UPDATE # 4 - March 28, 1997

PART 1: Chatting online with NASA experts
PART 2: Radio contact with the shuttle astronaut
PART 3: Preparing the trajectory for STS-83
PART 4: Learning how to do a ferry flight
PART 5: Visiting lots of ground stations for shuttle communication
PART 6: Status of STS-83
PART 7: Subscribing/unsubscribing: how to do it

A series of online chats with NASA experts is being planned. These
chats will let students connect live with interesting shuttle people.
For April, these chats will all be on Wednesdays from 10-11 a.m.
Pacific (1-2 p.m. Eastern). During the month of May, we may expand
the service to include other dates and times.

To chat, we'll be using a system called WebChat which lets you type
brief thoughts while others are doing the same thing. To participate,
you need only have access to a modern web browser (like Netscape or
Internet Explorer).

Our first Webchat with NASA expert Dennis Dillman is scheduled for
April 2 from 10-11 a.m. Pacific. Dennis leads a team which repairs
and upgrade the orbiters and now he is learning to lead ferry flights
(when the shuttle is moved on top of the special 747). Before
attending the chat, we strongly suggest that your students read
Dennis's biography and Field Journals.

If you plan to chat, you must register for the event. Sign up now by
sending a brief email note to rsvp-sto@quest.arc.nasa.gov
This RSVP is very important, since it will allow us to ensure that
the chatroom does not become too crowded.

For more details, and for the complete schedule, please visit:
http://quest.arc.nasa.gov/space/events/interact.html



RADIO CONTACT WITH THE SHUTTLE ASTRONAUTS


A program called SAREX lets schools use ham radios to communicate
with the Space Shuttle astronauts. A class will have about five
minutes to radio questions to the shuttle and then listen to the
responses live. Typically there is time to send 4 or 5 different
questions.

This is a popular program and the waiting list is about 4 years. Back
in 1993, Crittenden Middle School (Mt. View, CA) applied to SAREX.
Recently they were selected to participate in this upcoming STS-83
mission. Mr. Scott Coletti, the technology teacher at Crittenden, is a
big fan of the Internet and he wants to share the SAREX experience
online. So he is willing to take email questions from you and
consider them for broadcast to the shuttle crew.

If you are interested, think of some good questions and email them
to this address: sarex-sto@quest.arc.nasa.gov

Time is very short, and the questions must be sent in by Thursday,
April 3.

Scott and his students will select one question and radio it to the
astronauts orbiting in the space shuttle. Once they have the answer,
you'll be emailed the reply. The Crittenden crew will select
questions based on the following criteria:
  * Is the question one that gets the CrittKids interested in the answer?
  * Is the question generally interesting to middle school students?
  * Does the question illustrate points about the specific STS-83 mission?

If you want to follow the Crittenden's SAREX adventure live,
the CrittKids will be broadcasting their experience over WebChat.
Go to the Shuttle Team Online's unmoderated chatroom
(http://quest.arc.nasa.gov/space/events/webchats/sto.html)
during the appointed time and communicate live with the kids
who are speaking live with the space shuttle astronauts. The
exact time of the Crittenden SAREX session will depend on
the exact launch date/time. Presently, if the shuttle launches
on April 3 as planned, Crittenden's SAREX time will be April 8
at 9:23AM (Pacific). Any changes will be updated on the Web
as soon as they are known. For more details, see



[Editor's note: Eric works in Mission Control Center as a Flight
Dynamics Officer. His responsibility is to make sure the shuttle
follows the same path through space that was planned prior to
liftoff, as well as to react to any situation that is different from
the plan.]

PREPARING THE TRAJECTORY FOR STS-83
Eric Hammer - http://quest.arc.nasa.gov/space/team/hammer.html
March 27, 1997
As the Lead Flight Dynamics Officer for a Space Shuttle mission, my
primary responsibility prior to launch is to ensure the trajectory
design (the path the Space Shuttle will follow from launch to
landing) is acceptable from a technical standpoint. More
specifically, the trajectory must satisfy payload requirements
as well as Space Shuttle requirements.

After all, the payload, or the "Customer" as we sometimes refer to
it, is the reason we fly the Space Shuttle. The immediate customer
various from mission to mission, but the ultimate customer are the
citizens of the United States. The immediate customer for STS-83
is the Microgravity Science Laboratory (MSL). Their trajectory
requirements are not nearly as constrained as, say, a shuttle
mission that is scheduled to service the International Space Station
(ISS). Obviously, for a mission to service the International Space
Station, the Space Shuttle trajectory must ultimately be exactly the
same as that of the ISS. For MSL, they would like the initial orbit to
be nearly circular. The highest point of the orbit should not be more
than five nautical miles higher than the lowest point in the orbit.
The only other trajectory requirements to be met are those of the
Space Shuttle.

Trajectory requirements for the Space Shuttle on STS-83, in a
general sense, are to be high enough so that at the end of the mission
the spacecraft is still in orbit (or said another way, it has not
reentered the atmosphere), and to have acceptable landing
opportunities at the end of the mission. An acceptable landing
opportunity for the Space Shuttle is one that is within its
crossrange limits. During the entry, the Space Shuttle flies a lot like
an airplane and can fly left or right of its course nearly 800 miles.
Additionally, a landing during daylight is a less complex operation
than landing at night. Not only is a night landing harder from a pilots
point of view, but additional equipment, such as lighting, is required
and only increases the chance of having an equipment failure.
Therefore, to design a trajectory that meets these requirements,
computer simulations are run that predict where the Space Shuttle
will be when its time to come home. If these conditions are not met,
the initial orbit is changed until the desired conditions at the end of
the mission are satisfied.

