NASA has launched the DART mission to intercept an asteroid and deflect its path. The purpose is to demonstrate how satellites can be used as kinetic energy impactors to alter the course of asteroids and comets that may be on a collision path with Earth. The European Space Agency is collaborating, and the Italian national space agency has supplied a ride along cubesat to photograph the impact. The mission also contains an important development, a test version of an Aerojet Rocketdyne built xenon ion thruster that may form the basis for a new class of deep space satellite propulsion for missions with durations of a decade or more.Fuel cell technology has been around for decades but has been overshadowed by battery storage and electric motors for transportation purposes. But the field is far from obsolete, and a new way to power them they remove many of the obstacles created using pure hydrogen. New York-based Plug Power has opened a Rochester giga factory to produce hydrogen from electrolysis of water in support of fuel-cell technology and is supplying systems to multinational fertilizer consortium Fertiglobe for an Egyptian plant that will pioneer large-scale green ammonia production. Ammonia is a promising carrier for hydrogen and can itself be a green fuel for combustion engines and in fuel cells.Access all episodes of This Week in Engineering on engineering.com TV along with all of our other series.