"LIVE FROM THE STRATOSPHERE"          P R O J E CT  U P D A T E #19

PART 1: NASA TV schedule for this week
PART 2: Teachers from Utah and central Arkansas wanted
PART 3: Live data from the Kuiper as it flies!
PART 4: Correction to Activity 3C
PART 5: Virtual Kuiper: a student led project on MicroMUSE
PART 6: Star Census activity
PART 7: Ben Burress describes how the telescope is pointed

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Alas, the upcoming Space Shuttle mission has been postponed until after
the live KAO flights this coming Thursday and Friday. As a result,
"The Preflight Briefing" will be played over NASA TV on Wednesday
at 1PM, 4PM, 7PM, 10PM Eastern and on Thursday at 1AM Eastern.

On Thursday, "The Jupiter Mission" will begin live coverage at 2:30PM
Eastern. At 3:00PM a short break for the Video File will occur, and then the
LFS program will resume until the conclusion at 5:00PM Eastern

On Friday, "The Night Flight to the Stars" will be carried in its entirety
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We would like to identify certain Live From the Stratosphere participants.
If you are a teacher in Utah or in central Arkansas,  please send a brief
Email note to marc@quest.arc.nasa.gov and be sure to include a phone number
Thanks so much

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During the upcoming live KAO missions, data from the plane will
transmitted over the Internet to the LFS Web archives

For Webbers, use http://passporttoknowledge.com/lfs/livedata.html

This data will be sent every 5 minutes and will enable you to track various 
aspects of the mission's status. The following ten parameters will be sent: 
     time           ground speed      outside temperature
     longitude      air speed         cabin temperature
     latitude       altitude          cabin pressure
     heading

A sample set of lessons in using this data is also available.

For those without Internet access, the latitude and longitude readings will
be displayed during the television program. This will enable your students
to track the progress of the aircraft across the country. Get your large wall
maps ready!

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In final editing, an error was made in activity sheet 3C (on the back
of the poster). The sheet states, "Albedo is an index of how bright or
dark a surface is in visible light (the lower the number, the brighter).

This should have read:
the higher the albedo number, the more visible light is reflected and
thus the brighter the surface appears in visible light.

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A virtual Kuiper is under construction in cyberspace. This student-
led project may have special appeal for computer-oriented students,
particularly those familiar with MUDs, MOOs and MUSEs. If you'd like
to take a look at what is happening, telnet to micro.musenet.org.
Then @tel to room #2074. Look for edwardo online. For more
information about this activity, visit the "Kids Stuff" area online
or send Email to David at dcd@quest.arc.nasa.gov.

_______________________________________________________________________

A reminder about the Star Census collaboration. The quick look data
is due to marc@quest.arc.nasa.gov by this Friday at 10:00 AM Pacific
in order to be included in the Friday night broadcast. You are also strongly
encouraged to participate in the longer-term collaboration effort described
fully on line or in LFS #18

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POINTING THE TELESCOPE
By Ben Burress, Tracker Operator

It's 4:00 a.m., we're at 41,000 feet somewhere over Nevada
looking at the variable star GG Tau, in Taurus. I just
glanced out the little port hole next to the Tracker
station and saw a single light in a plain of blackness.
We often fly over lightly populated areas. The flight has
taken us from Ames to the skies of Oregon, Idaho, and
Montana, and we're now heading back toward home. The flight
has gone very well so far, although someone in the back of
the plane acquired some air sickness--that happens from time
to time. It's too bad we fly at night most of the time: the
views out the windows would be awesome with a little daylight
to see it by....

The hours of a KAO flier are pretty bad, as you might imagine.
It may sound exciting, but it can get downright tedious. I
don't think that anyone LIKES working all night under these
conditions, even the astronomers. The worst part is that we'll
be landing around 6:00 a.m., just in time to get into
morning commuter traffic!

There are basically four levels of Operator/telescope control
which aid in pointing at the correct object. First is a
specialized computer called "TIPS", the Telescope Inertial
Pointing System. TIPS uses the aircraft's heading, roll,
pitch, latitude, longitude, the telescope's orientation within
the plane, and current time to "dead reckon" where the telescope
is pointing, calculating from only this batch of information
the celestial coordinates that the telescope is pointing
at. When the additional information of the desired object's
celestial coordinates is thrown into the calculation, the
telescope's pointing coordinates and the object's actual
coordinates are displayed together in a graphic representing
the telescope boresight and the object. Initial acquisition
of the object field then is a boring video game of joy-sticking
the telescope until the cursor for the object lines up with
the spot for the boresight. At this point, the telescope
should be pointing well within the object's neighborhood,
within maybe half a degree--which is pretty good considering
that this was all done in the dark, without actually observing
the outside universe.

Now, I turn my attention to the wide field acquisition camera,
which when zoomed in has a field of view of about 2 by 3
degrees. I locate the position of the object in the
acquisition field by comparing that field with the acquisition
chart for the object. Perhaps a little more joy-sticking of
the telescope is required now, and by this time the object
resides within the field of view of the tracker telescope,
where most of my work is done.

Usually I have determined the star I will use for tracking
far in advance, and once I recognize that star in the
tracker telescope field I place an "AOI" on the star and
activate the tracker. The AOI is a small video box which
defines the region of the camera field that the tracker
computer sees. If the tracker sees a star in the window,
it calculates the position of the star's center and keeps that
star at a specified location in the field. It does this
is by determining if the star's center is on or off of
the specified tracking location; if it is off, the tracker
calculates how far and in what direction, then sends a
correction signal to the telescope compensation system,
which in turn sends an appropriate jolt of electrical
current to the telescope's magnetic torquer
motors, which moves the telescope in the right direction
by the right amount to place the track star on the
tracking location again. This measurement/correction cycle
takes place thirty times per second, so the telescope doesn't
drift very far before being torqued back onto position; in
the camera fields the stars look virtually motionless.

Once the tracker is set to tracking a star, I move the
telescope around in small motions by "tweaking": using a
hand paddle with buttons that instruct the tracker to move
the specified tracking location about. In this way, I place
the object of interest on the investigator's instrument
boresight.

One other aspect of KAO telescope pointing peculiar to
infrared astronomy involves the technique of "chopping" and
"nodding", which you may have heard described elsewhere. I
won't belabor my point by describing the reasons for doing
these things, other than to say that by chopping, the
investigators can separate from their object's infrared
signal the component contributed by our own warm atmosphere,
and by nodding they can separate out heat emissions from
our own telescope. The chopping motion of the Oscillating
Secondary Mirror (OSM) creates two images of everything in
the focal plane field of view:  stars, planets, and optically
invisible infrared objects alike. As part of the technique,
the investigators must observe both chopped images,
which is where nodding comes in: I set up the tracker to
track in one of two locations, each of which places one of
the object's chopped images on the instrument boresight.

At this point, after setting the tracker to track on either of
the two "beam" locations, the investigators are set up
to start taking data. If I do my job right, then the time
point when they can take data is two minutes or less--some
objects take more time, some less.

And that's what the main part of my job boils down to.
Simplicity at its best: I point the telescope wherever the
astronomers want it. The details of knowledge, the skills,
and the experience which allow me to do this job efficiently
and reliably add up to more than that, but that is true of
many straightforward-on-the-surface occupations. In fact,
I do more around the KAO than flying as a crew member. When
they don't have me flying, I can be found at my computer
working on various writing projects, from procedures to
newsletter articles to manuals.  I also keep in contact with
the various investigator teams, by email and phone, to anticipate
their needs on their next flight series:  everything from lab
equipment to cryogenic liquid supplies to serving as liaison
between them and the KAO staff.

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