| Smoother Sailing | Thomas Bio | A View from Space | Gravity |
Smoother Sailing
As the last American to live onboard Mir, Andy Thomas benefited from the maturing U.S.-Russian partnership. The Mir space station was now safer, more versatile, and more robust. Communications had improved both between ground and orbit, and between the two space programs. Yet at the same time, life on the outpost still posed many risks. Mir was aging, sailing past its planned lifespan into a time when things could be expected to break down with some regularity. Further, there remained the human challenges with languages, cultures, and politics.
But, Thomas had his own strengths and the experiences of his six NASA predecessors. He knew, better than they had known, just what to expect. He went to Mir to conduct an intense science program and to make the most of his 140 days in orbit. He succeeded. And, when STS-91 came to fetch him home, the Shuttle-Mir Program came to a successful end.
A naturalized U.S. citizen, Andrew S. W. Thomas had exploration in his blood. More than a century before his service on Mir, his great-great-grandfather had served on the first expedition to cross Australia from south to north. Born in Adelaide, Australia, in 1951, Thomas received a bachelors degree in mechanical engineering and a doctorate in mechanical engineering, both from the University of Adelaide. He began his professional career as a research scientist with the Lockheed Aeronautical Systems Company, researching fluid dynamic instabilities and aircraft drag. He became the head of the Flight Sciences Department and managed a research laboratory and wind tunnel facility.
In 1987, Thomas was named manager of Lockheeds Flight Sciences Division. He joined the Jet Propulsion Laboratory in 1989 and soon was appointed leader of their program for microgravity materials processing. NASA selected Thomas for astronaut training in 1992. In May 1996, he flew on Endeavour (STS-77) as Payload Commander during the time that NASA-2 Mir Astronaut Shannon Lucid was entering her third month onboard Mir.
On STS-77, Thomas carried with him an old steel flint, a memento of his great-great-grandfathers explorations in the Australian Outback. But, for all the adventure of his Space Shuttle and space station flights, Thomas said later that he didnt see himself "in the same league" with people such as Lewis and Clark or other early explorers, such as his great-great-grandfather. He allowed that the early explorers had "planned everything, and had a lot of support." However, "Once theyd gone, they were gone. They were alone." Thomas said, "When we do these flights, its true were alone up there. But, we have radio communications to a huge group of people [on Earth] who have a lot of resources to provide assistance in the event something goes wrong and a lot of guidance about what should be done next. So, in that sense were not alone."
When Thomas launched to Mir on STS-89 on January 22, 1998, the experience was already a different one for him. On his first Shuttle mission, he had sat on the flight deck with its many windows and its view of a receding Earth. For STS-89, Thomas sat on the mid-deck without a view. However, according to Thomas, "Not having an outside view lets your imagination provide the imagery, and this can give you an emotional rush, possibly even more than seeing."
In the first of his "Letters from the Outpost," Thomas related his liftoff to Mir. "The weather had been questionable that day and there was still some uncertainty as to whether or not we would actually go. But 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 flowa protection in the event of a depressurization during the climb-out . It was clearly getting serious as we waited those long last few minutes and seconds until liftoff. The three of us on 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, shuddering the Orbiter as its three engines were ignited and run up to full speed. We heard 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 as the solid rockets 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."
When Endeavour rendezvoused with Mir, Thomas caught his first glimpse of his new home. "We could see the station out the overhead windowsfirst 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 winglike 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."
After docking and the opening of the hatches, Thomas wrote, "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."
He later said, "It was a bit of a shock just how crowded it was and how much stuff was in there. And that took some getting used to. But you can get used to it . At no time did I feel claustrophobic up there . Theres enough room that you dont feel claustrophobic, but you are aware that its a confined environmentthat you dont have a lot of options of places to go."
