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EXP 7 FIRST LETTER BY ED LU



Submitted by Arthur - N1ORC

Greetings Earthlings!

By: ISS Science Officer Ed Lu

Greetings Earthlings! I've always wanted to say that. Now that things
are beginning to settle down here a bit, I wanted to tell you a little
bit about what life is like up here on ISS, and some of the things that
make this such a special place. 

Let me start from the beginning: how we got here. We launched a little
over 2 weeks ago from the Baikonur Cosmodrome on a Russian spaceship
called a Soyuz TMA. It is the latest in a series of spacecraft based on
the design of the spacecraft that the first man in space, Yuri Gagarin,
first flew into space over 40 years ago. In fact, we launched from the
very same launch pad that Gagarin launched from! 

Launch day, April 26th, started for Yuri and I at 1:30 in the morning
when we woke up, quickly dressed and ate breakfast, and were met by a
horde of well wishers at our room. After all the obligatory nice words,
we had the Russian traditional moment of silence before setting off on
our journey. On our door were signatures of all the cosmonauts who
stayed in this room before launch, dating back to the Apollo-Soyuz
mission in 1975 (Leonov and Kubasov stayed in our room). I remember
watching that mission on TV back in Webster, NY, at my friends Kevin and
Mark's place with the neighborhood kids. Now it was our turn to sign the
door. We then boarded the bus for the drive out to the launch area. Once
there, we suited up and pressure checked our suits, then at the
appointed hour marched out to report to the commanding officer of the
Cosmodrome that we were ready for launch. Then it was back on the bus to
head to the launch pad. The sun was just coming up, and crowds of
workers were standing along the road waving and saluting. 

At the launch pad, we wave to everyone before getting on the elevator to
the top. I see Christine and my brother Rick there waving, and I flash
them the Shaka sign before heading up. For those of you who have been to
Hawaii, you know what that is, and for those of you who don't know what
it is, you should immediately get on a plane and go to Hawaii to find
out! Once at the top, we literally crawl on our hands and knees through
a hatch in the side of the shroud into the Soyuz. 

>From there, we lower ourselves down into the descent module, which is
basically the cockpit. In our bulky pressure suits it is difficult to
maneuver into the seats and buckle up -- the two of us plus the load of
cargo in the right seat fill most of the cockpit. The Soyuz is a small,
simple spacecraft -- your basic no frills reliable ship. It was designed
to do one thing, fly humans to and from an orbiting space station. That
means it doesn't need to be large, just large enough to hold the
cosmonauts and their equipment for however long it takes to rendezvous
and dock with a space station -- which happens to take 2 days. My seat,
as the flight engineer, is on the left, and Yuri sits in the commander's
seat in the middle. We each have electronic displays in front of us that
we can use to call up a variety of different computer displays so we can
issue commands or look at status displays from the onboard sensors.
Spacecraft are a bit like humans in that there are leftover
characteristics from old designs that have remained but no longer serve
a purpose, like your appendix or your tonsils. In the case of the Soyuz,
even though there are new electronic displays, the commands are still
sent using a matrix of commands where you specify the row and column
number. This is simply a holdover from the previous Soyuz design, which
had mechanical switches arranged in rows and columns. Now, on the high
tech computer display, there is a picture of the old mechanical design,
which you use to issue commands! The same is true of the new electronic
displays in the Space Shuttle -- we have recreated pictures of the old
displays on our new advanced displays. In both cases the engineers
realized that it was simpler and more reliable to make gradual changes,
rather than to do a complete redesign. It's kind of like biological
evolution, but for spacecraft. 

Once we have strapped in, we check to make sure the hatches are sealed
tight by slightly over-pressurizing the Soyuz and waiting to see if the
pressure drops. We do a quick check of all our radios and communications
equipment, then we settle in for the roughly 2-hour wait until launch.
Talking to us from the bunker is our Soyuz simulation instructor, Andrei
Kondratyev, who will be our capcom (that's what we Americans call the
astronaut who talks to you from Mission Control) during the launch
phase. It is reassuring to hear his voice, since we have heard it so
many times before in the simulator. The two hours go quickly, in spite
of the fact that we are strapped into a rather tight spot and there is
no place to straighten our legs. Because of our busy training schedule,
this is about the first quiet moment we've had in almost 2 months! I
actually fell asleep for a little while. 

A few seconds before liftoff, the engines are fired up and you can feel
the vibration. It makes a dull roar in the cockpit, but it isn't really
that loud. The actual liftoff is smooth, and the G forces pushing you
into your seat due to the acceleration gradually build up over the first
few minutes. The first stage is much smoother than in the Space Shuttle,
which really rumbles as it takes off because of its two huge solid
rocket boosters. At a little before 2 minutes, the emergency escape
rocket is jettisoned because it is no longer needed. At this high
altitude and thin air, we no longer need such large rockets to escape
from the rocket below us if there was an emergency. I can feel a thud as
it shoots off the top of the Soyuz. A few seconds later, the 4 small
first stage boosters surrounding the main body of the rocket are
jettisoned, and there is an immediate drop in acceleration from about 4
Gs to maybe 1.5 or so. For those of you who don't know, when we say 1 G,
that is the force of your normal (on the ground) weight. 4 G's means 4
times your weight. 

