The runaway spatula?

[lynchmob98]

I just read about the spatula that the ISS spacewalker "lost" ... how long before it will burn up (I'm assuming that it's fate is to be in a decaying orbit which will eventually result in burning up)?<br /><br />If the spacewalker had thrown the spatuala towards the earth, would that make it burn up sooner? How much sooner?

 

[bonzelite]

makes me want some pancakes.

 

[tony873004]

Yes, throwing it towards Earth would make it burn up sooner.<br /><br />If he threw it at 100 miles / hour towards Earth (about the top speed of major league baseball pitcher), the spatula's closest approach to Earth would be 39 kilometers lower than the orbit of the ISS.<br /><br />However, if instead of throwing it towards Earth, he threw retrograde (opposite the direction the ISS orbits the Earth, and parallel to Earth's surface), the spatula's closest approach to Earth would be 155 kilometers lower than the orbit of the ISS, where it would experience a much greater drag than the spatula thrown towards Earth would experience.<br /><br />Additionally, the spatula thrown towards Earth would also have the highest point of its orbit raised by 39 kilometers. And it travels a little slower when its distance is greater. So it would spend over half its time orbiting the Earth higher than the ISS's orbit, where it would be experiencing less drag than at the altitude of the ISS. The one thrown retrograde will spend over 99% of the time closer to Earth than the ISS, and never higher than the ISS. It will always experience at least as much drag as it would at the altitude of the ISS, and usually a lot more.<br /><br />So throwing it in a retrograde direction would be far more efficent in bringing it down. How long? I don't know. There's lots of variables. How massive is it? What's the area of its cross-section? The density of the atmosphere can vary too depending on solar activity.

 

[enigma10]

The big question here is ,Bob, will they still have pancakes?<img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <em>"<font color="#333399">An organism at war with itself is a doomed organism." - Carl Sagan</font></em> </div>

 

[rfoshaug]

Thanks for the info, Tony. <img src="/images/icons/smile.gif" /><br /><br />ISS loses altitude quite fast, and has to be reboosted into a higher orbit at regular intervals. I guess the probability that the spatula and ISS have the same aerodynamic properties is close to nil. So is the probability that the spatula might come back to the ISS (and even if it did it would hit ISS at the same slow-floating speed relative to ISS as when it escaped).<br /><br /><br />The spatula's orbit might decay and eventually it will burn up in the atmosphere, but for such a small object (with a total density and weight-to-area ratio larger than that of ISS - because of ISS' large solar panels and air-filled modules), it might take decades or even centuries, I guess.<br /><br />I don't think the direction it left ISS with has much to say, as it was not thrown but just floated away.<br /><br /><br />Does anyone know if they can track it by radar or something like that? <div class="Discussion_UserSignature"> <p><font color="#ff9900">----------------------------------</font></p><p><font color="#ff9900">My minds have many opinions</font></p> </div>

 

[3488]

Aggred. The spatula will still keep in the same orbit as the ISS, as it was not 'thrown' as such. It will be on an orbital resonance with the ISS, making regualr returns to its point of the original departure point.<br /><br />However orbit decay mechanisms I.E its area is larger in proportion to its size than the ISS, means its orbit will decay sooner than the ISS. <br /><br />A good exmple are two doors. One is a normal sized door with a frame, but is filled with chicken wire (ISS) the other is a cat flap (spatula). <br /><br />Which one will be affected most by a strong wind? The Cat flap will be. Although it is smaller, it will have a grater surface area for the wind to blow against, where as the larger door, despite its considerably larger size, will have very little surface area, as most of it is full of holes with little 'area' for the wind to push against. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[lynchmob98]

Tony (et al) - THANKS for the replies! Can you recommend a web site that has some examples of the math used to determine the "39km" and "155km" figures you came up with? ... and maybe some pictures

 

[harmonicaman]

More info from NASA:<br /><br />NASA is tracking a new item of space junk that is streaking through orbit at 8km a second: British astronaut and Edinburgh University graduate Piers Sellers's putty knife.<br /><br />The $2700 spatula drifted out of Sellers's tool kit while he was conducting repair tests outside the shuttle Discovery on Wednesday. <br /><br />"My spatch has escaped ... it was tethered to me," he reported to ground controllers during his 7hr 11min spacewalk. "It's gone, gone, gone. Nobody's going to find it." <br /><br />Steven Lindsey, the shuttle commander, filmed the spatula through his window as it floated out the open cargo bay, over the starboard side of the spacecraft and into the darkness. "OK, rub it in," Sellers, 51, told mission controllers, who teased him by making him count up his remaining five spatulas before reboarding the shuttle. <br /><br />NASA and the US Space Surveillance Network, a system of high-powered military radars based at 20 sites worldwide, is tracking the object, which weighs 350g, to check that it does not become a hazard to Discovery or the International Space Station. <br /><br />The tool was orbiting Earth every 90 minutes on Thursday, travelling 6.4km ahead of the space station. Every time it completes a lap of the planet, the distance between them opens up another 3.2km. <br /><br />

