Presumably you'd have an array of 'slow' ion thrusters upstream of your test article in your vacuum chamber to generate your flow. Matching temperature and velo

Presumably you'd have an array of 'slow' ion thrusters upstream of your test article in your vacuum chamber to generate your flow. Matching temperature and velocity profile exactly is probably fairly tricky, but producing nominally 8km/s of very dilute gas shouldn't be particularly difficult.