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## Astronauts Begin Final Spacewalk To Repair Hubble94

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."
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## Astronauts Begin Final Spacewalk To Repair Hubble

• #### The batteries weigh what? (Score:5, Interesting)

on Monday May 18, 2009 @11:34AM (#27997451)
I'm willing to bet that the batteries don't weigh anything right now. ;) Of course using "mass" as a verb is just taking the piss, so I won't do that. I'm sure someone will.
• #### Re: (Score:3, Funny)

Or you could say "the batteries have a mass of <whatever> kilograms"

Because no one would have a clue WTF the Imperial unit of mass is.

• #### Re: (Score:3, Informative)

Um, it's the pound [wikipedia.org]. 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.

-Peter

• #### Re:The batteries weigh what? (Score:5, Informative)

on Monday May 18, 2009 @12:07PM (#27998167)

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

• #### Re: (Score:2, Informative)

Did you click the link? No one uses slugs. Pounds are commonly used to express mass as well as force (weight).

Since there is a mass version of the pound, and it is defined in terms of kilos the conversions actually work perfectly in any (or no) gravitational field. (Though the conversion factor is exactly 2.20462262, not 2.2.)

Don't get me wrong in all of this. I advocate the metric system. But I don't understand the seemingly willful misunderstanding of the modern imperial sys

• #### Re: (Score:3, Interesting)

modern imperial system

That, sir, is an oxymoron. Like "Military Intelligence" or "Deafening silence" or "clean coal"

The "mass pound" and "weight pound" may be equal at sea level in a certain location or whatever, but probably not equal at any other gravitational potential, which must make for some confusing equations and explanations. Therefore, Why the willful misunderstanding? Because its icky to have the same name for inertial mass and gravitational weight/force.

Thank you Peter for the info. Always a pleasure to converse

• #### Re: (Score:2, Informative)

There's no question that it's a kludge.

The "mass pound" and "weight pound" may be equal at sea level in a certain location or whatever, but probably not equal at any other gravitational potential

There's no "may" about it. For the Math to work they can only be equal at exactly 1G. The thing is, we never really use the "weight pound" in practice. I mean, if someone asks you what you weigh do you ask for a reference altitude (or gravitational force)? Absurd.

Put it this weigh (yuk-yuk), if you want to buy a

• #### The U.S. Customary system of units must die! (Score:2)

modern imperial system

That, sir, is an oxymoron.

I put forth a compelling argument for the United States to join the world with the International System of Units [gibibit.com]. Forward this to your friends who still think that ounces (fluid ounce or international avoirdupois ounce? British or U.S. fluid ounce? Apothecary ounce?), pints, and inches are the way to go.

• #### Re: (Score:2)

I always used slugs as an engineering student. The lb-m and lb-f system seemed wrong to me, and most of the people who used it ended up losing points because of the missing 32.2. When not working with the metric system, I would still opt to use slugs when needing to have a mass unit.
• #### Re: (Score:1)

How many stones [wolframalpha.com] is that?

• #### Re: (Score:1)

Stone is the plural of the unit of weight, stone.

Fourteen. But you knew that.

-Peter

• #### Re:The batteries weigh what? (Score:5, Informative)

on Monday May 18, 2009 @12:06PM (#27998141)

• #### Re:The batteries weigh what? (Score:5, Informative)

on Monday May 18, 2009 @11:55AM (#27997919)
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
• #### Re:The batteries weigh what? (Score:5, Insightful)

on Monday May 18, 2009 @12:18PM (#27998371) Homepage

Only true if the HST + shuttle were stationary and balanced on a very tall table rather than being in orbit. As they are actually in free fall, effective gravity is zero and hence the weight is zero too.

(Yes I do understand that gravity is acting on the HST + shuttle to keep it in orbit but there is no force required to support them which is the definition of weight)

• #### Re: (Score:2)

As they are actually in free fall, effective gravity is zero and hence the weight is zero too

Then what keeps it in orbit? If effective gravity were zero it would fly away in a straight line.

I do understand that gravity is acting on the HST + shuttle to keep it in orbit but there is no force required to support them which is the definition of weight

Every time these weight vs. mass discussions a

• #### Re: (Score:2)

They're weightless in an orbiting reference frame, they have weight in an inertial, Earth-fixed reference frame. You don't claim that a person in free-fall off of a building in weightless. In the Vomit Comet-type aircraft, you experience 'weightlessness' because the lack of windows effectively puts you in a free-falling reference frame. However, its all really the same thing and I think most of us here are able to recognize what is meant.

