Author Topic: LIVE: STS-120 Flight Day 12 - EVA-4 - P6 4B Solar Array Repair (Read 154970 times)

Lee Jay · « **Reply #640 on:** 11/03/2007 09:22 pm »

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psloss - 3/11/2007 4:11 PM

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Chris Bergin - 3/11/2007 7:49 AM

Best image ever...don't care if we all duplicate this:
Going way back in the day, but I'm especially looking forward to any stills Scott took out there, either coming or going, hopefully they'll end up in a gallery section soon.

His camera wasn't working properly, at least in the early part of the EVA. I'm not sure if he eventually got any or not, but I didn't see him getting any shots.

psloss · « **Reply #641 on:** 11/03/2007 09:55 pm »

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Lee Jay - 3/11/2007 6:22 PM

His camera wasn't working properly, at least in the early part of the EVA. I'm not sure if he eventually got any or not, but I didn't see him getting any shots.

That would be a bummer, because any shots out there would be instant hall of fame desktop backgrounds.

ETEE · « **Reply #642 on:** 11/03/2007 10:48 pm »

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jcopella - 3/11/2007 11:08 PM

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Bruce - 3/11/2007 5:41 PM

Any idea when they can pronounce the arrays healthy, in terms of their expected power generation capability? For the port arrays, that is.

According to Suffredini @ the MSB, there is some (very very slight) concern about a short resulting from the damage. After Discovery undocks, they will do a "shunt test" to confirm there is no such short. Right now, the array is functional and tracking, but no power from 4B is reaching the station, and it will remain that way until completion of that shunt test. So...extrapolating from that, probably some time on Wednesday.

Not quite right I'm afraid. At the moment the entire P6 array is generating ~209 amps which is roughly 20kW at 100V DC (the design rating). This current is being fed into a shunt, which is a load (or short circuit) placed across the output of the array. The P6 array is isolated from the station electrics. They will not switch the output of the array to the station until the orbiter leaves in case there are problems. After Discovery undocks they will test the array with it connected to the station. Only then will they give it a clean bill of health or whatever.

Kel · « **Reply #643 on:** 11/03/2007 10:51 pm »

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psloss - 3/11/2007 5:55 PM

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Lee Jay - 3/11/2007 6:22 PM

His camera wasn't working properly, at least in the early part of the EVA. I'm not sure if he eventually got any or not, but I didn't see him getting any shots.
That would be a bummer, because any shots out there would be instant hall of fame desktop backgrounds.

I agree. Would love to have rolling video from his helmet cam on the ride out to P6 too! I didn't see him take any shots during the repair sequence - in fact, he seemed like he needed 3 hands at times as it was. Awesome day

Bubbinski · « **Reply #644 on:** 11/03/2007 11:31 pm »

Did Wheels have a digital camera? If he did, maybe he could have gotten some great shots from his P6 vantage point.

j2_ · « **Reply #645 on:** 11/04/2007 12:09 am »

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Bubbinski - 3/11/2007 5:31 PM

Did Wheels have a digital camera? If he did, maybe he could have gotten some great shots from his P6 vantage point.

I remember seeing Parazynski stop and wave a few times, while Wheels took his picture.

Ford Mustang · « **Reply #646 on:** 11/04/2007 12:42 am »

Handheld video of the EVA... Not sure if this was posted or not!

Ford Mustang · « **Reply #647 on:** 11/04/2007 12:43 am »

Ford Mustang · « **Reply #648 on:** 11/04/2007 12:44 am »

Great shot

Ford Mustang · « **Reply #649 on:** 11/04/2007 12:47 am »

Video of the award given to Wheels!

nathan.moeller · « **Reply #650 on:** 11/04/2007 01:19 am »

I can't wait until tomorrow. Hopefully we'll see some pictures from Parazynski if he took any.

Lee Jay · « **Reply #651 on:** 11/04/2007 01:58 am »

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ETEE - 3/11/2007 5:48 PM

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jcopella - 3/11/2007 11:08 PM

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Bruce - 3/11/2007 5:41 PM

Any idea when they can pronounce the arrays healthy, in terms of their expected power generation capability? For the port arrays, that is.

According to Suffredini @ the MSB, there is some (very very slight) concern about a short resulting from the damage. After Discovery undocks, they will do a "shunt test" to confirm there is no such short. Right now, the array is functional and tracking, but no power from 4B is reaching the station, and it will remain that way until completion of that shunt test. So...extrapolating from that, probably some time on Wednesday.

Not quite right I'm afraid. At the moment the entire P6 array is generating ~209 amps which is roughly 20kW at 100V DC (the design rating). This current is being fed into a shunt, which is a load (or short circuit) placed across the output of the array.

