A Day in the Life of a Hot Fire, Part Three: Bunker and Test Stand

On Tuesday we told you about preparing to roll out for a hot fire. Wednesday was the journey to the test stand.

Today, what happens when we arrive …

Once we are at the test site, there is a flurry of activity. We attach the truss and fuselage to the test stand, a concrete slab rated for up to 80,000 lbf of thrust. It is a monster of a concrete pad, and contains various types of mounting brackets that can be used for a range of engine test stands.

Next to the test stand is our bunker. It is an old WWII ammunition storage bunker built by the US Navy Seabees for the Marine Corps, right around 1942. It is capable of withstanding the explosive energy of 435,000 pounds of TNT.


Shot atop the XCOR bunker, this photo shows the test stand in the foreground, and a bunker similar to ours in the background.

The bunker has very thick concrete walls and is covered by yards of earth. As a result it is cool in the summer and warm in the winter, with six inch-thick steel doors. It would make one heck of a man cave!


The interior of the XCOR bunker

We purposefully do not trick it out, because our philosophy is to have one culture at XCOR, not to have different mini-cultures grow up inside the company such as “the guys in the test bunker” or “those test stand fabricators” or “the composite team”. Everyone is one big team, and we all enjoy the simplicity of a day in the bunker!

As all of our test equipment is portable, very little remains out at the test bunker. When we arrive, the test stand is bolted to the test pad, cables are unreeled from the pad to the bunker, cameras are set up, and computer gear is electrically connected. Once everything is in position, gas and fluid cables for pressurization and valve control are attached and the “control room” inside the bunker goes live. The whole team is ready to ”get on checklist”.


XCOR senior shop mechanic Mike Laughlin checks a high-pressure hose fitting in preparation for a hotfire test.

Tomorrow we will show you the roles and responsibilities for the test, and you can decide what role you want to play!