The first lasers pumped solely by nuclear reaction products have been developed independently at two laboratories. This news has been welcomed partly because producing any phenomenon in a new way is of scientific interest. But part of the welcome has a more pragmatic flavor: If the large amounts of energy produced in a reactor could be efficiently channeled into a laser, the resulting device might be powerful enough for applications ranging from isotope separation, to laser fusion, to communications in space. These first reports, from Sandia Laboratories in Albuquerque, New Mexico, and from Los Alamos Scientific Laboratory in Los Alamos, New Mexico, indicate that such lasers are in principle possible although as yet far from practical. David McArthur and Philip Tollefsrud (Sandia) described their carbon monoxide laser in the 15 February issue of Applied Physics Letters, and Herbert Helmick (Los Alamos), James Fuller and Richard Schneider (both of the University of Florida, Gainesville) reported lasing from xenon in the 15 March issue of the same journal. Both of these lasers are excited byU235fission fragments that result from irradiating uranium foil with neutrons from a fast‐burst reactor.