Miniature piezoelectric valve for atmospheric descent sampling

Mass spectrometers (MSs) have been crucial tools for studying the composition of atmospheres and celestial bodies in our solar system. They've been utilized on missions to the Moon, Mars, Venus, Jupiter, Saturn, Titan, and various comets. However, like their counterparts operating in lab environments on the Earth, spaceflight MSs have to deal with a challenge of a gas sample introduction into the instrument interior, which operates at vacuum.

One specific challenge arises when using MSs on planetary probes. These probes need to let gas into the MS while maintaining a consistent mass-flow rate. This becomes tricky as the probe goes from the near-vacuum of the upper atmosphere to its final measurement altitude. For instance, picture a probe analyzing Venus' atmosphere during a 75-kilometer descent. The probe would encounter a massive change in pressure, going from just 20 millibars at 70 kilometers up to over 90 bars on the planet's surface – that's a pressure change of over three orders of magnitude.

To tackle this issue, we're developing a small, quick-responsive, and energy-efficient valve. This valve will have adjustable conductance, allowing it to control mass-flow in tiny increments. It's designed to work in environments with high external pressures, up to 60 bars. The technology behind this valve is based on micro-electro-mechanical systems (MEMS), and it will use a piezo-electric actuator for fast response times, measuring in milliseconds. This valve will operate in a linear or pulsed mode and will be a great match for an inlet system that can be integrated with the chosen mass spectrometer. Together, they will provide a practical solution for the atmospheric descent probes, making exploration missions more effective and robust.