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.
As you may have heard, about a week ago Marshall Space Flight successfully tested a rocket injector that was 3D Printed. Well actually the first tests were earlier than that, but everyone took notice when the video posted below (and others taken at the same time) were posted.
What you might not know is why this is just now a “breakthrough” when 3D printing in metal isn’t new. Shapeways has been printing metal pieces since 2009, and the technology was first patented in the 80s. The biggest difference is that traditionally 3D printing in metal has been done using Selective Laser Sintering (SLS) whereas this injector was printed in Inconel using Selective Laser Melting (SLM). If the difference isn’t clear… in SLS the laser fuses the metal powder together through a localized reaction, whereas SLM essentially melts (or welds) all of the metal in the part. There is a little bit of research going into the difference in properties etc. between the two. The two processes are being improved daily, but everything I have read or seen shows SLM to be stronger (though only marginally in most materials). If your curious, Marshall uses the M2 Cusing by Concept Laser. So the technology specific to printing this part is very new. Marshall just started testing out the technology a year ago.
Enter SpaceX. Yesterday SpaceX posted the video below showing off there cool Iron Man inspired 3D model viewing technology. At the end of the video they print a part to scale in inconel using SLS (specifically using this printer). So SpaceX posts a video where they 3D print an inconel engine part and everyone is too distracted by the shiny sci-fi-esque toy to really grasp that, while the call the part a “prototype”, it is a functional prototype and they could (& probably will) make the end product the exact same way. The only thing left to be seen (from my perspective) is if the SLS printed parts will hold up just as well as the SLM parts.
Oh, and did I mention that one of the SLM printed rocket injectors is currently at Stennis and I have been given the opportunity to handle it and give feedback? If you know me, you know how much I love both 3D printing and rockets, so of course I jumped at the opportunity. I wanted to tweet/post pictures at the time but I was told no I guess I’ll settle for writing this post, even though I have to leave out some of my coolest thoughts/opinions on the matter 😉