The Global Environmental Micro Sensors (GEMS) concept leverages technological advancements in micro and nanotechnology for a new atmospheric in situ observing system based on an ensemble of self-contained, low cost disposable probes. By substantially reducing the mass, size, cost, and complexity of GEMS probes, large numbers of them could be for research and operational missions thereby greatly expanding the amount of in situ observations, especially over data sparse oceanic regions. The GEMS system would be ideal for adaptive or targeted observing campaigns (field experiments, tropical cyclone reconnaissance, etc.) where it is only cost effective and practical to obtain in situ, high-resolution, spatial and temporal measurements over limited domains.

During the course of a two-phase study funded by the National Aeronautics and Space Administration (NASA) Institute for Advanced Concepts (NIAC), ENSCO, Inc. and collaborators identified the major feasibility issues for the GEMS system and mapped pathways for system development in a technology roadmap. When the two-year NIAC phase II project was completed in August 2005, ENSCO began developing GEMS prototypes as part of internal research efforts. In January 2006, ENSCO and NASA Kennedy Space Center (KSC) Weather Office scientists responded to a solicitation for dual-use projects implemented through the KSC Technology Transfer Office Innovative Partnerships Program (IPP). The project funded by the IPP was called GEMS Test Operations in the Natural Environment (GEMSTONE).

The current GEMS probe design features a super pressure balloon constructed using MylarTM film that is filled with helium to make it neutrally buoyant at different levels in the atmosphere. The initial prototype is about 1.0 x 0.6 meters and weighs 150 grams using commercial off the shelf technology. Once deployed, the probe measures temperature, pressure, relative humidity, velocity, and position information using micro sensors as it drifts passively with the wind. An onboard microprocessor controls all electronic sub systems which are powered by a combination of small batteries, thin film solar cells, and super capacitors. The data are communicated to ground stations via one-way radio frequency (RF) transmissions to low-earth orbiting satellites.

The various laboratory and field tests conducted during the GEMSTONE project were designed to characterize the sensor suite, the micro global positioning system, satellite communication capabilities, and overall system performance. A flight test in April 2007 was successful in demonstrating system functionality and robustness in the relevant environment including capability to acquire and transmit useful data in real time.

This paper will report on the results of the GEMSTONE project, discuss the challenges encountered in developing GEMS prototypes, and conclude with a roadmap for future development efforts required to yield a fully functional and reliable system.