London — Watch out, America.
A confident Europe believes it can snatch away about one-third of a global launching and satellite market from United States rockets and the American space shuttle program between now and 1990.
Europe is reaching for up to $6 billion worth of business from the Buck Rogers era just ahead, in which television, telephone, computer, and business signals will bounce from space satellites to bind the Western world closer together in an electronic unity.
As part of it, and only about four years from now, families in North America, Western Europe, Japan, and Australasia will be able to watch television programs from other parts of the world via dish antennas on their roofs receiving signals directly from space.
In recent days, the fourth test flight of the Columbia space shuttle was followed by space officials all over Europe - closely, but without apprehension.
Officials contacted in London and Paris brim with optimism as they list the advantages they see in their own three-stage launch rocket, called Ariane. A rocket is about to put its second communication satellite into orbit from its launch pad in the steamy, rain-soaked jungle of French Guiana, not far from the equator.
Officials see Ariane as a simpler system, requiring fewer restraints on the satellites it carries. It is more efficient, higher flying, and already proven. They also claim it is much cheaper per launching than the US Thor-Delta rocket that has been hoisting satellites for some years now.
Europe freely acknowledges the imagination and the technical sophistication of the space shuttle. But it is increasingly sure that in the satellite field, the shuttle has large problems.
Asked whether a reusable shuttle was not inevitably cheaper than a one-time, pre-stage rocket, one British official retorted: ''Let them prove it. Its costs have been rising all the time.''
The head of the Ariane project of the European Space Agency in Paris, Raymond Orye, told the Monitor that even some large US communications companies are turning to Ariane for launchings between now and 1986.
Among them: Western Union (which has booked its own Westar satellite on an Ariane launching next year), General Telephone & Electronics (two launchings in 1984); and Southern Pacific Communications of California (two for 1984).
Some US companies are making dual reservations on Ariane and the shuttle, but those three companies have made firm bookings.
The cost of launching a single satellite on Ariane in 1985 will be roughly $ 28 million to $30 million, according to Klaus Iserland, deputy director general of the Paris-based company Arianespace, which markets the European launch program.
This compared, he said, with about $36 million per Thor-Delta launch from Cape Canaveral, Fla.
As for the shuttle, the company estimates the cost per launching to be in the region of $26 million to $28 million. Some European officials believe the shuttle price cannot go lower because it does not include the cost of recovering massive US government subsidies for the first three operational years of the shuttle.
In another inducement, Arianespace offers a deferred payment plan, whereby up to 80 percent of the launch cost can be repaid in the first five years after the launching. This allows the owner to repay out of earned revenue instead of putting up all the money in advance.
The Ariane rocket is based on technology and fuel combinations worked out in France and West Germany over the last decade and on the basis of experience gained even before. Its final successful test in January this year orbited a maritime communications satellite and in September an Ariane rocket will launch two satellites simultaneously for the first time.
Ariane launchings are fully booked up for 1983, 1984, and almost all of 1985, according to Mr. Orye.
Worldwide, Arianespace estimates about 210 satellites will be launched in the last five years of this decade. About 150 of them are targets for the company after subtracting US civilian and military satellites incompatible with the rocket.
Arianespace expects to launch about 50 or more and perhaps as many as 65 -- about 23 to 31 percent of the worldwide total. The remainder will be launched by the US.
Arianespace believes that at an average of seven launches per year and an average cost of $70 million per launch (many carrying two satellites) after 1985 , European launch business works out to about $2.5 billion.
On the satellite side, the prime contractor for Europe is British Aerospace. A spokesman for the Stevenage plant said in an interview the company believed it could take at least 25 percent of the world satellite market. Using a more conservative estimate of 150 satellites to be launched by 1990, he felt the world market was about $5 billion in satellites alone. The European share could thus be about $1.25 billion. Other sources in Europe see the satellite share going as high as $4 billion.
Why is Ariane so competitive?
The US shuttle flies in low orbit -- about 300 miles from the earth. It is ideal for ferrying men and equipment to and from a space laboratory and it can also carry large payloads.
But as far as Europe is concerned, the real commercial excitement of this decade is much further out in space -- 22,500 miles from the earth. There, communications satellites fly in ''geostationary'' orbit -- maintaining a steady position above one spot on the earth's equator.
Companies beam signals up to them and bounce them back to specific areas of the earth. The life of such satellites is about seven years.
The shuttle has not yet launched a satellite, but European officials think it will do so for the first time in November. From its orbital height of 300 miles, it will push a satellite out and a separate rocket will shoot the satellite up to 22,500 miles in what is known as an ''interim upper stage.''
Then the satellite will have to be inserted into precise orbit and attitude. The US uses a spinning third-stage rocket both for the shuttle-carried satellite and for the conventional Thor-Delta rockets.
Thruster jets must be used to nudge the satellite into the exact position required, and these eat up fuel.
On the other hand, the Ariane rocket goes straight to 22,500 miles, and uses a super-accurate inertial guidance system to lob the satellite exactly into position.
In the final Ariane test in January this year, a maritime communications satellite was inserted into orbit with 100 times more accuracy than the shuttle or the Thor-Delta can achieve before using thruster rockets. This greatly exceeded the planned accuracy, which itself was five to six times better than the shuttle.
Dr. Iserland estimates that this means a fuel savings which lengthens the life of an Ariane-carried satellite by about one year. In turn, that means millions of dollars of more revenue for the owners of the satellite.
In addition, French Guiana is much closer to the equator than Florida, and the Ariane rocket needs less fuel for course correction. Mr. Orye of the European Space Agency claims a 13 to 17 percent savings in efficiency.