Bringing Mars to Earth: NASA Mars Sample Return Quiz

High end laboratory equipment like synchrotrons and mass spectrometers are the size of entire rooms and require massive amounts of power. These tools allow scientists to see individual atoms and isotopes within a rock. By bringing the samples back to Earth we can use these machines to find microscopic signatures of life that a rover simply cannot detect.

The Mars Ascent Vehicle does not require a perfectly flat landing pad because it uses a vector thrust system to stabilize itself during ignition. However the lander must still be relatively level to ensure the rocket clears the structure safely. Engineers have designed the landing legs to absorb shocks and settle into the uneven Martian terrain without tilting the launch platform.

Planetary Protection is a critical protocol designed to prevent back contamination of Earth. The samples are treated as a potential biohazard until proven otherwise. This involves sealing the sample container inside multiple layers of sterilized metal and ensuring that the exterior of the return vessel is never exposed to the Martian environment during the return trip.

The Mars Ascent Vehicle or MAV uses solid rocket motors because liquid fuels can freeze or boil away in the thin Martian atmosphere. Solid fuel is much more stable and reliable after sitting in freezing temperatures for months. This technology ensures that when it is finally time to launch the engine will ignite properly to carry the samples into orbit.

Interplanetary missions carry significant risks such as mechanical failures during launch or precision errors during orbital docking. A miss in orbit would mean the samples are lost forever in space. Furthermore the heat shield must withstand thousands of degrees during atmospheric entry. If any of these complex steps fail the entire multi-billion dollar mission could be lost.

Titanium was selected for the sample tubes because it is incredibly strong yet lightweight and it is chemically inert. This means the metal will not react with the Martian minerals inside or change their composition over time. Each tube is also coated in a white ceramic material to reflect sunlight and keep the internal temperature stable while sitting on the surface.

The Sample Retrieval Lander is equipped with a high precision robotic arm provided by the European Space Agency. This arm must identify the small sample tubes and carefully transfer them from the rover or helicopters into the Orbiting Sample container. The arm uses cameras and force sensors to ensure the tubes are locked securely into the rocket nose cone.

The Orbiting Sample container is designed as a sphere with a specific surface texture to make it easy for the orbiter sensors to track. Since there is no GPS around Mars the orbiter must use LIDAR and optical cameras to find a small ball in a massive orbit. The round shape ensures it looks the same from every angle for the tracking software.

The Earth Entry System is designed to survive the intense heat of entering our atmosphere at high speeds. Unlike many missions it is designed for a hard landing without a parachute to reduce the number of things that could go wrong. The structural design of the capsule is built to absorb the impact and keep the sample tubes perfectly intact.

The Earth Return Orbiter uses solar electric propulsion which relies on massive solar arrays to power ion engines. This method is much more fuel efficient than chemical rockets for long duration travel between planets. By using electricity to accelerate ions the orbiter can carry more scientific equipment and safely navigate the long journey back from Martian orbit to Earth.

To prevent Martian dust from reaching Earth the mission uses a specialized sealing process called brazing or explosion welding. This creates a metallic bond that is airtight and stronger than traditional seals. By isolating the samples within multiple layers of metal the mission ensures that no unsterilized Martian material can ever come into contact with the Earths environment.

Researchers are primarily looking for biosignatures which are chemical or physical traces of ancient microbial life. They are also highly interested in the mineral age of the rocks to determine the exact timeline of when Mars had water. These two pieces of evidence together help scientists understand if life ever had enough time to evolve on the planet.

Perseverance carries dozens of tubes but it does not keep them all on board. It has already deposited a backup cache of tubes on the floor of Jezero Crater as an insurance policy. If the rover breaks down before the lander arrives a set of retrieval helicopters can pick up these tubes from the ground to complete the mission.

A rendezvous is the complex orbital maneuver where the Earth Return Orbiter matches the speed and position of the sample container. This must happen perfectly at thousands of miles per hour. Once the two objects are close enough the orbiter captures the container and pulls it into a secure hold for the journey back to our home planet.

Removing the parachute from the entry design simplifies the engineering and removes a common point of failure. Parachutes can easily tangle or fail to deploy at high speeds. By using a crushable carbon structure the vehicle can hit the ground at terminal velocity and still protect the samples inside while ensuring a guaranteed landing in the target zone.

If the Perseverance rover is unable to drive to the landing site NASA will deploy two small recovery helicopters. These are based on the successful Ingenuity design but include a small robotic arm and wheels. They can fly to the cache sites pick up one tube at a time and fly them back to the launch platform.

Because we do not know if Martian material is hazardous the samples will be handled in a Biosafety Level 4 laboratory. This is the highest level of security used for the worlds most dangerous viruses. Scientists will use remote controlled tools and sealed gloveboxes to study the rocks ensuring there is zero risk to the public or the environment.

Jezero Crater is a high value target because it contains clay minerals and carbonates which only form in neutral or alkaline water. On Earth these minerals are excellent at preserving delicate biological structures. Finding them on Mars suggests the ancient lake was not too acidic or salty and might have been a perfect home for microbes.

The Mars Sample Return is a major international partnership between NASA and the European Space Agency. NASA provides the Perseverance rover the Sample Retrieval Lander and the Mars Ascent Vehicle. ESA provides the Earth Return Orbiter and the robotic transfer arm. This collaboration allows both agencies to share the high costs and technical expertise required.

The timeline for the mission is determined by the distance between Earth and Mars which changes as they orbit the Sun. A round trip takes years because we have to wait for the planets to align for both the trip there and the trip back. Including the time spent on the surface the entire process takes about a decade.