Andy Thomas - "The Flight Begins"
During his stay on the space station Mir, U.S. astronaut Andy Thomas
published several "Letter from the Outpost," to family and friends on
Earth. Here is one of them.
"The Flight Begins," by Andy Thomas, February 1998.
As I undertake this extended stay on the Mir Space Station, I am adapting
to a lifestyle that can certainly be called unusual, if not bizarre. Perhaps
it even defies adequate description. Nonetheless, I would like to attempt
to share the experience with friends, colleagues or anyone else who is
struck by the fascination for this kind of adventure. So I hope to find
time, over the coming months, to describe the sensations of the flight
and some of the events that make this experience so unique. I am hoping
then, that this will be the first in a series of letters home that will
give people some idea of what it is like to travel and live in space on
an orbiting outpost.
Of course, for me the flight itself actually began in Florida on January
22nd with the launch of the Space Shuttle Endeavour on mission STS-89
to carry supplies to Mir and to exchange me with David Wolf who had been
on the station since September. This was my second shuttle launch, and
I was one of the first to strap in on the mid deck, so I had a long wait
on my back before the engines were lit. The big difference between sitting
on the mid deck, versus the flight deck, as I had done for my first flight,
is that I had no window to look out of and watch the world recede. But
not having an outside view lets your imagination provide the imagery,
and this can give you an emotional rush, possibly even more than seeing.
The weather had been questionable that day and there was still some
uncertainty as to whether or not we would actually go. But a few minutes
before launch, all the launch controllers were polled by the launch director
and each gave a "go" for launch. The Control Center then called us to
start the auxiliary power units that provide the steering hydraulics and
we could hear the units spinning up to speed deep below us.....then came
the call to close and lock our visors, and to initiate our oxygen flow,
a protection in the event of a depressurization during the climbout....it
was clearly getting serious as we waited those long last few minutes and
seconds until liftoff. The three of us the mid deck shook hands together
and wished ourselves well for the flight. Then the cabin became quiet.
At six seconds before launch a deep rumble started Endeavour launches
onshuddering the orbiter as its three engines were January 22, 1998 ignited
and run up to full speed. We heard the pilot, Joe Edwards call out "three
at 104" signifying all three were running at rated power. But we were
still firmly bolted to the ground with eight very large explosive bolts
so the engine thrust made us lurch over, giving us the eerie sense of
falling forward. Suddenly, with the six seconds counted away, there was
a thundering roar with massive vibration and shaking as the solid rockets
were ignited, the hold-down bolts exploded, and we were driven off the
launch pad and upwards into the sky. You did not need a window to know
what was happening.
Climbing out, we did a roll maneuver to adopt the correct flight orientation
causing us to feel the whole cabin spin around while being shaken by the
eight million pounds of thrust accelerating us forwards. The flightdeck
crew called out the rapidly changing speeds and altitudes every few thousand
feet. We could feel the engines throttle back to prevent overstressing
the vehicle in the denser part of the atmosphere, then they came up to
full speed again driving us once more back into our seats. But burning
fuels at a combined rate of 12 tons a second quickly depletes even the
huge solid boosters and after about two minutes we could feel a noticeable
drop in acceleration. It actually felt as if we were slowing down and
pitching forward, but that was artifact of the senses as we were still
climbing upwards very swiftly.
There was a jolt as the solid boosters, having now become just dead weight,
were explosively separated at about 70,000 feet above the Earth. Then
the engines, feeling the sudden lost of mass, pushed us harder forward.
Now, the changing altitudes were called out not in feet, but in miles,
and the changes in speed in thousands of feet per second as we flew through
the upper atmosphere at hypersonic speeds.
At an altitude of 50 nautical miles, the traditional beginning to space,
we congratulated the novice crew members on reaching space, and I shook
the hand of the cosmonaut Salizhan Sharipov sitting to my left. The accelerations
steadily increased as our speed became faster and faster, and at 3-g acceleration
the engines were again slowed down to prevent excessive loads. But even
that meant that we would add nearly 4000 miles per hour to our speed every
minute.
And at that acceleration, our speed soon reached 17,500 miles per hour,
orbital velocity; we were at orbital altitude, and the engines shut down.
The sudden loss of acceleration again gave us the false sensation of pitching
forward. But in reality we were coasting in space and were now weightless.
This breathtaking sequence was over in a mere eight and a half minutes,
and it is an amazing technical accomplishment that we have the capability
to bring people to orbit in that short of a time.
But for us, engine cutoff and arrival in space meant Andy Thomas and
Dave the start of the work to reconfigure the shuttle as Wolf trade places
on a habitable functioning spacecraft. The payload bay Mir doors were
opened, the Spacehab module in the payload bay itself was activated, and
various systems were configured for on-orbit operations. Over the coming
days, this was to be our home, and for me, the transfer to Mir was not
far off. But before that could happen, it was first necessary to rendezvous
and dock with the Mir space station, followed by transfer of all the supplies
and logistics we were carrying. I shall talk about these experiences next
time.
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