Shuttle Columbia STS-107 Message Board

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Pastimes : Shuttle Columbia STS-107

Public Reply Prvt Reply Mark as Last Read File

Previous 10 Next 10 Previous Next

To: Bill Jackson who wrote (535)	2/14/2003 7:15:33 PM
From: ownstock	Read Replies (1) of 627

Bill: A volume of hot gas will be a so-called "black body" emitter, with spectral lines, just as I said. I should have added that at re-entry temperatures, there will be molecular lines (these are mostly IR lines) too. The atomic lines comes from atomic Oxygen and Nitrogen atoms. The main molecular constituents of the air are actually split into individual atoms for a few milliseconds (until they cool). These lines show up as absorption lines in some cases, and emission lines in others. Our Sun is a good example of a hot gas black body emitter, but is of course much hotter (and bigger of course) and therefore appears Yellow. The spectrum appears continuous on a simple toy prism, but upon closer examination, it has dips and peaks in it which correspond to various transitions from various elements. I would guess that most of the military assets would probably be targeting orbiting vehicles, or air breathers, not re-entry vehicles, so they are not optimized for the much higher temperatures. They would be optimized for the wrong part of the spectrum. Which is a big shame, because the imaging sensor technology that could do the job has been around for several decades. -Own

Report TOU Violation

Share This Post

Public Reply Prvt Reply Mark as Last Read File

Previous 10 Next 10 Previous Next