In 2024 the global space economy reached $415 billion, with commercial satellite activities totaling about $293 billion (71%). The number of active satellites rose from about 3,300 in 2020 to over 11,500 by end-2024 due to mega-constellations. SpaceX and OneWeb have joined traditional players like Airbus, Boeing, Lockheed Martin, Thales Alenia, Intelsat, SES, Eutelsat, and…
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SOHO (Solar and Heliospheric Observatory), launched in 1995, became the first satellite to continuously observe the Sun from the Sun–Earth L1 point and carries the LASCO coronagraph, enabling CME tracking and the discovery of more than 5,000 comets. ACE (Advanced Composition Explorer), launched in 1997, and NOAA’s DSCOVR (Deep Space Climate Observatory), launched in 2015,…
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September 2008: Falcon 1 reached orbit on its fourth flight, becoming the first privately developed liquid-fuel rocket to orbit Earth. December 2008: NASA awarded SpaceX a $1.6 billion Commercial Resupply Services contract to deliver cargo to the ISS. May 2012: Dragon cargo capsule became the first commercial spacecraft to rendezvous with and deliver cargo to…
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The Nancy Grace Roman Space Telescope is planned to launch in late 2026 (latest commitment by May 2027) aboard SpaceX’s Falcon Heavy to a halo orbit around the Sun-Earth L2, about 1.5 million kilometers from Earth. Roman uses a 2.4-meter primary mirror repurposed from Hubble and a 300-megapixel Wide Field Instrument that covers about 0.28…
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As of mid-2025, Starlink is available in over 110 countries and territories. In the United States, Starlink began with limited trials in August 2020 and the public beta “Better Than Nothing Beta” in November 2020, and now has nationwide commercial coverage including Puerto Rico and the U.S. Virgin Islands, with over 2.5 million subscribers as…
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The first space images were captured in 1946 from a sub-orbital U.S. V-2 rocket at about 105 km altitude. The first actual satellite photograph of Earth was taken on August 14, 1959 by the U.S. Explorer 6 satellite. In 1960, TIROS-1 transmitted the first television image of Earth from orbit, a milestone for weather observation.…
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About 75% of the planet is obscured by cloud cover or darkness at any moment, making optical imaging inaccessible. Synthetic Aperture Radar (SAR) satellites actively illuminate the ground with microwave radar and synthesize a large aperture by moving the antenna to produce high-resolution images. SAR can operate day or night and in all weather, providing…
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Iridium operates about 66 LEO satellites at roughly 780 km, offering truly global coverage including the poles with a one-way latency around 0.1–0.2 seconds. Inmarsat uses 3–4 GEO satellites at about 35,786 km, delivering near-global coverage (roughly ±70° latitude) with about 0.5 second latency, and IsatPhone 2 offers up to 8 hours of talk and…
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Radar altimeters on TOPEX/Poseidon, Jason-1, Jason-2, Jason-3, and Sentinel-6 Michael Freilich have provided a global mean sea level record since 1992, showing a rise of about 3.3 millimeters per year and roughly 10 centimeters over 30 years. Arctic summer sea ice extent has declined by about 12% per decade since the 1980s, with the Arctic…
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DGNSS improves GNSS accuracy by using stationary reference receivers to broadcast corrections to rovers, transforming standalone GPS accuracy from about 5–15 m to sub-meter or centimeter levels, with SBAS like WAAS (USA) and EGNOS (Europe) delivering about 1–3 m for aviation. Real-Time Kinematic (RTK) uses carrier-phase measurements and double-differencing to fix integer ambiguities, delivering centimeter-level…
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