Space Shuttle Return to Flight - Pt. 3

[shuttle_rtf]

Thanks SG <img src="/images/icons/smile.gif" /><br /><br />Quick reminder to all: Stafford-Covey Return To Flight Task Group meeting isn't far away, June 6.

 

[ozspace]

Nothing to do with this thread but we can always do with a laugh...<br /><br />"Apollo moon mission astronaut Neil Armstrong has threatened to sue a barbershop owner who collected Armstrong's hair after a trim and sold it for $3,000."<br /><br />http://www.floridatoday.com/apps/pbcs.dll/article?AID=/20050601/BREAKINGNEWS/50601009/1007/NEWS02

 

[drwayne]

The nerve of that barber. The least he could have done was cut him in!<br /><br /><img src="/images/icons/wink.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[Testing]

If I had only saved some of the pic's the Other SG posted! <div class="Discussion_UserSignature"> </div>

 

[najab]

><i>It is a mystery to me why the STS sat out on the pad and tested the tank soon to be removed when they could have just rolled the thing back and put on the new tank and then tested it.</i><p>Because they didn't know whether they had solved the problems that appeared during the first tanking test. As it was, the ECO sensor issue seems to have been solved, but the LH2 press-repress system still seems to have a problem. If the second tanking test had gone off without a hitch, they wouldn't have had to do the roll-back and stack swap.</p>

 

[haywood]

Was the issue of hydraulic fluid on some of the external blankets resolved?<br />

 

[Testing]

Not sure which term NASA use's but here are two versions.<br /><br />Unverified failure<br /><br />Un-explained annomoly<br /><br />Either of these can doom any piece of hardware, I don't care how big or expensive it is. If it can not prooven (and I don't mean beyond a reasonable doubt) as to the exact cause, the hardware has failed and is not flight worthy. I have seen a $250,000 piece of hardware become a door stop because of an erronious position indication. Was most likely a software glitch, but could not be duplicated in 6 months of trying. SCRAP <div class="Discussion_UserSignature"> </div>

 

[najab]

As I remember it, they decided that the blankets could fly as is. I don't know if they've decided to replace them since the vehicle is back in the VAB anyway, but the tight scheduling of the stack swap suggests not.

 

[shuttle_rtf]

I think I saw "TPS blanket replacement" in one of those long memos SG posted here.

 

[shuttle_rtf]

Interesting.<br /><br />And still the potential for a bit of 'fire' - I don't know how else to describe it, from the heat of the SRB next to the OMS Pod with the fluid on it?<br /><br />I know they said it wouldn't harm the Orbiter - but is that still the case?

 

[ozspace]

We now have a very good idea of the next steps toward launch for STS-114 to fly. But at what stage of flight readiness does the STS-121 hardware need to be at when Discovery launches for a possible rescue (STS-300)? <br />Will the stack need to be complete in the VAB and ready to roll out on launch day? Or would the ET & SRBs be stacked but with Atlantis in the OPF ready for reconfiguration for a rescue?

 

[najab]

The requirement is that Atlantis has to be 45 days or less away from launch. So yes, in the OPF ready to roll over would fit the bill.

 

[shuttle_rtf]

Sounds like they want to test both LH2 diffusers on the repress cycle issue. As in ET-120 (which is the test this weekend?) has the new diffuser with the double dutch weave, compared to the single mesh on ET-121 - if I'm correct?

 

[shuttle_rtf]

Shuttle Status report, June 3:<br /><br /><br />Discovery (OV-103)<br /><br />Mission: STS-114 - 17th ISS Flight (LF1) - Multi-Purpose Logistics Module<br /><br />Vehicle: Discovery (OV-103)<br /><br />Location: Vehicle Assembly Building (VAB)<br /><br />Launch Date: Launch Planning Window: July 13 - 31, 2005<br /><br />Launch Pad: 39B<br /><br />Crew: Collins, Kelly, Noguchi, Robinson, Thomas, Lawrence and Camarda<br /><br />Inclination/Orbit Altitude: 51.6 degrees/122 nautical miles<br /><br />In the VAB, orbiter Discovery was de-mated from its External Tank (ET-120) and Solid Rocket Boosters in high bay 1 on June 2. Discovery was lowered by crane onto the Orbiter Transporter System in the VAB transfer aisle.<br /><br />The vehicle will be moved in front of high bay 3 in preparation for being lifted and attached to its new tank, ET-121, on June 6. That tank was originally scheduled to fly with Atlantis on the second Return to Flight mission, STS-121. A new heater was added to the tank's feedline bellows, part of the pipeline that carries the liquid oxygen to the orbiter's main engines, to minimize the potential for ice and frost buildup.<br /><br /> Once mated to the new tank, technicians will work final closeouts on the fully assembled Space Shuttle stack, and perform liquid oxygen and liquid hydrogen electrical mates and an interface verification test. Discovery is scheduled to return to Launch Pad 39B on June 13.<br /><br /><br />Vehicle: Atlantis (OV-104) <br /><br />Location: Orbiter Processing Facility Bay 1 <br /><br />Launch Date: Lighted Launch Planning Window September 9 - 24, 2005 <br /><br />Launch Pad: 39B <br /><br />Crew: Lindsey, Kelly, Sellers, Fossum, Nowak and Wilson <br /><br />Inclination/Orbit Altitude: 51.6 degrees/122 nautical miles <br /><br />Technicians continue power-up testing on Atlantis in Orbiter Processing Facility bay 1 for its mission to the Space Station. Forward, mid-body and aft area closeouts continue. Atlantis is scheduled to be rolled from the processing facili

