-
#200
by
Chris Bergin
on 06 Sep, 2006 18:16
-
Some screenshots from one of the presentations on L2:
-
#201
by
Chris Bergin
on 06 Sep, 2006 18:17
-
-
#202
by
jacqmans
on 06 Sep, 2006 18:32
-
Nice view of Atlantis on the pad, some moments ago...
-
#203
by
Carl G
on 06 Sep, 2006 19:15
-
I don't know how they are going to get through all the data. There's about a week's reading's worth of presentations on L2, but the feeling I get from them is it needs a replacement power cell
-
#204
by
DaveS
on 06 Sep, 2006 19:18
-
According to the latest information being shown on NASA TV, the post-MMT meeting press conference is NET 4 pm EDT.
-
#205
by
nathan.moeller
on 06 Sep, 2006 19:33
-
I have to stand with Kal. It's a much better idea to take a few weeks, get a new fuel cell in there (assuming that's what has to be done) and fly it safely. It would be much, much worse to fly with the hope that it will work because it could mean failure.
If they have to swap out the fuel cell, the launch would be pushed back to October. Yeah it's a bummer but here's what could happen if they fly as-is is much worse.
Let's say they fly as-is. The cell could work fine. But imagine if it dies. That would mean an early ticket home for Atlantis. Not only would that cut the mission short and eliminate many major tasks, depending on what the day the failure occurs, it could mean bringing the P3/4 back to Earth. No shuttle has ever landed with that weight and it could be very dangerous to attempt. Not only would it be dangerous to land with the payload, that payload would have to be relaunched at some point so assembly can continue. That would mean hundreds of millions of dollars down the drain and possibly the elimination of flights down the road in order to squeeze in another mission to relaunch the STS-115 payload. Also, if a failure occurs after the P3/4 is installed, most major tasks would be left incomplete and flights down the road would have to pick up the slack. The missions would be jam-packed with tasks left over from STS-115.
It's much safer to wait a few weeks and do it right than risk it and possibly have to wait many months to try again in the event of a failure. NASA will make the right call. Let's just let the MMT do their work and they can tell us about it later. In any case, I'm confident we'll see Atlantis get off the ground sometime this year. Go Atlantis!
-
#206
by
joncz
on 06 Sep, 2006 19:33
-
Was it just me or did anybody else see the pad crew going out to repair the fuel cell?
-
#207
by
nathan.moeller
on 06 Sep, 2006 19:41
-
That's funny stuff Jon. Yeah NASA needs to look to Energizer or Duracell to make their fuel cells from now on. I guess we're still just waiting on word from the MMT?
-
#208
by
psloss
on 06 Sep, 2006 19:42
-
nathan.moeller - 6/9/2006 3:20 PM
Let's say they fly as-is. The cell could work fine. But imagine if it dies. That would mean an early ticket home for Atlantis. Not only would that cut the mission short and eliminate many major tasks, depending on what the day the failure occurs, it could mean bringing the P3/4 back to Earth. No shuttle has ever landed with that weight and it could be very dangerous to attempt. Not only would it be dangerous to land with the payload, that payload would have to be relaunched at some point so assembly can continue. That would mean hundreds of millions of dollars down the drain and possibly the elimination of flights down the road in order to squeeze in another mission to relaunch the STS-115 payload. Also, if a failure occurs after the P3/4 is installed, most major tasks would be left incomplete and flights down the road would have to pick up the slack. The missions would be jam-packed with tasks left over from STS-115.
The impact of a single fuel cell failure is basically loss of mission with the scheduling issues you describe -- not a crew, vehicle, or payload safety issue.
There's no point in starting a mission one can't successfully complete.
-
#209
by
Mark Dave
on 06 Sep, 2006 19:45
-
So the 24 hour change will be alot longer then huh?
-
#210
by
Chris Bergin
on 06 Sep, 2006 19:45
-
nathan.moeller - 6/9/2006 8:28 PM
I guess we're still just waiting on word from the MMT?
