I’ve been working at Stennis for a little over a a year now, and have worked at various NASA facilities off and on for the last 6 years, and whenever a friend asks me about “rocket fuel” they do it in hushed tones with the occasional glance over their shoulder. As if it were some national secret, and that if it were, I would somehow have the 411 and give them the insider scoop so long as they keep it on the DL… Well you are all in luck! I am going to let you in on a little secret, ssshhh! Ok, come a little closer to your computer monitor, we don’t want your coworkers overhearing what you’re reading. Ready?… Most rocket fuel is almost entirely liquid oxygen and/or liquid hydrogen. Surprise!
So while LOX and LH2 are amazing and beautiful, what many people think about is that rockets are powered by water. Yup. Water. Granted you have to separate it, and bring it down to liquid temperatures, but nonetheless these aren’t exotic materials; they are completely sustainable and clean burning.
So the cloud you see forming as the exhaust of a rocket engine is literally a could. Not to mention that when we are testing rocket engines we quench the flame with nearly 1 million gallons of water per minute. So after any test on site it rains immediately after, usually right on top of all of the people standing around watching it; and when the conditions are right, the exhaust creates rainbows. So there you are, probably the coolest way to make a rainbow.
here is a video I took of the RS-68 test yesterday that led to the above image.
And here are a few more photos in case you want more 😉
and for those that are curious, this is what it sounds like inside the building where I work during the test.