rockoon rocket

[rockoon rocket]

yes i live in the United States

 

[Lentamental]

A K730, for example, might get there if the rocket were small enough and the dry mass light enough. That's a 6 lb rocket. If you can make a nice carbon fiber launch tower, you might be able to keep the balloon's suspended mass under 10 lbs. That's probably around 1/6 the minimum lifted mass you'd need for an N5800.

If I ever do a space shot, it will be optimized to find out what is the smallest, cheapest rocket that can do the job. A camera will be the only payload other than GPS and altimeters. And I'm not sure about the camera.

See, this is the direction I was thinking. I really don't think we should be pushing for anything over the absolute minimum payload necessary for flight control, retrieval, and verification. Otherwise we are headed in the "bigger is better" direction that NASA has been taking, and as we have already discussed, that is far better done by ground launched rockets. Lets stick to the direction that rockoons are good at.

This could in theory be done with as little as a single raven + falconry transmitter, assuming the raven could be reprogrammed to handle a balloon launch (or any other similarly sized special made controller).

 

[New Ocean]

The only thing worse than spending extra money on a flight is spending the minumum and having the flight fail! In other words, if the extra few thousand greatly improve your odds of a flight, or improve the results (video footage) significantly, then it is worth it.

I love the N to N attempt simply because it is testing the limits of what is possible, and for the first time trying to get professional-like performance from hobby rocketry.

But if your goal is space and not to test the limits, I suggest the much more likely (but still very hard) P to N rocket. One benefit to that is you have experts already flying such a configuration, and we can use their considerable experience to trim down and improve performance slowly. That means getting the composites past mach 3, getting mass fractions near optimal, and most importantly getting a staging delay to work. I personally find this topic very exciting. I do not have the experience or money to try something like this myself, but am always very excited to see leaders in the hobby go after near-space and space. That is one reason why I think the rockoon strategy should be fleshed out to a logical conclusion before we totally give up on it. I mean why try something a few times, fail, and then give up?

 

[rockoon rocket]

I mostly want to do it to push the limits of how much it would cost to get rocket to space of course any one can go and buy a Tempest sounding rocket or pay a company but to do the same thing for under 20,000 now that is a challenge

 

[New Ocean]

So what steps will you take next?

 

[rockoon rocket]

the fist steps i would take fist would be to find all the electronic i need test if they work at 100,000 plus feet and test what hight I am going to get with a single n motor carrying the weight of the fist stage and 2nd stage

 

[MClark]

Your first step should be to contact the F.A.A. and find out where and what it will take to get a waiver. May I suggest using spell/punctuation check with the correspondence with government agencies?
If your plan is to launch offshore to get away from the U.S. government regulations it will take a real ship to go out far enough. You need to contact captains/owners to find one that would that will agree to launch a rocket from his ship.

There is no need for hardware if it cannot be launched.

Mark

 

[Lentamental]

There is no need for hardware if it cannot be launched.

I respectfully disagree. I think like in many cases, people are less likely to go along with your idea while it is still an undeveloped idea. Just like we were not particularly inclined to help rockoon here, because he hasn't personally shown any work, there is no way any FAA or ship owner will even talk to him till he has demonstrated at least small scale tests to demonstrate he is serious.

Like with everything, the first step should be to do it on a smaller scale, like launching a rocket from a balloon at 50 feet, just to test the systems of wireless launch, tracking, dual deployment, stability of an unmounted launch tower, etc.

 

[sylvie369]

Like with everything, the first step should be to do it on a smaller scale, like launching a rocket from a balloon at 50 feet, just to test the systems of wireless launch, tracking, dual deployment, stability of an unmounted launch tower, etc.

Hmm. Okay, I've probably come across so far as a rude skeptic here, so I'll try to be more productive this time. I think that you're right that he should demonstrate some ability to do what he's hoping to do before he takes it to the authorities. But I'd say that launching a rocket from a balloon at 50 feet should be not the first step but maybe the thirtieth or fortieth one.

(In spirit, I heartily agree with Lentamental's "do it on a smaller scale". But I think that "smaller scale" needs to be broken down much more finely)

I think the preliminary steps are fairly obvious - fly rockets, starting with some smaller ones, moving through L1 to L2, and demonstrate a reliable ability to build, fly, and recover those. In the meantime, learn something about electronics. Somewhere down the line I'd think he'd also need to demonstrate the ability to launch a high altitude balloon before we started thinking about putting a rocket on such a thing. If the goal is just to launch from a tethered balloon at 50 feet, I'd like to see him fly and recover such a balloon, with a payload similar in weight and shape to a rocket and launcher.

