Launching a glider from space

launching-a-glider-from-space

We get a ton of tips about weather balloon launches taking hobby electronics into space. But every once in a while one of them stands out from the rest. This project does send an electronic payload into space, but it also lets [David] fly his hardware back from near-space using an RC airplane.

The return vehicle is unpowered, but that shouldn’t be a problem as launching from a weather balloon will provide plenty of altitude for the flight. Because the temperature experienced in that part of the atmosphere is so cold [David] had to take several things into account. Obviously you want your batteries and control electronics to be insulated from the cold. But something that doesn’t usually pop into mind are issues with the servo motors which run the glider’s flaps. They usually have some white grease on the gears. At temps as low as -50C that grease will harden and make the servo stop working so he made sure to clean the gears thoroughly before the flight.

Unfortunately [David] had several problems capturing images and recorded video from the ground station. But his write up is still a fun read and the clip after the break gives a general overview of the entire project from the nose camera of the glider.

[Thanks Limpkin]

43 thoughts on “Launching a glider from space

  1. GPS + Autopilot… I wonder what the glide ratio is? With a stabilized camera platform, this approach could give the gorgon stare a run for it’s money.

  2. Wow! It’s really peaceful up there. I was tricked for a minute when I thought I saw the sea, and wondered how high up he must have been. Til he mentioned the lake. Still what an awesome clip of film to make for yourself.

  3. This is incredible! Some day I would love to try this. I’ve always wondered about how to get a good video feed while flying though. Would that 1 watt transmitter be legal in the US?

      1. Yes, US hams can use their frequencies for radio control, however it is quite limited. From what I’ve been able to determine, we are limited to a number of “channelized” frequencies in the 6 meter band (50-54 MHz) and the power output is limited to 1 watt. I don’t think that there are a lot of hams doing this, but I could be wrong.

        1. Why wouldn’t you use the 2m/70cm band? There’s digital stuff there like packet radio so I don’t see the issue.

          1. The lower the frequency, the lower the bandwitth of the data carried on it. The standard (although not only option) for radio packet or 2m is AX.25, an OLD OLD protocol, which usually handles data at 1.200 bps. That means about 120 bytes a second…You cannot send video over 120Bps… You need a higher freq carrier to be able to send a high speed signal.

        2. Radio Control would be the uplink segment, and yes, limited to certain bands. Downlink is video, aka ATV, and is quite common in the 1.2GHz / 23cm band. And there’s nothing saying you can’t run at higher frequencies, it’s just a question of making sure hams have an allocation there before you go crazy with the output power. Oh, and making sure your callsign is in the transmission somewhere. An electronic video overlay can add lots of other data (voltage, temperature, etc) along with the callsign, but it’s also common to simply stick a label or sign within the camera’s field of view somewhere.

        3. There’s a distinction between control signals you send TO the aircraft versus video sent from the craft to the ground. For control signals, FCC part 97.215 restricts you to one watt, but you’re not restricted to a specific frequency band. I think 6 meters is commonly used because it’s close enough to other common R/C bands to make it easy to adapt commercially available radio gear.

          For the video downlink, other rules apply. For a peek at what’s available, see hamtv.com . There are rules about bands, frequency allocations, and identifying information, but it’s well within the rules to transmit video at a quality equivalent to analog cable TV, using reasonably high power. I think the practical limiting factor for power would be the size and weight of the transmitter and its power supply.

      2. I urge caution (even if I am also hoping more people give it a go)…
        A camera on a free flying mechanism of any kind that exceeds 400 feet alt is still illegal in the US.
        They are trying to overcome this legal hurdle, but there is resistance and at last check the laws are still in place.

        1. With all due respect Stephen McA. that is a load of horse shit! There are possibly seem issues as to weight BUT, may I direct you to all the HAB kits that are sold, with GoPro cameras? So I guess all these companies and individuals that are doing this are criminals now?

  4. If he’d cleaned up the nose instead of just hacking it off flat, the glide ratio would have been better. Amazing it didn’t just drop with the balloon hanging off it.

    For a release it needed a way to cut all the cords loose from the plane. Some pairs of tabs sticking up, loops in the ends of the cords, pins through the tabs and loops. Yank them by connecting strings to the pins with the other ends of the cords connected to a spool on a servo. Activate the servo and it yanks all the pins and winds up the cords so they don’t cause drag.

