NSTX produced a spherical plasma with a hole through its center (a "cored apple" profile; see MAST), different from the doughnut-shaped (toroidal) plasmas of conventional tokamaks. The low aspect ratio "A" (that is, an "R"/"a" of 1.31, with the major radius "R" of 0.85 m and the minor radius "a" of 0.65 m) experimental NSTX device had several advantages including plasma stability through improved confinement. Design challenges include the toroidal and poloidal field coils, vacuum vessels and plasma-facing components. This plasma configuration can confine a higher pressure plasma than a doughnut tokamak of high aspect ratio for a given, confinement magnetic field strength. Since the amount of fusion power produced is proportional to the square of the plasma pressure, the use of spherically shaped plasmas could allow the development of smaller, more economical and more stable fusion reactors. NSTX's attractiveness may be further enhanced by its ability to trap a high "bootstrap" electric current. This self-driven internal plasma current would reduce the power requirements of externally driven plasma currents required to heat and confine the plasma.