Douglas Zimmerman, SFGATE.com Feb. 18, 2021
After a six-month journey from Earth, the Mars Perseverance rover landed safely on the red planet just before 1 p.m. Pacific Standard Time on Thursday, February 18. It will be NASA’s most sophisticated scientific rover sent to Mars, landing in a region that scientists believe is promising to discover signs of ancient life on the planet.
Shortly after landing the vehicle beamed back its first images from the surface.
“This will be the first time that we have peered in great detail into a past habitable environment, both with the tools on the rover and the samples when they come back,” explained Ken Farley, the Perseverance project lead scientist in a pre-landing press conference.
NASA broadcast Perseverance’s landing on its online television channel, NASA TV on Thursday, with live coverage and commentary.
“We’ll be able to show you in real-time what’s going on and show ourselves as well,” explained Allen Chen, a systems engineer in the Entry, Descent, and Landing Systems and Advanced Technologies Group at Jet Propulsion Laboratory.
After the first low-resolution images just after landing, it will take several hours for satellites orbiting Mars to be in the right position to beam back to Earth the first high-resolution images of the landing site.
After lining up the rover’s transmission antenna with Earth and a few weeks of tests to ensure all the rover equipment is working, it will move out to its first location to dig up the planet’s soil and take rock samples, most likely in the summer.
The Jezero Crater was chosen in particular for Perseverance because scientists have determined that the location has a high chance to discover the remnants of life.
“Jezero is a fascinating scientific location. It’s got great craters. It’s got rock fields, sand dunes,” explained Mars 2020 Deputy Project Manager Matt Wallace. “All of those things are interesting for the science community.”
A delta feature, most likely created by water when it flowed on the surface of Mars 3.5 billion years ago, could include mud deposits, which would be a prime location to find the remains of organic microbial life. Nearby, there are likely volcanic rocks that will also help explain the red planet’s geological history and its past and current climate.
To help it explore the Martian surface, Perseverance is equipped with seven different instruments. They include a subsurface radar, panoramic zoom cameras, a laser micro-imager, an ultraviolet spectrometer, an X-ray spectrometer to help detect elements on rock samples, a weather station, and a device called MOXIE, which will produce oxygen from Mars’ atmosphere, which is mostly carbon dioxide.
The rover will also deploy an experimental helicopter to attempt the first powered flight on Mars.
Perseverance will save promising soil and rock samples that a future mission will return to Earth for more analysis. The rover’s mission is expected to last for at least two (Earth) years.5
Although the vehicle landing was handled autonomously by the lander itself, NASA provided real-time flight data (albeit with a slight delay because of the red planet’s distance) of what is happening thanks to a data transmission link through the Mars Reconnaissance Orbiter satellite circling the Mars. The satellite link relayed data, at a speed of 8 kilobits per second, to Earth.
“That’s about half the speed of old-school dial-up if you remember that,” explained Chen. “But that will allow us to see a lot of different things of what the vehicle is doing.”
Despite the limited data transmission speed, NASA provided a lot of information about the landing using a virtual heads-up display of Perseverance’s landing on the broadcast, including the speed of the lander during its descent, its altitude, and even how much fuel the lander has.
Perseverance builds on the technology first used on NASA’s Curiosity mission to Mars in 2012 to safely land the rover on the surface.
During its ‘EDL’ (short for Entry, Descent, and Landing), the lander contacted the Martian atmosphere traveling about 12,000 mph. It first depended on the lander’s heat shield to protect it and help decelerate its speed, while thrusters on the back of the vehicle helped steer it to the proposed landing site in the Jezero Crater.
When the lander slowed to about 1,000 mph, it deployed a 70-foot diameter parachute, further slowing the lander down to about 160 mph.
Even after the parachute was deployed, it was still descend at a speed toward the Martian surface that is too fast to safely land.
At this point, the heat shield detached from the lander, exposing the rover and its attached jet pack and retro rockets.
The rocket-power jet pack and the rover jump out from the back shell of the lander, and the retro rockets further slowed the descent of the rover. Simultaneously, onboard cameras, part of a new terrain navigation system unique to Perseverance, will determine a safe landing spot.
About 70 feet above the surface, the rover separated from the jet pack and was lowered to the surface using a sky crane device. The crane is expected to gently land the rover on the surface at a little less than 2 mph.
Once the landing was complete, the jet pack will flew away to a safe distance from the rover.Read More
Douglas Zimmerman is the Online Photo Editor for SFGate. He also oversees SFGate’s Instagram and covers the Bay Area soccer scene. Zimmerman worked as a staff photographer for the LA Times Community Newspapers, photo editor for Fortune.com, and a photo producer for NYTimes.com.