Pete Theisinger, the longtime employee of NASA’s Jet Propulsion Laboratory who led the Spirit, Opportunity and Curiosity rover missions to Mars, died June 26 after a long illness. He was 78.

During a career at JPL that spanned more than half a century, Theisinger worked on missions to six planets. With JPL colleague Richard Cook, he was named one of Time Magazine’s 100 Most Influential People in 2013 for his work on Curiosity, and he was honored in 2017 with a lifetime achievement award from the Smithsonian’s National Air and Space Museum in Washington, D.C.

Born in Fresno in 1945, Theisinger was from an early age a “consummate engineer,” his family said in a statement. He earned a bachelor’s degree in physics from Caltech and planned on going to graduate school.

A summer job at JPL changed that trajectory. He would stay at the La Cañada Flintridge facility for the rest of his career, save for a three-year stint as a JPL contractor.

As an engineer, Theisinger worked on the 1967 Mariner mission to Venus, the 1971 Mariner orbiter mission to Mars, the 1977 Voyager mission to the solar system’s outer planets and the 1989 Galileo mission to Jupiter.

He was perhaps best known for his role shepherding Mars rover missions. The twin rovers Spirit and Opportunity launched in 2004 for what were intended to be 90-day missions on the Red Planet.

Both robots far exceeded their initial goals. Spirit lasted six years before getting stuck in a sand trap and sending its final communications in 2010. Opportunity roved the planet until 2018, when communications ceased after a massive dust storm. NASA declared the mission over in 2019.

“His integrity and sense of honesty emanated from JPL all the way to NASA headquarters,” said Rob Manning, JPL’s former chief engineer. “They trusted Pete not to pull the wool over their eyes, to do the right thing and be honest.”

Mere days before Spirit’s scheduled landing on Mars, the engineering team discovered a critical design flaw that could cause the robot to crash upon landing, said Manning, at the time a lead system engineer for the mission.

Manning and colleagues presented Theisinger with a fix that would radically restructure their carefully planned landing. With barely 12 hours to go before touchdown, Theisinger called a meeting and said that as long as the team agreed on the plan unanimously, he would back them up.

The plan worked. Spirit landed safely, and so did its twin rover three weeks later.

“He stood fast. He didn’t panic. He didn’t let us panic. He made us make the case and took full responsibility for the decision,” Manning said.

Theisinger’s next challenge was Curiosity, the largest and most sophisticated rover NASA had yet sent to Mars. Five times heavier than its twin predecessors, Curiosity required an innovative landing apparatus that had to unfold perfectly over seven carefully choreographed minutes. At the end of the famed “Seven Minutes of Terror,” Theisinger was among those who burst into cheers at JPL when the rover landed safely on Aug. 5, 2012. He retired from JPL in March 2017.

Theisinger is survived by his wife, Dona; four children, William, Peter Jeffrey, Tracy and Kelly; and granddaughter Sienna.

“He raised the IQ in whatever room he was in. Not just because he was brilliant and had a diverse set of interests,” his family said in a statement. “Rather, he made everyone around him smarter because they wanted to be better in front of him.”

Earning three Michelin stars and having your restaurant named the best in the world five times might be enough for most chefs, but René Redzepi has set his sights on something bigger: changing the way we eat.

The fare we take for granted today is at risk on multiple fronts. Climate change threatens all kinds of crops, including the most popular food in the world. Mass production by agribusinesses is marring the environment, while monoculture farming practices are giving deadly pathogens a biological edge. Underlying all these challenges is the persistent pressure to feed an ever-growing global population.

None of this was on Redzepi’s mind when he followed his best friend to culinary school at age 15. He quickly found his purpose, cooking in multiple Michelin-starred restaurants before opening Noma in his native Copenhagen 2003.

In the 21 years since, one thing has become abundantly clear.

“There’s something happening with our environment,” Redzepi said, “and how we produce and grow our food has a huge impact.”

That’s the starting point for “Omnivore,” which debuts on AppleTV+ on Friday. Created with his “old pal” Matt Goulding, a food writer and three-time James Beard Award winner, the documentary series raises big questions about the future of food by going deep on eight ingredients: chiles, bluefin tuna, salt, bananas, pork, rice, coffee and corn.

Redzepi and Goulding spoke with The Times about their new show and what they learned about sustainability while making it.

How did “Omnivore” come about?

René Redzepi: Noma was exploding, and I was being offered all sorts of opportunities. I never had the desire to be on TV unless we were informing the world about how magical and important and delicious food is in a way that would be more like “Planet Earth” than a cooking show or travel show.

It was always on the back burner. Then COVID happens.

