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astro_pettit OP t1_j3enwpx wrote

My first orbital star trail; taken during Expedition 6 in early 2003. I took this before we had low noise, nighttime-sensitive digital cameras. This photo was taken with a Nikon F5, 58mm noct-Nikkor f1.2 lens with Fujichrome ISO 800 film and a 65 second exposure. All the detail seen in my later digital star trails can be seen; atmospheric airglow appearing as a green key lime pie layer, the fainter upper atmospheric red f-region, cities streaking by from orbital motion, lightning storms flashing as a function of time, and star trails. The blips in the star trail arcs were caused by the ISS attitude shifting around due to a down mode failure of our control moment gyros. For high speed film, it would become fogged by cosmic rays after about a month and was typically flown only on short two week Space Shuttle missions.

I got special permission to fly this film, launching with us on STS 113 in November 2002 and was supposed to return on STS 114 in February. Due to the STS 107 Columbia disaster, STS 114 was delayed for 2½ years. I returned about 70 rolls of film on our Soyuz TMA-1 in May 2003. Working with the photochemistry engineers at NASA JSC, we developed one roll at a time to find the best development process that minimized the effects of cosmic ray damage. This photo is the result from that effort.

More star trails from space can be found on my Instagram and Twitter accounts.

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OptimusSublime t1_j3erkuy wrote

What was the reason behind the special permission for the film? Did it count towards your personal belongings weight allowance? Or was it something else?

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astro_pettit OP t1_j3orfks wrote

ISO 800 film was not flown to ISS for long duration missions due to cosmic ray fogging (remember, this was only the 6th mission to station). I asked the photo folks and they happily flew some for me.

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ajamesmccarthy t1_j3eqlpf wrote

Great shot! Was it tricky to stabilize the camera in the ISS? Curious if you had a good way to secure it against a window to minimize reflections and keep it from floating away!

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-DementedAvenger- t1_j3euk9j wrote

Probably just holding it against the window. I’ve done it before at home, and I don’t think the ISS vibrates much (could be wrong).

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ajamesmccarthy t1_j3evihf wrote

For 65 seconds it’s pretty hard to not move the camera, even when pressed against something. Seems like there would be an easy solution, just curious what it is

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Jakebsorensen t1_j3fa4dr wrote

Maybe taping it to the window? There’s no gravity, so it wouldn’t take much

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danielravennest t1_j3i5jj2 wrote

That would leave a tape residue. Bungies are probably the easiest method. Most good cameras have a tripod mount. So you can bring up a mounting adapter that can grab onto a hand-hold or other available hard point.

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astro_pettit OP t1_j3oqli4 wrote

We have Bogan arms that can clamp on fixtures near the window and steadily hold the camera in position

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tsokiyZan t1_j3fajq9 wrote

how on earth is this post not top of all time?

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Voodoo_Masta t1_j3f04zr wrote

This is amazing, thank you for sharing! Love the story behind the little blip in the star trails... that actually makes the photo more interesting IMO!

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astro_pettit OP t1_j3orvlv wrote

Normally there are 4 control moment gyros to hold station attitude, there was a failure so we were down to three and the control algorithm for this down mode was still being tweaked so some blips were expected

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TheSpaceExplorer1 t1_j3os8zh wrote

That is an absolutely incredible picture! Do you have any plans to fly in space again?

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PandaGoggles t1_j3g45zq wrote

This is absolutely the coolest thing. What an interesting description. We’re the first few rolls developed usable, and what effect do the cosmic rays have, like do they increase noise?

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astro_pettit OP t1_j3oqxu5 wrote

The nasa photo chemistry person would develop one roll, check it for cosmic ray fogging/low contrast, change the chemistry, and do another. It took perhaps 8 rolls to get it down

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PandaGoggles t1_j3os6ex wrote

That’s really cool. I bet the photo chem person enjoyed the challenge. When traveling with film I store it in a little shielded box. Usually TSA will check it by hand for me, but sometimes they’re really weird about it. Did you store your rolls in some sort of shielded box as well?

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MyBrightStar t1_j3haog2 wrote

Hello again mr.Pettit ! Always a pleasure to look at your art.

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PatReady t1_j3exu54 wrote

Could you fly a drone type of device in space from The ISS and get a video like this today?