If it's shorted (shunted) it's not at 100V - it's at about 0V. That's the definition of a short circuit. If it's generating 20kW at 100V, it's not shorted (shunted).

From the description at the MSB, it is shunted and is generating a short-circuit current of 217A. They can't test it at voltage without un-shunting it and giving it a load to drive (the station). I guess they'll wait for Discovery to leave before trying that.

punkboi · « **Reply #652 on:** 11/04/2007 02:15 am »

Is it just me but the NASA TV commentator right now is mistaking the Quest airlock for the Harmony module?

hornet · « **Reply #653 on:** 11/04/2007 02:17 am »

Shes made countless mistakes tonight

nathan.moeller · « **Reply #654 on:** 11/04/2007 02:29 am »

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hornet - 3/11/2007 10:17 PM

Shes made countless mistakes tonight

Who's on tonight?

ChrisC · « **Reply #655 on:** 11/04/2007 02:33 am »

I think her name is Lynette Madison.

Oh fudge, why are they playing FD highlights now? I tuned in for the Flight Director interview replay. Bah.

nathan.moeller · « **Reply #656 on:** 11/04/2007 02:40 am »

PAO can be a real headache during the flights. Don't take this as me putting them down, as I like to know what's going on during launch and landing but during the flight...lugh. A quick interjection to help people who just tuned in figure out what's happening is fine (when CAPCOM/crew aren't talking), but sometimes I wish they would let us sit back and listen to the flight loop instead of describing the entire scene to us when something is going on. It's kinda like 'Yeah, we can see what's happening. Thanks for confirming that our eyes are working. Care to repeat what the CAPCOM/crew just said? I couldn't hear over the commentary

'

EDIT: FD highlights rolling. Saw the view of Discovery from the helmet-cam. Amazing...just amazing.

ckiki lwai · « **Reply #657 on:** 11/04/2007 08:33 am »

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Lee Jay - 4/11/2007 12:22 AM

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psloss - 3/11/2007 4:11 PM

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Chris Bergin - 3/11/2007 7:49 AM

Best image ever...don't care if we all duplicate this:
Going way back in the day, but I'm especially looking forward to any stills Scott took out there, either coming or going, hopefully they'll end up in a gallery section soon.

His camera wasn't working properly, at least in the early part of the EVA. I'm not sure if he eventually got any or not, but I didn't see him getting any shots.

I did see him taking pictures of the Earth while Houston said that Scott should focus on something closer then infinity.
And that was only moments after the unforgettable image of the Shuttle + ISS.
If he did take pictures then, I will surely print one in postersize and put it above my bed

ETEE · « **Reply #658 on:** 11/04/2007 01:00 pm »

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Lee Jay - 4/11/2007 3:58 AM

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ETEE - 3/11/2007 5:48 PM

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jcopella - 3/11/2007 11:08 PM

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Bruce - 3/11/2007 5:41 PM

Any idea when they can pronounce the arrays healthy, in terms of their expected power generation capability? For the port arrays, that is.

According to Suffredini @ the MSB, there is some (very very slight) concern about a short resulting from the damage. After Discovery undocks, they will do a "shunt test" to confirm there is no such short. Right now, the array is functional and tracking, but no power from 4B is reaching the station, and it will remain that way until completion of that shunt test. So...extrapolating from that, probably some time on Wednesday.

Not quite right I'm afraid. At the moment the entire P6 array is generating ~209 amps which is roughly 20kW at 100V DC (the design rating). This current is being fed into a shunt, which is a load (or short circuit) placed across the output of the array.

If it's shorted (shunted) it's not at 100V - it's at about 0V. That's the definition of a short circuit. If it's generating 20kW at 100V, it's not shorted (shunted).

From the description at the MSB, it is shunted and is generating a short-circuit current of 217A. They can't test it at voltage without un-shunting it and giving it a load to drive (the station). I guess they'll wait for Discovery to leave before trying that.

The current flowing into the shunt is the maximum the array can generate. The unregulated output of the array is conditioned by electronics before being fed to the station and/or stored in batteries. My comments were based on the effective output of one array assembly after conditioning which is 20kW for each pair of wings or 80kW for the entire station when S6 is deployed. I did not say that the array was generating 100V across a shunt, merely that 200A would be needed at 100V to produce 20kW.

I can see why they were keen on repairing P6 which cost US$276 million.

ChrisC · « **Reply #659 on:** 11/04/2007 03:34 pm »

Oof, that Flight Director update is painful to watch for the first 2 minutes ...