At some point down the line he might become ready to fly a rocket from a balloon. What would you want to see from him if you were asked to RSO such a flight? There's some obvious stuff, like the ability to completely disarm the rocket (ignition system, recovery devices) remotely in case the balloon launch does not go as planned. I'll bet other folks here could come up with a pretty decent list of nontrivial things they'd want to see before approving the launch of even a MPR rocket from a balloon. There's a reason we're not all doing this kind of thing.

I've been associated with an annual contest asking teams of engineering students to build and fly rockets that perform tasks that might sound simple but turn out to be much harder than they seemed (steer a rocket under parachute to a spot on the ground, photograph a target from at least 3000 feet, deploy a ground vehicle that moves a distance across the ground after landing, etc.). The vast majority of teams failed in these tasks. "Safely launch a rocket from a balloon" may sound like Step One, but I'd put it far further down the line.

I do love the idea of dreaming big, and you certainly learn a lot from trying to figure out how to do something like this. I've learned a lot from reading this thread (any thread that gets technical responses from John, Bob, and Adrian is going to be pure gold). But the task has a LOT of component pieces to it that need to be mastered before anyone starts flying even MPR rockets from even low-altitude balloons.

 

[New Ocean]

It is possible that my strong advocacy for rockoons gave the wrong impression; launching rockoons is not nearly the first step a person should take. My argument was that it has a place in the hobby, and can offer cost savings, but it is among the MOST difficult ways to fly rockets, both technically and legally.

 

[rockoon rocket]

so
1 find/make all the hardware need
2 test every thing work
3 test it in a tethered balloon
4 test if every thing work up at 100,000 feet
5 test the system with a small rocket

 

[appleseedgunsmith]

I did this about 2005 . F motor 24" long rocket 3.5 lb with launcher. 6-ft weather balloon inflated with helium 110 tank to 5 ft. Lifting Force about 5 lb tethered to ground. Fired with Garmin 2-way. Cost: 300$ Naturally, nowhere near space, but it would've gone much higher than it did (2000 ft) if I'd let the balloon go.

 

[FredA]

Interesting.
I'm aligned with Mark on this as I'm pretty sure the FAA will not allow this, regardless of previous experience/qualifications.

The prime directive is don't piss off the FAA or your local launch-site landowner.

 

[appleseedgunsmith]

The FAA is the reason I tethered mine to the ground. I know it's not the grand scale being discussed. But it shows things are possible, and can be done cheaply.

 

[jsdemar]

The predicted recovery radius is the show-stopper for untethered rockoon flights. The FAA will only approve flights from a ship at sea. That complicates the logistics as well as the paperwork needed for international waters. There's a military restricted zone in the Gulf of Mexico that others have used. It requires more complicated negotiations and costs. Any savings realized in propellant is overshadowed by 99% of the additional costs for a rockoon mission. Just make a big booster motor.

PS: I used to work here: https://www.csbf.nasa.gov/

 

[Spacedog49Krell]

Fred Wagner launched a multistage model rocket from a balloon in international waters off the east coast of Florida back in the late 1960's. The radio signals from the balloon indicated the first stage of the rocket launched, but there was no way of knowing if all the stages fired or if the rocket flight was even stable.

Since then, I have reviewed flight data from several of Kip Daugirdas's flights and others above 100,000 feet. My analytical conclusion on Fred's rocket is that it went unstable immediately after launch in the thin atmosphere above 60,000 ft. The odds are better for a two-stage rocket reaching space than a rockoon.

 

[appleseedgunsmith]

Okay if stability is a problem for a small rocket at that altitude, what about installing a high-speed gyroscope? I pondered this myself and built one from a small DC motor and stuck it in the nose cone but never got a chance to use it

 

[Spacedog49Krell]

Okay if stability is a problem for a small rocket at that altitude, what about installing a high-speed gyroscope? I pondered this myself and built one from a small DC motor and stuck it in the nose cone but never got a chance to use it

The weight of the gyroscope and counter rocket spin from the gyro are two major issues for a small rocket using this method. To raise money for these ventures, people demand to see video evidence that is clear and with little motion. Joe Barnard is currently testing a fin tab system using MEMS gyros and small servos that shows great promise for supersonic flights under 120,000 ft. Hot or cold gas reaction control motors are necessary for attitude control above 120,000 ft.

