Backyard Skywatchers Find Tool Bag Lost in Space

Amateur astronomers have been monitoring a shiny tool bag that has been orbiting Earth ever since it was dropped last week by an astronaut during a spacewalk outside the International Space Station.

The bag is reportedly about magnitude 6.4, which under most sky conditions is too faint to see with the naked eye.

Veteran spacewalker and Endeavor astronaut Heide Stefanyshyn-Piper lost her grip on the backpack-sized bag on Nov. 18 while cleaning up a mess from a leaking grease gun she was carrying to help mop up metal grit from inside a massive gear that turns the space station's starboard solar wings.

The tool bag cost $100,000 and its loss meant astronauts had to share the remaining tool bag for subsequent spacewalks. The tool bag weighs about 30 pounds (14 kg) and is 20 inches (51 cm) wide, about a foot (30 cm) tall and a hand's-width deep, according to John Ray, STS-126 lead spacewalk officer for the flight. The bag contained two grease guns, a scraper tool, a large trash bag and a small debris bag.

After sunset on Nov. 22, Edward Light, using 10 x 50 binoculars, spotted the bag in space while he scanned the sky from his backyard in Lakewood, N.J., Spaceweather.com reported. On the same night, Keven Fetter of Brockville, Ontario, video-recorded the bag as it passed by the star Eta Pisces in the constellation Pisces.

The tool bag can be seen through binoculars, a few minutes ahead of the space station's orbit. The satellite tracker predicts that the bag will be visible through binoculars from Europe and western North America during a series of passes this week. By late next week, the tool bag should appear in the evening skies over most of North America.

Like other space debris, the tool bag's show will have a fiery end. "We currently predict that the errant tool bag will fall back to Earth in June of next year," said Nicholas Johnson, chief scientist for orbital debris at NASA's Johnson Space Center in Houston. "The date is dependent upon solar activity, so an earlier or later date is possible. As the reentry date draws nearer, a more accurate prediction can be made."

And he expects the entire tool bag will burn up upon reentry. "Although we have not yet conducted a detailed reentry survivability analysis for the tool bag and its contents, it is highly likely that no components will reach the surface of the Earth," Johnson told SPACE.com.

The tool bag is not the only piece of space trash from the station. Other junk includes an unmanned Russian cargo ship and a massive ammonia coolant tank the size of a refrigerator. The coolant tank was intentionally tossed from the space station in 2007, and it burned up in Earth's atmosphere earlier this month. The cargo ship undocked on Nov. 14, but will loiter in orbit for engineering tests before its planned disposal in Earth's atmosphere in early December.

An extravehicular activity (EVA) tool bag drifts away from the International Space Station during the mission's first scheduled spacewalk for STS-126.

You said — “There can be no “inertia” without force. The “bump”, which is not mentioned in the article, was apparently the “force” I inquired about. Thank you.”

It wouldn’t have to be a bump. The “force” was applied when their ship went into orbit. It had already been applied long before the bag was lost. And furthermore, as the astronaut was maneuvering into place to get to work, there was “force” applied — but that was force for the entire operation, itself — *including* the astronaut. So, it’s not *anything separate* from what the force was that was applied to the shuttle upon launching and/or the force that was applied to the astronaut to maneuver into position.

SO..., the “state of inertia” for the bag was applied (1) at the launch of the shuttle from land, and (2) at the launch of the astronaut outside the shuttle — but those were forces *applied to a large group of objects, all at once and *not* only to the bag, itself...

And so..., *no further force* would necessarily have to be applied — if simply — one were to “let go” (*without any applied force to the bag itself, but to the *entire astronaut* — only) — and then *without any additional force* being applied — the bag would float away....

So, you see — *no additional force* is needed for the bag to float away...

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Another simple way to see that *no force* need to be applied to the bag to lose it — is that the bag and astronaut are moving together — and all of a sudden you *apply force* to the astronaut to change direction or stop relative to the shuttle. BUT, you *do not apply force* to the bag — the result is the the bag floats away without having any additional force applied to it (while only force was applied to the astronaut — *alone*....

It’s *easy* to happen *without* any additional force being applied...

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Another simple explanation to let you see that *no force* (to the bag, itself) is necessary to lose the bag and have it float away from you. Here’s a potential scenario...

Astronaut and bag (and other gear) go outside the shuttle. Astronaut needs to move (i.e., float) over to another position about 30 feet away to work on some object. Astronaut, bag and other materials are all moving together, very gradually (and floating) over to the object, about thirty feet away. Something distracts the astronaut and hand is removed from holding the bag, while astronaut reaches for something else, and then, all of a sudden, astronaut notices he (she) is moving too fast and needs to slow down, so he does. But, astronaut has not grabbed a hold of the bag, again, which was moving at the same speed as the astronaut. But, the astronaut has now slowed down and the bag keeps moving at the same speed it was moving before (*no additional force applied*!!). Bag is lost in space...

