  A concept for an all-sky monitor mission substantially more powerful than the
RXTE ASM is presented in brief. It makes use of 31 Gas Electron Multiplier
(GEM) proportional counters to provide continuous monitoring of the entire
x-ray sky, except for earth occultations and a small region around the sun.
This coverage would allow the study of a wide variety of short duration cosmic
outbursts. At time scales longer than a few minutes, the sensitivity for the
monitoring of x-ray sources (1.5 - 15 keV) would be greatly improved over the
RXTE ASM, a factor of 6 in one day. This mission concept, the Advanced X-ray
Monitor (AXM), is described in more detail in Remillard et al. (2000).
