The combined crews of the International Space Station and space shuttle Atlantis are facing a "daunting" box-shifting job, following the successful transfer of the Raffaello multi-purpose logistics module from the space shuttle's cargo bay to the orbiting outpost's Harmony node. The station's robotic arm, Canadarm2, operated by …
It's OK - it won't weigh much.
Seems like a daunting task...
until you remember that they are in space and therefore all this cargo is weightless :)
.. but not massless.
I did a little editing on your artical.
They now just have to empty Raffaello of "0 pounds [0 metric tonnes] of spare parts, spare equipment, and other supplies - including 0 pounds of food - that will sustain space station operations for a year".
Objects have no weight in space :D
"Objects have no weight in space :D"
Nope. But they do have mass, of which the tonne is a measurement. Despite being weightless, you still wouldn't want to be squashed against the wall by a large crate moving at any speed.
"Objects have no weight in space"
Adding to Stanislaw's correction, this line does not fully apply here since they're in a microgravity environment: http://en.wikipedia.org/wiki/Microgravity
Gravity is actually around 88% of sea-level.
It's the centrifugal force of their orbit that makes them appear weightless.
Tonnes might be a unit of mass...
...but pounds are a unit of weight (force due to acceleration by gravity). So it should read:
They now just have to empty Raffaello of "0 pounds [4.26 metric tonnes] of spare parts, spare equipment, and other supplies - including 0 pounds of food - that will sustain space station operations for a year".
That done, they'll then pack it with "more than 0 pounds [2.54 tonnes] of discarded station gear" for return to Earth.
@stucs201 I upvoted your post, but...
I feel compelled to point out it should be, "exactly 0 pounds [more than 2.54 tonnes] of discarded station gear".
You're right of course.
My first thought was, surely with the ISS in free fall this stuff actually weighs nothing? Then I factored in momentum, possibly bulk, plus the fact that the astronauts themselves are floating around and pushing an object one way will push them the other way....
Zero gravity ain't easy (how does one drink a beer, for starters?)
through a straw is the safest way
I love reading this stuff, it blows my mind. Its easy to get a bit blase these days about what mankind has achieved with technology, ingenuity and courage. It almost sounds a bit 'matter of fact' until you start thinking about all the things that have to work properly and reliably to make attaching a skip full of stuff, swapping it for rubbish and bringing the skip back to earth possible!
You are forgetting that those objects may be "weightless" but that they are certainly not massless. So they will still be bloody awkward to shift ;)
That's a shedload of stuff!
"They now just have to empty Raffaello of "9,403 pounds [4.26 metric tonnes] of spare parts, spare equipment, and other supplies - including 2,677 pounds of food - that will sustain space station operations for a year".
Yeah, if it was B&Q or Sainsbury's, youl'd be rightly thinking that'd be a hard Friday afternoon job.
Now consider moving this fuc*king potentially heavy stuff, all 2½ tons of it, while it's maybe floating about. Not a job the Jobcentre could possibly interest me in. I wouldn't care if they stopped my benefit, or sanctioned me.
Count me in
Actually, if the job centre did have a vacancy for astronaut, I would be happy to apply! Even if it did involve less glamours things like box shifting.
Force = mass x acceleration
Work = Force x distance
So the mass is significant if you have to move it around because in order to do that you have to accelerate it to a useful speed (and then decelerate it) if you want to catch the last Shuttle home. OK it's easier than on earth becasue there's no friction.
"if you want to catch the last Shuttle home"
Well done, sir!
Tesco's van just arrived.
OMG! Sandy, did you put this on the credit card?
I'm not sure we can afford it this month.
Tesco van 2
"Sorry, we were out of fresh distilled water, so we replaced it with windolene...and there was no tomatoes, so we replaced those with Polo mints"
"Sorry no, I can only deliver to the hallway. You need to unpack these yourselves"
"...oh, and you're outside our normal delivery range...please sign here to accept the extended delivery charge of...$150,000,000"
Each space shuttle launch costs at least $300 Million, so it doesn't make much sense to charge that little, unless they are also delivering to other customers while they up there...
