My biggest concern is the apparent lack of testing and validation. After the Apollo 1 accident uncrewed flight of Apollo, we had half-a-dozen flights, 3 of which uncrewed, before they did an end-to-end validation on Apollo 10, to finally land with Apollo 11. Is NASA that confident SLS and Orion will perform adequately that they will add astronauts to SLS's second (and Orion 3rd) flight?