Soyuz-19 (Apollo–Soyuz)

The main engineering task of ASTP was not the docking itself but compatibility: the different cabin pressures and atmospheres required a transfer module, and the APAS-75 docking unit was made androgynous — with no division into active and passive halves. That scheme later underpinned the Shuttle and ISS interfaces. The crews of Leonov–Kubasov and Stafford–Brand–Slayton spent two days together, ran five experiments and exchanged flags. The programme was the first technical agreement of that scale between competing space powers. In the hall is a Soyuz-series descent module in the ASTP configuration with the programme livery and emblems.