Still meeting.
-
#211
by
nathan.moeller
on 06 Sep, 2006 19:46
-
Have they ever landed with that weight before? I thought I heard Cain say that they wanted to do everything in their power to leave it in orbit so as not to risk an extremely heavy landing. It would be challenging at least with an extra 18 tons on your back I'm sure.
-
#212
by
Stardust9906
on 06 Sep, 2006 19:46
-
Svetoslav - 6/9/2006 6:06 PM
After the restart the fuel cell works properly. We could say the problem has been solved, but there could be a more serious problem, as some people noted. My vote is launch as-is.
Better to take enough time to understand the problem and to replace hardware if necessary than to end up loosing a fuel cell and having to come back early. The engineers need to understand what’s going on with this fuel cell before they know if they can fly as is and as far as I can tell they don’t yet.
-
#213
by
astrobrian
on 06 Sep, 2006 19:55
-
MMT Press briefing is still being listed as NET 4 pm EDT
-
#214
by
daveglo
on 06 Sep, 2006 19:55
-
Could any of the knowledgeable folks expand on the pre-flight testing done on the fuel cells? I can't believe anything went to the pad without a thorough functional test prior to launch day. Given the number of times a fuel cell problem has caused a launch/flight issue, I'd have test run them several times in the days/weeks leading to this day.
-
#215
by
psloss
on 06 Sep, 2006 19:57
-
nathan.moeller - 6/9/2006 3:33 PM
Have they ever landed with that weight before? I thought I heard Cain say that they wanted to do everything in their power to leave it in orbit so as not to risk an extremely heavy landing. It would be challenging at least with an extra 18 tons on your back I'm sure.
They have to be able to land with the payload -- that's a safety issue. You want to leave it in orbit attached to the station because of the implications of having to launch it
twice. (Some of which you noted.)
-
#216
by
psloss
on 06 Sep, 2006 20:04
-
daveglo - 6/9/2006 3:42 PM
Could any of the knowledgeable folks expand on the pre-flight testing done on the fuel cells? I can't believe anything went to the pad without a thorough functional test prior to launch day. Given the number of times a fuel cell problem has caused a launch/flight issue, I'd have test run them several times in the days/weeks leading to this day.
First, I'm not sure they would load cryos in the OPF. Second, loading and unloading cryos probably takes away pad work shifts. And also why couldn't the fuel cell work fine during any number of pre-countdown tests and then fail during activation in launch count? (Operational lifetime is also an issue here -- i.e., MTBF.)
"Solving" one problem can also create more of them.
-
#217
by
nathan.moeller
on 06 Sep, 2006 20:04
-
psloss - 6/9/2006 2:44 PM
nathan.moeller - 6/9/2006 3:33 PM
Have they ever landed with that weight before? I thought I heard Cain say that they wanted to do everything in their power to leave it in orbit so as not to risk an extremely heavy landing. It would be challenging at least with an extra 18 tons on your back I'm sure.
They have to be able to land with the payload -- that's a safety issue. You want to leave it in orbit attached to the station because of the implications of having to launch it twice. (Some of which you noted.)
True. I feel really stupid now because I said that to my dad earlier. We were discussing the AOA (abort once around) option if something were to go wrong and how they'd have to be able to land with the payload in that case. In any case it would be difficult handling I bet if you're used to landing an orbiter with a near-empty payload bay. Sorry about that.
Cain: "We will do everything in our power to leave this payload in orbit"
*reporters chuckle*
Cain: "Preferably at the space station."
Suffredini: "...thank you..."
-
#218
by
psloss
on 06 Sep, 2006 20:08
-
-
#219
by
Chris Bergin
on 06 Sep, 2006 20:15
-
10 pm UK, 9pm GMT. Still meeting was the latest I heard though. Two hour MMT!