Tescos have something to explain!
No weight but momentum
Objects in a (stable) orbit have no apparent weight but still have mass and therefore manoeuvring a big container still requires care - once moving it will try to continue moving. Could make for an interesting insurance claim: "There I was, just minding my Canadarm, when this ruddy big Rafaello wiped out my solar panels!"
Paris, because you don't many of those to the Rafaello
It may even be worse than moving stuff on earth. Not only do you have to apply force to start moving each package but you have to apply an equal amount of force in the opposite direction to stop it, once it gets close to where you finally want to put it. You also have to apply more force to change the direction it's moving - to get it round corners f'riinstance.
In space you can't just put it down when you get tired of carrying it.
In space you can't just put it down when you get tired of carrying it.
Nor would you need to.
And I don't see you getting tired when one *small* push is all it takes to give the object a constant (air resistance not withstanding) speed. Doesn't need to be fast, afterall. Even with small direction corrections, it will still involve far less effort than here on Earth.
And I seriously doubt they're lugging removal-van sized brown boxes around here; it'll be small amazon-book-sized packages, and lots of them.
However, the confined spaces, and expensive pokey-outy-bits will make navigation tricky.
I guess IT people dont ever shift things
Having moved nearly that weight of rotted horse manure this morning using a wheel barrow and a shovel I think the people on the shuttle will only have trouble if they are impatient.
I'd guess the average astronaut to weigh in around 60 or 70 kilos and they have little trouble moving themselves around so if they shift 25kg at a time that’s only 100 trips or so. I could manage that on earth in a couple of hours on my own (unless the station is a real maze/squeeze) - and that’s lifting the stuff nearly two meters off the ground to get it on my shoulders.
I should add I'm a grossly unfit 120kg pisshead myself and not a trained astronaut so the only problem up there would be rushing it and getting in each others way. Unless of course some idiot has used velcro and string so it catches on everything as it passes.
If you don’t believe me go see how easy it is to push a small boat in water. The only way they'll break sweat is if the chilli sauce or porn has arrived.
A journey of a thousand miles starts with a single step
4.2 tonnes is more manageable though, when you consider it's 840 parcels of 5kg; so even at 5 minutes per 5kg parcel, that's a mere 70 person-hours of work*
* - chances are they'll be <1 minute per parcel, a few astronauts involved in a chain though, so somewhere in the region of 14 hours' work for say 3 astronauts.
Let's be honest
It's not like they have anything else to do.
Just give it all a "little push" in the direction of the big blue thing.
Burns up on re entry.
My consultation fees are waived for this contribution to common sense.
"for return to Earth" ?!
Surely: "for incineration as it burns up in the atmosphere from the friction of trying to return to earth" ?
It's going back down in the Shuttle. They're stuffing it back in the MPLM & the Shuttle middeck.
That's one of the Shuttle's unique abilities, to be able to return stuff.
"They are not now threatened"
That's what the Russians want you to think...
You know you're reading El Reg when half the comments on the article are weight-vs-mass related.
Not only do they have to dhift it
They have to put it somewhere, fasten it down so it doesn't drift off, and have mission control note where they put it so it doesn't get lost. The bookkeeping is a big chunk of the time.
should invest in some tech then
As companies such as Amazon, UPS etcetera do; Even the post office is capable of it occasionally; handheld scanners save time managing bookkeeping :-)
Large lads & lager & late payments
One drinks beer in space (according to NPR) this way:
@ Tom 7
"I'd guess the average astronaut to weigh in around 60 or 70 kilos"
For Yanks of their age your estimate strikes me as a bit light; I hail from the same demographic and would love to get back down to 70 kg... :-(, though the absence of access to beer would help!
Regrettably, I'm afraid we have put it all on the credit card....
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