Imagine the Curiosity rover as it begins to explore Gale Crater on Mars. From the mast of the rover, an instrument called ChemCam shoots a laser beam at a rock, burning into it while examining the smoke, allowing scientists to determine its composition.
What controls the laser beam? And how does the data from the smoke make it back to scientists on Earth?
The answer to those questions lie in the Radiation Tolerant Intelligent Memory Stack (RTIMS) developed by two researchers at NASA’s Langley Research Center in Hampton, Va. Jeff Herath and Tak-Kwong Ng had high hopes for where it would end up as they developed their technology to support the rapidly increasing resolution of space-based instruments. But they never imagined that it would ride to Mars on Curiosity.
“It was unexpected, but it’s the opportunity of a lifetime,” Ng said. “There is a very small group of people who can say they built technology that is going to Mars.”
RTIMS is perched at the rover’s highest point, inside the ChemCam Instrument on the Remote Sensing Mast (RSM). The system will send science data back to Earth, while controlling the laser beam on the ChemCam, which will study the composition of rocks and soil and help determine if chemicals necessary to support life were – or are – present on Mars.
RTIMS’ highly reconfigurable architecture allowed the ChemCam team to create the custom functions needed to bring the instrument to life.
RTIMS was a perfect candidate for Mars because of its radiation tolerance, real-time data processing, reconfigurable computing, environmental ruggedness and large memory array.
Costs and risks are small – and so is the size. It fits in the palm of a hand.
A new stacking technology, developed by 3D Plus, allowed different types of electronic parts to be built into a single RTIMS component. This new technique provides an 80-percent reduction in required volume or footprint for a given application. The stack weighs 60 grams, or a little more than two ounces.
Using the radiation mitigation techniques it will need on Mars, RTIMS has a memory array of one gigabit with triplication – that’s up to one billion bits of data. In a less challenging radiation environment, it provides two gigabits of error-corrected digital memory.
“That’s the ‘Intelligent’ in RTIMS,” said Herath. “It is flexible enough to compute and to control elements. And its functionality can be adjusted for the intended operational environment.” In the past, RTIMS has also been licensed and used for communication satellites.
“Back in 2003, RTIMS was the largest individual award from Advanced Information Systems Technology (AIST),” Herath said. “I want to thank them for that funding. It’s been worth the investment and I’m grateful that they took a chance on it, and our team.”
Since Herath and Ng have both also been involved with MEDLI (Mars Science Laboratory Entry Descent and Landing Instrumentation), they have found themselves greatly invested in this mission, along with about a hundred other researchers and technicians at NASA Langley.
“It’s still hard to believe, but that’s why we create these space-based technologies,” Herath said. “To give ourselves, and the next generation of engineers, the tools and the data to deliver on NASA’s missions and to hopefully go beyond what we can imagine today.”
The mission is managed by the Jet Propulsion Laboratory (JPL), Pasadena, Calif., for NASA’s Science Mission Directorate in Washington. Curiosity was designed, developed and assembled at JPL.