 

[shuttle_rtf]

Sounds like they want to target the over-cycling to the new diffuser.....with a request for a third tanking test if their results are inconclusive.<br /><br />However, a third tanking test isn't really going to help them with the evaluating of this diffuser, because if the single mesh version over-cycles on the pad then I've got a feeling everyone will surprised.<br /><br />I'm taking it the single mesh diffuser is the tried and tested version that you've launched with?<br /><br />This is very interesting, but pretty easy for someone like me to say "It's gotta be the new diffuser. Go back to the old one, problem solved." These things would have been tested over and over again, but is it your experience that these items can simply have issues once they've been intergrated into the complexity that is the STS?

 

[haywood]

Sounds like a good rationale for not having another tanking test before launch day.<br />If the new ET has a spec diffuser, I suspect that is that last we'll see of that problem.<br />

 

[shuttle_rtf]

Facinating, thank you.<br /><br />I suppose the obvious question is why did they move from the old diffuser to the double mesh version? Was there any performance/reliability issues with the single mesh diffuser?<br /><br />Or was it a case of the diffuser vendor simply saying "we've got a new and improved version for you guys"?

 

[drwayne]

Wouldn't be the first time...<br /><br />I remember a story from the LEM days about a vendor deciding to improve the quality of their stuff, I believe it was gycol, and ending up with something that, while purer, tended to form crystals more easily.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

Good luck sir.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[shuttle_rtf]

Excellent. Thanks SG.

 

[najab]

Cool -3 exclamation marks-<br /><br />SG, you never did tell us if you were able to find if you guys had done a stack swap in the past -question mark-<br /><br />[The shift and enter keys on my keyboard are not working.]

 

[teije]

Thank you. Very impressive photo series. <img src="/images/icons/smile.gif" /><br />I have a question that I wondered about for some time now and these photo's reminded me of it.<br /><br />It's about the propellant feed from the ET to the orbiter. I can quite clearly see 2 openings in the heat shield in some of these pictures that I presume are the locations of propellant feed. How are these locations protected during ascent? Is it even necessary to protect them? How does the seperation event take place at ET separation?<br /><br />Lateral question: Apart from these two openings there are also openings in the heat shield for the landing gear. How can you ensure a completely intact heat shield in these areas? Especially the propellant feed because these cannot be checked to be closed at launch.<br /><br />Thanks in advance!<br />Teije

 

[nacnud]

lol<br /><br /><br />So how did you get the capitals?

 

[shuttle_rtf]

Caps Lock on and Caps Lock off <img src="/images/icons/smile.gif" />

 

[najab]

Forgive the brevity of the explaination, as I pointed out earlier I have no shift or enter keys.<br /><br />During ascent the umbilical area does not require much protection beyond the simple closeout curtain installed after the orbiter is mated to the tank. The curtain is designed to keep FOD out of the umbilical well during the sit on the pad and during ascent.<br /><br />At ET sep, the Orbiter side unbilical connections retract into the umbilical wells. The opening is then covered by the umbilical doors, these are covered with TPS tiles to protect the area from heating. There is a system on the inside of the umbilical door which applies force -left parenthesis- I think it might be by filling the space with pressurised nitrogen -right parenthesis- to ensure that the door seals tightly with the surrounding TPS tile.<br /><br />The other openings in the TPS -left parenthesis- the landing gear doors -right parenthesis- are closed out during processing and do not usually open again until the vehicle is on final. They are sealed during pre-launch processing using a putty-type compound.