We highlight the advances made in amorphous silicon alloy photovoltaic technology leading to large-scale commercial deployment. The paper discusses multijunction devices made on lightweight flexible substrates; various aspects of attaining high efficiency devices are described. The eminent role of the roll-to-roll continuous deposition technique in propelling the technology to global market is elucidated. The logical emergence of this technology as a lightweight solar-power generator for extraterrestrial application is discussed. Results of high specific power under space conditions are presented. The future of the technology in terms of both device efficiency and product efficacy are given. (C) 2002 Elsevier Science B.V. All rights reserved.