On July 20, if all goes according to plan, the Perseverance rover will blast off from NASA's Kennedy Space Center atop United Launch Alliance's Atlas V 541 rocket. Between 9:15 a.m. and 11:15 a.m. ET, the rocket's engines will roar to life, sending Percy out toward our planetary neighbor.
The mission has a 22-day launch window that stretches from July 20 to August 11. If it misses that window, NASA will have to wait more than two years before the rover can attempt another launch for the Red Planet. The orbits of Earth and Mars align in such a way that they're on the same side of the sun once every 26 months.
To get this tricky orbital choreography just right, NASA pushed forward with the $2.7 billion mission despite the spread of the novel coronavirus. "It's very expensive if we have to take Perseverance and put it back in storage for a period of two years," NASA Administrator Jim Bridenstine, said at a June 17 press conference.
Perseverance isn't the only mission hoping to take advantage of the orbital alignment. China National Space Administration is also sending a rover (and orbiter) to the Red Planet—a first for the country. The United Arab Emirates is planning to launch its Hope Mars orbiter this summer, too. ESA and Roscosmos were supposed to launch their ExoMars rover, dubbed Rosalind Franklin, this summer, but work was delayed due to the spread of the coronavirus and the agencies postponed the launch. The rover will blast off in about two years.
NASA hopes that its newest rover, designed and developed in cooperation with partners from the European Space Agency, as well as researchers from Norway, Spain and France—will be the first to find evidence of life outside of our pale, blue dot.
"This is the first rover mission designed to seek signs of past microbial life by detecting it, by collecting and caching rock and soil samples that'll be returned to earth by future missions," says Lori Glaze, the director of NASA's Planetary Science Division. "The rover's instruments will also look for evidence of ancient habitable environments and monitor environmental conditions, which will help us better understand and protect future human explorers."
Eventually, a joint NASA-ESA lander, rover and orbiter will arrive to scoop up the samples that Perseverance left in its wake. Through a series of complicated steps, the spacecraft will work together to hurl those samples—and the secrets they carry—back to Earth. When the samples arrive in about ten years, we'll have enough martian material to keep scientists toiling away in laboratories for decades.
It'll take Perseverance about 213 days to travel the 309 million-mile stretch to Mars. The rover is scheduled to make its Martian debut on February 18, 2021. The mission was designed to last for one Martian year (that's 687 Earth days), but if past rovers are any indication, it could last a lot longer.
Seven Minutes of Terror
The entry into Mars' atmosphere is arguably the most dangerous part of the mission. The capsule will come barreling through Mars' atmosphere at an initial rate of about 12,100 mph. So begins the so-called "seven minutes of terror," when spacecraft enters the planet's atmosphere.
NASA will test a swath of new Entry, Descent, and Landing (EDL) features during this mission. To guide the spacecraft during descent and ensure it arrives safely, NASA added two new technologies to the mission: Range Trigger and Terrain-Relative Navigation.
Previously, spacecraft entering Mars' atmosphere deployed their parachutes based on their velocity. With Range Trigger, the spacecraft will deploy its parachute based on the rover's position relative to where it needs to land. This will help the spacecraft focus on a smaller target landing area.
Terrain-Relative Navigation will use the spacecraft's computers to avoid obstacles and safely navigate to the surface. As the Perseverance hurtles toward Mars, a camera will snap pictures of the quickly approaching surface and feed them to the ultrafast onboard computer. The computer will then analyze the images, select the safest spot to land, and nudge the spacecraft in that direction.
NASA has its eyes and ears on the prize. Commercial cameras will watch over the spacecraft as it hurtles toward the Martian surface and, for the first, there will also be audio recorders strapped to the spacecraft to capture the sounds of the mission. We'll get a front row seat to all the action.
"This is the first time that we have ever been able to see a spacecraft land on another planet and we're looking forward to that imagery, obviously," Matt Wallace, the Perseverance deputy project manager, said at the press conference.
Target: Jezero Crater
Once Perseverance safely lands, it will begin to explore Jezero Crater, a 28-mile-wide impact basin in the middle of a dried-up delta-lake system. The goal is to find evidence of microbial life on the Red Planet. Jezero Crater, which boasts some of the oldest rocks on Mars, is a prime target.
