印度和美國發射「首顆」衛星

India and the United States have joined forces to launch a groundbreaking satellite called Nisar, which is designed to keep a close watch on the Earth’s surface. This satellite is unique because it can detect even the smallest changes in land, sea, and ice, making it a valuable tool for scientists and disaster management teams. The mission is a collaboration between the Indian Space Research Organisation, known as Isro, and the American space agency Nasa. Nasa has described Nisar as the most sophisticated radar satellite they have ever built. The satellite was launched from the Satish Dhawan Space Centre in southern India, weighing nearly 2,400 kilograms. Nisar is the first satellite to use two different radar frequencies, called L-band and S-band, which allows it to observe the Earth in more detail than ever before. The satellite will orbit the Earth in a sun-synchronous polar orbit, meaning it will pass over the same areas at regular intervals. Every 12 days, Nisar will revisit the same spot, allowing scientists to track changes over time. This is important for monitoring natural disasters like earthquakes, landslides, and melting glaciers, as well as human activities such as farming and construction. The data collected by Nisar will help both India and the US, as well as other countries, to prepare for disasters and understand the effects of climate change. According to scientists, the Earth’s surface is constantly changing due to both natural events and human actions. Some changes happen slowly, while others are sudden. Nisar will be able to detect even tiny shifts, as small as a few centimeters, which can be crucial for early warning systems. The satellite will take about 90 days to fully deploy and begin collecting data after all its systems are tested. The mission cost 1. 5 billion dollars and took more than a decade to develop. Scientists from both countries worked together, even during the challenges of the Covid-19 pandemic. The chairman of Isro called Nisar a life-saving satellite and a symbol of India’s growing leadership in space. The Indian science minister described the mission as a defining moment in India-US space cooperation and a boost for Isro’s international partnerships. This launch comes shortly after an Indian astronaut visited the International Space Station, showing India’s increasing presence in space exploration. In recent years, India has achieved several milestones, including a successful Moon mission and its first solar observation mission. Looking ahead, India plans to launch its first human space flight in 2027, build a space station by 2035, and send an astronaut to the Moon by 2040. The Nisar mission is a significant achievement for both India and the US, and it promises to provide valuable information that will benefit the entire world.