Nerva became emperor immediately after Domitian’s murder in 96 AD. He had a lifetime of service to Rome and its emperors, and had served as consul twice, in 71 and 90 AD.

Six NERVA technology demonstrators were built between 1964 and 1973. The highest power threshold NASA could muster during testing was a scarcely believable 246,663 newtons (55,452 lbf) of thrust ...

The NERVA I engine would emit radiation not only while it was in operation; it would also generate spent nuclear fuel that would emit harmful levels of radiation for decades or centuries.

The NERVA-IIs and tank modules would dock in orbit to form four 54-meter-long, 10-meter-diameter nuclear-thermal stages, each with a mass of 309 tons. Of this mass, ...