Microlanders

Microlanders are a class of extremely small landers designed to touch down on a planetary body and carry a compact science payload. Typically weighing from a few kilograms up to a few tens of kilograms, microlanders are intended to deliver surface measurements with minimal mission cost and risk. They are often proposed as standalone small missions or as distributed elements within a larger mission, such as secondary payloads or swarms deployed from orbiters or larger landers.

Design goals emphasize simplicity, ruggedness, and energy efficiency. Key constraints include limited power, thermal control in extreme environments, and data handling with short communication windows. Descent and landing approaches vary with the target body: atmospherically rich worlds may use a combination of heat shield, parachute, and retro propulsion or legs to achieve a gentle touchdown; airless bodies rely on lightweight braking systems, thrusters, or impact absorption with springs. Power is typically solar or primary batteries; instruments are miniature and power-aware, such as touch-temperature sensors, magnetometers, seismometers, and small spectrometers.

Operations are usually brief, focusing on atmospheric or surface measurements, calibration tests, or technology demonstrations. Because of their small mass, microlanders face challenges such as surface roughness, dust, radiation, and the difficulty of robust entry and landing sequences. Their small size also enables swarm configurations that provide wider spatial coverage or redundancy.

Currently, microlander concepts exist mainly in research and mission-architecture studies. No dedicated microlander mission has flown as a stand-alone platform to date, but the concept informs ongoing discussions about distributed surface science, rapid-increment testing of subsystems, and potential low-cost exploration architectures.