ECN Forum Forums General Topics of the Trade General Discussion Area Shuttle astronauts to rewire space station

Hope they remebered everything and won't need to make "a quick run to the supply house"

Funny thing about 'grounding'. 'Space' is not a perfect vacuum, but in fact a very low pressure gas. Much of this gas is ionized, so Near Earth Orbit space is actually a very low pressure plasma, and thus electrically conductive.

It is actually quite important to maintain the bulk of the space station structure at roughly the same electrical potential as the surrounding plasma. This is done using devices known as 'plasma contactors'.

Volia: The space station ground rods: http://www.grc.nasa.gov/WWW/RT1998/5000/5430patterson.html

-Jon

P.S. interesting links that I had to follow to find the above, not directly relevant: http://standards.gsfc.nasa.gov/reviews/iso-dis-14302/iso-dis-14302-e.pdf http://www.grc.nasa.gov/WWW/ion/overview/overview.htm http://powerweb.grc.nasa.gov/pvsee/publications/tropix/Paper/AppA.html

Not to worry, if we had every wire, and cable marked, tested, and inspected many times over, and wired from a to - from list, our work would be out of this world!

The smoke trail that a rocket leaves behind as it leaves the pad makes a good "GEC" of a sort. In fact, the Apollo 12 mission was almost aborted when the vehicle was hit by lightning TWICE shortly after launch, with the current following the exhaust plume down to the launch pad.

The strikes knocked the spacecraft's fuel cells offline, and scrambled the guidance system pretty well. Luckily, the booster's backup guidance system let them get into a safe orbit, and a flurry of troubleshooting by the EECOM in Houston got the fuel cells back online to salvage the mission.

The Apollo 12 incident is one reason for the very strict weather guidelines for shuttle launches. The scrub the other night was simply because of the RISK of a lightning strike to the vehicle.

They just lifted off safely, on the way to the ISS for their rewiring job. Must be the most exciting ride to a service call for any bunch of electricians, huh? Glad they aren't charging by the mile for travel...

No ground no ground rod needed.

Typical you get there set up for the job....then the customer adds "while your here can you just.............."

more wing checks ordered

Day rates or contrtact?

Kenny
(edit to sort link)

[This message has been edited by Kenbo (edited 12-12-2006).]

Seriously, it would be a field technician doing the wiring work, using preassembled wiring assemblies most likely.