Rocket Man - nice touch!
But I thought Endeavour carried out the last EVA? Was this unscheduled?
Anyway, Kudos to Sir Elton for that one.
The crew of space shuttle Atlantis were woken this morning by Elton John's Rocket Man, followed by a personal message from Britain's national musical treasure. Sir Elton said: "Good morning, Atlantis, this is Elton John. We wish you much success on your mission. A huge thank you to all the men and women at NASA who worked on …
geek question.
beeing in micro gravity,
the stores weigh not a lot.
but they do have momentum the crew have to control.
just how much energy / callories is it taking to move the tonne of stuff around the station.
just a though, on earth it would be a back breaker, but in micro gravity, I have no idea.
= (mv^2)/2
so per tonne @ say 2 m/s => 2 kJ, 4 m/s => 8 kJ, 6 m/s => 18 kJ, etc
without counting the – quite important factor of – inefficiency of say astronauts needing to move themselves around, absorb momentum, change trajectories etc
similar to the work done to ride a bicycle, without the friction
work = Energy / time
so it's the work to move a 'tonne of stuff' in a set amount of time that you are thinking of, while the Energy involved is a different question
although I acknowledge that I said 'work' done riding a bicycle when strictly it was Energy I was referring to;
so say you call 1 – strong – human power = 0.5 horsepower ~= 375 watts, that's 375 J/s, would allow acceleration of 100kg at a tad less than 3 ms^-2, deceleration similarly.
conversion back to F=ma gives F=300N, similar to the weight of a 30kg load at normal gravity, so sounds right in a 'constant load' scenario, although human peak power reaches closer to 1kW => 4+ ms^-2 for that 100kg load in say a <10% duty cycle. As Andus says, that could be a surprise when sent Tesco style – NASA Breakfasts are high protein :-)
compare a cricket fast bowler who bowls a 150g ball at 150km/h, kinetic energy of 130J, baseball pitcher 105mph, kinetic energy 163J; the difference being that the amount of time for acceleration is an important limiting factor