I am part of a JPL team studying the upper atmosphere. Our plan is to take our test apparatus up in a helium balloon to 15 km and then, after it does its thing, we want to drop it in some kind of a UAV and have it return to us. The vehicle has to be able to carry a payload of 7 kg. What might be a good strategy for this? What types of UAV's would be best? If we use a fixed wing plane, will it be able to pull out of the free fall? Basically, we are seeking the advice of those more knowledgeable than us. If you could design this system as best as possible without any concern about cost, what might you do?
You need to be a member of diydrones to add comments!
I am surprised that no one has mentioned that since you are doing this as part of your JPL work, you will need a COA from the FAA to fly your UAV back down to the ground. I am not sure, but I don't think you would need one for a parachute recovery. I am also not sure whether you need one for the balloon launch, since this is a professional endeavor. I am sure your safety review board at JPL will know. I worked on a project that did something similar to what you described:
I liked Burt Rutan's design for Virgin Galactic. He tips the wing structure up to create an airbrake giving enough drag to control the craft and slow it down.
I wouldn't try and fly from that height, maybe just do a controlled fall, with a small parachute. Then release it.
Hi Chris
temperature is going to be a big concern.
The chaps in QinetiQs HALE team are used to dealing with these issues and originally used balloon launches. We're all busy flying in Yuma for a few weeks but PM me if you like.
I think that scenario you described is not legal in US, at least for amateurs. Balloon going up should be no problem, but glider/plane/UAV coming down ( as opposed to balloon) is legal no-no for us due to FAA regulations. Since you are working on NASA/JPL project YMMV
I don't recall the web site, but there was a group of hobbiests that did something similar. They built a stubby looking glider to glide back. They eventually lost the glider ... I think they thought it was higher than it was and they did a "controlled" flight into terrain, but terrain in this case was a pretty inhospitable mountain top with no easy access.
Just from my recollection of reading their site, you'll have to worry about things like extremely cold temperatures (not good for battery capacity). I think you will need an airframe that can tolerate extremely high speeds and possible tumbling until you get low enough for the control surfaces to become adequately effective. They were talking about airspeeds in excess of a 200 mph, so if you have a 7kg payload going a couple hundred mph and tumbling, you are going to need something that is built like a tank. On the other hand, if you keep the airspeeds up and don't care too much about stall speed, you could design smaller, stubbier, thicker aero surfaces and then think about some sort of parachute recovery for the final touch down ... I'm just brain storming here. I might be tempted to look into some sort of delta wing/blended/lifting body design that is compact, but has a lot of wing area for it's size.
Should be a lot of fun, but there are many challenges!
Replies
http://marsairplane.larc.nasa.gov/reliability_2.html
Let me know if you have any further questions...
http://www.arcturus-uav.com/newsitem_01.phpI wouldn't try and fly from that height, maybe just do a controlled fall, with a small parachute. Then release it.
temperature is going to be a big concern.
The chaps in QinetiQs HALE team are used to dealing with these issues and originally used balloon launches. We're all busy flying in Yuma for a few weeks but PM me if you like.
Just from my recollection of reading their site, you'll have to worry about things like extremely cold temperatures (not good for battery capacity). I think you will need an airframe that can tolerate extremely high speeds and possible tumbling until you get low enough for the control surfaces to become adequately effective. They were talking about airspeeds in excess of a 200 mph, so if you have a 7kg payload going a couple hundred mph and tumbling, you are going to need something that is built like a tank. On the other hand, if you keep the airspeeds up and don't care too much about stall speed, you could design smaller, stubbier, thicker aero surfaces and then think about some sort of parachute recovery for the final touch down ... I'm just brain storming here. I might be tempted to look into some sort of delta wing/blended/lifting body design that is compact, but has a lot of wing area for it's size.
Should be a lot of fun, but there are many challenges!
Curt.