NASA's next Mars rover is rolling off the drawing board and into its final design and fabrication phase, the agency announced today, during a televised event at the Jet Propulsion Laboratory that highlighted some of the mission's technology.
The one-ton Mars 2020 rover is based largely on its predecessor, Curiosity, but comes equipped with a different suite of science instruments designed to search directly for signs of ancient Martian life. The mission has cleared a project milestone known as Key Decision Point C, which keeps the portable science laboratory on track for launch in July or August of 2020, with a landing in February 2021.
"NASA has given us the go-ahead to complete development of the mission," said project scientist Kenneth Farley, standing next to a full-scale testing mockup of Curiosity. "This is a really big, important step for us."
During the rover's two-year mission, it will search for signs of past life in rocks known to preserve organic biosignatures. Mars 2020—which is now eligible for a Curiosity-like name now that the project is in phase C—will also collect rock and soil samples for a possible future Earth return, and extract oxygen from the Martian atmosphere to test technologies that may be needed for human visits.
The surface of Mars is not currently conducive to life, but Curiosity found that it may have been in the past.
"Billions of years ago, there were rivers and lakes on the surface of the planet," Farley said. "We're going to focus our exploration on this time in the distant past."
The completion of Key Decision Point C also means the project has received a baseline cost. NASA officials said it would take $2.1 billion to develop and launch the mission, and another $300 million to operate the rover during its primary mission of one Martian year—slightly more than two Earth years.
The Planetary Society has worked for 20 years to capture sound from Mars. Today, the Mars 2020 team announced the inclusion of microphones aboard their rover, as explained by Dr. Bruce Betts. The Society has been working with the project's SuperCam team, and discussing possible ways to collaborate on their microphone.
Landing and roving
In order for the Mars 2020 rover to look for signs of ancient Mars microbes, it must examine rocks formed while Mars was wet—approximately 3.5 billion years ago. Scientists have narrowed down a list of potential locations to eight candidates.
"The most important decision that we have ahead of us is where we're going to send the rover," Farley said. Safety is the biggest consideration, including both the entry, descent and landing sequence (EDL) and hazardous terrain the rover must cross to get to scientifically interesting spots. Over the course of the Curiosity mission, rough terrain has caused the rover's wheels to puncture and tear.
Lessons learned from Curiosity will be applied to the new rover, according to Allen Chen, the mission's EDL lead.
"We are looking at a new design of the wheels that should help mitigate that," Chen said. "Which principally has to do with thickening the wheels to be more robust to those puncture-type concerns that we've had with Curiosity."
The Mars 2020 landing sequence will resemble Curiosity's "seven minutes of terror," culminating with a hair-raising, rocket-powered descent and skycrane maneuver. But this time around, the size of the landing ellipse can shrink by about 50 percent, thanks to a smarter parachute deployment timing sequence and a feature called terrain-relative navigation.
"On Curiosity, once we popped the heat shield, we took pictures of the ground with a camera, but we didn't use that for landing," said Chen. "This time, we can use those pictures and match them up with an onboard map." Once the rover knows where it is, it can make further trajectory changes and land closer to the more hazardous targets that scientists prefer.
"We prefer landing on things that are flat," Chen said. "But they keep telling us that flat is boring."
Hearing the bells and whistles
The sights and sounds of EDL will be captured by a suite of cameras and a microphone. Engineers will get their first look at an off-world parachute deployment, while audio of critical events will help NASA piece together information about the landing sequence.
Another microphone on the SuperCam instrument will capture sounds from the surface as the rover trundles along. The Planetary Society, which helped fly a microphone on the ill-fated Mars Polar Lander in 1999, has been working with the project's SuperCam team and discussing possible ways to collaborate on their microphone. The Society also serves as the education and public outreach partner for the Mastcam-Z instrument.
Other bells and whistles on the rover include the possibility of a small helicopter drone, which appears to be visible in new renderings of the spacecraft. During today's event, however, the drone was downplayed.
"We have been asked to study the possibility of bringing a helicopter along with us, so this is under consideration by NASA," Kenneth Farley said. "But Mars 2020 is not yet certainly going to be flying a drone."
Whether or not Mars 2020 finds signs of past or present life, the mission could have far-reaching implications for future exploration of the planet.
The rover will fill about 30 sample tubes with rock and soil samples, and deposit them for pickup by a future retrieval vehicle. Those samples could then be shipped back to Earth for analysis. A Mars sample return was listed as one of the top priorities in the last Decadal Survey.
NASA's human spaceflight division is particularly interested in the results of the MOXIE instrument, which will ingest carbon dioxide from the atmosphere and convert it into oxygen. That oxygen could then be used for rocket propellant and breathable air.
As the event wrapped up, a viewer asked the JPL team when they believed humans would walk on Mars.
"The Journey to Mars will be a long one," said Allen Chen. "It's certainly ahead of us in our future, but I hope it comes soon."