Although Thomas was now safely onboard Mir, a potential showstopper occurred on the second day of docked operations. Before he could officially become a Mir-24 crewmember, joining Commander Anatoly Solovyev and Flight Engineer Pavel Vinogradov, Thomas custom-made seat-liner had to be installed in the Soyuz escape capsule and his Russian Sokol pressure suit had to be checked for fit. Surprisingly, Thomas and Commander Solovyev were unable to get Thomas into his suit. Microgravity had allowed Thomas spine to expand; he was now too tall for the suit. Two days of discussions on the ground and some re-tailoring of the suit by Solovyev took place before the Shuttle-Mir managers, and Thomas himself, became satisfied that all was safe to proceed.
After four days docked to Mir, Endeavour readied for its return to Earth. For Thomas, "This was a moment of mixed emotions . On the one hand, I was sorry to see my colleagues leave; but on the other [hand], it meant that I was now able to get on with the mission." The Space Shuttle was a breathtaking sight as it pulled away and flew around the station. In sunlight, Endeavour shone brilliant white. In Earth-shadow, plumes of flame from the maneuvering jets lit up the solar arrays of the station.
Andy Thomas made his home in the Priroda module. He set up a computer with access to the informational and recreational CDs that NASA had provided. He found the bag containing his books, music recordings, stationery and art supplies, and personal hygiene items.
He wanted to dive deeply into his scientific experiments. But, on January 31, only two days after the Shuttle departed, a Soyuz capsule arrived with his future crewmates: Mir-25 Commander Talgat Musabayev and Flight Engineer Nikolai Budarin. Accompanying the two cosmonauts was French researcher Leopold Eyharts, who would stay for the three weeks of handover and then return to Earth with the Mir-24 crew.
Thomas watched their approaching capsule. "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." He and his Mir-24 crewmates watched the final approach on a video monitor, and they felt a slight bump as the Soyuz docked to the station. After checking the integrity of all the seals between the vehicles, they opened the hatch and welcomed the new crew aboard. Thomas later wrote, "It was strange to see them all again here in orbit," because he had not seen them since he left Star City for Houston early in the previous December.
This mission was Musabayevs second Soyuz flight to Mir. Budarin had flown to Mir with his Mir-19 crewmate, the same Anatoly Solovyev he was now meeting again in space. That was onboard STS-71 in 1995, when Atlantis performed the first Shuttle-Mir docking and brought U.S. Mir astronaut Norm Thagard and his Russian crewmates back to Earth.
While the six crewmembers were onboard, Mir showed its erratic side when a software glitch in an onboard computer placed the station into free drift. This time, however, Mirs motion control computer never shut down, and Mirs briefly unpowered gyrodynes continued to spin while the crew corrected the problem. In other systems activities, the cosmonauts worked on one of Mirs 11 operational gyrodynes, replacing some electronics with spare parts brought up on STS-89.
Having two crews onboard Mir for three weeks limited workspace and stowage space. Thomas would later say that this was the hardest part of his stay on Mir, "when we had a lot of people aboard and it was very crowded." Spirits were high, however, and a Dutch observer, who recorded Mir radio traffic, reported, "The mood among the four cosmonauts, one astronaut, and one spationaute is excellent. There is a lot of joy and they do not complain about their modest housing."
The two cosmonauts and the French spationaute departed Mir in their Soyuz capsule, and they made a safe landing in Kazakhstan during a blizzard. Thomas later said from orbit that, after the Mir-24 crew left, "it then became a lot easiergetting into the work routine, the recreation routine. I became very comfortable onboard the station, and at no point did I feel like I needed to leave. It became a very sort of comfortable, easy lifestyle in some ways."
Thomas began his complement of science activities, which would focus on 27 studies in the areas of advanced technology, Earth sciences, human life sciences, microgravity research, and International Space Station risk mitigation. His investigations would conclude some experiments started on the six previous U.S.-Mir missions, as well as begin some new research. One of the first experiments he activated was an X-ray detector device, designed to gather information on the background cosmic radiation aboard the station. He started several experiments, including the astroculture unit, which provided a controlled environment chamber to support plant growth in space. He spent much time ensuring that the Biotechnology System Co-culture Experiment was rotating as expected and that the proper doses of media and nutrients were reaching the reactor chamber. And, he soon began collecting urine samples to support the Renal Stone Risk Assessment Experiment, which studied the risk of kidney stone formation due to a sudden absorption of calcium by the body during spaceflight.
