I joined the Japan National Railways forty some years ago and have been a railroad man for forty years and three months. I have been in the space field for only one year and ten months, so in school terms I am only in the second grade!

For most of us, aren't rockets the first thing that come to mind when someone mentions space? They carry the satellites. I was surprised to learn that from now on the principal role of satellites will be to observe earth. The only way to watch the earth from outside is from a satellite. Satellites will have a monopoly on observing how the earth's environment changes.

Rockets Travel More Than 100 Times Faster Than Bullet Trains

Do you know why they launch the rockets from Tanegashima Space Center? Rocket launches make use of the earth's centrifugal force. When a string with a weight attached to it is twirled round and round, the weight will fly off using that energy. In the same way, rockets are often launched to the east to take advantage of the earth's rotation. The earth's centrifugal force is strongest at the equator where the diameter of the earth is large. At the poles it is zero. In other words, Thus in the northern hemisphere (Japan) one wants to launch rockets from as far south a place as possible. That is why Japan has its rocket launch site in Tanegashima, which was the southernmost point in Japan before the reversion of Okinawa. America launches its rockets from Florida, and the Europeans' launch site is directly on the equator, in South America.

Now for a little space history. America's NASA (National Aeronautics and Space Agency) was formed in 1958. The former Soviet Union had sent up its Sputnik, and the shock of this was probably why NASA was created. In 1955, Japan's Prof. Hideo Itogawa was successful with his "pencil rockets." Apollo 11 reached the moon in 1969. In fact, in Japan that was the year that the National Space Development Agency was started and when work on rockets was begun in earnest. I am sure you realize what a high handicap we were operating under.

Japan's first success with a man-made satellite rocket was in 1975. The space shuttle first made its mark twenty years ago, in 1981. In 1986 came Mir, the Russian space station that recently fell to earth, and Europe's Ariane was launched in 1984.

To launch a rocket it takes 3 million horsepower to lift the rocket engines, and another 4 million horsepower for the solid rocket next to it, or 7 million horsepower in all. A jumbo jet needs a mere 20,000 horsepower. An eight-car bullet train motor has 10,000 horsepower. I believe you can understand just how tremendously powerful a rocket engine is. The maximum speed of West Japan Railway Company's fastest bullet train today, the Nozomi, is 300 km per hour; France's TGV trains go 300 km per hour. Yet for a rocket to break the bonds of gravity and fly into space it must move at a minimum speed of 30,000 km per hour or it will fall back to earth. Because it must go 100 times faster than a bullet train to leave the earth, it needs a huge engine of 7 million horsepower.

In the past the number of rockets launched by each country has differed greatly. Russia has had 2,600 launches, America 1,600, and Japan has launched only 70, and that is counting launches by both NASDA and the Institute of Space and Astronautical Science (ISAS). You probably have an image of Japanese rockets as a string of failed launches. The fact is, the first to the twenty-ninth launches were successful. The 30th and 31st launches failed, but the two since then have been successful. Japan does not have a bad record at all from the point of view of a successes-to-failures ratio.

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A Satellite's Life Expectancy Is Determined By How Long Its Fuel Lasts

There are many kinds of satellites. There are ones that fly low and ones that fly high. The International Space Station, military satellites, and satellites that monitor the global environment fly at comparatively low altitudes of approximately 400 to 800 kilometers. Since airplanes fly at an altitude of around 10 km, the "low altitude" satellites really aren't that low at all, flying at 400,000 meters above the earth. Stationary satellites like weather satellites fly as high as 36,000 kilometers (22,500 miles). Even though they are all satellites, low-orbit satellites and stationary-orbit satellites are totally different from each other.

The rockets are launched from Tanegashima, traveling in the direction of Chile. With the ignition of the second stage engines they enter into a low orbit. The technical term for this is a "parking orbit." The satellite circles the globe once at this low orbit, and then, with a new engine ignition, it is carried to an elliptical orbit (*1 on diagram). This is called the "transfer orbit." At its highest point the elliptical orbit passes through the location for stationary orbits, at an altitude of 36,000 kilometers. Placement of low-orbit satellites ends with the parking orbit, but when satellites like weather satellites are flown to stationary orbits the engines are ignited once again and the satellite is carried to a transfer orbit. The moment it reaches the highest point of the orbit (*2 on diagram) a small rocket on the satellite called an "apogee motor" is ignited and the satellite is placed in stationary orbit.