Matt Goulding: When René called, it all fell into place. His voice always had that kind of David Attenborough echo to it.

Of course we want to make food delicious and enjoyable, but we also want to understand what it means — not just political or cultural but also the natural world, the biological. All of those elements felt like they could be connected through the vessel of the ingredient.

How did you pick the ingredients?

MG: We thought about this like a recipe. What are some of the fundamental ingredients you would put at the heart of a recipe — the protein or the carb — and what are the seasonings? That’s why we have an episode on chile peppers. They don’t have an essential role in our survival, but they have an essential role in explaining the human psyche.

RR: For me, we need wheat to stay alive, but we need chile to feel alive.

You highlight traditional milpa farmers in the Yucatan and organic rice growers in India. If techniques like theirs were widely adopted, would we be able to feed everyone?

RR: We need large-scale agriculture to be inspired by traditional ways that have been used for thousands of years. At the same time, you need those ancient ways to adopt some technology that can actually help things move forward.

MG: It’s a question at the heart of the series, and the episode on corn is where we address this most directly. It’s built around the idea of a tale of two corns. One is a giant monoculture Iowa farm, and the other is the milpa, this polyculture system that was the way corn was grown during its rise in Mesoamerica.

What attracted us to the milpa was not just this romantic ideal of ancient wisdom. When you look at studies, you’ll find that polycultures can produce more calories per acre than a monoculture can.

Monocultures work on a one-dimensional plane — they just use surface area. With polyculture, you’re using using a three-dimensional space to create more food. There’s the crawling vines of the beans, the cover crop of the squash grown below, and the shade being produced by the cornstalks.

The peril of climate change is seen most acutely in the episode about rice. Farmers are so dependent on monsoons, and they’re not behaving as they were in the past.

MG: This single ingredient represents about 20% of the human diet. Figuring out how to continue to grow rice amid this incredible change in our climate is one of the most confounding problems of the 21st century.

Organic farmer Jayakrishnan Thazhathuveetil sows Kuruva rice seeds in Kerala, India, in the documentary series “Omnivore” on Apple TV +.

(Courtesy of Apple TV+)

We found JK, a southern Indian rice farmer who was just trying to grow rice for his community. He discovered that all these incredible varieties of rice that he grew up with were disappearing, so he took it upon himself to look for them. Maybe one of them will adapt better to the changing climate.

RR: Perhaps if we ate more different things, that would also be something that could help. Could we eat more seaweed? Could we eat more mushrooms? Could we eat more legumes? What about bugs? These things have the potential to be mini-staples.

Throughout the series, you show how much humans have literally changed the landscape in pursuit of a good bite to eat. Is this necessarily bad?

MG: Food has always been at the sharp end of the globalization spear. It’s been driving a globalized world since the Age of Discovery, looking for spices, trading salts along the Silk Road.

Master sushi chef Takashi Saito prepares bluefin tuna at his Tokyo restaurant in a scene from the documentary series “Omnivore” on Apple TV+.

(Apple TV+)

Bluefin tuna is a very potent example. What had been a trash fish for the better part of the 20th century could suddenly transform into one of the most sought-after ingredients through the innovation of this one individual at Japan Airlines.

Is this necessarily bad? I don’t think it has to be. There are good ways to do it and there are bad ways to do it. It’s a tough thing to draw a line in the sand.

You seem to have a love/hate relationship with global markets. They make it possible for premium coffee growers in Rwanda to be paid fairly for their labor-intensive work, but they also allow the United Fruit Company to take over big chunks of Latin America to grow bananas.

MG: The United Fruit Company is the classic example of a system that controls all means of production so you can maximize efficiency and profit and get a product around the world. The only thing they didn’t factor in is that you can’t control nature in the long run. This is what we’re seeing with Panama disease and bananas.

That a banana costs one-fifth of the cost of an apple grown right down the road from you is one of the most confounding things about our food system. But the true cost of that banana — to the workforce, the consumer, and the planet — is definitely much greater.

RR: If we can just make people aware that this is how food works, and make you think about what sort of systems you tap into, that will be powerful. Most people probably have no clue.

MG: When we eat, when we drink, we are voting for some world we want to live in. It’s an incredibly empowering thing to be able to do three times a day.

Did you learn anything while making “Omnivore” that changed the way you do things at Noma?

RR: When we go into Noma 3.0 next year, we will cease to operate as a 12-months-of-the-year restaurant and focus a lot of our attention and skills and team on tackling bigger questions in the food space. One of the projects I’m looking into is this thing that we call Future Staples of Food, which was inspired by a lot of the research we’ve done. I mentioned some of them before — the seaweeds, the mushrooms, legumes, and so on.