Bag can be said to be “dropped” because as it is “in orbit” — it is *continuously dropping* towards the earth (which is what an “orbit” is...)...

EVENTUALLY, as the bag *continues falling* (as it was from the beginning), it will finally “get to earth” (finish it’s falling...).

Easy!!

MosesKnows said — “This statement puzzles me. What force would cause the tool bag to float away?”

And then you said — “I don’t understand that either. Why doesn’t that force push the tool bag towards the astronaut? Or go straight up or straight down? Why don’t they have a leash on everything? Was this really an accident? Why doesn’t it stay in orbit? Shouldn’t it take off into infinity? If the tool bag falls to Earth why doesn’t the space station, too? Was the tool bag looking for Joe the Plumber?”

Well, as I was saying before, there is a scenario where no force needed to be applied, if the bag was traveling along with the astronaut and the astronaut didn’t hold it when he (or she) stopped. There would need to be no additional force applied to it (in that kind of scenario) for it to “float away”....

BUT, that’s not what happened from the video that was referenced here in this thread.

Here’s what the video shows... The astronaut was wiping grease off her gloves and picking out other things in the bigger bag that she had (which had the other items in it. It appeared that she was anchored and that the bigger bag was anchored. And so, when she took out the tool bag, out of the bigger bag (to apparently get it out of the way from some other stuff in the bigger bag [you know..., like “unloading some items out of your luggage”], she set it over to the side and reached back into the bigger bag. However, she gave it enough motion to not be within reaching distance when she reached back for it. In other words, it “floated away” from her at about (roughly) 1 MPH (my guess, from the looks of it, considering “walk speed is about 3 MPH). That’s a speed relative to her position.

It doesn’t matter if the speed is 1/4 MPH or 1 MPH or 2 MPH, it’s all going to result in greater and greater distance from her in a short matter of time. It was just a couple of seconds and it was *already* out of her reach, and she couldn’t grab it.

So, in this particular example, it was the astronaut that gave the tool bag some “force” — in bringing it out of the bigger bag, but not stopping the motion of the tool bag when she let go of it. So, she gave it enough motion to be traveling at about 1 MPH away from her, and it was quickly out of her reach.

Of course, she probably thought she had stopped its motion (relative to her) enough to be able to grab it again and put it back into the bigger bag. However, it appears that she was frustrated because of the grease that had gotten all over things and was in the process of wiping off the excess grease that was all over the place and then gave it just a “tad too much” motion to be able to grab it again, before it got out of the range of her arm.

You can tell she was frustrated (with the grease, presumably) because she kind of “jerked” the tool bag out of there and let go of it. But, then she almost immediately realized the tool bag had too much speed (away from her) and she grabbed for it again. And she almost got the strap in her hands but missed it. She grabbed about three times, it appeared.

Her words as it was floating away was, “Oh Great!” ... LOL...

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Your question was — “Why doesn’t that force push the tool bag towards the astronaut? Or go straight up or straight down?”

The “force” was her hand, and the motion of her hand when she grabbed the tool bag out of the bigger bag was away from her (like unloading a bag, to get to the other stuff out) — like she was trying to do. So, just imagine that you’re unloading your bag and you pick a smaller bag out of your bigger bag and put it over to your side (which she did) — and in space, the motion (from the “force” of her hand) causes it to “float away” — relative to her position.

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You asked — “Or go straight up or straight down?”

It’s going to go in the direction that she moved it — and stay moving in that same direction, relative to herself (which was away from herself, and she was attached to the space station, so it was also moving away from her position on the space station.

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You asked — “Why don’t they have a leash on everything?”

The did have a lease on several things, and they might have had one on that bag, too — but — she was trying to get it out of the bigger bag to get (apparently) something else in the bigger bag and gave it “too much force” — causing it to move faster away from her, and out of her range of motion with her arms, than the time she allowed to reach out for it again — and grab it once more. Once you see it, you’ll see it was very typical for what anyone would do, especially if they were frustrated with grease all over the place, when you’ve got a job to do....

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And then you asked — “Was this really an accident?”

From looking at it, it was obviously an accident.

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You also asked — “Why doesn’t it stay in orbit?”

It will stay in orbit for a while (fairly long while), until the friction up there slows it down so that its orbit decays and drops it into lower and lower orbits and it finally burns up.

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And then you asked — “Shouldn’t it take off into infinity?”

If it’s in orbit (which it is) it would take a lot more force to either raise it to a higher orbit or finally exceed the gravitational pull of the earth (and perhaps be captured by the gravitational pull of some other body) and/or then fly out into so-called “infinity”.... LOL... There’s nothing to apply that force, so it will simply remain in that orbit and friction will cause the orbit to decay until it burns up in the atmosphere.

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And finally you asked — “If the tool bag falls to Earth why doesn’t the space station, too?”

They keep applying “force” to it, to keep it in that orbit, otherwise, it would do the same thing as the tool bag is going to do.

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And there you have it....

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