 

[shockie]

A long time ago, in a galaxy far,far away I designed a Rockoon Rocket balloon launcher.

In the center of the balloon was a launch tube containing the rocket and launch electronics, perhaps a RC contolled relay

The balloon would be teethered to the ground .

You know I think somebody in the distant past actually tried this.
Another idea I had was for the BP ejection charge to blow out a balloon that would be inflated by a CO2 cartridge.

 

[lr64]

Okay if stability is a problem for a small rocket at that altitude, what about installing a high-speed gyroscope? I pondered this myself and built one from a small DC motor and stuck it in the nose cone but never got a chance to use it

The weight of the gyroscope and counter rocket spin from the gyro are two major issues for a small rocket using this method. To raise money for these ventures, people demand to see video evidence that is clear and with little motion. Joe Barnard is currently testing a fin tab system using MEMS gyros and small servos that shows great promise for supersonic flights under 120,000 ft. Hot or cold gas reaction control motors are necessary for attitude control above 120,000 ft.

Wouldn't it be possible to just borrow one from a model airplane or quad copter? I don't know how many gees they can handle, though I'd guess it's in the neighborhood of 10 or 20. One could use it with vectored thrust or one of the other tricks that people use for landing model rockets under power. Once the motor cut out, if the air was thin enough that fins didn't work, maybe it wouldn't matter if the rocket was going sideways.

Unless we are talking about really tiny rockets, I don't think 3 grams would be all that much of a problem, though obviously vectored thrust would add more weight.
https://www.spektrumrc.com/product/as3000-as3x-flight-stabilization-module/SPMAS3000.html

I don't know what it would do to the legality, but one might also set up the guidance so the rocket slants back toward the original launch point as it goes up, and have it plunge straight back down until reaching a reasonable altitude. This ought to reduce the recovery radius.

The following may contain errors. I don't do these calculations much.

The following site says that latex balloons can get above 130,000 feet! Let's be pessimistic and assume 120,000 feet. At that height, air density should be only about half a percent of that at sea level.
https://www.stratoballooning.org/faqs
https://www.digitaldutch.com/atmoscalc/
Neglecting air resistance, and also neglecting the slight reduction of g with increasing height, a 5 lb rocket, or let's say a 2.3 kg rocket, of which 1,8 kg was fuel, I think you'd need something like 3,100 N-s to get to 330,000 feet from 120,000. I'm not so sure about the following, but I think that might imply a required specific impulse of something like 215. So MAYBE an amateur could achieve that. Of course, the empty motor, instruments, airframe, etc. would all have to weigh 0.8kg. Or one could go to a two stager. We should remember that a lighter airframe may be possible, since, if I'm not mistaken, max q will be less and fins will not be required or useful. A barometric altimeter might not be much use, either.

 

[MClark]

I always say this.
The FAA will ask……
How are you keeping the rocket in the waivered area for the entire flight? Drift under balloon, off vertical launch, drift under parachute.
BALLS has the highest wavier the FAA can issue, 150 km. The radius (when I was doing it) was 17nm. Not so far adding up the possible drift.

 

[lr64]

I always say this.
The FAA will ask……
How are you keeping the rocket in the waivered area for the entire flight? Drift under balloon, off vertical launch, drift under parachute.
BALLS has the highest wavier the FAA can issue, 150 km. The radius (when I was doing it) was 17nm. Not so far adding up the possible drift.

Which is why I mentioned guidance, though of course guidance is a can of worms too.

 

[MClark]

Guidance in most cases is just a dream.
How will it be developed and tested under real conditions?

 

[MClark]

I don’t want to be Debbie Downer but Rockoons work great on paper but reality bites.

 

[lr64]

Guidance in most cases is just a dream.
How will it be developed and tested under real conditions.

Are you saying rocket scientists are not as smart as the people who develop electronics for quad copters and model airplanes? And not smart in a very particular way, since powered landings have been done by little rockets. Seems to me the latter is much more of a problem.

