What happened here?

marsmark

Last week, I had the pleasure of witnessing the launch of the Mars Reconnaissance Orbiter at the Kennedy Space Center (I helped develop the spacecraft). Of course, I took my camera gear! I used my Canon 20D with a Sigma 70-200 EX APO lens and the Sigma 2x teleconverter. We were viewing from the causeway between the NASA and Air Force sides of the complex, and were approx. 3.5-4 miles from the launch pad. Launch was at 7:45 am, so with the lens wide open (f5.6 with the teleconverter), I was at 1/2500 sec at ISO 400. I shot the below photo about halfway through the ascent, so the rocket was probably ~5 miles or more away. Notice the "ghost" image of the rocket - any thoughts as to what that might be? I originally thought it must have been out of focus, but I would have expected a blur evenly around the object. Could it be reflections off inner surfaces of the glass? The launch was to the East, above the low sun. I had a B+W UV filter on the lens, but also a sunshade...



Any thoughts?

Several images turned out this way, and they were all similar times and locations in the sky. Images from liftoff to shortly afterwards don't exhibit this.

Thanks!

-Mark

gus

Welcome to D/grin mark. I would have maybe shot it at ISO 200 ..shutter would have still handled it (then again i have never photographed a rocket !)

Heres my take on what you are seeing...'trans-sonic vapor'

The mist you can see is formed because the airflow over the rocket creates a lower pressure that the surrounding air. When the airpressure falls, so does the temperature, and the air cannot contain as much moisture as else. The water in the air forms a small 'cloud' over the rocket, only to dissapear once the air has passed over it. You only see this phenomenon when the air temp is almost the same as the dewpoint

Gus

gus

on 2nd thoughts i think im wrong & its a ghost image that will take the combined power of every Dr Who that existed in time to explain or wait for ian to chime in.

gubbs

Looks like camera shake

400mm at 1/2500 should be ok though, shouldn't it??

later thought::D

Wouldn't the 4-5 mile distance amplify any shake??

pathfinder

Warm, moist turblent air - creates multiple refractive indices for air -

I tried shooting the moon last night for ya 'gus, with a lovely L prime tele - it looked terrible - same reason - very, and I mean very, high humidity. I didn't even process them - I put'em in the circular file

marsmark

gubbs wrote:

Looks like camera shake

400mm at 1/2500 should be ok though, shouldn't it??

later thought::D

Wouldn't the 4-5 mile distance amplify any shake??

I wondered about this. I had a tripod for the initial liftoff shots (which look pretty good), but at some point I took the camera off and handheld for a few shots as it was getting hard to track with my alt/az pan head (plus it was getting pretty high in the sky). I'm not sure if this is one of those shots or not, but I hoped 1/2500 would still be fast enough... The whole thing was over in a couple minutes, so it's a bit tricky to remember what I did when and on what shot!

BTW, the liftoff shots are still a bit blurry, but I think that has more to do with the distance and humid atmosphere...
http://mandncolorado.smugmug.com/photos/32452976-O.jpg

-Mark

gus

pathfinder wrote:

Warm, moist turblent air - creates multiple refractive indices for air -

I tried shooting the moon last night for ya 'gus, with a lovely L prime tele - it looked terrible - same reason - very, and I mean very, high humidity. I didn't even process them - I put'em in the circular file

I got last nights for you here mate.

Yeah our winters whilst warm are low humidity. I will have to try it in summer as we see often see days over 90% humidity.

DJ-S1

marsmark wrote:

Last week, I had the pleasure of witnessing the launch of the Mars Reconnaissance Orbiter at the Kennedy Space Center (I helped develop the spacecraft).-Mark

You can't just drop a line like that and not explain! I'm not the only space enthusiast here, so what's the scoop? What was your area, and what was it like to see your work for the last few years finally go? Are you going to stay involved through the data collection phase, or are you moving on to a new challenge?

Back OT, I would chalk it up to humid Florida skies myself.

marsmark

DJ-S1 wrote:

You can't just drop a line like that and not explain! I'm not the only space enthusiast here, so what's the scoop? What was your area, and what was it like to see your work for the last few years finally go? Are you going to stay involved through the data collection phase, or are you moving on to a new challenge?

Heh heh... I never know how interested my audience will be so I usually ease into it!

I work for Lockheed Martin in Denver. We built the spacecraft for NASA (JPL), who manage the program. We also operate it from our own facility here. This is the first program that I have worked from proposal all the way to launch and operations, so I was pretty bent on getting down to see it go (it's actually my first launch of any kind, even though I've worked on several programs over the last 10 yrs).

My area of expertise is orbital mechanics and trajectory simulation - I will be heavily involved in the aerobraking phase of the mission, where we skim the upper atmosphere several hundred times in order to shrink the orbit into something where we can do useful science... I'll be involved with this one for the next year, but am already part time on the next Mars mission - the Phoenix lander.

Anyway, I had forgotten how much humidity and haze there is out east and down south - I'm spoiled living in Denver! The prior day's launch attempt was much hazier - maybe it was best it was scrubbed that day. I certainly didn't expect that much loss of sharpness (although I just got the teleconverter for this event - I don't normally shoot objects 4-5 miles away!).

-Mark

DJ-S1

I bet Mark must be busy preparing for this. Good luck guys!