During this time, among their other duties, Thomas crewmates replaced some hardware systems on the station, including two different water reclamation systemsone that recycled water from urine, and one that recycled water condensed out of Mirs atmosphere.
In a media interview in early February 1998, Thomas spoke about his life on Mir. There had been questions in the press about his Russian language abilities, especially pertaining to social conversations. Thomas agreed on the importance of socializing, "because we spend a lot of time together in a confined space, not just working as professionals but around the dinner table." Talking about things in general and "sharing experiences of the day" were important. Thomas said, "Ive been talking with Talgat a lot, and weve been working together in the Priroda module. Were having a good time together. We joke and kid around. Im sort of cueing him on English, and hes cueing me on Russian . Were telling a lot of war stories together and talking a lot about music and things, and having a good time." His conversational Russian would continue to improve.
Thomas also said that the Russian space station was "proving to be a very interesting place to live and work [in] . If you want to have fun, zero gravity is a great place to do it. But, I would have to admit that if you want to do very careful, detailed work, zero gravity is tough because youd be amazed how easily you lose things. You take something and you just let it go for a minute, and you turn your back and you come back and its gone somewhere. You wont find it again. Ive had a terrible time just losing things, putting things down and forgetting about them, and they come loose and go flying off somewhere. Tools and personal equipment. Your toothbrush. Your comb. Those are big adjustments in the lifestyle that you have to make when youre in this kind of environment."
Thomas confirmed what the previous NASA Mir astronauts had saidthat life on Mir was difficult in several ways. "Its hard because youre isolated. I mean, I have a very stimulating workday every day, with a lot of challenging activities. Of course, the view is always there, and its an amazing view. But, each day tends to roll into the next and there comes a certain monotony. You have to use your own resources to make the life interesting, to keep your motivation going. Its undeniably a challenge because youre in a confined space. Its crowded, and you have some difficult objectives. So, there are great challenges of taking on a mission like this. Theres no doubt about it."
For Thomas, the biggest issue on Mir was the shortage of stowage space. "Were always fighting this problem of storage, of where to put things in order to do work." Still, his biggest surprise was how quickly he had physically adapted to living in microgravity. To Thomas, weightlessness felt like a "perfectly natural thing."
On February 20, the Mir crew celebrated the 12th anniversary of the launch of the Mirs Base Block, as well as 700 days of continuous American presence in space. In 1986, the Base Block, perched atop a Russian Proton rocket, had launched from the Baikonur Cosmodrome in Kazakhstan to begin what was planned to be five years in Earth orbit. Now, in 1998, the Mir space station was composed of eight permanent modules. All but the punctured Spektr were habitable.
Also on February 20, the crew boarded the Soyuz capsule and backed away from Mir to free the Kvant-1 port for the redocking of the Progress capsule, which had been filled with trash and placed in a parking orbit on January 30. Instead of doing a fly-around as other crews had done, they held steady while ground controllers rotated Mir. Talgat Musabayev then manually flew the Soyuz back to a smooth docking at the transfer node recently vacated by the previous crews Soyuz. Back onboard Mir, the crew worked on life support systems, mainly atmospheric systems, such as oxygen generators, a carbon dioxide scrubber, and a pressure valve. On February 23, the Progress vehicle was redocked, mainly using the Kurs automated system but testing the manual tele-operated remote unit docking system that had posed serious problems to recent expeditions. When the crew reopened the re-docked Progress, a bad smell issued through the hatchprobably some overripe garbage.
