How Astronauts Reach International Space Station (ISS)

Context: The launch of the Axiom-4 Mission to the International Space Station (ISS) will be from the Kennedy Space Centre in Cape Canaveral, Florida.

How Astronauts Reach International Space Station (ISS)?

Pre-launch Preparation

Astronauts undergo rigorous training and preparation.

• Scientists select a precise time slot when the spacecraft trajectory aligns with the International Space Station (ISS) orbit.
• Astronauts board the Crew Dragon spacecraft, attached atop the Falcon 9 rocket at Kennedy Space Centre, Florida.

Launch and Ascent

• The Falcon 9 rocket lifts off vertically.
• The first stage (booster) propels the spacecraft through Earth’s dense atmosphere, powered by 9 Merlin engines.
• Around the edge of space (~80-100 km altitude), the first stage separates and returns to Earth for reuse.
• The second stage (single Merlin engine) continues to propel the Dragon capsule into orbit.

Orbital Insertion

• After reaching orbit, the Dragon spacecraft separates from the second stage.
• The spacecraft initially enters an elliptical (oval) orbit slightly below the ISS orbit (~200-250 km altitude).

Rendezvous and Orbit Raising

Over the next several hours, the Dragon performs orbital raising manoeuvres.

Approach and Docking

• As Dragon nears the ISS (within ~200 meters), it enters the “keep-out sphere“, a safety zone around the ISS.
• Autonomous Docking: Dragon aligns itself using GPS, cameras, and laser-based Lidar sensors, enabling precise positioning.
• The spacecraft gently moves toward the docking port on the ISS, matching speed precisely, effectively stationary relative to the ISS.

Docking and Hatch Opening

• After successful docking, the spacecraft is secured and undergoes thorough safety checks (~1-2 hours).
• Once cleared, hatches between Dragon and ISS open, allowing astronauts to enter the space station.

Sharing is caring!