PART 1: Juan provides details from a routine flight


             -= Flight Log of Kuiper Airborne Observatory - 5/10/94 =-
                     Juan Rivera - Airborne Telescope Operator

8:35 PM taxiing out for takeoff.
8:45 PM Off the ground and climbing

The oscillating secondary mirror wiring problem has been fixed and everything
looks good.  The OSM chassis was moved to another place in the console to make
room for the computer work station I am now typing on.  In order to move the
OSM chassis the interconnecting cabling had to be replaced with new wiring.
The new wiring had several bad splices which were occasionally opening up
causing intermittent problems.  So that is what caused the problems.

9:00 PM Passing through 27,000 feet. Time to turn off the flow of liquid
        nitrogen to the telescope cavity.

9:05 PM I have all my systems up and running now and I am ready to open
        the telescope aperture door when we get to about 35,000 feet.
        This door is one of the many unique features of this aircraft.
        Most planes don't fly along at Mach .74 with a huge door open in the
        side of the plane!  A great deal of time and money has been spent in
        getting the air to flow smoothly over this opening which is about
        6-feet square.  Since the telescope has to look through this flow
        of air blasting across the door, it's essential that it be nice
        and smooth.  Otherwise the image would be distorted by
        the turbulence.  Have you ever noticed heat waves coming off the
        surface of a hot road?  It causes everything to shimmer because the
        air is unstable.  It's the same thing here, only the air is moving
        hundreds of times faster!

9:12 PM We're up to 36,000 feet already.  Almost time to open up the

9:15 PM Now I'm opening up the aperture door which is also called the
        "dome".  I also have our powerful air compressors turned on.  There
        are three of them, and at any given time one is a standby unit and
        the other two are running.  Each one is driven by a 17 horse power
        electric motor that draws 50 amps of three-phase 220 volts.  That's
        gobs of power.

0728 UT OK, Let's get switched over to the type of time we actually use
        here which is 24-hour universal time, also known as GMT for
        "Greenwich Mean Time" or UT for "Universal Time".  UT time is
        the same all over the world with no time zones or daylight savings.
        So it is very easy to coordinate operations which span different
        parts of the world.  If we tried to use local time we would have
        to change our clocks about 5 times during a flight!

0738 UT In 11 minutes we'll turn on to our first observation leg and start
        looking at Alpha Boo.  The experimenters will use this to set up
        and adjust their equipment.

        One of the neat things about flying out of Hickam Air Force Base
        is that we can order these really nifty flight meals from the
        Air Force for $2.15.  It's the greatest deal on earth.  It comes
        in a cardboard box that says, "Hickam Air Force Base Flight
        Kitchen - Crossroads of the Pacific - Hale Aina Mokulele"
        Here's what I get for my $2.15:

               1 can of pineapple nectar
               1 tin of jello
               1 bag of peanuts
               1 chocolate-covered dry-roasted macadamia nut candy bar
               1 bag of potato chips (About to explode !!)
               1 piece of Sara Lee pound cake
               1 Apple
               1 Ham sandwich 
               1 Chicken leg and 1 breast

        Not bad for the money, eh?  Anyone know why the potato chip bag
        is about to pop?  The answer should be worth some extra credit
        to someone...

0805 UT I've now adjusted the infrared focus of the telescope for the
        experimenters.  It focuses at a different place than it does for
        visible light.  More extra credit...  Explain that!

0816 UT Headed up to 39,000 feet now.  The cabin altitude is 8200 feet.
        It's impossible to keep the cabin altitude at sea level because
        the pressure differential between the inside and outside would
        be too high for the skin of the plane.  It would not be able to
        take it.  As it is, the plane expands and contracts each flight 
        as the cabin is pressurized and then depressurized.  These pressure
        cycles are one of the things that cause metal fatigue and wear out
        jet aircraft after thousands of flights.

0826 UT We are now level at 39,000 feet.  We'll remain at this altitude
        until we've burned off some fuel and become a bit lighter.
        Sometimes we do short five-hour missions.  Then we don't have to
        carry nearly as much fuel and we can go directly up to 41,000 feet.
        The additional two and a half hours of fuel we carry on the longer
        flights makes a big difference in performance.

0830 UT I stayed up till 4:00 AM this morning and took a one hour nap
        today to try to get adjusted to nights.  Let's see if I can get
        through this mission without falling out of my chair...

0925 UT Things have settled down to routine now.  I just adjusted the
        gain settings for the chassis that controls the torquer motors
        that steer the telescope.  The computer says that I made it
        slightly worse by fooling with it.  I can't really tell the
        difference, and the investigators say it's better.  There's a
        saying, "If it's not broken, don't fix it."  Good advice
        sometimes.  I have to crawl under the table top and lay on my
        back on the floor and watch a monitor above me while I adjust a
        set of tiny little screws in a chassis near the floor.  It's hard
        to see in there and get the adjustment tool (we call it a
        "tweaker") on the screw while the plane is bouncing around in
        light turbulence.  I have a little flashlight I carry in my
        flight suit shoulder pocket for jobs like this one.

        Right now is typical of how the flights usually go.  There is
        not too much chatter on the interphone line.  People are all
        relaxed and going about their business.  I'll break out a book
        in a little while and read, but I have trouble really concentrating
        on these flights.  Between being tired and slightly hypoxic from
        less oxygen than I'm used to, it's hard to do much heavy thinking.
        Right now we're bouncing around as well.  That doesn't make for
        great reading conditions.  

0938 UT We'll be climbing that last 2000 feet soon up to 41,000. When we
        get this high we really just drift up the last few thousand feet.
        The plane is near its maximum cruise altitude and the air is just too
        thin up here to allow a much higher altitude at this weight.  We
        sometimes go up to 45,000 feet but it's a fairly big deal.
        Everyone on those flights has to have a current Air Force high
        altitude certification.  No one can have a beard since at least
        half of us will be on oxygen at all times.  Hair, makeup, and any
        oil-based creams are fire hazards in a pure oxygen environment.
        High altitude physiology is pretty interesting stuff.  If we lost
        pressurization at 45,000 feet, even 100 percent oxygen at ambient
        pressure would not be enough to keep us conscious.  We need to breath
        oxygen under pressure.  The regulator forces it into your lungs and
        you have to blow out to exhale.  I won't go into it unless I get a
        question from someone.  High school science or physics classes
        could have fun with this.  You get into partial pressures and
        a bit of physiology - how your body works.

1032 UT (12:32 AM Hawaii Time) Well, the flight is about half over now.
        We're cruising along 8 miles high and about 200 miles from the
        Hawaiian Islands at the moment and zigzagging in an easterly
        direction.  We'll fly north for another 21.7 minutes and then
        head south east for 45 minutes.  Then one fairly long leg back
        towards the Islands.

1256 UT Another hour and a half to go plus that much more once I get on the
        ground.  So far it's been an uneventful flight.

1344 UT Not too much time left so I'll end this and get ready to land.

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