Mars 2020 Rover tests proceeding
NASA’s next Mars rover is scheduled to launch in July 2020 when the Red Planet and Earth are in a good position relative to each other. However testing of the spacecraft’s systems and software are already taking place at the Jet Propulsion Laboratory in Pasadena, California.
Even though the hardware and procedures for the Mars 2020 rover are similar to those used for the Curiosity rover, which successfully landed on the Red Planet almost seven years ago in 2012, it’s still a new vehicle with many changes, including all of its the science packages. Additionally, the destination is completely different than Curiosity’s so the software has to be tailored to accommodate all these changes.
If all goes to plan, the next rover is expected to experience its own seven minutes of terror on Feb. 18, 2021, as it makes its descent and landing.
The rover and its landing system is designed to execute roughly 27,000 actions and calculations during its trip from space down to the Jezero Crater on the surface of Mars. The system taking the rover down through the Martian atmosphere and place it on the Martian surface consists of the aeroshell, parachute, descent vehicle, and structure for a sky-crane maneuver that should lower the 2,300-pound (1,050 kg) rover to the Martian surface on tethers.
This entire process happens autonomously as the distance between Earth and Mars is so great the radio signals travelling take minutes just to get here, which make any remote commanding of the spacecraft useless.
To ensure the greatest probability of success, the team at JPL is simulating the launch and flight to Mars and the landing time and time again to hopefully make sure all goes well when the actual mission occurs.
“We first landed on Jezero Crater on Jan. 23,” Heather Bottom, systems engineer for the Mars 2020 mission at the Jet Propulsion Laboratory in Pasadena, California, said in a NASA news release. “And the rover successfully landed again on Mars two days later.”
Bottom was the test lead for Systems Test 1 (ST1), the first evaluation of the mission’s cruise stage, entry capsule, descent stage and rover. The Mars 2020 engineering team, which is comprised of 72 engineers and technicians, got their first opportunity to test the systems and software during a two-week testing period in January.
“ST1 was a massive undertaking,” Bottom said. “It was our first chance to exercise the flight software we will fly on 2020 with the actual spacecraft components that will be heading to Mars—and make sure they not only operate as expected, but also interact with each other as expected.”
According to NASA, the development of the flight software for this mission was started in 2013. Testing and development of the software was originally performed on desktop computers and laptops and was later moved to spacecraft testbeds where it would interact with computers, sensors and other electronic components which were customized to imitate the flight hardware that will launch with the mission in 2020.
“Virtual workstations and testbeds are an important part of the process,” Bottom said. “But the tens of thousands of individual components that make up the electronics of this mission are not all going to act, or react, exactly like a testbed. Seeing the flight software and the actual flight hardware working together is the best way to build confidence in our processes. Test like you fly.”
So how did it perform?
STS1 was setup to make the spacecraft and rover believe they were actually taking flight, despite being tucked away safely in the High Bay 1 cleanroom at JPL. While the stages of the spacecraft have not been stacked together for flight, technicians used umbilical cords to provide power to each stage and allow them to communicate with each other.
Just like the actual mission, the test began with powering up of the spacecraft like it will be on launch day, simulating all the steps prior to and during launch, even though the spacecraft is actually sitting in the cleanroom instead of aboard the Atlas V rocket, which will launch it next year.
Testing of the journey to Mars, known as the cruise phase of the mission, came next. The team simulated trajectory correction maneuvers, seeing how the system performed them. They also tested how the system reacted to conditions when those did not go as planned, could it determine the needed navigation fix and execute it?
“From the test operations room, you could look out the windows onto the cleanroom floor and clearly see the flight hardware,” Bottom said. “Nothing was visibly moving, but underneath the outer structure, there were flight computers swapping sides, radios sending and receiving transmissions, fuel valves moving in and out, subsystems being energized and later turned off, and electrical signals being sent to nonexistent pyrotechnic devices. There was a lot going on in there.”
All this planning and testing paid off. According to NASA, the team “landed” successfully on Mars, simulated of course, not once, but twice. They “launched” from Cape Canaveral Air Force Station four times and successfully recovered from multiple in-flight off-nominal situations.
Not to rest on their laurels, there is more testing is yet come using different facilities.
“One of the future scenario tests will place the rover inside a thermal chamber and simulate being on the surface. It will step through mission critical activities at some very low Mars surface temperatures,” Bottom said. “Both literally and figuratively it will be a very cool test.”
Video courtesy of JPL
Lloyd Campbell’s first interest in space began when he was a very young boy in the 1960s with NASA’s Gemini and Apollo programs. That passion continued in the early 1970s with our continued exploration of our Moon, and was renewed by the Shuttle Program. Having attended the launch of Space Shuttle Discovery on its final two missions, STS-131, and STS-133, he began to do more social networking on space and that developed into writing more in-depth articles. Since then he’s attended the launch of the Mars Science Laboratory Curiosity rover, the agency’s new crew-rated Orion spacecraft on Exploration Flight Test 1, and multiple other uncrewed launches. In addition to writing, Lloyd has also been doing more photography of launches and aviation. He enjoys all aspects of space exploration, both human, and robotic, but his primary passions lie with human exploration and the vehicles, rockets, and other technologies that allow humanity to explore space.