 Because Boeing wants it to be certified so they can start launching normal missions with four astronauts on board instead of two. NASA normally, on a first flight, you only fly two astronauts just because it's safe and you don't want to risk more lives than you have to. But Boeing is going to want this thing certified. If you haven't been reading the news the last few years, there's been some bad headlines for Boeing. So they really want a success report.