Three days later, the crew got a much worse surprise. Smoke started issuing from a device that removed contaminants from the air in the Kvant-1 module. Thomas was exercising on the treadmill in Kristall at the time. When he finished, he floated past the Base Block and was alarmed to see thick smoke drifting throughout the cabin. Evidently, switches on the device had been misconfigured. It had overheated, causing a fire within the unit, and fumes were being blown into the cabin. When Commander Musabayev finally noticed the smoke, he quickly turned off the apparatus. Fortunately, this contained the fire within the unit. The fire was allowed to burn itself out, and extinguishers were not needed. Regardless, the cloud of smoke soon spread throughout the entire space station, and smoke and odor could be noticed in all the modules. Of further concern was the fact that the fire alarm system had failed to generate an alarm despite the obvious and thick smoke.
Over subsequent days, the air cleaners slowly removed the fumes; but the crew continued to feel their effects for some time. The crew took contamination readings and reported them to the ground, but these were thought to be unrealistically high and were attributed to instrument errors. However, analysis of air samples that were later returned to the ground showed that the readings were, in fact, accurate. Carbon monoxide levels had reached 20 times the recommended safety levels, and had remained very high for a couple of days. Fire had again produced one of spaceflights foremost perilspoisoned air in a small, confined place.
On March 4, Talgat Musabayev and Nikolai Budarin attempted the first of five scheduled spacewalks of the Mir-25 expedition. Their plan was to brace the Spektr modules damaged solar array. However, the cosmonauts could not open all of the 10 latches on the airlock hatch. The last latch was so stuck that Budarin broke or bent three of the wrenches available in the airlock trying to release it. Ground controllers called off the EVA and rescheduled it for later in the mission after the next Progress resupply vehicle could deliver new equipment.
During the extravehicular activity attempt, Thomas maintained voice contact with the Mission Control Center-Moscow. The Dutch radio listener on the ground reported, "He did this in reasonable and certainly comprehensible Russian." Both Musabayev and Thomas had earlier told reporters that their spoken communications had greatly improved. (Besides Russian and English, they could also use German. The Dutch listener complimented Thomas "excellent German" and reported that "it was clear that Musabayev had picked up a lot of the German language from the community of former Volga-Germans in his native country" of Kazakhstan.)
The cosmonauts began work to replace Mirs air conditioner, which had not been working since the last month of NASA-6 Mir Astronaut David Wolfs increment. Although Wolf had made the comment that he liked the heat because it "gave him more energy," temperatures in the Base Block had been in the 90s. The crew also had to rely on the dehumidifier on the Soyuz capsule and the Vozdukh carbon dioxide removal system to lower humidities.
In science activities, Thomas continued to work with the Biotechnology System Co-culture Experiment. He was having trouble with air bubbles forming in the facilitys rotating chamber. Researchers on the ground instructed him to reduce the rate at which media and nutrients rotated around the reactor chamber.
With 48 days onboard Mir under his belt, Thomas was asked in a television interview how he was dealing with the isolation and confinement. He said, "You need to be able to psychologically remove yourself from it. And, for that you use recreational aids, much like you would on Earth actually. We have music, CDs, and tapes. Ive got a good repertoire of movies on videotape that I can play. I brought some paperback books to read. So, these are the kinds of things that I use in order to just relax and unwind and relieve tension and get away from things."
Recreational aids may have been available, but at this point in the mission there was little time for relaxation. Musabayev reported to ground controllers that the work burden was too high and procedures often took longer than the time scheduled for them. Thomas was having problems doing all of his scientific work while fitting in the physical exercise necessary to counter the effects of microgravity.
On March 15, the older Progress separated from Mir. The vehicle burned up in the Earths atmosphere, east of New Zealand, over the Pacific Ocean. A new Progress resupply spacecraft arrived on March 25; but in the last moments of approach to Mir, its alignment wasnt perfect. Commander Musabayev switched over to the manual tele-operated remote unit docking system for the last 20 meters and docked it to Mir. In an interview later, Thomas called the docking, "seamless, a beautiful piece of work . We felt a slight nudge and a shudder in the station as the docking took place and as the systems latched together. It was all very benign, really, and went very well; and the commander executed the work flawlessly."
