Underground coal gasification (UCG) offers a relatively low cost, environmentally sound method to produce clean fuels from coal. The coal resource for UCG is vast, widely distributed and is unminable by present-day techniques. Field tests to date have confirmed the potential economical and environmental advantages. Major milestones of the DOE UCG program include: Gasification with air producing low Btu gas (165 Btu/scf) at a production rate of 8.5 x 10/sup 6/ SCFD. This experiment was conducted by the Laramie Energy Technology Center and was in continuous operation for 55 days. Steam/oxygen gasification produced medium Btu gas (263 Btu/scf) at 1.7 x 10/sup 6/ SCFD. This test was carried out by the Lawrence Livermore Laboratory and was in continuous operation for 58 days of air gasification with a scheduled 2 day oxygen test. The results of the field testing have been very encouraging. The ultimate objective of the DOE program is to develop sources of commercial gas for SNG and power generation by 1987. A number of key issues must be resolved to move the technology into the commercial sector: demonstration of reliable link at bottom of the coal seam, control of water influx, minimization of gas losses, subsidence control, process control with good gas quality, environmental control, technology transfer to industry, and larger multi-module tests to demonstrate control of interacting modules. (LTN)