retropropulsion

Backward propulsion, especially the use of rockets to brake or change direction.

Recent studies have concluded that Viking-era entry system deceleration technologies are extremely difficult to scale for progressively larger payloads (tens of metric tons) required for human Mars exploration. Supersonic retropropulsion is one of a few developing technologies that may enable future human-scale Mars entry systems.

Alternative form of retropulsion (“abnormal tendency to step backwards”).

At the autopsy Pierret found sclerosis of the columns of Goll, and he thinks that disease of these columns explains the tendency to propulsion and retropropulsion experienced by the patient as well as the uncertainty felt in maintaining the erect posture.

There was complete loss of automatic associated movements with lateropropulsion and retropropulsion to a degree rarely so complete in the juvenile form of parkinsonian disease.

Alternative form of retropulsion (“forcing something to move backwards or inwards”).

Also, the retropropulsion of blood through the mitral valve caused a “gyration” of the heart at each beat; […]

Relative indications for surgery include: […] radiological evidence of spinal instability, complete vertebral collapse or retropropulsion of bone fragments […]