 

[tony873004]

<i>"Tony (et al) - THANKS for the replies! Can you recommend a web site that has some examples of the math used to determine the "39km" and "155km" figures you came up with? ... and maybe some pictures "</i><br /><br />There's two ways to do it. <br />1. Do the math<br />2. Simulate it<br /><br />Here's how to do the math:<br />http://orbitsimulator.com/BA/spatula.htm<br /><br />Here's 3 screen shots from Gravity Simulator. <br />http://orbitsimulator.com/BA/ISS12.GIF spatula in a circular orbit<br />http://orbitsimulator.com/BA/ISS13.GIF spatula thrown 100 mph towards Earth<br />http://orbitsimulator.com/BA/ISS14.GIF spatula thrown 100 mph in a retrograde direction<br />

 

[erioladastra]

"Does anyone know if they can track it by radar or something like that?"<br /><br />Yes, it is being tracked.

 

[drwayne]

I know NORAD tracks a lot of stuff even smaller than the spatula...<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>Which one will be affected most by a strong wind? The Cat flap will be. Although it is smaller, it will have a grater surface area for the wind to blow against, where as the larger door, despite its considerably larger size, will have very little surface area, as most of it is full of holes with little 'area' for the wind to push against<p><hr /></p></p></blockquote><br /><br />Density is also a factor. A cat flap made of lead will decay more slowly than a cat flap made of aerogel. This is because the more massive an object is, the more inertia it has. The more inertia it has, the more drag it takes to slow it down a given amount.<br /><br />Light things (like spatulas, foot restraints, and other things lost by spacewalkers) tend to decay fairly rapidly. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[cosmictraveler]

Ummmmm....blueberry pancakes, yummy! <div class="Discussion_UserSignature"> <p>It does not require many words to speak the truth. Chief Joseph</p> </div>

 

[mikeemmert]

I'm surprised nobody has mentioned the square/cube law in all this. If you take an object, keep it's density and proportions the same, and increase it's size, then it's surface area increases as the square of increase in size, but it's volume, and therefore mass, increases as the cube of the size. Double it's length and it's surface area, which corresponds to aerodynamic drag, becomes four times as large, but it's volume, which determines it's mass, gets eight times as large. That's why massive objects like space stations have their orbits decay more slowly than light objects like spatulas.<br /><br />Generally speaking, of course. There are aerodynamic details, such as solar panels and radiators. From the details of the spatula's orbit, it appears that the much larger size of the ISS makes it much more streamlined. <br /><br />But still, think: the relatively heavy blade of a spatula compared with the light wooden or plastic handle will tend to align the spatula blade first, like the fins on an arrow. It would be relatively streamlined, although that won't overcome the enormous size differential.<br /><br />You never hear about solar power satellites any more. One of the major killers of that concept was the orbital debris problem. The systems studied were in geosynchonous orbit, where aerodynamic forces are extremely small. Natural meteorites would have a very large target, literally square miles, to knock pieces off. With no friction, the fragments would continue in an orbit which would periodically intersect the powersat, which would knock off more debris. The debris population would increase exponentially, not doubling every generation, but increasing more like 10 or 100 times. After 30 years, any satellite in that orbit would be sandpapered into uselessness in months or even days.<br /><br />So, how about a sun-synchronous orbit? This is a low near-polar orbit (actually slight

 

[mkofron]

<blockquote><font class="small">In reply to:</font><hr /><p>The $2700 spatula <p><hr /></p></p></blockquote><br /><br />For that price it better have been made out of platinum.

 

[lynchmob98]

I just read an article in my local newspaper yesterday, triggered by the recent loss of bolts by the astronauts, an update on the spatula ... that it's expected to burn up in about month (ie. mid-October) ... so it just taking about 3 months for it's orbit to decay to the point of demise ... which then makes me wonder how, as this newspaper article talked about, there can be ~100,000 objects in orbit ... I guess the initial orbit of the spatula was a pretty low orbit ...

 

[Boris_Badenov]

It's official, SpatSat will return in the first week of October. <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[alokmohan]

You mean spatula is alive?What about pancakes?

 

[MeteorWayne]

It also had very little mass.<br />Now if one of my daughter's pancakes had been lost, not only would it stay up a long time, but you wouldn't want it landing on your house! <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>

 

[lynchmob98]

I haven't seen any confirmation that our favorite spatula is indeed no more ... but perhaps the next Orbital Debris Quarterly News (http://www.orbitaldebris.jsc.nasa.gov/newsletter/newsletter.html) will give it a mention ...<br /><br />Have you seen any news?

 

[lynchmob98]

http://www.space.com/missionlaunches/061123_eva17.html<br /><br />... says this about the "golf ball" hit last year ...<br /><br />NASA officials estimate the ball will travel about a million miles round the Earth before deorbiting and burning up in the planet's atmosphere in 2 to 3 days.