Author Topic: $28m contract for local KSC firm for Ares I Lightning Protection System Towers  (Read 14756 times)

Offline brihath

  • Member
  • Full Member
  • ****
  • Posts: 877
  • Liked: 18
  • Likes Given: 20
Quote
pippin - 30/7/2007  11:29 AM

As I understand Florida these towers should be more or less standing in water. Shouldn't that make grounding faily straightforward?

I think Ed's point is well taken- you want to direct the charge into the ground in a specific direction and away from other wiring, cables, etc. in order to prevent damage to critical systems.  As in my example above, the lightning charge travelled through the ground about 50' before it did damage in my house.  It came in the ground wire for my house wiring- melted the contact in the outlet my UPS was plugged into.

Online edkyle99

  • Expert
  • Senior Member
  • *****
  • Posts: 12939
    • Space Launch Report
  • Liked: 4001
  • Likes Given: 761
Quote
pippin - 30/7/2007  10:29 AM

As I understand Florida these towers should be more or less standing in water. Shouldn't that make grounding faily straightforward?

It probably helps, but soil type plays a role, and the system has to be designed to work during dry spells too, when the local water table around the pad might drop a bit.  Also keep in mind that the launch pads are built on what are essentially man made islands that probably consist of compacted clay and that were designed to drain water away.

 - Ed Kyle

Offline pippin

  • Regular
  • Senior Member
  • *****
  • Posts: 2566
  • Liked: 291
  • Likes Given: 39
Quote
Jim - 30/7/2007  1:24 PM

There wasn't a mast for Saturn V's, only for Apollo/Soyuz


So what exactly is that white structure on top of the tower for?

http://www.hq.nasa.gov/office/pao/History/alsj/misc/apmisc-KSC-66PC-75.jpg

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32440
  • Cape Canaveral Spaceport
  • Liked: 11187
  • Likes Given: 331
Quote
pippin - 31/7/2007  8:29 AM

Quote
Jim - 30/7/2007  1:24 PM

There wasn't a mast for Saturn V's, only for Apollo/Soyuz


So what exactly is that white structure on top of the tower for?

http://www.hq.nasa.gov/office/pao/History/alsj/misc/apmisc-KSC-66PC-75.jpg

Was referring to the "real" mast vs a lightning rod

Offline pippin

  • Regular
  • Senior Member
  • *****
  • Posts: 2566
  • Liked: 291
  • Likes Given: 39
Ah.
Why was it added only for ASTP? I would understand it after Apollo 12, but that late in the program...

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32440
  • Cape Canaveral Spaceport
  • Liked: 11187
  • Likes Given: 331
Quote
pippin - 31/7/2007  9:10 AM

Ah.
Why was it added only for ASTP? I would understand it after Apollo 12, but that late in the program...

Because ASTP was launching in July.  It couldn't afford a delay if the Soyuz was already launched.

Offline renclod

  • Extreme Veteran
  • Full Member
  • ****
  • Posts: 1663
  • EU.Ro
  • Liked: 8
  • Likes Given: 2
http://www.nasa.gov/pdf/160648main_Kennedy Space Center (KSC) Pad B Catenary Capability Analysis and Technical Exchange Meeting (TEM) Report.pdf


Offline punkboi

  • Extreme Veteran
  • Full Member
  • ****
  • Posts: 589
  • Liked: 0
  • Likes Given: 0

The KSC gallery page currently has a page devoted to Constellation.  There are pics of one of the lightning towers now undergoing construction at LC-39B

http://mediaarchive.ksc.nasa.gov/search.cfm?cat=169


Offline STS Tony

  • Extreme Veteran
  • Full Member
  • ****
  • Posts: 1648
  • Los Angeles
  • Liked: 29
  • Likes Given: 64
Yeah, there's been update images from pad rats taking photos and publishing them on L2 :)

Offline punkboi

  • Extreme Veteran
  • Full Member
  • ****
  • Posts: 589
  • Liked: 0
  • Likes Given: 0

NOW you tell me... Haha just kidding. :bleh:


Offline kraisee

  • Expert
  • Senior Member
  • *****
  • Posts: 10483
  • Liked: 415
  • Likes Given: 19
Quote
pippin - 31/7/2007  8:29 AM

Quote
Jim - 30/7/2007  1:24 PM

There wasn't a mast for Saturn V's, only for Apollo/Soyuz


So what exactly is that white structure on top of the tower for?

http://www.hq.nasa.gov/office/pao/History/alsj/misc/apmisc-KSC-66PC-75.jpg

Just for clarity - there *WAS* a lightening mast for Saturn-V.   It was just a different design.   I have the 1st October 1964 blueprints in my hand right now.   Document number 75M05128.

It wasn't the big white cylinder design, like ASTP and Shuttle used, but it was the small trellis structure in tapering triangular profile shown very clearly in the image you linked above.

It was changed to the "spiral cylinder" design in time for ASTP simply because the old one was rusting away and needed replacing after Skylab 4 flew from the same tower.   They decided to change the design at the time, and that same design led to the Shuttle design which we see today.


You can see the original lightening mast design quite visibly in all Saturn-V rollout and launch pictures.   It used to be folded down just before entering the VAB and somewhere there is a cool picture showing it being lifted just as the LUT exited the VAB on one mission.   I'm not sure where that image is right now, but it must have been a really great view for the workers at the top of the Crane while rolling out.

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
-Robert A. Heinlein

Tags: