I’ve lived in the South for about 20 years now. Over that time, I’ve heard and learned all kinds of quirks of regional dialect and colloquial sayings. I’m quite sure that I’ve even picked up a few myself. Oh well. One particular expression shared with me by a former training partner in the gym was a compliment. She told me that I had good “home training.” That is a shorthand way of saying that my parents taught me to have good manner.
With that in mind, and in consideration of what we’ve been calling the first hot-fire test of J-2X development engine E10001 (i.e., the “burp test”), I respectfully and bashfully declare:
In the early evening of Thursday, 14 July, E10001 generated a burst of ignition and thrust with something like a 30,000 pounds of force — enough to toss five or six crew-cab pickup trucks into the air. That’s one heck of a burp. Yep, we were successful. NASA Stennis Space Center in Mississippi, coordinating with the Upper Stage Engine office at the NASA Marshall Space Flight Center and with Pratt & Whitney Rocketdyne in Los Angeles, California conducted a full-duration, 1.9-second test. Here is a picture of what a burp that big looks like:
Here are a couple of pictures of the engine prior to the test. These are taken from a deck inside the test stand basically looking down on the engine. The nozzle extends through the deck to the next level below.
You’ll note that there’s some misty fog hanging around the engine in those pictures. While it is true that most of the time you can almost see the thickly humid air of southern Mississippi in July, this is something different. This fog is being created by the presence of cryogenic propellants in the lines. These lines are so cold that they effectively condense water in the air around them, even at a distance, to create a fog. Here are some close-up frosty pics of lines chilled down prior to test:
Out of one end comes smoke and fire while the other end is frosty cold. This is a good illustration of the broad span of environments that exist within a rocket engine.
So, what’s next?
As exciting at this brief test was, what we didn’t do is light the gas generator and get the turbomachinery up to full speed. That’s the goal for the next test. In addition to spinning up the turbopumps with helium and lighting the propellants in the main chamber, as we did for the burp test, we’ll take the next step in the start sequence and light off the propellants in the gas generator. This will provide the turbopumps with the power necessary to reach mainstage, steady-state operation. And that — those initial few seconds of mainstage — will be our first glimpse at genuine engine operation like that which will propel spacecrafts into orbit and then outwards across our solar system.