At about 2 and a half minutes, we are above almost all of the
atmosphere, so we no longer need the launch shroud which protects the
Soyuz from aerodynamic forces at low altitude. At this point the shroud
is just dead weight, so it too is jettisoned. Before that, there is
nothing out the window since the entire spacecraft is enclosed in the
shroud, but when the shroud goes off the sun comes shining in my window
to my left. It is blindingly bright, and it shines right on my face
making it almost impossible for me to either read my checklists or to
even see the readings on the control panel in front of me. I spend the
next few minutes trying to block the sunlight using my left hand and my
checklist! 

On the radio, we can hear Andrei reading to us our engine parameters and
trajectory information. Interestingly, we don't have any displays in the
cockpit with this information, I guess because there isn't anything we
can do about it anyhow. If there is a problem, we have a launch escape
system which will take us away from the rocket, and we would just land
in the capsule under parachute. During the second and third stages, the
rocket occasionally sways back and forth, perhaps it is the engines
swiveling underneath us to control our trajectory. It is a little
unnerving because at this point the Space Shuttle is rock solid and
smoothly accelerating. When we drop the 2nd stage, there is a momentary
drop in acceleration, then you are rapidly pushed back into your seat
when the 3rd stage lights off. At 528 seconds after launch, the 3rd
stage engines stop, and our capsule separates from the 3rd stage --
actually it feels more like we are ejected from the 3rd stage since it
is quite a shove. Yuri has a pencil and eraser tied off on strings in
front of him, and they begin floating telling us that we are now
weightless. It is nice to be back in space! 

For the next two orbits (about 3 hours), we remain strapped into our
seats while we check out all the systems of the spacecraft, including
the motion control system. The motion control system is basically the
sensors and gyroscopes which tell the ship which way it is pointing, the
small jets situated around the Soyuz which allow the spacecraft to
maneuver, and the computer which figures it all out. After all the
checks are complete, we orient the ship so its solar panel wings are in
direct sunlight, and we spin the ship like you would spin a bottle on
the floor so our solar arrays stay pointed at the sun. The ship is
naturally stabilized like a top, so we can then power everything down
including the jets and motion control computer. This makes for an
interesting view out the window since the ship is rotating end over end
about once every 2 minutes. 

After that, we get out of our seats, head "up" into the living
compartment, which is nothing more than an 8-foot diameter sphere
attached to the top of the descent module. There, we take off our
pressure suits and get ready for the first rendezvous maneuver. By then,
the ground has tracked our orbit well enough to calculate how much we
need to increase our speed to raise our orbit just enough so that our
docking will occur at the proper time 2 days later. We go back down into
the cockpit and execute the first engine firing to raise our orbit. We
only fire the main engine for about 40 seconds or so, enough to increase
our speed by about 50 MPH. This is only a small change in our speed,
since we are going near 18,000 MPH already, but it noticeably raises our
orbit. The ground really looks like it is going by fast since our
initial orbit is only maybe 100 miles above the Earth's surface. 

By then it is bedtime, and after a very long day I have no problem
falling asleep. We each have sleeping bags and I squeeze myself down
into the cockpit, while Yuri sleeps up in the living compartment. The
second day is a light day, with just one orbital correction burn we have
to make to touch up our orbit based on the ground's updated
calculations. Besides that we just have to monitor the spacecraft
systems occasionally to make sure everything is going well and set up
the equipment that we will need to use if our radar system fails during
the rendezvous with the station. 

The next day is rendezvous day, and it is a busy one. Up until this
point we have relied on ground radar tracking to provide our trajectory
information so we can rendezvous with the station. Even though the
ground can accurately measure our trajectory, there are still slight
errors, so we have an on-board radar system which will make corrections
to our estimate of our position relative to the station. For those of
you who are pilots, the system works similar to a VOR/DME at large
distances, and like an ILS for the final approach to docking. For the
rest of you that means the computer can figure out our exact orientation
with respect to the station (and vice versa) so that it can calculate
when to fire the engines, and more importantly in what direction. I'll
write more about the mechanics of space rendezvous in a later
installment. 

We are on the night side of the Earth for most of our approach, but at a
distance of about 500 meters we come around to the daylight side. Only
then is the station visible. The Soyuz has a periscope in the cockpit,
and we see the station there on the viewing screen. Yuri remarks that it
looks just like a model floating there in space. In fact it does -- it
looks just like one of the computer-generated images we are so familiar
with from the simulator. The station looks a bit like a huge mechanical
insect with appendages and solar array wings sticking out. We are busy
checking all the data as we make our final approach to docking, and of
course we are also looking carefully at the view in the periscope to
make sure we are all lined up properly with the docking port on the
station. It lines up perfectly, and with a thud, we dock with the space
station. Of course, more pressure checks follow to make sure we have a
tight seal before we open the hatches. We can hear Nikolai, Don, and Sox
(Expedition 6) on the other side of the hatch knocking while we wait! 

Once we finally get the hatches open, they introduce us to our new home,
and of course after that the next order of business is lunch!

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