Space Technology Overview
📌 The discussion covers various aspects of Space Technology, beginning with familiar tools like telescopes (refracting and reflecting types) used to observe stars.
🔭 Advanced ground-based telescopes, such as the one located at Doi Inthanon, Chiang Mai, utilize large concave mirrors to gather and process light for clearer astronomical images.
📡 Radio telescopes are highlighted as a key technology, employing the principle of radio waves (a type of electromagnetic wave) to study distant stars, capable of penetrating clouds which block visible light.
🛰️ Space technology extends beyond Earth-based tools to include satellites, spacecraft, space probes, and space stations.

Electromagnetic Spectrum in Astronomy
📻 Radio telescopes operate using radio waves, one of the seven types of electromagnetic waves, which also include microwaves, infrared, visible light, UV rays, X-rays, and gamma rays.
💡 Radio waves are advantageous because they can penetrate Earth's atmosphere and clouds, unlike certain other electromagnetic waves such as X-rays and gamma rays, which are blocked by the atmosphere.
🌠 Space telescopes are deployed outside Earth's atmosphere, such as the James Webb Space Telescope (JWST), which primarily observes using infrared waves, offering clearer views of planets like Jupiter and Saturn compared to older visible light telescopes like Hubble.

Satellite Orbits and Functions
🚀 Launching objects into space requires achieving the escape velocity of at least 11.2 km/s to overcome Earth's gravity.
🔄 The required orbital speed for a satellite decreases as its altitude increases; for example, at an altitude of 1,600 km, the orbital speed is about 25,000 km/h, while at 35,880 km, it drops to approximately 11,052 km/h, allowing for a 24-hour orbit matching Earth's rotation (Geostationary Orbit).
🌎 Satellites orbit in three main levels: Low Earth Orbit (LEO) (up to 1,500 km) for high-resolution imaging; Medium Earth Orbit (MEO) (9,900 to 19,800 km), often used for polar-to-polar coverage; and Geostationary Earth Orbit (GEO) (around 35,000 km, equatorial) where satellites appear fixed relative to the Earth's surface.
📡 Specific Thai satellites mentioned include communication satellites like Thaicom 1, 2, 5, 6, and 8, and resource exploration satellites like THEOS.

Spacecraft and Human Life in Space
🪐 Spacecraft are vehicles designed for travel outside Earth, categorized as unmanned (e.g., Ranger missions, Cassini to Saturn) or manned (e.g., Apollo missions).
👨‍🚀 Manned missions, like the Apollo program (1969–1972), allowed humans to conduct experiments and exploration firsthand.
🦾 Life in space presents significant physiological challenges, including potential vision impairment due to lack of proper fluid circulation and decreased immune system function.
🏋️ Astronauts must exercise daily using treadmills with restraints or resistance equipment to counteract muscle weakening caused by weightlessness.

Key Points & Insights
➡️ The minimum escape velocity required to leave Earth's gravitational pull is 11.2 km/s.
➡️ Radio telescopes are vital because radio waves can penetrate atmospheric interference like clouds, unlike visible light.
➡️ Satellites in Geostationary Orbit (GEO) travel at 11,052 km/h at an altitude of about 35,880 km to maintain a 24-hour orbital period matching Earth's rotation.
➡️ Space Technology has yielded numerous terrestrial applications, including vacuum packaging (originally for space food) and memory foam.

📸 Video summarized with SummaryTube.com on Dec 24, 2025, 06:34 UTC