Lightweight Flexible Space Solar Arrays, Past, Present and Future

Since the first spacecraft was flown with photovoltaic power (Vanguard 1) more than 60 years ago, the desire for more power, higher specific power via light weight, and lower cost solar arrays has driven designs for advanced space power sources. Ultimately, three basic array architecture design families have resulted in flown hardware using both Si and III-V solar cells. Evolved versions of these designs are presently qualified and on orbit, or about to be flown. The advent and improvement of multi-junction III-V solar cells in the 1980's and 1990's slowed innovation and advancement in lightweight solar array mechanical technology by doubling PV efficiency. Now that an effective PV efficiency plateau has been reached, the advent of reliable, affordable electric propulsion is creating a demand for renewed interest in improved, higher power alternate lightweight solar array designs requiring further innovation.