LEGO

Two of the payloads launched were designed by MINDSTORMS Community Partner, Brian Davis. We got a chance to interview him about his robots and this historic event.

How did you get involved with the H.A.L.E. project?

I actually noticed the University of Nevada at Reno balloon missions long before the project was kicked off, and started planning and dreaming of doing a mission like this with the materials I had at hand (namely, LEGO). When the H.A.L.E. opportunity was presented, I jumped at the chance, submitting two payloads to improve my chances of being accepted. To my surprise, both were approved, so I set to work on two very different projects.

Why are you interested in High Altitude LEGO?

Well, since MINDSTORS NXT came along with it’s stronger construction and stronger motors, I’ve been much more interested in outdoor, “all terrain” robots. I built LNE/PackBot as a high-mobility “supertank” for running around in my house and yard (it also handles small steps, curbs, and rough snowfields). I then went on to construct Serenity, a robotic boat. Both of these are “pure LEGO”, and I’d yet to make a robot for the air, so… High Altitude LEGO seemed like the next obvious step.

Even more exciting to me is the fact that these robots have to work right the first time, and handle things I don’t know about. In the language of space missions, they must be “fault tolerant”, and handle all their own decisions, under conditions where there is no possibility of help. These are not robots I can help out of the corner when they get stuck… and that challenge really got my interest.

Is it safe to send LEGO MINDSTORMS into the stratosphere?

Perfectly safe… but I’m having trouble convincing the minifigs that will ride along of that :). Seriously, the NXT can function under the near vacuum conditions, and will function at low temperature (although the payloads do have insulation and heaters to try to keep them warmer than the -60° C temperatures outside). So for the NXT, conditions aren’t a major problem.

However, both my payloads have an additional element of risk. Gypsy’s primary support is from two large LEGO turntables and studless beams. If those pull apart, or become brittle in the bitter cold and shatter, the payload could fall… and that’s a loooong fall! So it will have a “back up tether”, a string that should support it if those turntable supports fail. For Lil’ Joe the risk is even greater: if anything goes wrong, it will hit the desert floor at something like 300 mph (around 500 kph). So it has been tested a lot… but there’s still some risk.

How are you sending your robots into the stratosphere?

The robots are held on a string that hangs below a balloon. Just like you could attach a minifig to the string of a small helium balloon, the HALE mission uses the same idea. Instead of a small party balloon, it uses a very large weather balloon that can lift many pounds. And instead of a minifig or two, the HALE mission will carry half a dozen payloads in addition to GPS and radio equipment. This “infrastructure” (the stuff you need to support the mission) is being provided by the folks at the University of Nevada at Reno, who have experience in this sort of thing.

One of your projects, “Lil’ Joe” involves the longest NXT free-fall. How long is the free-fall? Aren’t you afraid that you’ll risk breaking your NXT?

Lil’ Joe is named after Col. Joseph Kittinger who was instrumental in the early days of upper atmosphere exploration as part of Project Excelsior. He is best known for a world record jump from a balloon above 100,000 feet… which in a very small, experimental way I was curious if I could replicate with a LEGO robot. The payload will hang below the main payload string, to be released at high altitude without a deployed parachute (in other words, in free fall). After a short time (nothing like Col. Kittinger’s 14 minute free-fall, more along the lines of a 20 to 40 second free-fall) it will try to deploy its own internal parachute, HOPEFULLY descending on it’s own. It will contain its own satellite location system, and the parachute & cords are not LEGO… but everything else, from the computer controlling the mission to the motor releasing the parachute to the software running on the NXT and the sensor detecting free-fall will all be “stock LEGO”.

The length of the free-fall is actually left up to the robot - it estimates how high it is upon release, and makes a very conservative estimate of the maximum safe free-fall time. Since there are so many unknowns on this, I’m not trying to set a really impressive, multi-minute free-fall record (although I suspect this payload could). First make sure it works, then maybe the next time make it work better. While all this is going on, Lil’ Joe will also be logging the accelerations experienced by the payload just before, during, and after the free-fall portion of the mission, to better understand what is happening to a payload under these conditions.

Your second project, the “Gypsy (a.k.a. Nadar 2.0),” will take video and pictures. Why are you taking pictures?

Gypsy is an improved version of a project I put up on NXTlog named “Nadar“. The goal with Gypsy (named after a robot from the TV show “Mystery Science Theater 3000″) is to automate an off-the-shelf digital camera to take both still images as well as video. This way I could get a pre-programmed variety of images and movies during the mission, instead of the typical “one picture every 30 seconds” technique that is commonly employed on balloon missions like these.

Additionally, I wanted to be able to control the cameras’ pitch (how far up or down it is pointed) to get images up and down the payload string as well as towards the horizon. Gypsy will be following a complex “script” of commands during the mission (”take 10 photos, tilt to look straight down, take four photos, take 40 seconds of video”, etc.), and in addition to controlling the camera, will by logging more than 10 different environmental variables (sound, pressure, light, temperatures, etc.) at intervals of a few seconds, storing these using a “data compression” technique to fit as much as possible into the NXT’s memory. If this sounds complicated it is, but when it’s all done the program is surprisingly small - about 17k in the NXT. NXT-G can churn out some amazingly compact efficient code if you work with its strengths (My Blocks and wires).

What are you hoping to accomplish at the end of this event?

Primarily, showing that a nearly “pure LEGO” robot can do some very impressive stuff in such a hostile environment. Personally I love the challenge of trying something new, and these two payloads have pushed my understanding and use of the NXT, electronics, and NXT-G much further. There may be better ways to do everything I’m trying to accomplish… but doing it with LEGO allows single individuals or small groups to do this sort of thing at a fairly high level for very low cost.

