Colored Gas Clouds on Shuttle Ascent

[n221ua]

While watching the fantastic shuttle launch tonight, I was wondering what the gas-like cloud surrounding the space shuttle as it make its ascent? Is it plasma or something else?<br /><br />I hope I didn't post at the wrong forum but if I do please correct me <img src="/images/icons/smile.gif" />

 

[MeteorWayne]

Welcome to Space.com!<br /><br />How long after launch were you talking about?<br />Was it during the first 2 1/2 minutes when the Solid Rocket Boosters were burning?<br />Finally, were you asking about a video image, or something you watched from (how far) away?<br /><br />It might be a better question for Missions and Launches, but here is fine. It's a tossup. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[n221ua]

It was at the external tank separation...here's an image describing what I was referring to: <br /><br />http://img.photobucket.com/albums/v601/N221UA/116_65.jpg

 

[n221ua]

Actually I found a few more here, looks very amazing to a space dummy like me <img src="/images/icons/tongue.gif" /><br /><br />http://img.photobucket.com/albums/v601/N221UA/get-attachment-thumbnail-1.jpg<br /><br />http://img.photobucket.com/albums/v601/N221UA/get-attachment-thumbnail.jpg<br /><br />

 

[qso1]

It looks like it might be the glow phenomenon observed on other shuttle flights under certain conditions. The phenomenon is thought to be related to atomic oxygen.<br /><br />But it could also be the SSME plume expanding, as it does when it encounters less atmospheric resistance. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[qso1]

I left room for some doubt in my answer as to atomic oxygen being a possible cause. It just appeared with the coloration to me to be AO because of images of that phenomenon from previous shuttle missions. What I'm not certain of is whether AO is present at ET sep altitude.<br /><br />More than likely, if this was a night shot...there won't be a readily available answer until NASA scientists can evaluate the footage to determine with as much certainty as possible what the nature of the effect is.<br /><br />Unless the vid was shot during ET separation. I don't think the shuttle maneuvers with ACS at all when attached to the orbiter in a nominal ascent. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[mikeemmert]

I've seen other (daylight) shots of the shuttle separating from the ET. The best shots seem to be when the shuttle and the tank form a little less than a 90 degree angle; these pretty plainly show that the phenomenon is caused by the ship hitting the thin air at 8 kilometers per second. There have also been shots of a thin fireball forming from what must be the shuttle's nose at certain speeds.<br /><br />Scientific American had a print article about that a few years ago (pre-internet). Try googling "shuttle glow". It was explained that the glow is a result of oxygen and nitrogen atoms in the plasma resulting from the Shuttle impacting air at very high speed recombining to form various molecular gases. It has been observed many years at the much higher altitude of orbit.<br /><br />It is generally the same type of phenomenon as a neon or flourescent light. The process is quite efficient so it takes very little air to get a good glow. Neon and flourescent lights are a near vacuum inside the bulb.<br /><br />It's also the same phenomenon that forms the glow of a meteor; meteors generally become visible at about the same altitude. Most visible meteors are about the size of a pinhead but are moving far faster than the Space Shuttle.<br /><br />This phenomenon makes it quite hard to design hypersonic airbreathing boosters. There are several molecules involved, ionized and neutral atomic nitrogen and oxygen, nitric oxide, nitrogen dioxide, possibly nitrous oxide and nitrogen dioxide, and various states of excitement. Density is an important factor; the closer these molecules and ions are together, the faster they recombine. The light carries away energy, which cools the gas, obviously temperature is important too.<br /><br />I would think that actually watching this phenomenon in action on a working spaceship would be easily important enough to install a spectrograph to analyze the light under the various conditions of flight. This could verify models (although an airbr

 

[mikeemmert]

What is the altitude of the shuttle a minute or two before MECO? At MECO? Unfortunately I can't remember the exact mission number, but the altitude is consistent with the glowing gas that this thread is about.<blockquote><font class="small">In reply to:</font><hr /><p>As I recall the atomic oxygen glow is observed around 150 miles and above up to and beyond 250 miles.<p><hr /></p></p></blockquote>Are you refering to the flourescence of the atomsphere from solar ultraviolet radiation, which is a constant natural feature and is not manmade? The glow this thread is about is observed from the shuttle's tank camera, the one installed to watch for foam coming off.

 

[MeteorWayne]

Anyone know of a graphic showing the altitude vs time for an ISS launch of the shuttle? That MECO height is about 65 miles at about +8:23. So on the timeline, when does the shuttle shift from gaining altitude to gaining velocity horizontally? I know it's a smooth transition, but when does the effort shift to gaining speed?<br /><br />I'm asking since from my location I only see the shuttle after +6:00. At that point is it pretty much just travelling nearly horizontal? <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

I figured it would not be totally perpendicular. But still, the vector at that point is still aimed more at gaining speed rather than altitude. I assume that the path is designed to get above the sensible atmosphere, then tilt over more toward horizontal to use the thrust to add velocity. That's why I'd love to see a graph of the vertical and horizontal data. It's on a numerical display during the first few minutes of launch on cable outlets, but I've never seen anything on NASA TV. I assume that the commercial TV displays are based on nominal info, not real time data from the launch in progress. <br /><br />Besides, a well designed graph can display much more information.<br /><br />A graph is worth a thousand pictures, a picture is worth a thousand words, therefore a graph is worth a million words <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>