saadzmirza
Well-Known Member
- Joined
- Nov 12, 2013
- Messages
- 78
- Reaction score
- 29
deleted
Thanks for the input, Xtrain.
I can assure you that from my experience, the TA4000 will be able to lift 23kg to 31km.
If you input the data on the Random Aerospace balloon calculator I linked to earlier, the TA4000 has a burst diameter of 15.06 meters (50 feet). Using Hydrogen, (My group has access to free lifting gas due to a generous donation from the local welding company), the balloon will be able to lift 50 pounds to 100K feet at 4m/sec.
These are big balloons. Volume increases faster than area.
The wind predictions, from my experience with balloons, are quite shaky until the final GFS wind models about 12 hours before launch. If the ccalculations are done right, the landing is within a 15km radius.
Of course, it is designed for balloons, not rockets.
Overall like you said, at best we'd be able to say the balloon will probably drift over this large body of water.
The chance a favorable situation to arise would be very minute for landing, however, it does work out for August 5th interestingly. Try a launch from 100m launch altitude, 4m/sec ascent rate to 33000 meters(assuming a payload well under 15kg) at 1340 Zulu from the coast of Lake Ontario near Lockport, NY.
Hoping for it to descend back over land may be a bit too much.
I am still puzzled as to how to use these programs. Could you give me a few pointers?
I tried to import some rocksim files and load up some motors, but changing the launch altitude makes things screwy.
Any suggestions for a launch veichle as well?
View attachment 179931
The president for my school's rocket club wants to do a rockoon as well. I, as well as every other rocketeer and engineer I've spoken with, has spoken out against the idea. First, the landing area is increased by 100 miles across, in addition to the rockets flight. And you can't be sure the rocket is going to go straight when you launch from altitude. How do you intend to keep the launch system vertical during ignition, how fast does the rocket need to go before the fins can provide stabilization to the rocket, what tracking system do you intend to use that can track above 60k MSL&Mach 2?
Do you intend to mix your own propellant and custom build the rocket, or buy an off the shelf solution?
Launching a balloon to 100,000 ft is easy, launching a rocket to 100,000 ft is far less so, and you need a rocket that can go roughly 100,000 ft MSL from sea level to reach space from 100,000 MSL.
From experience working a rockoon design for a large diameter rocket for an entire year, ditch the idea and have your club learn how to launch rockets first, learn electronics and staging second, and propellant manufacturing third.
There is a reason people don't do rockoons, and it's not because they're so cheap, easy, and effective.
Well, if you or any other team is serious and legitimate enough about a rockoon to go through with such an operation. I potentially can provide a solution for the oceanic part of the equation. My family owns a vessel that is plenty large to both safely travel in the open ocean and with enough deck space to conduct a fairly major rockoon operation. It would be a two day trip to travel out the 100 miles from the nearest shore, conduct 12-16 ish hours of operations, and the return trip. I am fairly sure we could do it with just reimbursment for fuel, but I make no promises in either direction. Fuel costs for the two day trip is about 500 gallons of diesel so ~$2k depending on fuel prices. We currently have enough safety equipment and bunks for 4-5 possibly 6 people in addition to what is needed to run the boat.
A few caveats is you need to get tickets to fly up here to Alaska which are about $600 round trip per person as long as you plan far enough out in advanced. We have a few established routes to get commercial reloads up here if you want, similarly priced to what you get down where you are at. If you are doing EX for your motors we will just have to talk about the options.
So if there are any teams out there go ahead and send me a PM and we can start discussing it further. Considering the liability involved in this I have a pretty high expectation that you have a pretty solid idea on what you are doing. You don't have to have every detail ironed out at this point, but the first thing you tell me shouldn't be about how you plan on filling this large hydrogen balloon by hand. :eyeroll:
The current test motor is in the Q range, so there's no way to ship it up to Alaska, plus it'd have to be 100 miles+dispersion plot from space+FAA controlled airspace. Somewhere around 150-200 miles total to be sure you don't land in US airspace. That's in addition to the massive difficulty in launching a large rocket off a balloon, and the difficulty of building the hardware to carry it all into near space.
If you do a risk analysis on the systems required for each launch method, you'll find how much risk is added to hoist a rocket up that high.
Hi Xrain,
I think the only way to find out for sure would be to contact the FAA.
What is the procedure for this?
....
Unless the FAA has gotten stricter since then, to me, that makes a boat seem unnecessary for launch. Perhaps for recovery (if wanted).
I think looking into rocketry a bit more is a good plan for our club.
50 pounds isn't unbelievably light to aim for 200,000 feet for one reason. At 100,000 feet, barometric pressure is only 1% compared to sea level. This should mean negligible drag, for a much higher altitude. This is the whole principle of the rockoon.
What's "GSE"?
All simulators will give you different results they use different assumptions in their models so they will give different feedback to you.
The Class III waivers are handled by the FAA Office of Commercial Space Transportation. You can certainty call them now, but personally I would wait until I at least had some level 2 HPR launches under my belt. Since you would be able to better answer the questions that they have for you. Honestly, It might also be a bit akward if they ask about your rocketry experience and you say the largest you have launched is a model rocket.
50 pounds is light because you have to include your GSE (Ground Support Equipment) into that number as well, so your 50 pound rocket is now 30 pounds or less. The lack of atmosphere definitely helps, but to hit the 300k ft. total that you want your rocket will roughly need to hit 100k ft. if it was launched on the ground.
As for what the HALO team did, I am not sure what they did to get authorization to launch like that. The best answer would be to see if you can get into contact with any of the team members and ask, since they have already done it before and none of us have. Could be because they used a hybrid rocket but I really cant tell you for sure.
To add to that, with 1% of the atmosphere you have 1% of the restorative effect the fins give, so any asymmetric thrust is going to throw the rocket wildly off course, especially when it's swaying in a sling under a huge balloon.
Using Hydrogen, (My group has access to free lifting gas due to a generous donation from the local welding company), ...
Anyone else concerned with launching rockets near hydrogen? Hindenburg springs to mind
Do you think an Apogee Aspire could withstand H impulse range? And does it have a payload section?
Enter your email address to join: