India successfully soft-landed Chandrayyan-3 on the Moon on August 23. The whole world was anxiously waiting for the soft launch and at around 6.04 PM, the Vikram Lander touched down the Lunar South Pole. After four hours and settling of the dust, Pragyan Rover rolled out to the Moon’s surface. As of this writing, both Vikram Lander and Pragyan Rover have been working well. You should note that soft landing a lunar lander on the Moon involves several complex steps and algorithms. We asked ChatGPT to reveal the computer algorithm for Moon landing. The chatbot has provided a high-level overview of the process and the key algorithms involved. You should note that the actual algorithms used in spacecraft guidance and navigation can be quite intricate and specific to the mission.
Orbit Determination and Planning
- Calculate the spacecraft’s current position and velocity based on telemetry data.
- Plan a trajectory for the descent that accounts for the Moon’s gravitational field and other environmental factors.
Descent Phase
- Initiate the descent burn to slow down the spacecraft and initiate its descent towards the Moon’s surface.
- During descent, continuously update the spacecraft’s position, velocity, and orientation using sensors like accelerometers, gyroscopes, and star trackers.
Terrain Recognition and Mapping
- Use onboard cameras and radar to identify the lunar terrain and obstacles.
- Compare real-time imagery with preloaded maps to determine the spacecraft’s position and adjust the descent trajectory if necessary.
Throttle Control
Adjust the engine’s thrust to control the rate of descent and maintain a safe landing speed.
Sensor Fusion
Combine data from various sensors (such as accelerometers, gyroscopes, altimeters, and cameras) to create a more accurate and reliable understanding of the spacecraft’s state.
Trajectory Correction
Calculate any necessary trajectory corrections based on real-time sensor data to ensure a precise landing.
Landing Sequence
- As the spacecraft approaches the surface, reduce its velocity to a low hover using the engine.
- Utilize sensors to detect the moment of contact with the lunar surface.
Soft Landing
Control the engine thrust to achieve a controlled and gentle touch down on the Moon’s surface.
Post-Landing Procedures
- Shut down the engine and other systems.
- Begin communication with the mission control for post-landing checks and further instructions.
The next step after the successful touchdown of the lander on the Moon is to prepare for the rollout of the Rover. This could take 2 to 3 hours depending upon the scenario.
It’s important to note that the algorithms used for lunar landings are highly mission-specific and can vary based on factors such as the spacecraft’s design, the precision required for the landing, the available sensors, and the autonomy level of the spacecraft. Advanced algorithms like Kalman filters, PID controllers, and model predictive control may be used for various aspects of the landing. For a real lunar mission, these algorithms would be developed, tested, and refined through extensive simulations and testing to ensure a safe and successful landing.
