Boeing’s entry into NASA’s commercial crew program for the International Space Station, has suffered multiple technical delays, but has launched with two astronauts soon. The test flight is critical both for Boeing and for NASA, who need a backup system to guarantee crew access to orbit with two redundant systems. The fourth system besides NASA, Boeing and SpaceX, is the Sierra Space Dream Chaser lifting body vehicle. An uncrewed cargo version is now at NASA’s Kennedy Space Center for testing and will be launched by a ULA Vulcan Centaur rocket. Soon, there may be four separate ways to lift humans into orbit from US soil. * * *Want to watch this podcast as a video? This Week in Engineering is available on engineering.com TV along with all of our other shows such as End of the Line, Designing the Future, Manufacturing the Future, and the Engineering Roundtable.