To casual observers, landing a rover on Mars can seem kind of like old news, believe it or not, especially after all of NASA’s successes. But many are likely not aware of the so-called “Mars Curse.” The fact is, many of the spacecraft that attempt to land there fail and crash.
Next to run the gauntlet of the Mars curse is NASA’s Perseverance rover. It’ll attempt its long-awaited landing at Jezero Crater on February 18. The people at NASA have given the Perseverance rover some finely tuned tools to get it to the Martian surface safely and to beat the Mars curse.
The Perseverance rover is landing at Jezero Crater because NASA thinks they can do the best science there. The mission’s goal is to seek signs of ancient life and collect samples for a potential return to Earth. Jezero Crater is an ancient, dried-up paleo-lakebed. It holds both preserved sediments and a delta. According to NASA, the crater is one of the “oldest and most scientifically interesting landscapes Mars has to offer.” Scientists think that if there’s any fossilized evidence of ancient life, they may find it at Jezero.
But it’s also hazardous to land in.
“Jezero is 28 miles wide, but within that expanse, there are a lot of potential hazards the rover could encounter: hills, rock fields, dunes, the walls of the crater itself, to name just a few,” said Andrew Johnson, principal robotics systems engineer at NASA’s Jet Propulsion Laboratory in Southern California. “So if you land on one of those hazards, it could be catastrophic to the whole mission.”
Jezero Crater on Mars is the landing site for NASA’s Mars 2020 rover. Credit: NASA/JPL-Caltech/ASU
About 60% of all spacecraft sent to Mars fail. Perseverance will use what’s known as terrain relative navigation (TRN), a technology first used in cruise missiles, to avoid that same failure. In broad terms, TRN consists of two elements: an onboard map of the landing area with elevations and hazards, and a navigation camera. As Perseverance approaches its landing ellipse, the camera compares its real-time images with the onboard map and commands the lander’s rockets to direct the craft away from known hazards.
Overall, the rover’s autonomous landing system is known as landing visions system, or LVS.
“For Mars 2020, LVS will use the position information to figure out where the rover is relative to safe spots between those hazards. And in one of those safe spots is where the rover will touch down,” Johnson explained in a press release.
This type of system has been under development for some time now. NASA’s OSIRIS-REx used one in its risky sample-collection maneuver at asteroid Bennu. That system was called Natural Feature Tracking (NFT) and it effectively guided the spacecraft down to Bennu’s boulder-littered surface. OSIRIS-REx’s mission was successful, and the samples should arrive on Earth in September 2023.
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But a system like Perseverance’s doesn’t come without a lot of hard work and lead time. It’s been in development for several years, and hopefully, all that development and testing will pay off.
Swati Mohan is the guidance, navigation, and control operations lead for Mars 2020 at JPL. The first two stages of testing were hardware and simulation, and they were both done in a lab. In the press release, Mohan said, “That’s where we test every condition and variable we can. Vacuum, vibration, temperature, electrical compatibility—we put the hardware through its paces.”
Once the hardware has been subjected to all that scrutiny, it’s time for simulations. “Then with simulation, we model various scenarios that the software algorithms may encounter on Mars—a too-sunny day, very dark day, windy day—and we make sure the system behaves as expected regardless of those conditions,” Mohan said.
After that, the system was ready for flight tests. But not autonomously. Instead, it was tested on a helicopter, where it was used to estimate the helicopter’s altitude and position.
A prototype of the Lander Vision System for NASA’s Mars 2020 project was tested in this Dec. 9, 2014, flight of a Masten Space Systems “Xombie” vehicle at Mojave Air and Space Port in California. Credit: NASA/Tom Tschida
“That got us to a certain level of technical readiness because the system could monitor a wide range of terrain, but it didn’t have the same kind of descent that Perseverance will have,” said Johnson. “There was also a need to demonstrate LVS on a rocket.”
The LVS system was tested repeatedly in the field on a rocket. That rocket, the Masten Space System Xombie, served as a test-bed for LVS starting in 2014. NASA’s Flight Opportunities Program funded those tests.
This illustration shows Jezero Crater — the landing site of the Mars 2020 Perseverance rover — as it may have looked billions of years ago on Mars when it was a lake. An inlet and outlet are also visible on either side of the lake. Credit: NASA/JPL-Caltech
“Testing on the rocket laid pretty much all remaining doubts to rest and answered a critical question for the LVS operation affirmatively,” said JPL’s Nikolas Trawny, a payload and pointing control systems engineer who worked closely with Masten on the 2014 field tests. “It was then that we knew LVS would work during the high-speed vertical descent typical of Mars landings.”
“The testing that Flight Opportunities is set up to provide was really unprecedented within NASA at the time,” said Johnson. “But it’s proven so valuable that it’s now becoming expected to do these types of flight tests. For LVS, those rocket flights were the capstone of our technology development effort.”
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Credit: NASA
The LVS system is complex. Not only can it guide the Perseverance rover to the surface, but it can do so in the most fuel-efficient fashion. Fuel for the lander’s rockets is limited, obviously, so there’s really only one chance to get it right. Altogether, the system was tested successfully and is now only days away from the real deal: the landing at Jezero Crater.
But even with all of the thorough testing of the autonomous system, there can still be surprises. Real life is always different than simulations, and though NASA is confident in the system, they’ll still be ready to respond and adapt to any problems or changing conditions.
“Real life can always throw you curve balls. So, we’ll be monitoring everything during the cruise phase, checking power to the camera, making sure the data is flowing as expected,” Mohan said. “And once we get that signal from the rover that says, “I’ve landed and I’m on stable ground,” then we can celebrate.”
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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
