Astronauts Begin Final Spacewalk To Repair Hubble
An anonymous reader writes "Astronauts John Grunsfield and Andrew Feustel began the fifth and final spacewalk of their Hubble Space Telescope repair mission this morning at 8:20AM. During their spacewalk the two will install the second battery group replacement in an equipment bay above the Wide Field Camera 2 and next to the compartment where the first battery set was installed on the second spacewalk. Each of the battery module weighs 460 pounds and contains three batteries. The batteries provide electrical power to support Hubble's operations during the night when there's no sun to power the solar arrays."
Check it out on NASA TV if you haven't had the chance yet. Viewing Hubble the way the astronauts see it is a neat experience.
It's actually Wide Field Camera 3 now. It has been exchanged in the first spacewalk.
http://twitter.com/Astro_Mike
one of the astronauts is live blogging on twitter from the shuttle
According to my back-of-an-envelope calculations, I get their true weight to be 1729N.
F=GMmr^-2
=G * Mass of earth * mass of box * (Earth's radius + Hubble orbit height)^-2
=(6.67x10^-11 * 5.9742x10^24 * 208.7) * ((6378 + 559)x10^3)^-2
=1729.20 N
Pound-mass or slug, your choice.
Um, it's the pound. Doesn't everyone know that? 2.2 lbs to the kilo.
While weight certainly means the force created between two masses due to gravity, it is almost always used interchangeably with mass in practice.
Still messed up. Trying to compare a metric unit of mass to a imperial unit of weight using a conversion factor that only works at roughly sea level on earth.
Metric unit of weight - Newton N
Metric unit of mass - Gram g
Imperial unit of weight - Pound lb (you know, like Pound Sterling being a pound of silver?)
Imperial unit of mass - Slugs
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Technically the batteries have the same mass while on Earth as they do while orbiting it. The weight in orbit is zero. (which is the point the above are making)
See here: http://en.wikipedia.org/wiki/Mass_versus_weight
wot no sig