This time, when the crew opened the hatch, they were greeted with a clean aroma of fresh apples. Other welcome items onboard the Progress included letters from home, a computerized photo album for Thomas, new latches for the airlock hatch, new tools, fresh food, a CD player, and three 2-volume sets of Beatles music. On March 22, Thomas 60th day in orbit, the Mir crew and the Shuttle-Mir Program marked two years of a continuous American presence on Mir.
Musabayev and Budarin began preparing for a series of what would be five extravehicular activities in the month of April. Thomas worked at his science investigations, including an immunity experiment for which he periodically took blood and saliva samples. This investigation compared the human bodys ability to produce antibodies in microgravity with its ability to produce antibodies on Earth. Thomas also processed samples for the material science experiment called the Queens University Experiment in Liquid Diffusion (QUELD).
This joint U.S. and Canadian experiment used a special furnace to analyze the phenomenon of diffusion, which is the slow mixing of materials by the random movement of molecules of one substance into another.
On April 3, Musabayev and Budarin performed a 6 1/2-hour spacewalk to install handrails and foot restraints, install a new workstation, and brace a solar array. All of this work was performed on the damaged Spektr module. Thomas monitored their progress and recorded their efforts on video. The work took longer than expected, so they had to postpone the work station and bracing jobs. Also, in a short but somewhat chilling event, contact with Musabayev was lost for several seconds. When it was restored, he reported that he had accidentally turned off his spacesuits power supply, stopping many functions, such as communications, cooling, and ventilation.
Three days later, the cosmonauts conducted a fatiguing 4 1/2-hour spacewalk. They completed the installation of handrails and foot restraints on Spektr and stabilized Spektrs solar array with the special brace. But, ground controllers instructed them to return to the station before working on the Kvant-1 boom propulsion system. While they were outside the station, a problem had developed with Mirs attitude toward the Sun, and the cosmonauts were needed inside Mir to direct firings of Prirodas thrusters.
In an April 10 interview, Thomas talked about his life on Mir. He said the view was always gorgeous. "You see texture. You see color. The mountains you can see as folds in the land. And, you can see things like mountain ranges as a collection of mountain ranges . You can see the way theyre all folded together, a bit like a rumpled carpet, and theyre all connected . The areas that are farmed stand out, as opposed to the natural areas with different shades of green. Of course, it depends on the season."
Thomas praised the Russian food. "The soups are outstanding and the juices are just marvelous, and theres plenty of it. I also have an abundance of American food at my disposal. We exercise regularly. Im on a treadmill running 2.5 to three kilometers . . . every day, something that Im not perhaps as disciplined [to do] on Earth as I should be." He said his mission was going well. "I feel good. Thats one of the amazing things . . . you can feel very good in this environment, whichif you think about itis a very alien environment to us."
He had lost some weight, said Thomas, which "was probably not a bad thing." He had experienced a few aches and pains that he thought were a consequence of spinal extension due to microgravity. But, he had had no ear or stomach problems. "I feel very normal, and feel very healthy and comfortable. So, I have no complaints about it at all."
On April 11, the two Russian cosmonauts performed their third spacewalk. Thomas continued to document their work and provide ground controllers with systems data. This extravehicular activity, which took 6 1/2 hours to complete, went very smoothly. The spacewalkers achieved their planned goal of detaching the old thruster and pushing it away from the space station. Thomas videotaped their progress from inside Mir. On April 17, Musabayev and Budarin went outside again to work on the boom jet assembly. This time, something went wrong with Budarins communications; but he was able to use a backup system. On April 24, they performed yet another extravehicular activity, and finished their boom jet work. The total spacewalk time for their five April excursions was just over 30 hours.
Toward the end of April, Thomas learned that the launch of Discovery (STS-91) in June would be delayed five days to accommodate launch preparations at Kennedy Space Center. In an interview, Thomas said, "I wasnt too surprised. Ive done a lot of support work at the Cape. I know theyre under a very demanding schedule with the processing flow. So, it didnt surprise me too much, and its only five days." Thomas was then nearing his 100th day in orbit. He said that what he was really looking forward to, upon his return to Earth, was a period of not having "schedules in my life, and just being able to be free to do what I want [to do]. To take a walk or go to the store. Or go to visit friends. I think thats going to be the best part about being back."
