Naj-<br />For what it's worth, many Navy aircraft, from F-14 Tomcats to C-9 type airliners use LOX instead of High Pressure Gas for breathing Oxygen. I was always scared when I worked with the stuff. But just like fuel lines are shrouded to vent safely overboard incase of leaks, LOX could be, too. Yes, it is mean stuff, not only does it want to rapidly burn everything that could possibly burn, but it expands several thousand to one when it changes from a liquid to a gas, which is also dangerous.<br /><br />However, I still can't believe it's a "show-stopper", like it has been for the past 20 years in the Shuttle Program. But even if it is just too dangerous to fly liquid payloads in the bay, there has got to be a "good" way to put a little extra fuel/LOX in the ET, and get that into a fairly stable orbit for a few days. I don't know how much deltaV is required by that OMS burn right after ET seperation, but I would guess that we could "bump freight for fuel", in other words, leave some freight and carry extra fuel. It wouldn't be the most efficient way because the weight of the tank itself has got to be pretty heavy, plus the fuel/LOX inside, but it would keep the Orbiter's payload bay "dry". Plus the SSME's would do the boosting all the way to orbit, but maybe the OMS are used because they can be more precise, I don't know.<br /><br />I'll bet dollars to pesos there is a good way to do it. <div class="Discussion_UserSignature"> </div>