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Zymoria t1_j3evat3 wrote

I'm sitting here going "Now how does one get a camera up that high and stabilized long enough for that exposure."

Then I'm like "NASA astronaut... that would do it."

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fquizon t1_j3hu4jl wrote

I thought this was in /r/photography at first and I was like, this is just mean

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FastWalkingShortGuy t1_j3eux8r wrote

It's hurting my brain seeing that thunderstorm lightning trail going a different direction than the star trails, and trying to think about how the space station is moving one direction while the earth rotates another direction.

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Scholesie09 t1_j3ge92n wrote

It's not really to do with the rotation of the earth, the iss is moving across the face of the earth which moves the thunderstorm straight left, but it's also rotating as it orbits to keep the same side facing earth, so relative to the background stars it is rotating, getting the curved trails.

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I-am-the-stigg t1_j3f8jfz wrote

I think what is the craziest thing about this picture is the fact that it was taken by 1 of about 10 (maybe less) possible people on reddit of the hundreds of millions of users that can have this type of experience. That's the cool part for me.

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TheVastReaches t1_j3er8im wrote

I can see the refraction in the trails, bending as they approach the horizon. That’s awesome. What an opportunity !

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astro_pettit OP t1_j3osddz wrote

Yes! The star arc slope changes as the star light passes through more dense atmos layers; i can talk about the visible natural phenomenology in a star trail photo for at least 30 minutes.

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[deleted] t1_j3fng65 wrote

You are coolest guy I have ever seen on reddit, bar none.

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Highspdfailure t1_j3etsh9 wrote

Follow his Instagram. These photos need to be seen by all.

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davtheminer t1_j3ev1na wrote

What do you do now? If you don't mind me asking. Curious as I'm guessing you aren't still doing space flights

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okhan3 t1_j3etsa5 wrote

This is cool as hell. Want to share to r/AnalogCommunity ?

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Hector_Savage_ t1_j3gy7cg wrote

Oh s**t! Don Pettit himself is here on this sub! Didn’t know that. I watched many videos where you were interviewed, sir, you are a legend! And beautiful picture

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Atheios569 t1_j3exeti wrote

It looks amazing! Does the ISS shake from time to time? I noticed there may have been a bump during the exposure. If so that’s fascinating as I never would have imagined the ISS shaking.

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CoolAndyNeat t1_j3go369 wrote

It’s amazing how that much movement happened in only 65 seconds. Awesome photo!

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lith1x t1_j3fo394 wrote

What causes the star trails? Is it the rotation of the ISS..?

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whiskysinger t1_j3fzhrd wrote

Yes - it is exactly the same mechanism as the star trails taken from Earth's surface. Except the ISS is orbiting much quicker than the Earth is rotating. This is why the trails in this photo are so long for such a short exposure*.

Interestingly, the celestial pole is different on the iss than what we are used to on earth (Polaris in the northern hemisphere) because the orbital axis is not the same as Earth's axis of rotation, as demonstrated in the gif below.

https://gfycat.com/meagerscientificbengaltiger

*The ISS takes 90 minutes to orbit the earth. This means it is completing one trip around its orbital axis 16 times per earth day. The photo took 65 seconds of exposure. To capture star trails of this length on earth would take 16 x 65 seconds = 1040 seconds = 17m20s of exposure. (I think! Please correct me if I'm wrong)

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astro_pettit OP t1_j3osr8p wrote

Thanks for taking the time to answer; the physics behind the motion is different than what an Earth centric star trail would make you think.

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MD_Tarnished t1_j3g5fp9 wrote

How many astronauts are in space now? Seems like we can see space pictures quite often

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zeeblecroid t1_j3i433q wrote

Currently ten: seven on the ISS and three on Tiangong.

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MD_Tarnished t1_j3l336c wrote

Must be an insane accomplishment to go to space, considering the population on earth and only 10 people are there.. It's also pretty sad to think about our life span is not long enough to see the world progress

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FriedFreya t1_j3gx2mg wrote

This photo is so beautiful, I am literally teary typing this. Thank you so much for sharing.

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0-KrAnTZ-0 t1_j3fymxa wrote

Deconvolute the psf from the white line and you'll get a sharp image

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