At this point, the trajectory has been determined and we are ready
to fly! See you in orbit.



[Editor's note: Dennis supervise a bunch of engineers who help keep
the Shuttle Orbiters ready to fly. If any of the systems on an Orbiter
don't work right, Dennis' team figures out how to fix them or they
design something new to make the problem right. He is now learning
to lead ferry flights. Also, Dennis will be featured in this week's
upcoming chat - see above for details]

LEARNING HOW TO DO A FERRY FLIGHT
Dennis Dillman - http://quest.arc.nasa.gov/space/team/dillman.html
March 13, 1997:
In my last journal, I mentioned how we fly Orbiters (the airplane
shaped part of the Shuttle) to Palmdale, California to go through
what is called Orbiter Maintenance Down Period (OMDP). For these
trips, the Orbiter sits on the back of a modified Boeing 747
airliner. Well, the man who manages the 747 flights (called "ferry
flights") is getting set to retire, and my office has been tapped to
take over that job.

Right now the Orbiter Endeavour is at Palmdale, just finishing an
OMDP. When we ferry it back to the Kennedy Space Center, I will get
to ride along on the trip to start learning-the-ropes. I will fly a few
minutes ahead of the 747 in what is called the "Pathfinder" airplane
that scouts out any bad weather and carries a team of people ready
to repair the 747 or the Orbiter if something breaks during the flight.

If the weather cooperates, we will leave Palmdale the morning of
March 25 and fly to the naval station in Corpus Christi, Tx. The
afternoon of the 25th, the public will be invited to come see
Endeavour on top of the 747, and possibly tour the 747. Maybe I'll
see some of you there!

The next morning, weather cooperating, we will fly to Houston for
a quick fuel stop, then on to Kennedy.

Why do I keep saying "weather cooperating"? Well with an Orbiter on
its back, the 747 can't fly high enough to fly over most of the
weather en-route like a normal airliner can, so sometimes we will
get stuck on the ground waiting for the weather up in front of us to
clear up.

Anyway, I'll write a journal either en-route or when we finish.



[Editor's note: Rebecca helps train the ground controllers (who are
in charge of shuttle communications) by practicing with them and
inserting malfunction scenarios to see reaction times and failover
procedures from the GCs. She also trains the astronauts to
understand the communciation system onboard.]

VISITING LOTS OF GROUND STATIONS FOR SHUTTLE COMMUNICATION
Rebecca Aubin - http://quest.arc.nasa.gov/space/team/aubin.html
March 26, 1997:
Hi! My name is Rebecca Aubin. I work at Johnson Space Center in
Houston, Texas. I am 22 years old and never thought I would be
working in the Space Industry.

Let me tell you a little about my job here. I work in the
Network/Communication System section. I know all about the
communications equipment on the Shuttle and on the ground. I know
what happens to data as it flows from Mission Control in Houston to
one of several Ground Stations around the world or to the Tracking
Data Relay Satellite (TDRS) to the Shuttle and then back to Mission
Control. My degree is in Computer Science, so knowing computers
really helps. The way data is processed on the Shuttle is somewhat
similar to how data is processed in a computer.

Growing up without brothers, I never was really exposed to
electronic kits or chemistry labs to play with. I guess my parents
never felt the need to buy them for me. I regret not having them as
a child, because there was a lot missing from my knowledge of
science. Math, on the other hand, was no problem. I have always loved
math. I knew that I wanted to have a technical degree, so I could
learn for myself the science I was never exposed to. That is why this
job is so great!!!!!!!

The ground stations I talked about earlier are so wonderful to learn.
The Mission Control Center cannot send commands directly to the
Orbiter because of "line of sight" constraints with Mission Control's
signal. "Line of sight" means that the signal has a certain range that
the ground antenna at Mission Control can project. Ground stations
are used as a means for this signal to go father in range. The signal
will move from Mission Control to a ground station and then either
directly to the Orbiter, during ascents and entries, or from the
ground station to a Tracking Data Relay Satellite during orbit phase.

What is so great about this job is that I get to research all
equipment at all ground stations around the world, as well as the
Tracking Data Relay Satellite System at Whitesands, New Mexico,
and also the orbiter communication equipment. As part of my job
I have visited Goddard Space Flight Center for TDRSS classes,
Whitesands, New Mexico, Jet Propulsion Laboratory, Dryden Research
Flight Center, Goldstone Deep Space Network Station, Meritt Island
Launch Area, Ponce De Leon ground station, MLACC-bd tracking
station, and to Cape Canaveral to view an actual Shuttle launch.

I will tell you what kinds of things I had to research for my job
during my next journal.
See you then!
Rebecca



STATUS OF STS-83


The next scheduled shuttle mission is STS-83, a 16 day microgravity
lab scheduled for launch on April 3 at 2:01 p.m. EST. Before launch,
we'll provide periodic updates about preparations for the mission.
These reports will contain jargon and unfamiliar terms; our intent is
not to confuse you, but to provide a glimpse at all the details involved.
Detailed daily reports can be found at the NASA Shuttle Status web
site at http://www-pao.ksc.nasa.gov/kscpao/status/status.htm
Since the last updates-sto message, the pad was closed to load
dangerous hypergolic propellants into the orbiter's reaction control
system. Ordnance installation was completed without incident. Aft
engine compartment close-outs are underway and the aft compartment
doors are scheduled to be installed this weekend (March 29). Launch
countdown preparations are happening and the countdown is scheduled
to begin at the T-43 hour mark at 2 p.m. Monday, March 31. Other plans
include the crew arrival (2:30 p.m. March 31) and the start of external
tanking operations (5:11 a.m. April 3)




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