Letters from Mir

Subject: The Flight Begins

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.....

Endeavour launches on January 22, 1998

At six seconds before launch a deep rumble started shuddering the orbiter as its three engines were 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.

Andy Thomas and Dave Wolf trade places on Mir

But for us, engine cutoff and arrival in space meant the start of the work to reconfigure the shuttle as a habitable functioning spacecraft. The payload bay 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.

Subject: Rendezvous and Docking with Space Station Mir.

Following launch of STS-89 and its configuration for on-orbit operations as a spacecraft, the process of synchronizing our flight path to that of the Mir space station began. This is not as easy a process as one might first think, and you cannot just point towards Mir and fly over to it.

The reason has to do with the fact that both vehicles are in Earth orbit, and constrained by the laws of orbital mechanics. For example, imagine you want to catch up to another spacecraft ahead of you. If you just accelerate toward it, you will increase your speed around the Earth slightly. But this makes you spin a bit faster around the Earth, which throws you outward to a slightly higher altitude. Here the orbit is slower...so you will actually slow down and recede from the craft you are trying to catch up to. And the converse happens if you are trying to separate from another orbiting spacecraft. The consequence of this seemingly paradoxical behavior is basically that you have to slow down to catch up to a spacecraft ahead of you, and vice versa.

The shuttle crew used a carefully controlled sequence of jet firings to account for these effects and provide the right relative motion to bring the shuttle close in to the station. Then they manually flew the remaining distance using visual cues from targets located on the Mir docking module.

We could see the station out the overhead windows, first as a point of light off in the distance that slowly grew brighter as we approached. Soon the characteristic shape of Mir could be made out with its cruciform layout of modules and their protruding solar arrays. These panels are very wing like in their shape, and indeed Mir has often been likened to a giant insect in its appearance. We slowly approached Mir from below toward the Kristall module that carries the docking fixture.

Mounted on our Spacehab tunnel was a similar docking fixture, and these latched together when the vehicles made contact in the final moments of the rendezvous. Locking latches were then activated and screws pulled the craft together to seal the attachment. We were now one large orbiting complex.

After checking the integrity of the pressure seals, we were finally able to open the hatch and meet up with the Mir 24 crew, Anatoly Solovyev and Pavel Vinogradov, as well as David Wolf, the US astronaut I was to replace. We proceeded into the Mir and joined them in the Base Block, or central core module of the station for exchange of gifts, as well as a meal.

I have to admit, my first views of the station were a little daunting, and it was very confining as we floated down the Kristall module to the Base Block. There was a lot of equipment stowed on all the panels and in every available location. But it did open out at the base block which is more spacious by comparison.

The second docked day was the day I officially became a Mir crew member. This took place with the change out of David Wolf's seat in the Soyuz capsule for mine, as well as checking the Russian pressure suit used during landing. At this time its fit and pressure integrity are checked, and these are significant events, because the Soyuz is the return vehicle that is used in the event of an emergency evacuation of the station. The suit fit is particularly important, and to put it on you have to be able to pull it over your head. But the Mir commander and I were unable to get me into my suit. In zero-g your spine expands a little making you taller and this, as well as the original very tight fit of the suit prevented me from donning it. The commander and I agreed, with concurrence from specialists in Moscow to let out some of the adjustment built into the suit so that I could get it on. The suit then fit properly, and I became the NASA 7 Mir crew member.

The next few days were spent in transferring all the supplies to the Mir, as well as bringing back all the instrumentation, equipment and experimental results from David Wolf's tenure on board. We also carried water over to the station and used the shuttle oxygen supply to boost the oxygen level in the station.

STS-89 pulling away from Mir

On the fourth docked day, after quite busy work by the STS-89 crew, it was time to say farewell, close the hatch and undock. This was a moment of mixed emotions for me. On the one hand I was sorry to see my colleagues leave, but on the other, it meant that I was now able to get on with the mission and work assigned to me. The shuttle was a breathtaking sight as it pulled away and flew around the station. During the daylight phase of the orbit the brilliant white of its tiled insulation system was caught in the sunlight. In the night passes the plumes of flame coming from the jet control system would light up the surrounding elements of the station.

It was not long before they were out of sight and I was now totally committed to my stay on Mir for the next four months.

As soon as the shuttle had left, I then had to prepare my living area and also prepare for the arrival of the next Mir crew coming to assume the operations of the station.

Subject: The First Days on Mir

After the departure of the shuttle, I began to set up home in Mir. The Priroda module, meaning 'nature' in Russian, is the most recently built of all the modules and is used for environmental monitoring of conditions on the surface of the Earth. It also housed most of the equipment that I was to operate, so it seemed only logical to make it my home. I unpacked those items that I thought I would be needing on a fairly immediate basis. I was able to set up a computer, and access the array of informational and recreational CD ROMs that NASA had provided for me. I found the bag containing all the books I had chosen to take with me, as well as music cassettes and CDs, plus all the stationary supplies, and personal hygiene items I had brought along.

As I was unpacking and stowing all of these things, I came up against the one thing that makes space flight both interesting and, at the same time, very frustrating, namely zero gravity. It can be a joy to experience, but also can really make your work day difficult. The most frustrating thing is that you are forever losing things. You might be rummaging through a bag to find one item, while all the other contents are floating away, and before you know it, they are gone, and lost. They may even be close by to you, but as you look around you tend to focus your gaze only on surfaces, where we are accustomed to seeing things, and not look at the empty space just in front of us. In zero-g you have to learn to change this behavior. So it is inevitable that as you adjust to the environment of weightlessness you lose things and are always having to pay attention to tether, or velcro everything down. Items like pens and pencils are a particular problem, so I brought plenty of them along.

It was not too long before I had a reasonably comfortable habitation area set up in Priroda, keeping in mind that I was on a space station, and I was able to start the scientific program. I needed to get established fairly quickly because the Mir 25 crew, Talgat Mysabayev and Nicolai Budarin, were due to arrive in their Soyuz, along with French cosmonaut Leopold Eyharts. Although they would ultimately replace the Mir 24 crew, we would be conducting joint operations for a while and I knew that we would need all the work space that we could find.

Their Soyuz appeared over the horizon, first as a small point of light, that slowly grew to its identifiable shape with its attached habitation module and protruding solar panels. We could watch their final approach on a monitor, and could feel a slight bump as they docked to the station. Some time later, after the checks of the integrity of all the seals between the vehicles, we opened the hatch and welcomed them aboard. It was strange to see them all again here in orbit, as I had not seen them since I left Star City back in early December.

We spent the next three weeks working together on board the station. This was not easy, as work space and stowage space was very limited, but we all knew that it was temporary, and that we were able to overcome the obstacles.

After three weeks it was time for the Mir 25 crew to assume operations of the station, and for the Mir 24 crew, who had arrived on orbit last August, to leave. Leopold returned with them. They had spent some days preparing their capsule for the journey, and checking its flight control system, and when all was in order, they climbed in and closed the hatch and undocked a short time later. The view from the window of the Priroda module was impressive as we watched the capsule pull away from the station and slowly drift out of sight. Within a couple of hours we heard that they had landed safely in Kazakstan and that all was well.

With their departure, we were now able to settle in to day-to-day operations and establish a daily routine that was to carry us through the next three months.