in place when Lucid arrived at Mir, had been moved forward at least twice: once because of late delivery from the Khrunichev factory and once because a commercial Proton launch in early April took precedence. But on April 23, Priroda was launched from Baikonur atop a SL-13 Proton rocket for a three-day orbital trip to Mir. One of the two battery-powered electrical systems on the spacecraft dropped off-line, eliminating the backup power source for the automatic docking system. If the primary electrical system had also malfunctioned, the Mir crew would have immediately initiated a manual docking. The Priroda module had a mass of 19.700 kg, a length of ~12 m, a max diameter of ~4.35m and a pressurized volume of ~66 cubic meters. it was the last of the six permanent habitable Mir modules. Priroda was, like Spektr, designed by RKK Energia in the mid- to late-1980s and was built and assembled in the Khrunichev plant between 1989 and 1991. The module's two propulsion systems included one for orbit correction during the flight to Mir and rendezvous with Mir and one was for berthing and stabilization during the docking phase. The Priroda module included an unpressurized instrument compartment and an instrument/payload compartment. The Kurs automatic docking system on Priroda worked flawlessly, as did the electrical system. No problems were encountered on the April 26 docking of the new module at the -X port at the front of the Mir base block. On April 27, from inside the station, the Mir 21 crew controlled Priroda's repositioning with the Lyappa arm to the +Z docking port, directly across from the Kristall module. Thus the Mir complex, with its six habitable modules and Docking Module, attained its final basic configuration. Henceforth, the shape of the complex would change only temporarily, with dockings by Progress, Soyuz and Space Shuttle Orbiter spacecraft. Because of concern about possible sulfur dioxide leaks from the malfunctioning battery system, a test of the modules' atmosphere was made before the crew entered. Once inside Priroda, the crew's first task was to unbolt the batteries, cap their connectors and place them in plastic bags. The 168 batteries would later be placed in Progress M-31 for disposal. The crew then connected Mir power sources to the Priroda systems and troubleshot the battery problems. May 1996 - Progress M-31 Resupply and EVAs Progress M-31 Brings New Supplies A new Progress cargo spacecraft was