NASA installs robotic toolkit in Mars 2020 rover
NASA's Mars 2020 rover has received a key piece of equipment for the collection, containment, and eventual return to Earth of samples of the Red Planet. At the Jet Propulsion Laboratory in Pasadena. California, engineers have installed the bit carousel of the Sample Caching System that will be used to store and sort out the tools and containers for core samples as well as move them about inside the rover for processing.
Since the first Viking landers touched down on Mars in 1976, landing missions have used increasingly sophisticated ways to collect and analyze Martian rock and soil samples. This has shed an impressive amount of light on the nature of Mars and its intriguing history, but until now these experiments have been of a collect and discard nature where the robotic spacecraft acquires samples, run tests on them, and then tosses them aside.
With Mars 2020, NASA and its international partners are trying something much more ambitious. As the unmanned rover explores the surface of Mars, it will not only collect and analyze samples, it will also package a number of these into a special container, which will be left on the surface for a later rover to collect and then return to Earth for detailed study.
This poses a number of challenges for engineers – not the least of which is how the samples are handled once they've been collected by the rover's robotic arm. For Mars 2020, the Sample Caching System uses a bit carousel that NASA compares to being similar in function to an old-fashioned 1960s slide projector.
According to the space agency, the carousel holds an array of nine drill bits. Two of these are for abrading rocks, so they present a clean area for drilling. Meanwhile, there is one bit for regoliths, and six for coring samples.
This is similar to previous designs, but the clever part is that the core samples use lightweight one-off bits that are hollow and carry a sample tube. When the drill presses the bit into a rock, the core sample is collected in the tube and then the bit breaks off. The bit and the sample tube are then returned to the carousel, which then moves it to a different part of the rover, where an internal robotic arm takes the bit and tube and places them inside the sealed collection vessel that will later be left on the surface.
"The bit carousel was the last piece of the Mars 2020 rover's Sample Caching System to be installed," says JPL's John McNamee, project manager of Mars 2020. "And while the rover interior is essentially complete – a battery and a camera used during landing are planned in coming weeks – the assembly and test team will not be resting on their laurels. Months of evaluation and fine-tuning lie ahead to make absolutely certain this rover is on the launch pad and ready to go on July 17, 2020."