Feasible ways to ignite and Reignite Propellent for High Altitude Rocket

Hi everyone, I'm currently doing research on ways to ignite and reignite propellent for a rocket this is planning on reaching heights of 100,000 feet. I'm looking specifically for ways to ignite at liftoff as well as for the second stage as this would be for a two-stage rocket. Any help is appreciated!

What type of propellant, APCP?

Yes ACPC for the first stage for sure. I would assume so for the second stage as well but we may be using liquid fuel for that stage

Not to be "that guy", but if you're shooting for 100k, you should already know the answer to this.

Either way- are you trying to stop/restart a motor, or start one motor, and then start a second once the first one burns out. If it's the second, there are several altimeters that will do this. If it's the first, you'll find it hard to do with solid propellant.

haha Its ok, that's why I posted here to help find the answer, I have a general idea of what needs to happen but I was looking for guidance. I had found out earlier today in my research the best way to ignite the second stage feasibly would be to use an altimeter of some sorts. I also know basically what needs to be done to light the first stage, I'm more so looking for other options and such. Thanks for your help!

I guess I'll be the one this time to suggest starting small. Join a group (national organization, and local club), then get a mentor. Start single stage, and work through the certifications. Then you might be ready to try for 100Kft. You don't know enough yet to know what you don't know. That is not good in rocketry.

Where are you located? What is your age?

Gerald

While I do appreciate your post, I already am on a team for this. I actually just came back from competition where we launched a rocket to 30,000 ft. I was just looking for other options as I know how we ignited our system for that competition. Instead of everyone telling me I should know the answer or I need to start smaller I’d appreciate if you and everyone else could spread the knowledge they have, if they have the answers. Thank you

Dream big but it's a lot of work and you should scope out the threads of those who have flown high. It's very sobering to read about the difficulties of high speed flight and staging. If you're young, good. You have the
years ahead of you to figure this out. Don't expect to get it all done in 1 to 2 years! Kurt

Cody Monteith said:

While I do appreciate your post, I already am on a team for this. I actually just came back from competition where we launched a rocket to 30,000 ft. I was just looking for other options as I know how we ignited our system for that competition. Instead of everyone telling me I should know the answer or I need to start smaller I’d appreciate if you and everyone else could spread the knowledge they have, if they have the answers. Thank you

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Unsurprisingly, folks generally don't respond enthusiastically to "tell me everything that can be known about X" unless they're interviewing for a job doing X.

Was your 30k attempt successful? Did you try more than one kind of startup arrangement? If so, was one more successful than the others? Why did you go with the one you ultimately chose?

G_T said:

I guess I'll be the one this time to suggest starting small. Join a group (national organization, and local club), then get a mentor. Start single stage, and work through the certifications. Then you might be ready to try for 100Kft. You don't know enough yet to know what you don't know. That is not good in rocketry.

Where are you located? What is your age?

Gerald

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I guess I'll be the one this time to guess his age, somewhere between 12 and 17.

rcktnut said:

I guess I'll be the one this time to guess his age, somewhere between 12 and 17.

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profile says he's 21.

Cody, let me see if I can help.

About once a month or so a young kid shows up with no experience and huge aspirations to send a rocket to space or 100K or similar. Neither inexperience nor huge aspirations are bad things, but they don't play well together. Asking how to ignite propellant while also stating you want to 2-stage to 100,000 feet shows the combination I just described. This is why others are asking about your age and experience.

You'll find that in addition to rocketeers being helpful, they're also cautious and work hard to protect inexperienced rocketeers from themselves and the hobby from incidents that may cause it pain (such as an incident that may bring on more regulation).

You gave very little information in your OP when asking your question. You're new to this forum and since people aren't familiar with you, we don't know your capabilities. All we know is you're a member of a team that sent a rocket to 30,000 feet.

Rocketeers can be the most helpful people around, but you gotta give us something to work with. Who are you? What's your background in rocketry? What team are you on? What is your position on the team? What was the rocket you sent to 30,000 feet? Where did you launch it? What motor did you use? How did you ignite it? Are you familiar with any hobby rocketry electronics? What are the details on the rocket for your next project?

If you flesh out your original question and provide more information about yourself and your team you'll probably get more cooperation here.

Assuming you just got back from IREC and are looking at your next big project. First of all, you can learn from the high altitude 2 stage demo (Ohio State?) there where the second stage didn’t light. 2 stages are hard and lighting the second stage is just the beginning. For a successful flight you’ll need good stability, straight flight, good separation, and a bunch of other stuff.

You can practice all of these things with H through K motors on far cheaper and easier to build projects than your 100K shot. Doing that practice will make it far more likely that the big shot is successful.

There are a lot of resources here that you should look through before asking for the answers. Jim Jarvis has some great threads, there’s a Kip (sorry, forgot the last name) thread that just was updated, and a nice thread about choosing a 2-stage kit. All of those have some great information that will help you be successful. In addition to what Exactimator said, many people here get grouchy about being asked for answers when the asker hasn’t apparently done much research.

I have found the best way to start a motor on the ground aka sitting on the pad is with a rocket motor starter. These little things go up the nozzle into the motor. A battery is used to start the starter which starts the motor. Complicated ain't it? The second stage is similar. It still uses a starter and battery and usually uses an altimeter (saw on TV a guy had trained some hamsters to row a boat, that may be an option for second stage ignition). Main difference is the rocket shouldn't still be sitting on the pad when this stage ignites.

2 e-matches and Pyrodex pellet will ensure redundancy & failsafe ignition of upper stage, using low current altimeters or timer. There are other exotic pyrogens out there, but they require previous experience with dangerous mixes. Zirconia, Teflon/Mag BKNO3 & many..many more.

However you must also decide how long a coast delay after Stage 1 burn out, and how to keep igniter in place.
From nozzle taped to stick? Or using a head end ignition closure. { modified forward closure, so ignition wires are attached to it.] Lighting motor from the front/top.

But then you have safety issues that must be addressed.
Don't light the sustainer unless; it's not off vertical more than 15-20degrees, reaches altitude of [x] staging ....velocity must be at least [X] to keep sustainer vertical.
Ejection [normal]charges cease to operate at high altitudes [50,000] and measures must be taken to address that.

How will all this be safely armed at the pad. This one trumps all.
It would take a few hours of serious discussion to cover what you need to know for this, not a simple post, but this should get you started.
When all this and more criteria have been answered correctly, you are ready to go.

Prydex pellet or other black powder related means may not give sufficient heat transfer, burn rate, or pressurization, when lit in a near vacuum. Success likely depends on altitude and current thermal conditions. In my ignorance, of course!

Lighting at 20Kft may be a lot easier than lighting at 50Kft. Decide the flight profile first, or at least a straw man version. Then start working on the engineering details. Storyboard scenarios. Figure all the ways you can of what might go wrong. Design to minimize the odds of those things, or to eliminate them. Etc.

Gerald