By early May, Thomas was finishing up some of his scientific investigations. He processed the final pair of samples for the QUELD and completed the second of three experiment sessions of the study into the risks of renal stones in microgravity. He had photographed the Arenal volcano in the Philippines and a large dust storm that swept from the Sahara to the Mediterranean Sea. He also talked about the large fires in Honduras and the Yucatan Peninsula, and the smoke from these fires that was sweeping out of Mexico and darkening skies as far away as Houston. Thomas said that the Yucatan was so covered by smoke that he could not make out the coastline.
In mid-May, Thomas began packing his belongings and scientific hardware, and conducting an inventory of the U.S. equipment aboard the station. His Russian crewmates performed maintenance on thermal loops and on the Kvant-1 Elektron oxygen-generating system. They found a small leak in the condensate recovery system, which they fixed by replacing a separator unit and resetting a valve. Also, the primary cooling loop for the Kvant-1 module shut down automatically. The cosmonauts checked for leaks but found none, so the loop was brought back online.
The crew loaded refuse into the Progress docked to Mir, and launched the vehicle away from the station to prepare for the arrival of a new resupply ship that carried a surprise for the crewa guitar for Talgat Musabayev.
Thomas scientific research program was wrapping up with the focus of his attention on the biotechnology experiment. The air bubbles in the chamber had not hampered the growth of the three-dimensional cells, and the experiment would remain powered on until the arrival of the Space Shuttle Discovery.
But, before Andy Thomas could depart the station, the attitude control computer failed again. The crew had to use the Soyuz jets to face Mirs arrays toward the Sun and regain solar power. They were able to activate the gyrodynes in time for STS-91s docking on June 4.
Back on Earth, the American astronaut described his feelings of being on the American Space Shuttle, pulling away from the Russian Space Station Mir. "Perhaps one of the most moving moments, though, was as we drew further and further away. We went into the night side of the planet, and I could see stars, and the running lights of the station were on. You couldnt see the station. All you could see was lights flashing, and they were just going off into the distance, these flashing points of light fading out slowly. That was kind of an emotional moment, because I knew that would be the last time I would see itever."
NASA-7
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| Smoother Sailing | Thomas Bio | A View from Space | Gravity |
Thomas Biography
Andy Thomas was born in Adelaide, South Australia. He earned a bachelors degree and a Ph.D. in mechanical engineering at the University of Adelaide. After coming to the United States, Thomas worked for Lockheed Aeronautical Systems Company and led a research department engaged in experimental and computational studies in fluid dynamics, aerodynamics, and aero-acoustics before becoming manager of Lockheeds Flight Sciences Division. He later joined NASAs Jet Propulsion Laboratory, investigating such areas as aerodynamics and microgravity materials processing.
Thomas was chosen for astronaut training in 1992. He provided technical support to the Space Shuttle Main Engine Project, the Solid Rocket Motor Project, and the External Tank Project at the Marshall Space Flight Center. He flew as payload commander onboard STS-77 in May 1996 and performed more microgravity research.
In his oral history, Thomas talked about exploration. Even after his remarkable achievement onboard Mir, Thomas did not see himself "in the same league as Lewis and Clark or the people who explored the Antarctic and the Arctic regions. Because when they went off on those very courageous journeys, they went by themselves . Once theyd gone, they were gone. They were alone. When we do these flights, its true were alone up there. But, we have radio communications to a huge group of people [on Earth] who have a lot of resources to provide assistance in the event something goes wrong ...."
Thomas continues with the NASA astronaut program, preparing for future flight assignments and working in the International Space Station Program.
