Attaching a camera to a helium-filled balloon, a group of students from MIT recently managed to get some pretty decent photographs of our beautiful planet from an estimated 93000 feet up. Nothing remarkable there you might say - high altitude balloon photography has been around a long, long time - until you consider the cost of the experiment: about USD$150.
The balloon took roughly four hours to rise the estimated 17.5 miles into the upper stratosphere before popping and taking just 40 minutes to return. The Canon A470 payload continuously snapped the whole magnificent journey, as evidenced in the gallery.
The onboard GPS only managed to track the ascent up to just under 20,000 feet due to software limitations. The students managed to keep it within visual range for a short while but ended up having to estimate its final height using a combination of linear extrapolation of velocity, flight information from similar missions and the images retrieved from the camera.
The students launched the balloon from an open field in Sturbridge, MA. After traveling some 20 miles, it landed in a soft-earthed construction field in Worcester, MA without any serious damage to the equipment. Even though the parachute slowed descent, recovery was marred slightly by the GPS antenna being buried in the ground on impact.
By far the most remarkable feature of the flight though is the cost. All of the equipment used was common, off-the-shelf electronics. The GPS receiver was a Motorola i290 "Boost Mobile" prepaid phone with internet and GPS capability which cost USD$50 (although subsequent searches revealed that it could have been obtained for as little as USD$30). The Canon camera was bought for just USD$40, including an 8Gb memory card.
Providing additional power was an AA battery charger containing lithium batteries rated to withstand temperatures as low as -40F and to further protect the equipment from the cold, the students slotted some disposable hand-warmers near the electronics. Another USD$17.
The sounding balloon and helium added another USD$40 to the cost, and a parachute a few more dollars. An antenna from an old wireless router, a styrofoam beer cooler, some duct tape and zip ties were all obtained without additional cost to the project.
The electronics were carefully placed in a box and attached to the balloon, which was then readied for launch. The rest, as they say, is history.
If you would like to try this for yourself or just have a look at the MIT low-budget achievement, full details are available on the project website.