    1. Or yo could just buy this http://www.hobbyking.com/hobbyking/store/__13365__HobbyKing_Glider_Nose_Tow_Line_Release_11_7x42mm_.html
      or make this.

      http://www.rcaerotowing.com/1540-fabricating-a-simple-and-inexpensive-tow-plane-release-mechanism.html

      The glider is an interesting issue. Something like a Gentile Lady or Metric would have given you a much better glide ratio. Even a HLG like one of these http://www.fatlion.com/sailplanes/hlg.html Would have had longer glide ratio. But a short wingspan could be a real benefit for this use. A short strong wing will have a better chance to survive the potential high speed events that such a project might experience, A slop glider might be a good choice but frankly this was pretty dang spectacular.

    2. He had a release mechanism. The problem was that he lost contact with the glider and couldn’t activate the release before the balloon popped.

    3. I assumed the nose was fared over prior to flight, but evidently not. If not, this reminds me of a graphic from an aerodynamics class, pointing out that a 6’x6″ metal fence post, traveling sideways in air, generated more drag than a 747.

    4. A good glide ratio could be a liability – if you loose control it could fly so far you’d never find it – even with a CW beacon.

  5. When GoPro makes a camera that records stable video instead of recording an image that wobbles and warps all over, then the Pro in the company name will actually be accurate.

    The way they record video, those cameras are expensive pieces of junk. Should be GoAmatuer. Why pay hundreds of dollars for a camera that wobbles the video sideways, makes it look like it’s using a glass block for a lens or does barrel, pincushion, fisheye distortion (or any combination of the above) whenever it’s moved?

    GoPro, how to make a lot of money selling a shite product.

    1. The wonderful thing about capitalism is it allows you to put your money where your mouth is. I look forward to doing my part in making you filthy rich by buying your superior products.

    2. Fantastic project. Shame the video wasn’t recorded to microSD on-board.

      A GoPro costs less (a lot less) than pro optics offered by camera manufacturers. The distortion can be corrected in post if the end user wants to.

  6. Awesome video! You’d better use a GoPro, or something more professional without any data transmission (this seems to be the weakest point of the project, although it’s only about the documentation.)

    1. My guess is that “space” is used to grab attention. As no balloon or glider can reach space unpowered. The artical is also claiming “near space”. Space is above 100km.

      If you do want to put a plane into space. Try KerbalSpaceProgram, it has planes, and space, and rockets. And you can put a plane into space (and on other planets)

    1. So what if you need FAA permission of not. Unless you skirt the law there is really not much you can do as an individual without paying a lot of money. I.E if you are not a business making a lot of money your screwed if you want to innovate these days. You need to go outside the norm to be innovative and going outside of it is either expensive or there is some law preventing you to do so.

      1. Hey! A lot of soldiers died just so you can be free to complain about your lack of freedom, even if it is the only one you have left. So shut up and enjoy your democracy. Or else.

  7. Oh yes, my friend Ed considered an RC glider like this to be released from the shuttle some time in the latter 70s and early 80s, and we looked into it. His idea was to use reject shuttle tiles. The purpose was to study radio black out issues due to ionization. This was the era of GAS-Cans (Get-Away-Special) candidates. I got the complete list of people who had GASs from NASA HQ. Complications: this was beyond a GAS: the cold war: any reentry could be mistaken for an ICBM without lots of foreknowledge. Ed was rich (richer) back then. There are other sensitive communication issues.

  8. Im working on a similar project, but it’s a more autonomous plane. Check out my blog http://nearspaceplane.blogspot.com. All software is open source. The project is manly inspired by the already posted “members.shaw.ca/sonde”-flights from 2005. It is likewise complex, but much lighter and cheaper because of the technical progress.

  9. Be extremely cautious with flights like this. There are huge legal issues you can get into. Always file an FAA flight plan and get approval before launching any aircraft that will exceed 500 feet. Even something as small as this can down a jet if it gets sucked into the jet engine.

  10. I like his project. The antenna information is interesting and being able to point it properly to a moving object couple of km high is also quite a feat. On the other hand, with the strong signal his antenna could be a bit wider to maker it easier.

    Unfortunately he probably broke more than few rules in Sweden as well. At least if Sweden adheres to European treaties regarding RF emissions.

    The exact frequencies aren’t mentioned anywhere so just in general:

    1) 1.2Ghz band has some HAM segments allocated to video, but I do not see any callsign information on his website. This band also contains radio navigation service for planes so check the frequencies before you try this in your country.. (1W is a very strong signal).

    2) 433Mhz band is limited in power and/or duty-cycle and 2W (7W) is (a long) way above the allowed levels. There are only three channels around 448.6 that can be used with 5W transmitter here in CZ, the rest is 500mW and less. Sweden might be different, but I do not expect the differences to be that big.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s