"We went to the Moon as technicians; we returned as humanitarians." --Edgar Mitchell

"We came all this way to explore the moon, and the most important thing is that we discovered the earth." --William Anders

Tuesday, February 5, 2013


This week, I went into the Mitchell Library on campus and walked around the Current Publications section. The article I chose was from the AIAA's Journal of Spacecraft and Rockets, which means that it's a bit more technical than the last article I chose. It was definitely more brutal. First paragraph, and I learn a new word: rovibronic. I'm still not entirely certain what that means.

The article that I chose was "Absolute Radiation Measurement in Venus and Mars Entry Condition" by Brett A. Cruden, Dinesh Praghu, and Ramon Martinez. It can be found in the November-December 2012 issue of the Journal of Spacecraft and Rockets (Volume 49, Number 6). Picking this article might have been a mistake. From what I understand, because the composition of different planetary atmospheres is different, this results in different levels of radiative heating. Previously, it was mostly convective heating that was mostly predicted, but the size and speed of the entering body (....) can make this less accurate.

Now, I've taken optics and chemistry, and I understand that different chemicals and elements emit different spectral lines. I understand that as you heat things up, they emit blackbody radiation. Basically, we're all glowing due to our heat. This paper explored how the velocity and pressure caused the different elements and chemicals in the atmosphere to glow. Essentially, as the body moves at different speeds through the atmosphere, it "triggers" different elements to emit radiation that can be detected through these spectral lines. This is in addition to the blackbody radiation that occurs from the heating up of the gasses. I think.

Part of what this paper was trying to establish, however, was whether the software that they had been working on (at NASA Ames) would be an effective model/tool for predicting the radiance that would happen from planetary entry. The authors decided that not only did this software need work, but that the experimental methods needed to be refined. This part was the take-home lesson for me. Even though these guys are spending their entire work week doing research and working with million-dollar pieces of equipment, at the end of the day they still produce an article that explains how they can be better. It might be good to keep that in mind.