Interplanetary Entry, Descent, and Landing (EDL) Techniques

Entry, Descent, and Landing (EDL) are crucial for interplanetary missions. They involve atmospheric entry, deceleration, and safe touchdown on another planet, often employing heat shields, parachutes, and propulsion systems to overcome extreme conditions.

NASA's InSight lander used an innovative heat shield design. The shield's ablative material dissipated heat by lifting hot air away, keeping the probe cool. This technology is crucial for surviving the intense heat of atmospheric entry.

The Mars 2020 Perseverance rover's supersonic parachute was the largest ever deployed on another planet. It had to withstand forces over 60,000 pounds, deploying reliably at supersonic speeds to slow the rover's descent.

Pioneered by the Mars Curiosity rover, the sky crane maneuver allows precise landings. After parachute deployment, rocket-powered descent slows the rover, which is then lowered gently to the surface by cables, a technique essential for heavy payloads.

Modern landers utilize autonomous software for landing. Perseverance's Terrain-Relative Navigation helped it avoid hazardous terrain during descent. The software used real-time image processing to divert the rover to a safe zone autonomously.

Communication between Earth and Mars can take up to 22 minutes round trip. Consequently, EDL sequences are fully automated, with the spacecraft performing pre-programmed maneuvers, unable to be piloted in real time due to the delay.

Future missions may use inflatable heat shields or aerodynamic decelerators for larger payloads. These technologies aim to enable human missions and colonization efforts by supporting larger, heavier, and more complex landers and habitats.