What about insects?

RR: For sure. It’s definitely a superfood. It’s unbelievable the amount of calories and nutrition you get. It’s mind-blowing.

But to change habits and have more things in our diet, we need to make them utterly delicious so that people choose them. Deliciousness is the change factor.

This interview has been edited for length and clarity.

We usually talk about summertime heat in terms of how hot the air is, but there’s another metric that matters: the temperatures of roads, sidewalks, buildings, parking lots and other outdoor surfaces. Hot surfaces can make the places people live and work more dangerous, and can increase the risk of contact burns.

Just consider this image, captured recently by satellite, of surface temperatures across Phoenix.

Around noon on July 10, huge parts of the nation’s fastest-growing large city were 120 degrees Fahrenheit, about 49 Celsius, or hotter to the touch. Had you been unlucky or unwise enough to actually touch it with bare skin, it could have caused injury within minutes.

On the city’s desert fringes, in territory governed by Native American nations, the land was even hotter, 150 degrees or more.

So far this summer, the Arizona Burn Center, which serves Phoenix and the broader Southwest, has admitted 65 people for severe heat-related burns, according to Dr. Kevin Foster, the center’s director. Six of these people died from their injuries. Last summer, the center recorded 14 such deaths.

Yet even that figure is small compared with the 645 heat-related deaths that were identified last year in Maricopa County, which includes Phoenix. That was the highest number on record for the county. (This year, the county has so far reported 23 heat-related deaths and is investigating 322 more.)

Surface temperatures are just one of many factors that cities are thinking about as they try to protect residents from extreme heat, said Ladd Keith, an associate professor in the School of Landscape Architecture and Planning at the University of Arizona.

In an environment as complex as a city, heat can harm people, pets and wildlife in many different settings and circumstances, Dr. Keith said. For officials, it can be tricky to figure out which exact combination of policies and actions might prove most beneficial to public health.

Phoenix, for instance, is trying to plant more trees and increase shade. The city’s “Cool Pavement” program has treated 120 miles of asphalt to help it reflect more sunlight and stay cooler as a result. But from a cost-benefit perspective, might it make more sense to put those resources toward building more heat-tolerant homes or addressing homelessness instead? “It’s really hard to know what that mix is,” Dr. Keith said.

What’s clear, he said, is the need to figure it out quickly. “Heat deaths are climbing faster than any of our investments to prevent them,” he said. And human-caused global warming keeps increasing the frequency and intensity of dangerous heat waves. “We’re chasing a moving target very slowly,” he said.

Sacramento is known, with pride, as the City of Trees. But tree cover isn’t distributed equally there, and neither is exposure to broiling heat. On the northern and southern sides of California’s capital, residents of low-income neighborhoods have long contended with a shortage of shade and green space on sweltering days like last week’s.

Victoria Vasquez is the grants and public policy manager for California ReLeaf, a coalition of nonprofit groups that protect and grow the state’s urban forests. Funding for such work is always tight, Ms. Vasquez said. That hasn’t changed very much even as the West suffers through more and more record temperatures. “I wish that it did,” she said.

Still, she sees signs of movement in the right direction. Sacramento is considering a plan to increase citywide tree cover to 35 percent from 19 percent by 2045. Under the Inflation Reduction Act, the United States Forest Service received $1.5 billion to support urban forest programs.

When neighborhood associations see how quickly they can reap the benefits of planting and maintaining trees, Ms. Vasquez said, “that is an infectious, positive change.”

In Portland, Ore., tree-filled areas like Forest Park, on the city’s west side, provided oases of cool last week. Yet Vivek Shandas, a professor of urban planning at Portland State University, and his colleagues recently discovered that the city’s overall tree cover decreased somewhat between 2014 and 2020. One likely culprit? Trees are often removed when houses are sold and residential areas redeveloped.

The medical examiner’s office in Multnomah County, which includes Portland, said last week that it was investigating five deaths for links to the recent blistering heat.

In many ways, Portland has become much more attuned to heat threats ever since a heat dome killed hundreds of people in Oregon and Washington in the summer of 2021, Dr. Shandas said. The city is communicating the risks more actively. It has provided portable cooling units to low-income residents. Still missing, Dr. Shandas said, are the changes to building codes and construction practices that would truly ready Portland for the hotter years and decades to come.

“The things that are low-hanging fruit right now, I think have pretty much been picked,” he said. “The longer-term, sustained, deep retrofit that the city needs in order to be prepared for the increasing intensity and frequency of these heat waves? I have yet to see any of that.”