Perseverance deputy project scientist Katie Stack Morgan and her colleagues hope to find biosignatures, patterns, and textures in rocks that are formed by living things. Stromatolites, layered mounds that form from the fossils of long-gone algae, are a type of biosignature found on Earth. These small, blobby rocks are evidence of some of the first signs of life on our planet.
"At Jezero, we'll have access to some of the oldest rocks in the solar system," Perseverance deputy project scientist Katie Stack Morgan said at the press conference. The rover will have the opportunity to collect samples along the crater rim, some of which date to around 4 million years old.
Stack Morgan says the rover will also study carbonate rocks on the Martian surface. "Based on what we know about carbonates here on Earth, we think those are another really important astrobiology target for the mission," Stack Morgan said.
Planetary geologists have studied the site for years and have found evidence for at least 5 different types of rocks to study. Drilling into these rocks will help researchers get a better sense of how Mars and other rocky planets formed and evolved over time.
A Suite of Instruments
The rover has to be tough. Temperatures on Mars can drop to minus 200 degrees Fahrenheit at night, and Martian dust is a constant worry. (RIP Opportunity.) "It's very difficult to build mechanisms for a rover that has to operate flawlessly 100,000,000 miles away with no human intervention," said Wallace.
Fortunately, it has brand new wheels to help it navigate the tough terrain. "They're more capable of dealing with the surface of Mars and pretty much anything that Jezero Crater can throw at it," Wallace said.
In addition to helping it land safely, the onboard computer will also help the rover process images more quickly, which means it won't get bogged down trying to figure out where to go next. "That allows us to drive at about twice the speed as Curiosity is able to drive," Wallace added.
The rover's got a suite of seven instruments that will be used not only in the search for life, but to help assess and address challenges that future Martian explorers might face. Here the high-tech science payload that Perseverance will bring to the Red Planet:
A High-Flying Stowaway
The Ingenuity Mars helicopter is a technology demonstration designed to explore the Martian atmosphere. The 4-pound rotorcraft will be the first to explore the skies on another world. There aren't any scientific instruments aboard the tiny helicopter, and its mission is simple: fly the Martian skies.
Mars has one third the gravity that Earth does and an atmosphere that's just a fraction as thick as Earth's. Generating lift will not be an easy task. The remotely operated rotorcraft will conduct a series of test flights on the Red Planet, each lasting about 90 seconds long. The small helicopter is designed to travel as high as 15 feet and as far as 60 feet. If successful, Ingenuity could open up an entirely new way of viewing distant worlds.
At the end of its 7-foot-long arm, Perseverance has a sample collection robot that will drill into the rocks and soil and scoop up to 43 vials of material. The robot will transfer the tubes into a cartridge within the rover and seal it in preparation for travel back to Earth.
"Our sampling system was particularly challenging in that we've also had to keep it very, very clean," Wallace said. "In fact, this is probably the cleanest system that we've ever launched to Mars."
Once the Perseverance rover identifies and collects its samples, the rover will scatter them on the Martian surface where they'll wait to be scooped up during a future mission. Eventually, a joint NASA-ESA lander will arrive on the Red Planet to pick up the samples.
The lander will deploy a rover, which will locate each of the samples, collect them and deposit them into a small rocket attached to the lander. With samples in tow, that rocket will launch from the lander into Mars' orbit. Once it is safely in orbit, the sample pod will jettison from the rocket and rendezvous with an orbiter, which will have launched in 2026. In 2031, the samples will return to Earth for analysis.
“If it sounds complicated, it is,” Glaze said. There's a lot of room for error, but researchers from every single NASA campus are working on the effort, along with scientists and engineers from ESA.
So, why go through all that trouble? "Scientists have wanted samples of Mars to study for generations," said Glaze. "We have meteorites on Earth that came from Mars, but it's not the same as getting an actual sample—pristine Mars rocks and soil to study."
The launch is just a month away and Perseverance is now at NASA's Kennedy Space Center. The team has finished testing the spacecraft and will now will begin the encapsulation phase of integration.
"We actually clamshell the spacecraft in between its two payload fairings, which will protect it while it's exiting Earth's orbit and on its way to Mars," Perseverance deputy electrical integration and test lead Luis Dominguez said in the press conference. Soon after, the spacecraft will be transported to Launch Complex 41, where it will be fixed atop the Atlas V rocket and stored until launch day.
"The spacecraft is a very small part of the launch vehicle but the most important part and we're hoping she gets there safe," Dominguez said.