Retropropulsion

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.

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.

‘This 80-year-old woman has Parkinson’s disease. Please assess the severity of the condition.’ […] It is probably a little dangerous to look for propulsion or retropropulsion (see Table 15.57).

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 […]

Be aware also that the mandibular support of the tongue may be compromised in jaw fractures and can easily obstruct the airway, in addition to soft tissue swelling and retropropulsion of mid-face fractures.