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| Smoother Sailing | Thomas Bio | A View from Space | Gravity |
A View from Space
May 2, 1998
As I have orbited around the Earth, I have spoken to many amateur radio operators as well as [to] television journalists conducting interviews. The questions perhaps most frequently asked are, "What is the view like from space?" and "What can you see?" Over the course of the four months that I have been on Mir, I have taken many opportunities to look out the window and take photographs, and the view is captivating, both day and night.
When you first look down on the Earth you see its obvious curvature, and the thin layer of atmosphere on the horizon with the dark blackness of space above it. It is striking to see the abundance of clouds carpeting the planet. Very seldom do we see extended areas that are free from cloud cover, particularly in the tropics. We can see these clouds building to thunderstorms during the day, and then collapsing at night back down to Earth and spreading out in huge circles as if they had been poured down onto the planet.
As you continue to watch the Earth, you begin to recognize land forms and can see that some countries have broad features allowing them to be recognized at a glance; northern Africa has its desert regions, South America has its forested regions, and Australia [has] its redness. Then there are the characteristic coastlines that we are so accustomed to seeing on a map that stand out very clearly from space; the boot shape of Italy, the Red Sea, the Mediterranean, the Florida peninsula, the Gulf of California, and so on. Finally, there are readily identifiable geographic features that only occur in certain places: the huge expanse of Lake Baikal, the Namib Desert, the Himalayas bounding the plains of Tibet and the fertile areas of India, and the Andes separating the rain forests from the western deserts of South America. After even a short time in orbit, we learn to recognize these and can quickly know our approximate position above the Earth from a glance out the window.
Evidence of human habitation is visible from low Earth orbit. Cities can be seen, although, surprisingly, they do not stand out readily. But we can make out their grid-like patterns of streets. In remote areas, certain roads and railway lines can be seen as faint lines across the Earth, such as the road through the rain forests of Brazil, and the long straight railway line crossing southwestern Australia, but generally these are too small to make out clearly. The fencing off of farmland into individual fields can also be made out, particularly in the Midwest of the U.S. and Canada. There is even one area in South America where they alternate their growing cycles on adjacent fields, giving rise to a very obvious checkerboard pattern. Of course, national boundaries do not stand out by themselves as on a map, but some national boundaries can be seen where there are different land usage policies in effect on each side of a border, giving rise to different surface texture or color. In this way the southern border of Israel can be made out, as can part of the division between the U.S. and Canada. The stories about the Great Wall of China being visible from space may be true, but I have yet to see it.
One of the most readily visible signs of human presence is the occurrence of contrails from aircraft in the upper atmosphere. These are crystals of ice formed from water, a byproduct of the combustion process in the aircraft engines, [that] is collected into the wake vortices of the aircraft. [Contrails] are very long-lasting, and can be seen over virtually all parts of the world as white streaks across the sky. They can be striking around cities that are major air traffic hubs, and can oftentimes be seen radiating out from these cities, like spokes in a wheel.
The view of the Earth at night is equally spectacular, and cities can be made out very clearly with all their streetlights. Some areas stand out very noticeably such as Japan, where the high population density is given away by the abundance of nightlights. In fact there are so many lights you can delineate the shape of the Japanese island chain with ease. The presence of myriad small points of light offshore, probably fishing boats, betrays Japans heavy reliance on seafood.
There is a host of natural phenomena that is spectacular at night. In the temperate zones, we can see vast thunderstorm fronts stretching for miles and being lit up by huge flashes of lightning. Occasionally, I have seen lightning start at one point on a storm front and trigger a cascade of lightning flashes propagating along the storm front, like a falling row of dominoes.
Of course, stars are visible at night, but without any atmospheric attenuation, so they can be seen clearly. They look much as they do when viewed from an isolated desert region away from city lights, but of course they do not twinkle. Perhaps one of the most sublime of all the cosmic sights I have seen to date is the Aurora Australis over the southern polar regions. Only visible at night, it is an eerie curtain of pale green phosphorescence that waves and twists above the Earth, stretching for hundreds of miles.
