From: nospam@127.0.0.1   
      
   On 1/24/2021 4:40 PM, JF Mezei wrote:   
   > On 2021-01-24 08:03, Jeff Findley wrote:   
   >   
   >> Because standard experimental practice is to only change one variable so   
   >> you can compare the results of two tests.  In this case, they've made   
   >> changes which impact the final landing burn.   
   >   
   >   
   > Hence my question on whether terminal velocity at time of final landing   
   > sequence would be the same whether you launch to 50 or 10.  If it is the   
   > same, wouldn't it be fair to state that a test to 50km would have   
   > identical conditions at the time of the final landing sequence?   
      
   I don't think so. To get to 50km you need more propellant than to 10km.   
   If you are studying/testing internal tank pressure (head pressure) you   
   might want to profile at different propellant loads. Since the last test   
   at given propellant load X failed, you'd probably want to re-test with   
   the same load factor. If successful then move on to Y. Note that if   
   successful, and the engines/tanks etc. aren't damaged in any significant   
   way, the next flight can take place quickly. Here quickly means weeks   
   not months.   
      
   >   
   > With regards to winds, does this mean a "cold turkey" escalation from   
   > 10km up/down  to orbital because higher than 10/12 km, you get winds   
   > that exceed cross range capability?   
   >   
      
   Doubtful. Propellant load should be able to handle whatever altitude you   
   are testing for. Winds aloft will be known ahead of time, so that should   
   provide limit bars for cross range. BTW, Elon has tweeted in the past   
   the cross range of a typical sub-orbital Starship is on the order of   
   10,000 km, that's for coming down from well above these test altitudes   
   however. The cross range for these tests is, comparatively speaking,   
   quite limited I'm sure. But that's fine, even if lost, these are test   
   vehicles, easily replaced.   
      
   > For testing of starship, would an alternate landing side be in the plans   
   > to allow mid altitude testing with landing elsewhere ?   
      
   Doubtful, until he gets those oil rig platforms converted and presumably   
   placed at various spots in the Gulf of Mexico. There aren't any Starship   
   landing sites yet at the Cape (or anywhere else) for the time being.   
   Maybe in a year or two?   
      
   Dave   
      
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