click to view large image

If the job of the satellite's apogee motor can be carried out by the second-stage engine, igniting the second-stage engine for a third time, this spares the fuel in the satellite's own rocket. Satellites have life spans of six to seven years on the short side and ten to twenty years on the long side. No matter to what heights a satellite soars, gravity eventually brings it down. From time to time it is necessary to use the satellite's own engine to adjust its altitude. This is why when a satellite runs out of fuel, its fate is sealed. Consequently, how long the fuel can last is crucial. This is why the fact that the second-stage rocket engine can perform this role is so helpful. We have been successful with this high-level technology.

Worldwide, 5,433 man-made satellites have been launched. Japan has launched 88 as of February of this year. Around half of the 5,433 satellites are still in orbit today, and 75 of them Japanese. Approximately 2,000 of the 2,600 that are still in orbit are either out of fuel or have had some physical damage and are non-functioning. Of the 600 that are still operational, 25 are Japanese. Of these 600 in operation, communications satellites make up the greatest number, at 300, followed by 30 observation satellites, 30 scientific satellites, and so on. But 2,000 of the total 2,600 in orbit are space garbage, and just what to do with them has become a major issue. They fall to earth from time to time, but it is not outside the realm of possibility that one might unluckily collide with the Space Station.

As for launches to come, H-II A testing for the last financial year has ended. During this financial year we will launch a communications satellite, in September. In March through April we will launch information-gathering satellites, a type of security satellite. Also next year, we will finally launch our long-delayed new type of weather satellite. It is also Japan's plan to launch a ground observation satellite, a technical experiment satellite, an Internet satellite, a lunar orbiter, and we will also send up a series of Japanese-made parts to the Space Station.

Sometimes there is the misapprehension that the rockets are launched for military purposes. Practically none of these rockets can be used for weapons. The missiles used in Afghanistan and Iraq all use solid fuel. The auxiliary rockets I mentioned earlier also use solid fuel. Practically all the large rockets launched today worldwide use either liquid oxygen and liquid hydrogen as fuel. A mixture of liquid oxygen and liquid hydrogen is burned to launch them. Fuel tanks take up about 70% of a 53-meter rocket. Satellites weigh between 4 and 10 tons, yet they are launched by rockets that weigh 300 tons and move at a speed of 30,000 km per hour. They use an enormous amount of energy. Since 290 tons of the 300 tons are thrown into the ocean, a big problem is to make them as light as possible.

Large rockets use both liquid oxygen and liquid hydrogen, but since the temperature of liquid hydrogen is minus 250 degrees Celsius and that of liquid oxygen is minus 180 degrees, as soon as these are loaded the rocket becomes super-chilled and, if left in the rocket, the fuel will gradually damage part of the rocket's structure. In the same way that if you were to jump into a sea filled with ice floes you would die, when a rocket at normal temperature suddenly has liquid oxygen at minus 250 degrees pumped into it, this damages the rocket. That is why the fuel is not loaded into a rocket until immediately before launch. On the video the launch was at 11:45 AM but at 4:00 AM, but 7 hours prior to this, they had to correctly predict what the weather would be 7 hours later. If the wind speed is over 25m (per second) the rocket will be blown sideways and so it cannot be launched. Neither can it be launched if there are clouds below 800 meters. The decision whether or not to begin fueling depends on being able to accurately predict what the weather will be 7 or 8 hours later. It takes 6 to 7 hours to complete the fueling.

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Environmental Issues Are the Road to Survival for the Development of Japan's Space Program

The objective of space development is not rockets, it's satellites. When you think about what satellites do, the first things that pop into your mind are probably weather satellites, BS or CS television broadcast satellites, and GPS (Global Positioning System) satellites.

Broadly speaking, the satellites that are the most in use today are broadcast and communications satellites. Broadcasting satellites (BS) and communications satellites (CS) have become full-blown businesses. Unfortunately, Japanese industry has practically no orders for these on the world market. This is because it can't compete with the number of satellites turned out by Europe and America, and also because following a trade dispute with America five or six years ago, under "Super Article 301," Japan's satellites must be procured internationally. The costs are quite different for a company that builds ten satellites a year compared to a company that builds only one or two. Mitsubishi Electric Corporation finally got an order to build two, but because wages are so high in Japan, the unfortunate reality is that it is not a good business.

