STS-122 (1E) Updates

[centsworth_II]

I really don't follow all this very well, but in the course of the last<br />few days, have recommendations ranged all the way from allowing<br />fight with no working sensors all the way to requiring all sensors to<br />be working been considered? That seems like an astonishing swing<br />in thinking to me for such a mature system. Or do I have no clue<br />about what is going on? <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

They have never advocated flying with no working sensors.<br /><br />The previous LCC (Launch Commit Criteria) was 3 of 4 had to be working.<br /><br />Due to the problems (which they thought had been fixed) it has now been tightened to require all 4 be working.<br /><br />They did briefly consider having only 2 of 4, with input from the additional instrumentation installed for the last few flights, but the feeling was there hasn't been sufficient time to properly integrate that data into the system. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[usn_skwerl]

so they're flying tomorrow? ETD? <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

That has not been determined yet. Tentatively, yes, But they have a MMT meeting this afternoon to decide. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

Replay of Yesterday's New Conference on NASA TV now. <br /><br />Edit, sorry it was just excerpts. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[vulture2]

>>requiring multiple redundancy, this was the only way that the safety of the crew could be assured without designing the orbiter with a detachable crew compartment.<br /><br />Redundancy is not equivalent to reliability. Obviously there are situations where redundancy makes sense, i.e. if the redundant systems are completely independent with no common failure modes and any one of them can do the job; an example is the spelunker who carries three flashlights. But in an aerospace system the redundant systems are usually closely linked, creating additional and often unanticipated failure modes, and always adding weight, volume, and cost, increasing the parts count and the probability that at least one component will fail.<br /><br />NASA insists there be "no single point of failure", that the system be "fail operational, fail safe". In my humble opinion, this approach is simplistic and stems from the perspective of the manager looking at a block diagram of the system, not the tech who gets his hands dirty with the hardware or the engineers who design the actual chips and valves. Suppose there is a common failure mode? Suppose the failure is in the voting system or some other element that is "single path"? Suppose multiple components fail? In a real aerospace system, it is usually cheaper in the long run to increase the reliability of the components, and once a failure mode is known it can usually be designed out. In reality the Shuttle has a lot of potential single point failures; the TPS comes to mind. But we overlook them because they don't fit the "fail operational"philosophy.<br /><br />Of course design changes are slow and expensive in "man-rated" vehicles. But this slow and expensive modification process actually makes the vehicle LESS safe by delaying improvements, Challenger comes to mind; a new SRB joint was "in the pipeline" when the seven astronauts died. What good did all the man-rating paperwork do for the Challenger 7?<br /><br />The root cause is the m

 

[usn_skwerl]

update so far.....1 minute launch window. saves fuel, less reliance on the ECO sensors. will fly if no issues at tanking, from what it sounds like... unless of course im watching a replay... <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

That was a replay...see my scribblenotes above. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[montmein69]

<font color="yellow">So all you have to do is go thru the process of getting a new unproven component man rated. Piece of cake, right?</font><br /><br />I never said it is an easy decision.<br />But could you certify at the moment that LH2 ECO sensors,the wiring and the electronic box, are "proven components man rated" with such erratic behaviour ?<br /><br />If they'll never have to work in any launch till 2010 , you may say we have been lucky with that russian roulette ... <br />Because if the tank is near to be empty and ECO sensors are "dry" .... only few milliseconds remain before the pump cavitation happens and the engine is down .. <br /><br />The crew can't react even if a red light appears on the control pannel or if the Mission Control say "you have a low H2 level alert"<br />The MECO must be triggered by the electronic chain and the computer action. And at the moment this is not reliable. <div class="Discussion_UserSignature"> </div>

 

[billslugg]

vulture<br />I am totally with you in terms of favoring reliability over redundancy. However, when the payout on reliability spending is miniscule, it is time to bring in the backup systems. I argued against adaptive fixes my whole paper making career. <br /><br />If we had a hole appearing in the sheet say, every 250 feet, some people would advocate installing a stock spray, spurting every 6 seconds to fill the hole in. I would say - lets go fix the cause of the hole. They would say "We don't know how to do that."<br />In our presentations to management I would pointedly refer to their proposals as "The spending of capital dollars to enhance our ability to run poorly." It usually got the point across. <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>

 

[MeteorWayne]

Post MMT News Conference scheduled NET 4PM EST, about 10 minutes from now.... <br /><br />Edit <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[bobblebob]

MMT Briefing NET 4:30 now <img src="/images/icons/tongue.gif" /><br /><br />

 

[MeteorWayne]

We're shocked <img src="/images/icons/laugh.gif" /><br /><br />Remember I picked 5:15 EST <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

From the NASA site:<br /><br />Dec. 8 - 4:15 p.m. EST <br />Today’s Mission Management Team meeting has concluded. We are “go†for a Sunday launch attempt.<br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

I know y'all are shocked, but the news conference has been delayed until NET 4:45 EST <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[bobblebob]

Excellent news <img src="/images/icons/smile.gif" /><br /><br />Looks like you won then, wont be as late as i said <br />

 

[erioladastra]

Plan is to launch tomorrow if they show 4 of 4 ECOs at T-31. Another wrinkle now is that ISS is having a power problem. Several RPCMs have tripped on the starboard BGA and folks are assessing the power impacts on the mission. BGA is now parked in the docking position but likely won't be able to go to autotrack.

 

[centsworth_II]

<font color="yellow">"The previous LCC (Launch Commit Criteria) was 3 of 4 had to be working....<br />it has now been tightened to require all 4 be working."</font><br /><br />Thanks for the explanation. I normally don't follow the shuttle this closely<br />but I, like many others I'm sure, realize that if I am to see a shuttle launch, <br />I'd better start getting serious. I'm only a couple hours away but with work,<br />it's tough. This past Thursday was the first try. Luckily(?!) it got called off<br />before I hit the road. <div class="Discussion_UserSignature"> </div>

 

[ozspace]

T- 5:30 <br />They are showing various camera views of the vehicle now and I don't ever recall seeing the two cables that appear to be hanging off the ET lower connection points with the orbiter, May just be a depth of feild thing and not attached to the stack at all. Any ideas?

 

[ozspace]

Liquid hydrogen sensor # 3 has just failed "not good news" to quote NASA PAO

 

[ozspace]

This will almost cetainly cause a scrub and revert to a tanking test to gather data,.

 

[MeteorWayne]

Yep, that ain't good news at all. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[ozspace]

Scrub now official.

 

[MeteorWayne]

Official scrub for the day <img src="/images/icons/frown.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[earth_bound_misfit]

****** these bloody sensors! I've been hanging for this launch and I bet the crew are too. <img src="/images/icons/frown.gif" /><br /><br />So what's the options now? <div class="Discussion_UserSignature"> <p> </p><p> </p><p>----------------------------------------------------------------- </p><p>Wanna see this site looking like the old SDC uplink?</p><p>Go here to see how: <strong>SDC Eye saver </strong>  </p> </div>