 

[Spacedog49Krell]

Wouldn't it be possible to just borrow one from a model airplane or quad copter? I don't know how many gees they can handle, though I'd guess it's in the neighborhood of 10 or 20. One could use it with vectored thrust or one of the other tricks that people use for landing model rockets under power. Once the motor cut out, if the air was thin enough that fins didn't work, maybe it wouldn't matter if the rocket was going sideways.

Unless we are talking about really tiny rockets, I don't think 3 grams would be all that much of a problem, though obviously vectored thrust would add more weight.
https://www.spektrumrc.com/product/as3000-as3x-flight-stabilization-module/SPMAS3000.html

I don't know what it would do to the legality, but one might also set up the guidance so the rocket slants back toward the original launch point as it goes up, and have it plunge straight back down until reaching a reasonable altitude. This ought to reduce the recovery radius.

The following may contain errors. I don't do these calculations much.

The following site says that latex balloons can get above 130,000 feet! Let's be pessimistic and assume 120,000 feet. At that height, air density should be only about half a percent of that at sea level.
https://www.stratoballooning.org/faqs
https://www.digitaldutch.com/atmoscalc/
Neglecting air resistance, and also neglecting the slight reduction of g with increasing height, a 5 lb rocket, or let's say a 2.3 kg rocket, of which 1,8 kg was fuel, I think you'd need something like 3,100 N-s to get to 330,000 feet from 120,000. I'm not so sure about the following, but I think that might imply a required specific impulse of something like 215. So MAYBE an amateur could achieve that. Of course, the empty motor, instruments, airframe, etc. would all have to weigh 0.8kg. Or one could go to a two stager. We should remember that a lighter airframe may be possible, since, if I'm not mistaken, max q will be less and fins will not be required or useful. A barometric altimeter might not be much use, either.

The current MEMS gyros require TVC, fin control, or a hot or cold gas thrusters to maintain attitude control. TVC only works during the motor operation and the coast phase of the flight could be 10-20 times longer than the thrust duration. Fins only work in the denser atmosphere, so we are left with hot or cold gas thrusters for space applications or spin stabilization without video. I do not know of any amateurs working on hot gas micro thrusters. I have worked on CO2 cold gas thrusters with some success.

It does matter if a rocket starts to tumble. Kip Daugirdas's rocket missed 100km space by 10 km due to his rocket tumbling above 200,000 feet. The old Viking #6 only reached 40 miles due to it losing a fin after burnout.

The success rate for rockoons is not 100%. The IGY rockoons were around 64% and Project Farside was 67%.

 

[MClark]

Are you saying rocket scientists are not as smart as the people who develop electronics for quad copters and model airplanes? And not smart in a very particular way, since powered landings have been done by little rockets. Seems to me the latter is much more of a problem.

Those who make quadcopters and model airplanes can test at operating altitude.
A rocket to be launched at 100k plus it is difficult to test under those conditions.

 

[lr64]

The current MEMS gyros require TVC, fin control, or a hot or cold gas thrusters to maintain attitude control. TVC only works during the motor operation and the coast phase of the flight could be 10-20 times longer than the thrust duration. Fins only work in the denser atmosphere, so we are left with hot or cold gas thrusters for space applications or spin stabilization without video. I do not know of any amateurs working on hot gas micro thrusters. I have worked on CO2 cold gas thrusters with some success.

It does matter if a rocket starts to tumble. Kip Daugirdas's rocket missed 100km space by 10 km due to his rocket tumbling above 200,000 feet. The old Viking #6 only reached 40 miles due to it losing a fin after burnout.

The success rate for rockoons is not 100%. The IGY rockoons were around 64% and Project Farside was 67%.

So the air can be thin enough that fins won't work, but thick enough to create significant drag? That seems counter-intuitive. I am not familiar with TVC mechanisms. Could one make a motor with a long end burning section, like a slightly overpowered delay charge, to allow TVC most of the way to apogee?

 

[lr64]

Those who make quadcopters and model airplanes can test at operating altitude.
A rocket to be launched at 100k plus it is difficult to test under those conditions.

Doesn't TVC work about the same when the air gets thinner? If you have to do something before you do it, there may be a problem. Maybe work up to it in stages? Hasn't NASA already solved these problems?


BTW, just how far offshore do the FAA's restrictions extend? People often sail relatively small boats all the way across. What would they think if you launched the balloon from shore, but didn't set off the rocket until well offshore?

 

[MClark]

I think the days of going out in the ocean and doing whatever you please are long over.
There are many airways over "international waters".