How satellites go to space? Get to know the rocket launch sequences.

How satellites go to space? Get to know the rocket launch sequences.

How do satellites and spacecraft go to space? Let's take a deep dive into the launch procedure, from liftoff until entering operational phases.

   Firstly, after completing the integration of all components, including the power, communications, and essential payloads, the satellite will undergo an extensive testing period. From passing a vibration test to surviving the harshness of vacuum, heat, and space radiation, ensuring that the satellite will thrive and remain operational once it reaches orbit.

   Then, the satellite will be shipped out of the clean room via a special container, it will then be integrated into the launch vehicle, ready for deployment once it reaches orbit.

   The majority of launch vehicles started their journey to space from spaceports, which were specially designed to support the launch of that specific rocket type. The launch date will then be scheduled with consideration of its destination orbit, and coordination with organizations such as the meteorological department, and the aviation agency.

   Upon the scheduled liftoff time, the engine will create a massive amount of thrust, which propels the entire rocket toward its powered ascent. Rockets can be separated into multiple stages, so they can achieve an orbital velocity of more than 27,000 km/h, at an altitude of more than 100 kilometers from sea level.

   The riskiest moment of space launch usually occurs during 'Max Q' or Maximum Dynamic Pressure. At approximately 1 minute after liftoff, the rocket will endure maximum mechanical stress as it accelerates through the dense part of an atmosphere at a very high speed. Even though rockets continue to accelerate after Max Q, they will pass through less dense air at a higher altitude.

   The first stage will exhaust all its fuel at about 2-3 minutes after liftoff, followed by stage separation, and second-stage engine ignition. The second stage will continue propelling the payload into its designated orbit, before separation at approximately 8 minutes up toward 1 hour after launch.

   For example, GISTDA's THEOS-2 satellite, launched with Arianespace's Vega rocket, was placed into the Sun-synchronous orbit at an altitude of 621 kilometers from the surface. The satellite was separated from the AVUM third stage at 54 minutes 22 seconds after liftoff.

   After separating from the launch vehicle, satellites will enter their commissioning phase, which includes establishing communication, checking satellite health and system status, generating power, as well as calibrating all necessary sensors for the mission. This is the process where collaboration between experts and agencies is crucial to preparing the satellite for its operational phases.

   The duration of the commissioning phase will be related to the challenges and difficulties of each mission, which could last for a few months. Then the satellite will be ready for operation and begin its designated mission. The THEOS-2 satellite has completed the commissioning phase, and began providing Earth observation in July 2024.

   Apart from the THEOS-2 mission, GISTDA also hosted the National Assembly and Integration and Testing Center, which facilitates the Thai space industry to test and develop its payload for space missions. GISTDA also studies the possibility of creating a spaceport in Thailand, which could help drive the Thai space economy and the industry as a whole.