NASA Building 'First Sample Depot on Another World,' on Mars
NASA has chosen a spot called Three Forks to drop off some of the Perseverance rover's rock collection.
NASA is still planning how to get to Mars to pick up tubes full of rocks to bring back to Earth, but an important step in that journey is about to happen. The Perseverance rover is ready to build "the first sample depot on another world," NASA said in a statement Friday.
The sample depot is what NASA is calling the drop-off spot for some of the tubes the rover has already stuffed with rocks and regolith (crushed up rock and dust). These are the focus of Mars Sample Return, or MSR, a complex NASA-European Space Agency mission that could get those rocks to Earth in the 2030s.
Ideally, Perseverance will still be rolling around Jezero Crater when MSR arrives, and will be able to greet the mission in person to deliver its rock samples. But the mission is too important to leave that up to chance. We know how tough Mars can be on our robotic emissaries. The sample depot will offer another way to collect the rock tubes. Percy has been drilling samples in pairs so it can drop one at the depot and keep the matching partner on board.
NASA has chosen a spot named Three Forks for the sample depot. It wasn't easy to pick it out. The site needed to be level and free of rocks on a planet that's notoriously rocky. MSR will have two small, sample-fetching helicopters with it. Those rotorcrafts are inspired by the success of the Ingenuity Mars helicopter. They require a safe place to land to pick up the tubes.
Percy will drop 10 sample tubes from its belly onto the ground. The tough titanium tubes will fall 2.9 feet (88.8 centimeters). "You can't simply drop them in a big pile because the recovery helicopters are designed to interact with only one tube at a time," said MSR program manager Richard Cook. NASA said the tubes will be deposited in an intricate zigzag pattern at distances of 6 to 49 feet (5 to 15 meters) apart.
This map shows the zigzag pattern Perseverance will use to drop off sample tubes at the Three Forks site in the Jezero Crater on Mars.
This isn't going to be quick. Percy is expected to start building the depot in the coming days and will spend over a month getting it right. The process will involve extensive documentation so the tubes can be located even if the Martian winds cover them with dust or sand.
Scientists suspect Jezero Crater was once an ancient lake bed. Percy has found rocks with volcanic origins and ones that are tied into the planet's history of water. It's spotted organic molecules in some rocks, but we'll need to get those samples into labs on Earth to determine if they contain evidence of ancient microbial life.
Perseverance has its work cut out for it, but the rover team is still planning ahead. Once it's done building the depot, Percy will climb to the top of a long-dry river delta it's been exploring. The views should be spectacular, and NASA hopes to find more tantalizing rocks to sample. Onward.