Through my GSRP fellowship, I'm classified as a Marshall Space Flight Center intern this summer, and because of this, I was invited to attend an all-day tour of MSFC on Wednesday. Our group consisted of 24 summer students, about a quarter of which were female.

Out first stop was the Payload Operations Center, which handles all the science payloads for the International Space Station and the Space Shuttle. We were first taken to see the HUNCH training mock-up of the ISS Destiny module. We spent quite bit of time in there playing around. Afterwards, we were taken to see the ISS Payload Operations Integration Center control room. Unfortunately, we were there during one of the regular signal outages, so we didn't see much activity. Our guide explained that once the ISS is completed and the crew is enlarged, more science will be done on the Station.

Next we visited the Flat Floor facility, the flattest floor of its size in the world. We watched an automated rendezvous and docking robot demonstration. The feet of the robot push air down onto the floor, which lifts the structure enough such that there is almost no friction when the robot moves, simulating the frictionless movement in space. We then took turns sitting on a similar bench-like air-lifted structure and being pushed around the floor. It reminded me of bumper cars.

Our next stop was a high bay which contained several very large thermal vacuum chambers. MythBusters recently filmed three episodes there, including two about the Apollo Moon landings, which will be aired starting August 27.

The next stop was a new facility I hadn't seen before, the location of two large welding tools, still under construction. One of them is the largest friction stir welding tool in the world. The machinists there explained to us how stir welding works, which is a pretty neat technique.

Next we drove around to the various rocket test stands. We explored a historic area where an old Saturn I rocket stage and a "mothballed" Saturn I test stand are rusting. It's a shame they're just letting a historic area go to ruins. We were taken to a building where we descended into tunnels that lead to all the test stands. During the Cold War, those tunnels were also designated a nuclear fall-out shelter. Back upstairs, we watched some videos of test firings and wished we could return the following morning to view a firing of a large engine. On the way out, we passed by the Saturn V test stand, but we weren't allowed to climb it because it's undergoing refurbishments for future Ares rocket tests.

We visited another facility where they are manufacturing something, but they didn't clearly explain what. They had a to-scale Ares I rocket stage mock-up made from wood and plastic that we could climb into, but they didn't really explain if it served a purpose other than a tree house for visitors.

The next facility we toured was the National Center for Advanced Manufacturing, where we watched CAD simulations depicting manufacturing of Ares, including the use of the large stir welding tool we had seen earlier. The benefit of modeling the manufacturing process before constructing is to discover and prevent collisions. We then saw examples of small structures made by the very cool rapid prototyping technique, which builds using dust and lasers, layer by layer. In the Advanced Materials for Radiation Shielding lab, we saw products made from carbon fiber materials.

We then toured another lab I hadn't seen before, the Electromagnetic Interference (EMI) Test Facility. We were taken to a large room padded with foam cones which absorb microwaves. When sealed, the room acts as a Faraday cage, in which emissions from electronics can be better recorded and tested. We were shown a simple but effective demonstration using a toy remote-controlled car in a large lobster pot and a number of different kinds of lids to show what creates or disrupts a Faraday cage.

Finally, we toured what used to be called the Propulsion Research Center, but now has a new name which I've forgotten. We were shown a plasma gun which shoots tiny metal or nylon balls to simulate micrometeorite impacts in space or rain impacts on high-speed aircraft or missiles. We were taken to a lab with a copper floor where I unexpectedly ran into a friend who works there. The man giving us the tour didn't effectively explain what his lab does, but he did provide us little hand-held spectrometers through which to view a fluorescent ceiling light. The naked bulb, which emits mostly in the near infrared, showed clear mercury emission lines, while the part of the bulb with the phosphorescent cover emits "white" light in the visible range. Fluorescent lights wouldn't be nearly as effective as ceiling lights if it wasn't for the useful luminescence process of fluorescence. For a physicist like me, it was a wonderful little demonstration of everyday physics.

We wrapped up the day of tours by climbing into a large vacuum chamber where they do non-nuclear testing of fission surface power technologies. There I was told that it was highly impressive that I could walk over grates and climb structures with ease in high heels. I was also told that I asked the most questions out of everyone there, which I hadn't realized until they mentioned it, but they're probably right. I'm a very curious person, I enjoy learning, and I'm not intimidated by science or technology, so why not ask? It shows the tour guides that they're spending their time teaching to visitors who are actually interested. It was a great day, and I'm glad I got the opportunity to tour a highly productive NASA Center again.