Meteors are visible from space, too. However, we have the unique vantage of being able to look down on the Earth and see meteors streaking into the atmosphere way below us. Having that perspective is a compelling reminder that we are indeed flying in space.
Unfortunately, this orbital vantage also gives us a unique view of the deleterious effects of human habitation. As I write this, there are huge areas in Central America that are burning. A giant pall of smoke is blanketing the entire southwestern peninsula of the North American continent and is being carried in the winds over much of the United States and as far north as Canada. Indeed, at the northern extreme of one of our orbits, while crossing the Great Lakes, I could see the smoke haze coming up from the distant south and blanketing the land below us. This kind of perspective from space allows us to appreciate that all lands are connected into a common biosphere and that the environmental policies in one country have far-reaching effects in other countries.
Andy
Read more letters from Andy Thomas
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| Smoother Sailing | Thomas Bio | A View from Space | Gravity |
Getting
Back to Gravity
When an astronaut returns from spaceflight, he or she is reminded: Gravity is not just a good idea; it is the law. Readaptation to gravity begins immediately, but it may take several months to recover fully.
NASA-2 Mir astronaut Shannon Lucid said that in her first months on Mir, "I had several dreams that I was on Earth, but floating like I was in zero-g." However, she remembered only one dream of being in space, while she slept back on Earth. During re-entry, Lucid said, "The first thing that made me feel like I was coming home was when we did the deorbit burn and you sort of sense the first onset of g's. You feel very heavy. You think, Yes, I'm really returning, really coming back." For Lucid, "The readaptation process started pretty much like it had after other flights I made. Within twenty-four hours, I was feeling pretty much back to normal."
According to Shuttle-Mir flight surgeon Michael Barratt, readaptation includes many systems, all of which recover at different rates. Typically, the astronaut first encounters a problem with the neurovestibular system. "You're essentially rebooting your guidance software, " Barratt said. Even while still onboard a recently landed Shuttle, astronauts have to be careful with head movements, or with anything that might be disturb their inner ears. NASA-7 Mir astronaut Andy Thomas related that he felt fine, right after he landed, but when he turned his head to speak to a crewmate, the sudden vertigo surprised him.
Gravity also affects the cardiovascular system. An astronauts heart is not used to pumping against gravity, and even sitting upright might prove difficult. According to Barratt: "All of a sudden you've got a gravitational challenge, and to get the blood up to your head is a little bit more work than your heart's been doing for a while." Also, the neuroregulatory mechanisms that maintain normal blood pressure are deconditioned by microgravity.
Furthermore, bones and muscles have lost calcium and mass over the long months in microgravity, and although the astronauts might have exercised religiously in orbit, they now find themselves weaker, compared to before their missions. Returning astronauts swim and do physical exercises. Barratt said, "We have to very careful, but decisively, challenge that system to try to get it back up to what it was prior to flight."
NASAs Mir astronauts had fairly similar experiences during their readaptations to the 1-g gravity, back on Earth.
For NASA-1 astronaut Norm Thagard, the sense of heaviness went away, a few hours after landing. However, Thagard said, "I still didn't feel totally gainly. I felt a little awkward, more so than on my shorter Shuttle flights. I had a real sensation that if I were to bend forward if I weren't careful I'd continue to go forward, and if I bent back ... I'd continue to go back." One day after his earlier Shuttle flights, Thagard had felt like he "had never been in space.... But it was five days before that was true after Mir."
NASA-3 John Blaha and NASA-6 David Wolf allowed themselves to be carried off their returning Space Shuttles, on stretchers a practice preferred by flight surgeons and medical researchers. Soon after Blaha landed, he remarked, "I feel very wobbly. I don't feel like I'm not capable of walking, although I've noticed I'm improving a little bit." Five months after his return from Mir, David Wolf said that he felt "eighty or ninety percent back. The delay ... is not just from spaceflight; it's the busy life that comes with completing a mission like this.... There's still a lot of mission to go...." including debriefings, public speaking, and relating scientific and engineering information to researchers, "So it's a very busy job for at least four months or so after landing."