Another big field is earth observation satellites. The only way to look at the condition of the earth from the outside is with satellites. Satellites are the most accurate and a unique way of observing changes taking place on planet Earth. A good example of this is the Himawari weather satellite. We can safely say that we would not be able to go about our normal lives if there were no Himawari. As to broadcast and communications satellites, even if we were to persist in building them we cannot realistically catch up to America, unfortunately.

Given all this, I believe that in the future it is global observation and astronomy that will carry Japanese satellite technology into the top ranks in the world. The future of Japan's space and, particularly, satellite technology hinges on what can be accomplished in global observation. Putting it differently, communications and broadcast satellites are already well beyond the research and development phase and have become businesses, and I think that global observation is the greatest satellite mission for the nation to be undertaking. Consequently, it is fair to say that environmental issues create the path to the future survival of Japan's space program development.

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A Weather Satellite Network With Advanced Information Exchange

There are two principal problems that make space difficult. There is a powerful electro-magnetic layer, called the Van Allen belt, which surrounds the earth, blocking out a tremendous portion of the radiation that streams toward earth from space. Human life exists thanks to the protection of the Van Allen belt. When one travels past it, however, space becomes a world in which massive amounts of dangerous radiation is flying around, and that is why it is no simple matter for humans to stay in space for long periods of time. And it isn't just humans; the computer parts that make up the satellites are destroyed by radiation. The computer chips and other parts used in satellites are made especially for space use; if they aren't protected from radiation, they can't be used.

The other problem is that while on earth, due to the atmosphere and the oceans, there is not a large temperature change between day and night, in space, where there is no atmosphere, there is an extremely large difference in temperature between places where the suns shines and where it doesn't. The temperature can be as high as 800 degrees where the sun shines, and minus 100 degrees ~ 200 degrees where it doesn't. A satellite's materials and solar battery paddles must be able to withstand these temperature changes. The technological experiment satellites are for researching and developing these.

Manned satellites aside, we can say that the main functions of satellites from now on will be broadcast and communication, positioning, global observation, weather, astronomical observation, technological experiments, and security and defense. These will be the primary jobs of satellites to come. Of the man-made satellites launched in the 1990's, broadcast and communications were in the overwhelming majority; 60% were communications satellites and 7% broadcast satellites, followed by astronomical observation satellites and global observation satellites. These will be the main roles for satellites.

How do we use global observation data? For starters, we can observe hurricane and heavy rainfall conditions. We can also monitor ice floe conditions, the status of pollution of the oceans, the distribution of vegetation, geological changes, the advance of urbanization, and the advance of deforestation. We also can observe volcanic activity, the temperature of the ocean surface and the density of plankton. We can observe the changes in the organism that is earth, including the depletion of the ozone layer, in real time. I trust you realize that this is a very valuable asset and a valuable means of taking measurements.

The weather satellites of the world exchange data in a very friendly fashion. Let me introduce you to their network. Weather satellites are all stationary satellites and are at an altitude of 36,000 kilometers. All stationary satellites are placed at an altitude of 36,000 kilometers, because this is where centrifugal force and gravity are in balance. The American (NASA) GOES-W is at 135 degrees west longitude, GOES-E is at 75 degrees west longitude; the European (EUMETSAT) MEEOSAT-7 and MEEOSAT-5 are directly above England at 63 degrees east longitude. Russia's GOMS, India's INSAT, China's FY-2, and Japan's Himawari all exchange data and make observations for the world's weather bureaus. What is more, because these can only watch a certain area due to their being stationary, Russia and America also have two satellites in low orbit. These satellites can move about, so they can watch anywhere. World weather observations are reported using the combined data from these two types of satellites.