• #### Re: (Score:3, Insightful)

You're wrong, GP is right. Weight is the amount of force needed to hold an object stationary, or equivalently, the amount of gravity acting on the object. Regardless of the actual amount of opposing force. You don't look up at a falling anvil and think, "whew, good thing it's weightless!"
• #### Re: (Score:1)

You missed the centripetal force of the orbit they're in :)
• #### Re:The batteries weigh what? (Score:4, Funny)

on Monday May 18, 2009 @12:54PM (#27999007) Homepage
What is the equivalent of that in unladen swallows?
• #### Re:The batteries weigh what? (Score:4, Funny)

on Monday May 18, 2009 @01:01PM (#27999113)
African or European?
• #### Re: (Score:1)

African or European?

I don't know that! (AAAAARRGGHHHHHH!!!)

• #### Re: (Score:3, Funny)

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

Ah, but I see you failed to calculate the mass of your envelope...

• #### Re: (Score:1)

hmm... interesting calculations
• #### reminds me of ... (Score:2)

Doing my final upgrade on my system with AGP. You just know this is it :(
• #### Watch it live (Score:5, Informative)

on Monday May 18, 2009 @11:41AM (#27997593)
Check it out on NASA TV [nasa.gov] if you haven't had the chance yet. Viewing Hubble the way the astronauts see it is a neat experience.
• #### Re: (Score:2)

I've spent most of this week studying for finals, and this has been great just to leave up in the background instead of music. It's unfortunate from an entertainment stance that this is the final spacewalk, however I do realize just how dangerous that it is to be out there.

• #### Re:Watch it live (on Linux too) (Score:4, Insightful)

on Monday May 18, 2009 @12:38PM (#27998737) Homepage

If it redirects you to the "no player found" page (as it did for me), try:

mplayer -playlist 'http://playlist.yahoo.com/makeplaylist.dll?id=1369080&segment=149773'

(The original link is http://www.nasa.gov/55644main_NASATV_Windows.asx [nasa.gov], but MPlayer doesn't seem to be able to handle multiple levels of playlists.)

As one who (perhaps from Kubrick's 2001) had a sense of EVA actions being slow, deliberate things, it's neat to see that the work's going practically as smoothly as if it was being done in a lab.

• #### Re: (Score:2)

Nasa TV is also available unscrambled on Echostar 7 (119.0 West) if you have a FTA (Free to Air) receiver and a circular LNB.
• #### Not above the WFC2 (Score:5, Informative)

on Monday May 18, 2009 @11:41AM (#27997599)
It's actually Wide Field Camera 3 now. It has been exchanged in the first spacewalk.
• #### Re: (Score:2)

Awww, you made me cry, you bitch.

Oh WFPC2, I will miss your tell-tale chevron superimposed over the sky like a Batsignal. Also, I will miss your useful filter set, so unlike that on WFC3 which treats nebular astronomy as if it were a mere curiosity. Galactic astronomers are such telescope hogs.

If I were still in the biz I would curse thee, WFC3! But, given all of the bad luck HST has had over its lifetime that would just be piling on.
• #### Astronaut helmet cams (Score:5, Insightful)

<info AT devinmoore DOT com> on Monday May 18, 2009 @11:42AM (#27997629) Homepage Journal

Let me just say, thanks NASA for the astronaut helmet cams! That footage lets me live out my astronaut fantasies without all the space-induced nausea and military training.

• #### Re:Astronaut helmet cams (Score:5, Funny)

on Monday May 18, 2009 @12:41PM (#27998785)

That's the only thing holding you back?

• #### First tweets from space (Score:5, Informative)

on Monday May 18, 2009 @11:54AM (#27997903)

one of the astronauts is live blogging on twitter from the shuttle

• #### Re: (Score:2)

Hmm, apparently being an astronaut is hard work, but it's also a great experience, and the views can't be beat!

Why even bother writing from space when he could have simply written those generic updates ahead of time? (Perhaps because that approach didn't work out so well [astroengine.com] for the Chinese.)

• #### batting .900 for the mission so far (Score:2)

They fixed everything they supposed to during the first four space walks except for part of an instrument that was to far gone. They fixed some things that werent even deisgned to be serviced.
• #### Can't wait for the Duracell commercial... (Score:5, Funny)

on Monday May 18, 2009 @12:00PM (#27998021)

"If you think all batteries are the same, consider this: when NASA decided to install new batteries on the Hubble telescope, they trusted duracell. So whether it is for powering your vibrating inflatable girlfriend or charge a two-billion dollar space telescope, it just has to work.
Duracell. Trusted everywhere."

• #### Re: (Score:3, Informative)

Sorry to reply to my own post but... I just realized that Duracell already did a space commercial [youtube.com] about an IMAX camera being used in space.

