STS-115 Status - Part II

[rhodan]

The old thread was getting a bit long. You may find it here: STS-115 Status. Please continue your discussions in this new thread.

 

[lysol]

Ok, restate what i said before.<br /><br /><br />NASA is nuts for even considering risking Alantis and the ISS component bleh screw that...the crews lives. To meet scheduleing demands and prevent embarassment.<br /><br /><br />Its inexcuseable. irresponisble and is asking for more mishaps and disasters down the road.<br /><br />If i were the mission commander i be kicking engineer butt up and down the pad for risking the entire US manned flight program on a hunch and a butt pucker that the shuttle is green.

 

[paul_bacon]

I dont think Nasa would risk the safety of the mission if they werent sure (as sure as you can be going into space) that everything was ok. Nasa know that if anything went wrong this mission and we lost the crew, it would probably mean the end of the shuttle program, and in turn would mean the ISS would not be finished.<br /><br />

 

[lysol]

could have fooled me. NASA would have scrubbed it to fix the problem several years back. But politcal pressure from the disaster and the PR fallout of repeated delays.<br /><br /><shrugs /><br /><br />

 

[earth_bound_misfit]

I'm not surprised their having trouble with the ECO sensors. They should've just brought the delux ones <img src="/images/icons/smile.gif" /> <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>

 

[lysol]

Hey Tonka made them just barely at specs =P and for 50 million a pop.

 

[JonClarke]

Got evidence to support these assertions? Remember there are people here who actually work on launching the shuttle. These are the people you are calling irresponsible. You had better be sure you know what you are talking about.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[foochar]

"NASA is nuts for even considering risking Alantis [sic]and the ISS component bleh screw that...the crews lives. To meet scheduleing [sic] demands and prevent embarassment [sic]. "<br /><br />There is risk involved in everything including walking from your house to your mailbox. You can not eliminate all risk, you have manage the risks versus the rewards. Based on what I have heard here and elsewhere, in this case I think the risk is actually relatively small. <br /><br />To sum up the comments and discussion I have heard here and elsewhere: The orbiter has 3 fuel cells, this issue is only affecting one of these fuel cells. That fuel cell is still functioning and supplying power. The coolant pump for that fuel cell is operating on two phases of power, not all 3 as it normally would, the short is in the phase A power supply to that pump. The breaker for the phase A power to that pump will be pulled during launch so that this short can not further affect other systems. If one of the other phases on the coolant pump were to go out they would have to shut that fuel cell down, leaving them with only two fuel cells. If that were to happen they would switch to a minimum duration mission profile, that according to what I have heard here would still allow for docking with the ISS and unloading the truss. According to what I have heard here the pump is only on for about the first 30 minutes after launch, and presumably during landing, at times other than that the ambient cold of space takes care of the fuel cell cooling needs. There is basically only a 30 minute window where this problem can affect the mission. <br /><br />It seems to me that the people that know the most about the situation have made a reasoned decision. According to comments made at the press briefing this is not even a constraint to launch in the documented flight rules, however they wanted to make sure that they were hearing all the relevant opinions on this issue before proceeding.

 

[strandedonearth]

Not the ECO sensors again! C'mon, Atlantis, I want to see those supersize candles lit! Unless excessively unsafe, of course.<br /><br />And thanks for the bday wishes guys <img src="/images/icons/smile.gif" /><br /><br />Off to work I go. I hope I'll see good news here when I get home.

 

[farmerman]

If I remember correctly there are four sensors, and I thought that they could fly on three. Am I right or is my rusty ole brain letting me down.

 

[SpaceKiwi]

There are four sensors, and the LCC is that 4 of 4 must be good in order to launch, with a couple of exceptions.<br /><br />This currently observed problem is not one of those exceptions, so it appears to me as though they are re-writing the rule on the fly.<br /><br />I am <b>really</b> surprised at this development. I would have expected a 24 hour scrub by now. Perhaps they are still debating the pros/cons, and may yet abort this launch attempt, but it's not seeming like it from the NASA commentary at this time. <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[rfoshaug]

They can fly on three sensors. They have 4 to have some redundancy.<br /><br />Problem is that if they launch knowing that one sensor is faulty, they don't have any redundancy for unforeseen errors during ascent. They then only have 3 sensors and all of them must work or they have a bad day.<br /><br />But I have confidence in the engineers and management that if they decide to launch, they have data supporting that decision. <div class="Discussion_UserSignature"> <p><font color="#ff9900">----------------------------------</font></p><p><font color="#ff9900">My minds have many opinions</font></p> </div>

 

[paul_bacon]

The scrubbed Discovery last time when they were strapped in ready to go for the same problem, so it could happen again.

 

[SpaceKiwi]

Yes, this is true, and I can't find any information to suggest a final decision has been made one way or the other, so it may be that the matter is still being discussed by mission managers. <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[paul_bacon]

Although if the sensor is faulty (which is clearly is for whatever reason) then the procedure is staight forward. Scrub for at least 24 hrs.<br /><br />So you would think they would of decided what to do before strapping them in the shuttle. Who knows though

 

[SpaceKiwi]

George has just reported mission managers are discussing the problem with the ECO sensor, and how to proceed.<br /><br />Based on the previous experiences, the choice is clear ... scrub. <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[nyarlathotep]

>>"According to what I have heard here the pump is only on for about the first 30 minutes after launch, and presumably during landing, at times other than that the ambient cold of space takes care of the fuel cell cooling needs."<br /><br />I'd just assumed that they just didn't need as much power during after they dumped the SRB's. <br /><br /> />"Although if the sensor is faulty (which is clearly is for whatever reason) then the procedure is staight forward. Scrub for at least 24 hrs. <br /><br />Scrubbing for 24 hours would be pointless, the sensor is still going to be dead. It's either a rollback or launch with three of four sensors. I think they've made the right call, launch with three. Godspeed Atlantis!

 

[rfoshaug]

<blockquote><font class="small">In reply to:</font><hr /><p><br />Based on the previous experiences, the choice is clear ... scrub.<p><hr /></p></p></blockquote><br /><br />Is that your opinion or that of the mission managers? <br /><br />Edit: I guess if it had been the mission managers opinion they would have scrubbed already. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#ff9900">----------------------------------</font></p><p><font color="#ff9900">My minds have many opinions</font></p> </div>

 

[paul_bacon]

If they scrub for 24hrs like the launch procedure states, what testing do they do on the sensor between now and Saturday?

 

[SpaceKiwi]

That is the demonstrated behaviour of mission managers previous to today. <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[SpaceKiwi]

Yes, should they launch now, there is going to be some mighty impressive 'dancing' in post-launch briefing.<br /><br /> <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[SpaceKiwi]

<blockquote><font class="small">In reply to:</font><hr /><p>I'm not surprised their having trouble with the ECO sensors. They should've just brought the more expensive ones<p><hr /></p></p></blockquote><br />Radio Shack were having a sale, and Michoud had a coupon. <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[cello]

"If they scrub for 24hrs like the launch procedure states, what testing do they do on the sensor between now and Saturday?"<br /><br />they can unload and load tank again, and see how the sensor will perform.<br />they can not access sensor on the pad. only electronics.

 

[earth_bound_misfit]

I'm feeling a bit worried at the moment. Maybe a scrub might be a good idea considering all the faults that have been discovered. If they go, well I wish Atlantis and her crew a great flight. <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>

 

[SpaceKiwi]

As you know I'm pro-flight at every opportunity, and I don't wanna say schedule pressure, but it does seem like they're doing a pretty nifty two-step around the concerns. <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>