A portable launch rig (PLR) may include a support structure including two side supports defining an interior space for lifting and filling a balloon envelope of a balloon. Wheels on each of the side supports enable the PLR to be moved in various directions in order to prepare the PLR for launching the balloon. The side supports are connected by a lateral support beam having a pair of cranes arranged thereon. Each crane has an arm arranged over the interior space that is connected to a spreader beam. The spreader beam includes a lift assembly configured to lift and inflate the balloon envelope within the interior space. The PLR includes a platform and perch for supporting and moving the balloon envelope. A door assembly of the PLR includes a plurality of hangar doors configured to block wind from a respective direction of each hangar door entering the interior space.