From Wikipedia:

In physics, jerk is the rate of change of acceleration; that is, the derivative of acceleration with respect to time, and as such the second derivative of velocity, or the third time derivative of position.

The higher derivatives subsection continues:

In classical mechanics of rigid bodies there are no forces associated with the higher derivatives of the path, nevertheless not only the physiological effects of jerk, but also oscillations and deformation propagation along and in non-ideally rigid bodies, require various techniques for controlling motion to avoid the resulting destructive forces. It is often reported[where?] that NASA in designing the Hubble Telescope not only limited the jerk in their requirement specification, but also the next higher derivative, the jounce.

Question: What were Hubble's jerk and jounce limits? Did JWST have the same?

note: per @ErinAnne's comment jounce is also known as "snap", as discussed in Wikipedia as well as in Don Eyles' book Sunburst and Luminary.

  • $\begingroup$ Somewhat related: How much jerk do astronauts experience? Is there a safety limit? $\endgroup$
    – uhoh
    Apr 30, 2018 at 13:29
  • 5
    $\begingroup$ "Snap, crackle, and pop" as the ongoing derivatives of motion originated in the Instrumentation Lab at MIT while the Apollo software was being written (according to "Sunburst and Luminary" by Eyles). Those are generally the preferred terms in my experience. If not, they've at least got spaceflight heritage :) $\endgroup$
    – Erin Anne
    May 1, 2018 at 15:40
  • $\begingroup$ @ErinAnne indeed! I've added a note to the question, thanks for mentioning the book, I haven't read it yet, will look for a copy. $\endgroup$
    – uhoh
    May 1, 2018 at 17:51
  • 2
    $\begingroup$ I'm having a really tough time getting my head around jounce (snap). I've met design requirements for jerk... but have no idea what mechanical aspect of design to pay attention to or is affected by jounce or how it would be tested. What would a jounce control limit look like on a shaker table control plot? Maybe I'll track down a vibe lab specialist from the Environmental Effects Engineering Dept of the company I retired from and ask if they've ever dealt with this. $\endgroup$
    – BradV
    May 22 at 18:42


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.