Investigations to characterize multijunction solar cells in thestratosphere using low-cost balloon and communication technologies

摘要

The use of current balloon, control and communication technologiesto test multi-junction solar cells in the stratosphere to achieve nearAMO conditions has been investigated. The design criteria for thetechnologies are that they be reliable, low cost and readily available.Progress is reported on a program to design, launch, fly and retrievepayloads dedicated to testing multi-junction solar cells. The systeminvestigated includes a state-of-the-art multi-junction solar cell andtwo-axis suntracker that weighs less than one pound. Data acquisition iscarried out with a module that employs programmable microprocessors, A/Dconverters, digital I/O lines, AX.25 encoding, GPS, and VHF, UHF and HFtransmitters. One flight has been carried with a 1000 gram extensiblehelium balloon and payload that weighed under six pounds. During aflight that lasted about two hours, the balloon traveled to an altitudeof 87,000 feet and data were downlinked. The payload was retrieved about40 miles from the launch site