(copied from GrassrootsMapping Wiki)

Prototype a helium-filled kite that flies in low wind but does not drop due to wind:

See this [Ram Sled](http://www.blueskylark.org/zoo/single/sled/index.html#ramsled) for a possible design: swap out the rammed air cylinders for helium?

<div markdown='0' style="float:right; width:280px;padding:14px;"><img src='http://farm5.static.flickr.com/4037/4490725478_7913580b01_m.jpg' /></div>

## Black Knight 1 ##

At [WhereCamp 2010](http://wherecamp.org) at Google Mountain View, a few of us built a prototype helium kite from a single 99 gallon trash bag.  (JeffreyWarren, DanLyke, ReidBeels, and a few more)

See photo gallery here: [Flickr photos of Black Knight 1](https://www.flickr.com/photos/tags/blackknight1)

### Goals ###

* made from a single 99-gallon trash bag
* minimal extra bits needed; packing tape, duct tape, 2 key rings, string, scissors
* flies in light winds

### Lessons learned ###

* the connection of the side reservoirs to the center line (belly) burst immediately; it really needs to be an order of magnitude stronger
* should add 4 bridle points instead of 2 so we can adjust the angle of attack in flight tests. Ours didn't climb enough.
* make it bigger, or out of thinner plastic: we used 2.7  mil and it was a little less than neutral buoyancy.

## Black Knight 1.1 ##

**Suggestion:** try making 2 cylinders of helium that are reinforced and sealed with rings of tape. Then connect them with a membrane.

<div style="float:right;"><a href="https://www.flickr.com/photos/jeffreywarren/4532118199/" title="Balloon-Kite testing by jeferonix, on Flickr"><img src="http://farm5.static.flickr.com/4068/4532118199_8ec00c6395_m.jpg" width="240" height="160" alt="Balloon-Kite testing" /></a></div>

NathanCooke, OliverYeh, and JeffreyWarren prototyped some small balloon kites using a plastic bag welder from MIT's D-Lab. 

[See photos on Flickr here](https://www.flickr.com/photos/jeffreywarren/tags/blackknight11/)

We used 2.7 mil plastic with the welder set to 5.5. Triple seams were tough - like in 3d where three lines meet, which is how the old Black Knight design worked. 

**Suggestion:** try just sealing horizontally instead of doing a complex joint.

We also tried just sealing a bag closed, then welding lines down the middle, so we use the bag as-is, water-tight, but create pontoons. Easier to show in a picture than explain in text, so here:

<a href="https://www.flickr.com/photos/jeffreywarren/4532183811/" title="Simple balloon-kite from trash bag by jeferonix, on Flickr"><img src="http://farm5.static.flickr.com/4060/4532183811_e6de11c4bd.jpg" width="500" height="334" alt="Simple balloon-kite from trash bag" /></a>

###Flight tests:###

<a href="https://www.flickr.com/photos/jeffreywarren/4532184483/" title="Balloon-kite wind tunnel tests by jeferonix, on Flickr"><img src="http://farm5.static.flickr.com/4002/4532184483_65d09c81de_m.jpg" width="240" height="161" alt="Balloon-kite wind tunnel tests" /></a>

## Kite / Balloon Hybrid History ##

Domina Jalbert (of the parafoil fame) experimented with these under the name "Kytoon". They generally seem to be teardrop-shaped balloons with kite-style wings. Here's a [reprint from an old Popular Mechanics article](http://blog.modernmechanix.com/2008/01/25/kite-balloonkytoon/).

Also see the "Helikite": [Helikite on YouTube](https://www.youtube.com/watch?v=e9vDCCxUu-0&NR=1)