• #### Re: (Score:2)

Hmmm. Was duracell used on that electric wrench?
• #### Re: (Score:1, Flamebait)

Good job shilling for your viral advertising job! As an American who has been away since 2002, these sorts of obvious shilling probably look like innocouous comments, but to me, viral shilling is as obvious as a dick on a pumpkin. I've never heard of this weak-ass slogan before, and I can't conceive of any reason to repeat it, other than you are a paid shill or a creature of such zero life as you can be enhanced by repeating someone's slogan.
• #### I love NASA TV (Score:4, Interesting)

on Monday May 18, 2009 @12:09PM (#27998199)
I've been listening to and occasionally watching all the space walks streaming live on NASA TV while at work. Thats one video site they havent banned yet. I'm listening to the fifth space-walk now. The view is straight down at earth behind the shuttle.

Every once in a while I hear them count off. I think they are counting seconds they apply a tool, but I haven't been paying close attention.
• #### Re: (Score:1)

They're counting turns on bolts or number of guide-lines still visible as they slot something in.

Or sometimes the amount of O2 they have in their tanks.

• #### Re: (Score:2)

How do I watch NASA TV????
Using firfox on winxp here at work and it keeps redirecting me to a help page.
http://www.nasa.gov/help/multimedia/odplayer.html [nasa.gov]

Apparently it thinks I need to install more plug ins... but I never even get a chance to see the webpage with the video.

Have a stream address I can plug into VLC?

• #### Re:I love NASA TV (Score:4, Informative)

on Monday May 18, 2009 @01:00PM (#27999095) Homepage Journal

mms://209.73.189.79/bcpenc252181?StreamID=81684353&pl_auth=56e0ca2df8a3b81fa447c77c49dbf0f1&ht=120&pl_b=00CEBE2C2D18A488577820B4444A1179CB&CG_ID=1369080&Segment=149773

• #### Re: (Score:1)

Thanks.
• #### Orbit? (Score:1)

Considering the Hubble's orbit is 96-97 minutes, When exactly would it be night for the hubble? Or do the batteries click on and off every other 45 minutes? That's one heck of a recharge/discharge cycle.

• #### Re: (Score:2)

Yes, when sizing out the power system for a spacecraft you figure out the eclipse period, as well as total power requirements. From there, you can size the solar cells to collect the power needed for a whole orbital period (probably double the power requirements, assuming a 50% eclipse period, which is likely in LEO), and then the battery size, based on the power required and expected eclipse time.

All LEO satellites, except those in sun-synchronous orbits that keep them situated above dusk/dawn all the tim

• #### Really live? (Score:2)

Is the audio feed delayed? What happens if an astronaut lets loose an f-bomb when a tool goes drifting off?
• #### Re: (Score:2)

Fbomb is not prohibited on the Internet.

• #### The Hubble has replaceable batteries (Score:3, Funny)

on Monday May 18, 2009 @02:04PM (#28000257)

but the ipod and iphone can not?

• #### Re: (Score:1)

Welcome to modern capitalism in accordance to The Cult Of The Pod People (c)(tm).

• #### Re: (Score:2)

Astronomers calling NASA hotline to have the Hubble batts replaced == iPodders calling Apple hotline to have their iPod batts replaced. I haven't noticed astronomers changing the Hubble batteries on their own.
• #### Space Walk (Score:2)

The last space walk is suppose to last 6 hours.

That is incredibly dangerous to be outside for that length of time in such primitive suits.

I wish them good luck however, and pray they return safely.

God speed!!

-Hackus

• #### Re: (Score:2)

I submit all space walks are dangerous, but given the history or death and injury during space walks (ZERO) I don't think you have any valid basis for attacking the suits.

• #### Re: (Score:2)

That is incredibly dangerous to be outside for that length of time in such primitive suits.

I would not call today's suits primitive. Especially compared to the suits used during the Mercury/Apollo era.

Is there still room for improvement? Always. Massive improvements? Maybe not. Barring improvements in fabrics / construction technology.
• #### Why not go the source?? (Score:2)

Why would the OP link is story to some obscure third party blurb site when a direct link to WWW.NASA.GOV would make far more sense.

You could even watch live at the Nasa site:
http://www.nasa.gov/multimedia/nasatv/index.html?param=public [nasa.gov]

• #### Great Job! (Score:1)

I've been glued to NASA TV since this began and I just have to say, the Atlantis crew kicked some serious ass! They hit some hurdles but overcame everything and went beyond everyone's expectations. Here's a summary of what got added/repaired:
• Wide Field Camera 3
• New gyros
• New batterys
• Repaired the Advanced Camera for Surveys (this is the camera responsible for the pretty photos), they got the wide-field channel working, but not the high-res channel. This was expected. Now, they have redundant commu
• #### Insignificant figures (Score:2)

460 pounds. That makes it 208.656755845 kilograms, right?

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