PURPOSE: To open/close a protective cover with simple and compact constitution by turning the protective cover, which covers possible to open/close an interface part, through a cam mechanism by pressing a protrusive part when a plurality of space equipments approach so as to be connected.

CONSTITUTION: At normal time, that is, before a space equipment main unit 2 is connected to a pay load 1, an interface part 9 provided in a coupling surface 7 of the space equipment main unit 2, is covered with a protective cover 11 energized by a spring 8. Here, a protrusive part of the protective cover 11 is engaged with a hole part of the coupling surface 7 where the interface part 9 appears. When the space equipment main unit 2 approaches so as to be connected with the pay load 1, a damper 15 provided in a coupling surface 5 of the pay load 1, is brought into contact with the coupling surface 7 of the space equipment main unit 2 to press the protective cover 11. Then by successively moving a cam pin 22 in a cam groove 21, each interface part 9, 10 of the space equipment main unit 2 and the pay load 1 is connected to each other.