Long Fall Boot

During the testing of the ASHPD, the observers came across a reproducible human error - due to the conservation of the momentum of on object (or human) travelling through a portal, test subjects where reaching great heights, falling and dying on impact with the Chamber Floor, most likely due to damage to internal organs or because of huge blood loss. This  meant  that test subjects were letting go of their ASHPD's as they died, and the equipment hit the floor and broking. The equipment was expensive, and was costing Aperture Science money, time and effort, so Cave Johnson devised the Long Fall Boot as a solution to the problem of falls from height leading to broken equipment, by a way of cancelling out the momentum conserved between portals.