What do global observation satellites do? The first MOS-1 was an ocean observation satellite and it was a small-scale experimental satellite for observing oceanic weather and fishing operations. JERS-1 was a global resources observation satellite whose mission was to locate resources like forests and oil. ADEUS, sent up several years ago, is a global observation satellite. As a general global observation satellite it covered fisheries, forests, and the seas. Its paddles were damaged, unfortunately, and as a result it only lasted a few months. TRMM is aboard an American satellite, but its Japanese sensors are making a name for themselves and are highly regarded by the Americans. ALOS, which will observe land conditions, will be launched about two years later. There are plans to launch GCOM as the next generation ADEOS. A satellite called GPM that measures only rain is also being readied. You would be correct in thinking that the satellite unit of NASDA is devoting all its efforts to global observation. It's now possible for there to be an organization of satellites launched all over the world, exchanging data with each other and cooperating in global observation

Next is the distribution of readings taken by the satellites of the temperature of the ocean surfaces. With this information we can make long-term forecasts of changes in the weather. It's possible to make fairly accurate readings of the ocean surface temperature. Participation radar (PR) can measure rainfall, and in fact not just the rain but the extent of the moisture content over land can be known. Comparing February and August 1998, in August the zone of heavy rainfall on the African continent extended considerably to the south as the Sahara desert but dried up in the winter. The status of this sort of soil moisture can be seen accurately with a satellite. Observations of ocean surface temperatures all around the globe can be made constantly, and accurate readings of the surface temperatures of the oceans can be made with the TRMM mentioned earlier. The AMSR-E we launched last month can also read ocean surface temperatures precisely.

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Using the Himawari in Space for Environmental Issues

Since space has no national boundaries and global environmental issues are at the worldwide level, there are at present two large organizations. The first is CEOS (Committee on Earth Observation Satellites). A group of international professionals who have launched global observation satellites get together and make international regulations regarding satellite design, utilization of data, global change research, and global observation in space. Forty-three space-related agencies participate. A cooperative international research organization was put together by Satellite space companies almost 20 years ago, and it meets every year. Last year, the chairman was Yoji Furuhama, the Executive Director of NASDA.

The other organization is IGOS (Integrated Global Observing Strategies), a very important group formed in 1998. While CEOS is an organization that has meetings of professionals operating global observation satellites, IGOS is a huge organization whose participants are not just space agencies but international organizations like UNEP, UNESCO and WHO, all the institutions who utilize the data broadly. The IGOS Partnership is an aggregate of utilization principles for how to use space observation and how to apply it to the global environmental and agricultural problems on earth. Japan chaired the 2001 meeting. The conference was in Kyoto last fall. At the time I made a suggestion. "In the same way that weather satellites forecast the weather, we should create a regular organization that makes daily observations throughout the world by global observation satellites of such global changes as the advance in increase or depletion of the ozone layer, or the increase in CO2, and passes them through the IPCC (Intergovernmental Panel on Climate Change)." This received a lot of favorable comments, and so I am moving in that direction. What I'm saying is, let's make something like the Himawari for the global environment.

On board America's AQUA satellite, launched on May 4 2002 from Vandenberg Air Force Base on a Delta rocket is a Japanese-made sensor called an AMSR-E that use electromagnetic waves to measure things like ocean surface temperature. The satellite carries the sensor that, using radio waves from the satellite, can measure water vapor, precipitation intensity, sea surface temperature, the quantity of water in clouds, ocean surface wind speed, the temperature on the surface of the sea, and land temperature. Starting with Japan, space is increasingly being used for global observation.

As a platform, the ADEOS-II can carry a variety of sensors for other nations. This Japanese satellite, the standard-bearer for global observation, will be launched this fall or next year. If its launch is successful I believe it will become a satellite of international renown. This satellite is already ready and is being kept at Tanegashima, If it succeeds, I believe it will be a very important first step for Japan's global observations.

GCOM is a next-generation satellite and is being developed. We are also researching a satellite, called GPM, whose mission will be to measure rainfall around the world, and are preparing to launch it five years from now.

In closing, I would like to say that cooperation between Japan and America in the field of global observation is progressing. The American TRMM satellite I mentioned earlier carries a Japanese-made radar for measuring tropical rainfall that is playing a very active role. The American satellite TERRA carries a Japanese sensor called ASTAR. AMSR-E is on board the AQUA satellite. Including the AURA satellite, they are all global observation satellites (EOS: Earth Observation System).

The upcoming Japanese ADEOS-II will carry an American sensor called Sea Winds. ALOS is a land observation satellite that monitors desertification and vegetation. GPM and GCOM are in research and development, and will monitor global warming and climate change, enable improved weather forecasts, and will also deal with the depletion of the ozone layer, forestry, and fisheries controls.

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