Loading ...
Sorry, an error occurred while loading the content.
 

> 2. UV degradation of latex (?)

Expand Messages
  • K. Mark Caviezel
    ... things will be a lot colder. The Huntsville guys (Bill WB8ELK and Gary N4TXI) both launched some very interesting flights last year. Both had modest
    Message 1 of 3 , Aug 30, 2005
      > Subject: UV degradation of latex (?)

      > I don't think we can cheaply prove that UV
      > degradation causes balloon
      > failures at altitude, but this simple experiment
      > might provide a
      > little weight one way or the other.

      >>>>> uhmmmm how about flying at night? of course,
      things will be a lot colder. The Huntsville guys
      (Bill WB8ELK and Gary N4TXI) both launched some very
      interesting flights last year. Both had modest free
      lift, slow ascent rate which stalled at altitude when
      solar illumination went bye-bye and had very
      significant endurance after that point. Daytime slow
      ascenders don't do nearly so well.

      - KMC ng0x Denver
    • Mike Manes
      Ah yes, the counter-countervaling argument arises! Go figger ... 73 de Mike W5VSI ... -- Mike Manes manes@attglobal.net Tel: 303-979-4899 Things
      Message 2 of 3 , Aug 30, 2005
        Ah yes, the counter-countervaling argument arises! Go figger ...
        73 de Mike W5VSI

        "K. Mark Caviezel" wrote:
        >
        > > Subject: UV degradation of latex (?)
        >
        > > I don't think we can cheaply prove that UV
        > > degradation causes balloon
        > > failures at altitude, but this simple experiment
        > > might provide a
        > > little weight one way or the other.
        >
        > >>>>> uhmmmm how about flying at night? of course,
        > things will be a lot colder. The Huntsville guys
        > (Bill WB8ELK and Gary N4TXI) both launched some very
        > interesting flights last year. Both had modest free
        > lift, slow ascent rate which stalled at altitude when
        > solar illumination went bye-bye and had very
        > significant endurance after that point. Daytime slow
        > ascenders don't do nearly so well.
        >
        > - KMC ng0x Denver
        >
        >
        >
        >
        > Yahoo! Groups Links
        >
        >
        >
        >

        --
        Mike Manes manes@... Tel: 303-979-4899
        "Things should be made as simple as possible, but not more so." A.
        Einstein
      • wb8elk@aol.com
        Not sure whether UV degradation had any effect on our floater flights in December 2004 but here s some details of the 4 flights: All four floater flights were
        Message 3 of 3 , Aug 30, 2005
          Not sure whether UV degradation had any effect on our floater flights in December 2004 but here's some details of the 4 flights:

          All four floater flights were pretty much as follows:

          Scientific Sales 1500 gram balloon (Sept 2004 batch)
          1.5 lb flight train
          1.75 to 2.50 lb nozzle lift

          Ascent rates from 275 to 400 ft/min

          The December 4th flight was launched in the morning - 400 ft/min ascent rate....it achieved float for just 2 hours before bursting in mid afternoon.

          Flights 2 and 3 in Dec. 18th were launched around 1:00 pm or so....and never achieved maximum altitude before losing sunlight....they levelled off at 98 and 105k ft.....one was heard again the next morning near Nova Scotia and apparently burst 3 hours after sunrise after 22 hours in the air....it had apparently been slowly descending during the night since that's the only way it could've hit winds that would put it in New England.....  275ft/min and 350 ft/min for the seperate balloons.

          Flight 4 on Dec 26th

          Launched around 1:00 pm and reached maximum altitude in late afternoon before sunset....batteries froze out after sunset after a few hours of float on it's way to the Bermuda Triangle.

          Perhaps a series of identical floater flights both during the day and some during night would answer the UV question.

          - Bill WB8ELK

          I'm going to try an intentional floater flight soon using these same conditions from the same batch of balloons...perhaps this weekend.
        Your message has been successfully submitted and would be delivered to recipients shortly.