The hot carbon, oxygen, and nitrogen echelle spectrograph (HotCONes) soundi
ng rocket payload allows a unique probe of the local interstellar medium th
rough R=lambda/delta lambda greater than or similar to 200 000 spectroscopy
of C+3, N+4, and O+5. It is a practical proof of the low-order echelle spe
ctrograph design, which may prove extremely useful in conjunction with emer
ging technology. We present the scientific motivation, instrument design, a
nd measured performance. (C) 2001 American Institute of Physics.