1. Aerobraking: As the spacecraft plunges into the upper atmosphere, it experiences intense friction with the air molecules, causing a rapid increase in temperature on the spacecraft's outer surface. This phase is known as aerobraking. The spacecraft's heat shield, designed to withstand these extreme temperatures, protects its internal components.
2. Plasma Formation: The high temperatures and ionization of the surrounding air molecules create a plasma field around the spacecraft. This plasma disrupts radio communications, making it challenging for ground control to maintain contact with the spacecraft during this critical phase.
3. G-Forces and Deceleration: As the spacecraft descends further into the atmosphere, it encounters denser layers of air, leading to increased atmospheric drag and deceleration. This rapid deceleration generates significant g-forces that the spacecraft and its occupants must withstand.
4. Communication Blackout: The intense heating and ionization of the air during re-entry can cause temporary communication blackout. This is due to the disruption of radio signals caused by the plasma layer. Ground control may lose telemetry data during this phase, but spacecraft systems are designed to endure the blackout and restore communications once the spacecraft exits the most intense phase of re-entry.
5. Parachute Deployment: To further slow down the spacecraft's descent, parachutes are deployed at an appropriate altitude. The parachutes help stabilize the spacecraft and reduce its velocity, enabling a controlled descent towards the intended landing site.
After successfully navigating the challenges of re-entry, the spacecraft will finally descend and land at its designated location, usually a remote ocean landing site or a designated landing zone on land. The spacecraft is then retrieved, and its data and samples collected for scientific analysis and research purposes.
