retropropulsion

From retro- +‎ propulsion.

retropropulsion (countable and uncountable, plural retropropulsions)

1. (astronautics) Backward propulsion, especially the use of rockets to brake or change direction.
   • 2014, Karl T. Edquist et al., “Development of Supersonic Retropropulsion for Future Mars Entry, Descent, and Landing Systems”, in Journal of Spacecraft and Rockets, volume 51, number 3, →DOI, Abstract, page 650:

     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.

2. Alternative form of retropulsion (“abnormal tendency to step backwards”).
   • 1883, James Ross, A Treatise on the Diseases of the Nervous System, volume 2, page 69:

     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.

   • 1924, Transactions of the Section on Nervous and Mental Diseases of the American Medical Association ‎, volume 75, page 213:

     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.

   • 2010, Nicholas J. Talley, Simon O’Connor, Examination Medicine: A Guide to Physician Training, 6th edition, →ISBN, page 391:

     ‘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).

3. Alternative form of retropulsion (“forcing something to move backwards or inwards”).
   • 2001, John Richardson, Enteroviral and Toxin Mediated Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Other Organ Pathologies, →ISBN, page 49:

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

   • 2006, Y. Lawrence, R. Pfeffer, “Radiotherapy in advanced cancer”, in Raphael Catane, Nathan I. Cherny, Marianne Kloke, editors, Handbook of Advanced Cancer Care, →ISBN, page 34:

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

   • 2023, David M. Nott, “Trauma Surgery/Principles of Trauma Care”, in M. Asif Chaudry, Shahnawaz Rasheed, James Kinross, editors, Clinical Surgery, 4th edition, →ISBN, page 801:

     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.

• retropropulsive