Today: Watch astronauts space walk outside the ISS

Not sure if this has been posted yet. Today members of the ISS will work outside on the space lab, to prepare for a Russian Module.

Tuesday's spacewalk is the first of two that Expedition 36 crewmembers Cassidy and Parmitano will make together this month, with the second coming on July 16. Both excursions will help prepare the $100 billion orbiting laboratory for a new Russian module and address a variety of maintenance and repair needs, officials said.

During Tuesday's spacewalk, for example, Cassidy will route power cables to support Russia's Multipurpose Laboratory Module, which is scheduled to arrive at the station at the end of this year. The MLM, dubbed "Nauka," will be used as a research facility, docking port and staging ground for Russian spacewalks, NASA officials said.

here is the link to the LIVE FEED for those who are interested in watching.
Not the most exciting thing to watch for some I know - but its mankind working outside in SPACE, dont get to see that often.

Enjoy, its only on for 6 hours or so
Link (fox news)

posted already

Not the most exciting thing to watch for some I know - but its mankind working outside in SPACE, dont get to see that often.

In all the years of EVAs from the shuttle or the ISS, has anyone ever heard an astronaut talk about seeing the stars?

Originally posted by GaryN

Not the most exciting thing to watch for some I know - but its mankind working outside in SPACE, dont get to see that often.

In all the years of EVAs from the shuttle or the ISS, has anyone ever heard an astronaut talk about seeing the stars?

I've spoken with astronauts and heard them recount their amazing views of the stars. I didn't ask about spacewalks specifically, they're just a little bit busy during EVA, but as Barbara Morgan recounted to me, the entire sky was like a giant canvas filled with stars as seen from the flight deck of the shuttle when the lights were shut off when on the night side of earth.

*Oh and I know where you'll probably go with this, so let me stop you right there; while docked to ISS on her STS-118 mission, the shuttle's flight deck windows were facing up and away from earth.
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reply to post by GaryN


During one spacewalk, while they were on the night side of earth, the external ISS lights were turned off and the astronaut (can't remember which, sorry) reported seeing Jupiter and its moons. I assume he also saw stars, because Jupiter's moons have approx the same magnitude.

Space tourist Anousheh Ansari reported seeing stars like "diamond dust scattered over black velvet". spaceblog.xprize.org...

The main issue with seeing stars in space (or anywhere else, for that matter) is that stars are very dim. If you're in a brightly lit spaceship, or look at the sunlit Earth or Moon, your eyes wouldn't be able to adjust to the level required to see stars. That's why you read astronauts reporting that they saw no stars.

Originally posted by GaryN
In all the years of EVAs from the shuttle or the ISS, has anyone ever heard an astronaut talk about seeing the stars?

Yes, live during a spacewalk. I'll get to the details in a minute.

First, we'll have to confront the tragic truth:

Stars, when viewed in space, are not much brighter than when they are viewed from Earth.

Intuition tells us they should be, because above the atmosphere there's nothing to absorb or scatter the light. As is so often the case, intuition is wrong for the simple reason that our atmosphere really doesn't block much light.

You don't have to take my word for it, or NASA's or some guy on TV. You can verify it for yourself with no special equipment other than your own two eyes. Actually, you can use just one eye. Oh, and you don't have to be launched into space, either (I know - Dang!). Heck, you can even do it in the daytime.

When you look straight-up, you are looking through 'one thickness' of the Earth's atmosphere.
When you look up at a slant, you are looking through more than 'one thickness' of the Earth's atmosphere.
Obviously, it follows that the closer you look to the horizon, the more atmosphere you are looking through.
With a little trig, you can calculate that roughly 30 degrees above the horizon (~1/3rd of the way from the horizon to the zenith), you are looking through two-times the vertical thickness of the atmosphere. At ~20 degrees above the horizon, you are looking through three-times the vertical thickness of the atmosphere. At ~15 degrees, it's four-times.

Here is the important thing: The difference between looking through two atmospheric thicknesses and only looking through one thickness (or the difference between two & three thicknesses, or three & four) is the same as the difference between looking through one thickness (straight-up) and looking through no air at all (i.e. being in space).

Thus, the change in brightness of an object (the moon, the sun, another star) as it rises & sets tells us how much light the atmosphere absorbs, and therefore how much brighter the stars.

Suppose we say, "The stars in space must be 10 times brighter than here on Earth!"
That would mean that only 10% of the light reaches the Earth's surface through one thickness of the atmosphere, and each additional thickness we look through would reduce the light by another 10 times.
This is testable using our eyes: If one thickness of atmosphere reduces the light by 10 times, then the sun, moon & stars will be only 1/10th as bright when they are 30 degrees up as compared to when their straight overhead. When they sink to 20 degrees, they will only be 1/100th as bright. At 15 degrees, only 1/1000th as bright. Clearly this is not the case.

Suppose we say, "Maybe the stars are twice as bright in space, compared to here on Earth."
In that case, the sun, moon & stars will be half as bright when they are 30 degrees up as compared to when they're straight overhead, 1/4th at 20 degrees, and 1/8th at 15 degrees. This is closer to reality, but clearly the absorption is significantly less than 50%.

That's just using your eyes. If you like, I can tell you how to test it further with cameras (video & still).

The real stumbling block for astronauts seeing stars is the same one for the rest of us poor schmucks here on Earth: How well dark adapted are their eyes?

When I walk my dog at night, I'm stepping out of a well-lit room and don't see many stars. The longer I stay out the better-adapted my eyes get and the more I can see - but only to a point, because even if I'm not looking up at streetlights, I'm looking down onto a sidewalk that's lit by streetlights. If I want to get truly dark-adapted then I have to go to nearby park and not look at any lights for several minutes. Then the sky turns beautiful.

This brings me to the answer to your question. Normally, astronauts work in well-lit cabins or, if they're on EVA then they are in the sun or using work-lights, both of which totally kill their dark-vision. Normally they don't have time to look away from their work for the many minutes it takes to dark-adapt. An inadvertent exception happened on STS-61; the first Hubble repair mission. On EVA 2 they had to replace a bad solar panel. To jettison it, Kathryn Thorton stood out at the end of the robot arm with her back to the lighted Shuttle bay, and held the 5m panel with the dark solar cells facing her. This was on the Earth's night side. They waited 12 minutes for their orbit to bring them around to the day-side so the pilot could see the panel to maneuver away from it. When Thorton let go of the panel and the Shuttle backed away, her dark-adapted eyes suddenly had the whole universe before them. Surprised, she exclaimed loudly at the beauty of the stars.

reply to post by Saint Exupery

The main issue with seeing stars in space (or anywhere else, for that matter) is that stars are very dim. If you're in a brightly lit spaceship, or look at the sunlit Earth or Moon, your eyes wouldn't be able to adjust to the level required to see stars.

This is nonsense, and you can easily prove it yourself. I can look at my outside porch light, a compact fluorescent that actually hurts my eyes to look at for too long, and immediately look up and see stars. Yes, I can see more of them if I look for a while, I'm not saying dark adaptation doesn't exit, but there are many stars visible even if I have all my outside lights on.
Depending on viewing angles and geometry, it is quite possible that astronauts will still be looking through some of Earths atmosphere, and be able to see stars. Once outside of all atmosphere, in cislunar space say, can you see stars? Not according to Armstrong.
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One other thing that puzzles me is why NASA makes no mention of augmented or synthetic vision in space. If night vision binoculars can video the stars in real time, surely there must be some use for night vision devices in space, but no mention is made of them. Do they work in space? Nobody knows, it seems.