The Air Force is considering whether it should increase production of its Delta IV launch vehicle in light of rising tensions with Russia that could pose a threat to space access. The service's dependence on a Russian-built engine, the RD-180, to power its Atlas V launch vehicle has come under serious scrutiny in recent months. Gen. William Shelton, outgoing commander of Air Force Space Command, told reporters on July 22 that the events surrounding the downing of Malaysia Airlines flight...