SpaceX Dragon Docking with ISS
The SpaceX Dragon spacecraft, carrying Indian astronaut Shubhanshu Shukhla and three others, successfully docked with the International Space Station (ISS) at 4 pm IST. Docking, a complex procedure, involves joining two spacecraft in space and requires extreme control and precision.
The Challenge
- The capability is crucial for missions involving heavy spacecraft that cannot be launched by a single vehicle.
- The ISS is composed of 43 modules and elements assembled since 1998.
- Docking requires aligning orbits of spacecraft traveling at thousands of kilometers per hour, using algorithms and sensors.
- Only four countries, including India, have demonstrated this capability.
The Docking Process
- Rendezvous:
- Aligning orbits of spacecraft and ISS over several hours.
- SpaceX Dragon uses 16 Draco thrusters to adjust trajectory and orientation.
- The last major burn occurs at 7.5 km from ISS for trajectory alignment.
- Final Approach:
- Vehicle enters "final approach corridor," utilizing laser ranging and thermal imagers for precise measurements.
- Multiple checkpoints assess system health and approach status.
- The final checkpoint "Waypoint 2" is 20 m from ISS, allowing potential position hold.
- Contact & Capture:
- The Dragon's soft capture ring makes "soft contact" with the International Docking Adapter (IDA).
- "Hard capture" occurs with the Dragon’s hooks locking into IDA, completing docking in about ten minutes.
- Pressure equalization and leak checks are performed before hatches are opened.
