Fifty-three years ago today, on March 2, 1972 (January 17, 1972 in the lunar calendar), the United States launched a spacecraft to investigate Jupiter. The United States launched the Pioneer 10 spacecraft today. According to the plan, it will make the longest and farthest interstellar voyage in the history of aerospace, that is, it will reach Jupiter after a 21-month flight. After some delay at the critical moment due to technical problems, the launch finally started at 8:50 pm. Officials say the spacecraft is in orbit and is traveling at a speed of 31,413 miles per hour. The spacecraft weighs 570 pounds and has four nuclear generators to power various systems and all instruments. The purpose of the ship's trip is to detect Jupiter's hydrogen-rich atmosphere, cloud cover and radiation belt. When Pioneer 10 arrived at Jupiter in December 1973, it will take the first close photo of the largest planet in the solar system. The orbit of Pioneer will enable the spacecraft to approach Jupiter within 100,000 miles and make a close observation of Jupiter for four days. In this way, the spacecraft can photograph 3/4 of the planet's surface. After the encounter with Jupiter, Pioneer will fly to the outer edge of the solar system, becoming the first spacecraft to enter outer space. The spacecraft carries a record of greetings from earthlings to aliens and about the planet on which we live. Aliens may be able to hear us in space.