Once inside the Sample Return Tube (3), the gas and sample flow at high speed towards the Sample Container.

At the same time, the retrothrust nozzles fire to reduce the overall impulse to the spacecraft (the excavation nozzles are essentially вЂrocket enginesвЂ™). Some of this ejecta flows back into the Sampling Head where it is hit by the gas coming from the transport nozzles. The excavation nozzles stir up Phobos regolith and create ejecta (2). All three sets of nozzles fire gas at the same time. Once the two valves open, the gas will flow from the N2 tank, down the N2 Gas Tube, and into the three sets of gas nozzles: two of them are pointed down (excavation nozzles), two are pointed up (retrothrust nozzles), and two are pointed into the Sample Return Tube (transport nozzles). These valves can modulate gas flow duration, pressure, and frequency: that is, it is possible to send a constant or pulsed gas stream, depending on the requirements. Once actuated by the spacecraft computer, the two redundant valves between the N2 tank and the Sampling Funnel open (see 1 in the image, below). (Image Credit: Honeybee Robotics)ДЇigure 3 details the PMPвЂ™s operational steps. The Control Box itself houses all the components needed to actuate the pneumatic system, as well as the gas tank, valves, beam breaker to detect regolith particles within the Sample Return Tube, and finally the Sample Container itself.ДЇigure 2. The Sample Return Tube transports the collected regolith and gas towards the Sample Container within the Control Box. The N2 Gas Tube connects the gas tank within the Control Box to the nozzles within the Sampling Head. The Sampling Head, integrated into the lander footpad, contains three sets of nozzles and a funnel to collect regolith samples. The P-SMP consists of three main subsystems (Figure 2). Since we do not have much knowledge of the physical properties, chemical properties, and the geotechnical conditions on the surface of Phobos (e.g., compositions, temperature gradient/variation, porosity, grain size distribution), operating two MMX sampling systems that utilize entirely different sampling approaches is prudent. The double sampling approach not only enhances the scientific merits of MMX, but also reduces risks associated with sampling materials on Phobos. The P-SMP, on the other hand, will selectively sample the surface veneer and provide a reference for the surface material gathered by the C-SMP. The C-SMP, a core soil tube deployed by a robotic arm, will provide access to the building blocks of Phobos beneath the surface, and will collect a mixture of near-surface material. To fulfill the mission goals, MMX employs a dual sampling approach using a JAXA-developed Coring Sampler (C-SMP) and the NASA-contributed P-SMP. An SMD-sponsored team at Honeybee Robotics is developing the Pneumatic Sampler (P-SMP) that will enable MMX to capture surface material on Phobos and prepare it for return to Earth for laboratory analysis. These observations and sample analyses will allow new insights about the origins of the Martian moons and how water and organics were delivered to the inner rocky planets, including Earth. Led by the Japanese Aerospace Exploration Agency (JAXA), MMX has two mission goals: (1) determining the origin of the Martian moons and (2) observing processes in the circumplanetary environment of Mars, based on remote sensing, in situ observations, and laboratory analyses of returned samples of Phobos regolith. The Pneumatic Sampler (P-SMP) is attached to the leg of the lander.

The Martian Moons eXploration (MMX) mission (courtesy: JAXA/NASA).

Nasa mars mission