“The reason is that they don’t want to have oxygen getting in during the early startup because an oxygen rich environment (or oxygen rich pockets) could damage the engine. Hydrogen is a lot less chemically active, and less likely to corrode critical parts of your engine at an inopportune moment. So that hydrogen exhausts out the back of the rocket and, then being hydrogen, it rises up very quickly. And at some point, one of the sparks from the will set it on fire and you will have this ginormous[sic] fireball which runs up the side of the rocket.”
I didn’t catch the name of the spark generators. Something like “rofies”. No doubt a nickname for something more technical. I couldn’t Google up any likely names. Perhaps it’s just slang for “pyrotechnics”.
Note that hydrogen burns with a pale blue flame, so we’re apparently seeing other stuff being burned by the hydrogen fire. The surface of the rocket certainly gets scorched, and it may be that material that produces the orange flame. It may be a number of other things as well; whatever happens to be down there.
I might be mistaken, but Hydrogen Flame colour depends on flame temperature and Oxygen ratio when burning as far as i remember. Might be impurities too, but afaik the rocket Hydrogen should be very very pure.
ROFI is an acronym for Radially Outward Firing Initiator - spark generators specifically for igniting escaping fuel to prevent a build up and explosion.
It was very cool to watch Electron get to orbit. They’ve joined a very small family of groups that have made it to orbit and should be proud. I also looked into working with them because living in NZ would be pretty sick so that’s cool too.
My TA last semester is doing his PhD thesis on those for the airforce! I wish I could remember more particulars like what fuels but I remember that the thrust is comparable and the specific impulse is even better than mmh & n2O! Pretty cool stuff.
Old 'n Busted and the New Hotness all in 1 photo…We’ve got a lot of problems but we’ve also got a lot going for us right now. The future is a wonderful place.
I’m personally hoping to host a small (IRL “launch party”) on the date of the falcon heavy launch. Even if it isn’t live I’m also encouraging friends to bring their kids, gotta inspire the younglings.
Of course, to get people out you also have to promise casual board games, food, and other social activity besides nerding out over a rocket launch
Edit: in an effort to share the passion and love for space with people
For me, there are two things that make a live launch so amazing
Seeing the rocket go from the ground into space. This sounds dumb, but I mean being able to see. in a single glance, the rocket trail that leads from the ground into space. That thing the size of an office building just went into outer space in about two minutes, right in front of my eyes! Right now! The sad thing is that the film never shows that. The in-person launches always inspire me to think in science fiction terms of a space-faring civilization. But when I watch on the screen, it’s always that tracking closeup, which produces a rather detached experience (no pun intended).
The sound. The power of these rockets, and especially that of the Falcon Heavy with its incredible level of thrust, is astounding. The test firing surely demonstrated that to a lot of folks who were unfamiliar with this sort of thing. I suggest finding some really good subwoofers and playing back that test firing until you’re sure that it will make them feel that launch. Then be ready to flip the switch when the launch takes place.
If only SpaceX provided a view of the launch without the commentary. (Play the commentary on a different device).
Now I have to go play the test fire again a few times.
They also host a technical stream which only has the data & status callouts and not so much the commentary from the hosts or the infographics. I know they used to have it and I hadn’t heard anything about it going away…although the next launch is FH, for the next one you watch the stream for try searching for the technical webcast on youtube. It should be there! Sometimes they switch to less often shown views as well especially during the prelaunch procedures.
Sounds like a lot of fun! That’s the sort of thing you need to spread the fun around and make launches seem cool.
I’m also encouraging friends to bring their kids, gotta inspire the younglings.
