Soyuz 7K-T

From 1973 to 1981 the Soyuz flew without solar panels. The model, known as the 7K-T, was a complete redesign of the spacecraft following the Soyuz 11 tragedy. Because the spacecraft would be used to ferry crews to the Salyut, it relied on battery power instead of the solar wings.

The 7K-T flew thirty times, including the first Interkosmos flights. It was also fitted with solar panels again for special missions: once for the Apollo-Soyuz Test Project, once for the ASTP test flight, and twice for standalone science missions that did not dock to a Salyut.