow around them, nothing personal but I do hope your "west of England" launch is well west...
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