From: jrfrank@ibm-pc.borg.retro.com   
      
   kac@dynacon.ca (Kieran A. Carroll) wrote in   
   news:d87d73a5.0406291214.574a17b4@posting.google.com:   
      
   > henry@spsystems.net (Henry Spencer) wrote in message   
   > news:...   
   >> In article ,   
   >> David Given   wrote:   
   >>   
   >> >How about fitting the shuttle out with a lifeboat? Stick it   
   >> >somewhere in the cargo bay. If a shuttle gets sufficiently damaged   
   >> >that it can't reenter, you use the capsule to get the crew down.   
   >>   
   >> It's been proposed many times.  It presents some problems of physical   
   >> layout, its mass puts a considerable dent in the payload capacity...   
   >> and note that it wouldn't have saved Columbia's crew, since they   
   >> didn't know something was badly wrong until too late.  (Nor is there   
   >> any plausible scenario where they would have.  Suspicions about TPS   
   >> damage were focused on the tiles, not the RCC leading edge, and no   
   >> plausible imaging -- from the ground or from elsewhere in space --   
   >> would have been at all likely to notice a small dark hole in a black   
   >> surface.)   
      
   Hmm... some corrections here:   
      
   > However, for *future* Shuttle flights, the plan is for the entire TPS   
      
   Correction: just the wing leading edge will be inspected by the boom/laser.   
   And even that will be fully inspected only on the first few flights. Impact   
   sensors installed behind the RCC panels will be used to "target"   
   inspections to specific spots after that.   
      
   > to be scrutinized, using a high-resolution 3D laser ranging imager   
   > system (being developed by Ottawa's Neptec),   
      
   Correction: the boom is being baselined with only Sandia's LDRI laser for   
   return to flight. The Neptec will only be added when it's ready, which is   
   not likely for the first flight.   
      
   (The *original* plan was to have both lasers for return-to-flight, but   
   Neptec has since had some schedule delays.)   
      
   > which will be maneuvered   
   > around on the end of an extension boom (being developed by MDRobotics   
   > in Brampton), mounted on the end of the Canadarm.   
   >   
   > NASA's current plan for what to do, in case a TPS failure is   
   > discovered once on-orbit, seems to be a combination of patching it (if   
   > it's small enough to be patched using the in-development-now patch   
   > kit), and decamping to the ISS to await a rescue flight (if the TPS   
   > failure is not amenable to a field repair). Hence the decision to fly   
   > future Shuttle missions only to ISS (presumably inspection would also   
   > be easier using vantage points from ISS).   
      
   Correct. The acreage tiles on the underside will be inspected by flipping   
   the orbiter over at a range of 600 ft below ISS and having the ISS crew   
   photograph it. The resolution and depth measurement requirements are much   
   more lax for the acreage tiles than for the wing leading edge.   
      
   --   
   JRF   
      
   Reply-to address spam-proofed - to reply by E-mail,   
   check "Organization" (I am not assimilated) and   
   think one step ahead of IBM.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)