If the pressure drops, the soil pressure increases and this leads to subsidence at the ground level. Since exploitation of the Slochteren (Netherlands) gas field started in the late 1960s the ground level over a 250 kmÂ² area has dropped by a current maximum of 30 cm.
Confidence votes 18.5K. There are quite a few tools that the Astronauts use, though for construction and maintenance in space, the Pistol Grip Tool (PGT) is the primary tool of choice. Its predecessor was the Power Ratchet Tool (PRT), originally developed and created for servicing the Hubble Space Telescope.
The Manned Maneuvering Unit is an astronaut propulsion unit that was used by NASA on three Space Shuttle missions in 1984. The MMU allowed the astronauts to perform untethered EVA spacewalks at a distance from the shuttle. The MMU was used in practice to retrieve a pair of faulty communications satellites, Westar VI and Palapa B2. Following the third mission the unit was retired from use. A smaller successor, the Simplified Aid For EVA Rescue, was first flown in 1994, and is intended for emergen