Keith's 30 June update: This RFI has been cancelled. Funny how these things happen, eh?
"NASA/JSC is hereby soliciting information about potential sources for use of human rated centrifuges that can simulate the Orion spacecraft ascent and entry accelertation environment. Specific information solicited is: The accelerations levels that can be achieved and sustained. The change in acceleration levels (jerk) or the rate of acceleration onset that can be achieved. The ability to produce or accommodate vibrations during the runs including magnitude and frequency limitations. This may include a vibration spectrum that the facility is capable of producing; as well as, the vibrations that could be accommodated if the NASA provided seat system were to generate vibrations...."
Keith's 29 June note: Why is JSC putting this notice out in the first place? Are they not aware of the agency's existing capabilities - a prime example being the 20 G centrifuge at NASA ARC? You can find it using Google. Clearly the folks at JSC know where ARC is - they send astronauts there to fly the VMS all the time.
Check the video below and you can even see it spin!