Two of the payloads launched were designed by MINDSTORMS Community Partner, Brian Davis. We got a chance to interview him about his robots and this historic event.

How did you get involved with the H.A.L.E. project?

I actually noticed the University of Nevada at Reno balloon missions long before the project was kicked off, and started planning and dreaming of doing a mission like this with the materials I had at hand (namely, LEGO). When the H.A.L.E. opportunity was presented, I jumped at the chance, submitting two payloads to improve my chances of being accepted. To my surprise, both were approved, so I set to work on two very different projects.

Why are you interested in High Altitude LEGO?

Well, since MINDSTORS NXT came along with it’s stronger construction and stronger motors, I’ve been much more interested in outdoor, “all terrain” robots. I built LNE/PackBot as a high-mobility “supertank” for running around in my house and yard (it also handles small steps, curbs, and rough snowfields). I then went on to construct Serenity, a robotic boat. Both of these are “pure LEGO”, and I’d yet to make a robot for the air, so… High Altitude LEGO seemed like the next obvious step.

Even more exciting to me is the fact that these robots have to work right the first time, and handle things I don’t know about. In the language of space missions, they must be “fault tolerant”, and handle all their own decisions, under conditions where there is no possibility of help. These are not robots I can help out of the corner when they get stuck… and that challenge really got my interest.

Is it safe to send LEGO MINDSTORMS into the stratosphere?

Perfectly safe… but I’m having trouble convincing the minifigs that will ride along of that :). Seriously, the NXT can function under the near vacuum conditions, and will function at low temperature (although the payloads do have insulation and heaters to try to keep them warmer than the -60° C temperatures outside). So for the NXT, conditions aren’t a major problem.

However, both my payloads have an additional element of risk. Gypsy’s primary support is from two large LEGO turntables and studless beams. If those pull apart, or become brittle in the bitter cold and shatter, the payload could fall… and that’s a loooong fall! So it will have a “back up tether”, a string that should support it if those turntable supports fail. For Lil’ Joe the risk is even greater: if anything goes wrong, it will hit the desert floor at something like 300 mph (around 500 kph). So it has been tested a lot… but there’s still some risk.

How are you sending your robots into the stratosphere?

The robots are held on a string that hangs below a balloon. Just like you could attach a minifig to the string of a small helium balloon, the HALE mission uses the same idea. Instead of a small party balloon, it uses a very large weather balloon that can lift many pounds. And instead of a minifig or two, the HALE mission will carry half a dozen payloads in addition to GPS and radio equipment. This “infrastructure” (the stuff you need to support the mission) is being provided by the folks at the University of Nevada at Reno, who have experience in this sort of thing.

One of your projects, “Lil’ Joe” involves the longest NXT free-fall. How long is the free-fall? Aren’t you afraid that you’ll risk breaking your NXT?

Lil’ Joe is named after Col. Joseph Kittinger who was instrumental in the early days of upper atmosphere exploration as part of Project Excelsior. He is best known for a world record jump from a balloon above 100,000 feet… which in a very small, experimental way I was curious if I could replicate with a LEGO robot. The payload will hang below the main payload string, to be released at high altitude without a deployed parachute (in other words, in free fall). After a short time (nothing like Col. Kittinger’s 14 minute free-fall, more along the lines of a 20 to 40 second free-fall) it will try to deploy its own internal parachute, HOPEFULLY descending on it’s own. It will contain its own satellite location system, and the parachute & cords are not LEGO… but everything else, from the computer controlling the mission to the motor releasing the parachute to the software running on the NXT and the sensor detecting free-fall will all be “stock LEGO”.

The length of the free-fall is actually left up to the robot - it estimates how high it is upon release, and makes a very conservative estimate of the maximum safe free-fall time. Since there are so many unknowns on this, I’m not trying to set a really impressive, multi-minute free-fall record (although I suspect this payload could). First make sure it works, then maybe the next time make it work better. While all this is going on, Lil’ Joe will also be logging the accelerations experienced by the payload just before, during, and after the free-fall portion of the mission, to better understand what is happening to a payload under these conditions.

Your second project, the “Gypsy (a.k.a. Nadar 2.0),” will take video and pictures. Why are you taking pictures?

Gypsy is an improved version of a project I put up on NXTlog named “Nadar“. The goal with Gypsy (named after a robot from the TV show “Mystery Science Theater 3000″) is to automate an off-the-shelf digital camera to take both still images as well as video. This way I could get a pre-programmed variety of images and movies during the mission, instead of the typical “one picture every 30 seconds” technique that is commonly employed on balloon missions like these.

Additionally, I wanted to be able to control the cameras’ pitch (how far up or down it is pointed) to get images up and down the payload string as well as towards the horizon. Gypsy will be following a complex “script” of commands during the mission (”take 10 photos, tilt to look straight down, take four photos, take 40 seconds of video”, etc.), and in addition to controlling the camera, will by logging more than 10 different environmental variables (sound, pressure, light, temperatures, etc.) at intervals of a few seconds, storing these using a “data compression” technique to fit as much as possible into the NXT’s memory. If this sounds complicated it is, but when it’s all done the program is surprisingly small - about 17k in the NXT. NXT-G can churn out some amazingly compact efficient code if you work with its strengths (My Blocks and wires).

What are you hoping to accomplish at the end of this event?

Primarily, showing that a nearly “pure LEGO” robot can do some very impressive stuff in such a hostile environment. Personally I love the challenge of trying something new, and these two payloads have pushed my understanding and use of the NXT, electronics, and NXT-G much further. There may be better ways to do everything I’m trying to accomplish… but doing it with LEGO allows single individuals or small groups to do this sort of thing at a fairly high level for very low cost.