-
#180
by
DaveS
on 06 Sep, 2006 17:07
-
Svetoslav - 6/9/2006 6:53 PM
Oh, and it seems that the press conference is 10 minutes from now ( If I calculate the time zones properly ), am I right?
Nope. That when the
MMT meeting begins. When the actual press conference might begin is anyone's guess.
-
#181
by
Mark Dave
on 06 Sep, 2006 17:16
-
Hopefully the problem will be fixed before tomorrow.
-
#182
by
Svetoslav
on 06 Sep, 2006 17:19
-
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.
-
#183
by
DaveS
on 06 Sep, 2006 17:21
-
MarkD - 6/9/2006 7:03 PM
Hopefully the problem will be fixed before tomorrow.
It isn't as much about fixing the problem, but question of flying with suspect critical hardware that has behaved very unusually on the ground.
-
#184
by
nathan.moeller
on 06 Sep, 2006 17:21
-
I hate to say it but I hope they don't launch until Friday...only because I won't be able to see it tomorrow!!
-
#185
by
Joffan
on 06 Sep, 2006 17:24
-
I'm with you Svetoslav but I don't think that NASA is. The process appears to be that any issue has to be proven benign or survivable without flight objective impact.
Personally it seems to me that the impact of not launching with a survivable fault such as this is greater than a full investigation and whole program delay. Even a shortened mission would allow the orbiter to leave the P3/P4 truss on the ISS and safe, after which a program of ISS crew spacewalks might recover some of the slip.
-
#186
by
logickal23
on 06 Sep, 2006 17:25
-
I will be truly, truly surprised (and disappointed) if the team chooses to fly as-is. This is almost a perfect litmus test of the safety vs. schedule pressure arguement.
-
#187
by
Mark Dave
on 06 Sep, 2006 17:27
-
If you miss it, tape the launch in advance. I always do that.
As to the fuel cell, I recall a water spray boiler problem mentioned on STS-104 where it was dropping 1.5 degrees every 15 minutes, but they flew the vehicle anyway. IMO just keep an eye on it if it seems to be a worry for some.
-
#188
by
jacqmans
on 06 Sep, 2006 17:30
-
maybe a stupid question from me, but can the Shuttle fly with 2 full cells ?? (I know there were two missions cut short in the past due to Full cell failures, STS-2 and STS-83), but is it possible to launch with 2 ??
-
#189
by
nathan.moeller
on 06 Sep, 2006 17:30
-
logickal23 - 6/9/2006 12:12 PM
I will be truly, truly surprised (and disappointed) if the team chooses to fly as-is. This is almost a perfect litmus test of the safety vs. schedule pressure arguement.
Amen to that. It's better to swap it out and wait another six weeks to make sure it works instead of getting go-fever and launching into a botched mission like STS-83. I'm sure Congress won't allow NASA to relaunch a mission just because they couldn't wait six weeks. It's a shame to wait but it'll be for the best if they do so.
-
#190
by
DaveS
on 06 Sep, 2006 17:32
-
MarkD - 6/9/2006 7:14 PM
If you miss it, tape the launch in advance. I always do that.
As to the fuel cell, I recall a water spray boiler problem mentioned on STS-104 where it was dropping 1.5 degrees every 15 minutes, but they flew the vehicle anyway. IMO just keep an eye on it if it seems to be a worry for some.
Huge difference. The WSBs are part of the APU/HYD system which isn't used until landing. The FCs on the other hand is used during the entire mission. Loose one, and you get a early ticket home. Not the same thing if you loose a WSB.
-
#191
by
DaveS
on 06 Sep, 2006 17:34
-
jacqmans - 6/9/2006 7:17 PM
maybe a stupid question from me, but can the Shuttle fly with 2 full cells ?? (I know there were two missions cut short in the past due to Full cell failures, STS-2 and STS-83), but is it possible to launch with 2 ??
No. That's why you get an early ticket home if you loose one FC out of three.
-
#192
by
Svetoslav
on 06 Sep, 2006 17:35
-
And if there's a delay what about the shedule? A lot of major components for ISS won't be installed at all. How do you expect the station to be finished in the configuration we want if there are more delays?
-
#193
by
logickal23
on 06 Sep, 2006 17:39
-
A 3-6 week delay in 115 isn't going to throw ISS assembly into disarray. Flying a shortened 115 where you don't meet your assembly goals during flight will have much more impact down the road.
-
#194
by
Mark Dave
on 06 Sep, 2006 17:40
-
Yeah, the ISS needs this stuff, or what's the point of building it? It won't be finished if delays keep some of the vital parts from being added. 2010 is the end of shuttle flights, and worse if the station isn't done by then with no vehicle to carry the large pieces to add.
-
#195
by
Svetoslav
on 06 Sep, 2006 17:44
-
a 3-6 week delay is currently trowing the mission to late October. Unless there's a chance for a late september launch ( I don't have the document for launch opportunities because I'm not subscribed to L2 ). And the launch window in October lasts only two days. And if the weather is bad or there's yet another technical issue, we are late...
Meanwhile, Russia plans to launch a segment in 2007 or 2008, not sure when exactly. And it will use its own Proton boosters.
-
#196
by
Chris Bergin
on 06 Sep, 2006 17:44
-
If you wish to discuss ISS assembly hits, or anything along those terms, go to that relevant part of the forum. This is a live update page for information relating to the launch attempt and scrub.
-
#197
by
Joffan
on 06 Sep, 2006 17:44
-
Schedule pressure is part of the safety equation. Launching later has its own risks, as in a crowded later flight manifest and flying Shuttles later in their lives (although I fully acknowledge that flight age is the major consideration, calendar age does have its effects too). Changing out hardware carries a risk. Rolling back carries a risk. So I'm hopeful that the MMT will consider both kinds of risks, fly now and fly later, and balance between them.
-
#198
by
Chris Bergin
on 06 Sep, 2006 18:01
-
On the flow charts, the one below the official reason notes: "1. Wire Short To Ground Between H2 Pump Motor Wiring Split To Coolant Pump Motor"
-
#199
by
mkirk
on 06 Sep, 2006 18:13
-
Chris Bergin - 6/9/2006 12:48 PM
On the flow charts, the one below the official reason notes: "1. Wire Short To Ground Between H2 Pump Motor Wiring Split To Coolant Pump Motor"
Hey Chris-
That is just one of the failure modes on the fault tree.
I should also point out that the coolant pump and the H2 pump are two different things. However, they are both powered by AC1 in this case (for fuel cell 1) by looking at how much power they draw (normally .5 amps for the coolant pump and .3 for the H2 pump) you can try and deduce the health of the component or the health of the AC Bus.
Mark Kirkman