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NASA’s Mars Helicopter Opens the Door for Flight on Other Worlds

January 19, 2023 Admin Leave a comment

On April 19, 2021, a toaster oven-size helicopter named Ingenuity spun its rotors and rose 10 feet above the surface of Mars, becoming the first craft to perform a powered flight on a world beyond Earth. It won’t be the last.

Three more extraterrestrial fliers are already under development at the National Aeronautics and Space Administration and other space agencies, and many more uncrewed copters, hoppers and floating machines are on drawing boards. These aerial robots could survey the clouds of Venus, search for life on Saturn’s moon Titan and scout out resources for Mars astronauts who might arrive in the late 2030s.

Those missions face daunting technological hurdles, says Theodore Tzanetos, an engineer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Flying on other worlds requires ultra-lightweight materials, autonomous navigation and adaptations to extreme temperatures and different atmospheres. “With larger flying vehicles things get more complicated,” Mr. Tzanetos says. “How do you get them there? How do you make them reliable?”

But if he and his fellow rocket scientists pull it off, we will soon be touring the solar system like never before.

“There are so many things you can do with aerial mobility that you can’t do with a lander or a rover,” says Geoff Landis, a physicist at NASA’s John Glenn Research Center in Cleveland. “If you want to do global exploration, from pole to equator, you need something capable of flying.”

NASA’s six-rotor Mars Science Helicopter, currently under study, could be used as an aerial scout carrying scientific instruments.

Photo:

NASA (Rendering)

NASA’s Ingenuity shattered expectations of what a helicopter can achieve on other planets. Conceived as a low-budget technology demonstration and scheduled to make just five flights, the tiny craft so far has taken to the Martian skies dozens of times. Ingenuity proved that miniaturized components and large, counter-rotating rotor blades make controlled flight possible in an atmosphere that is about 100 times thinner than Earth’s. Along the way, it has provided unprecedented aerial views of the red planet’s surface and supported NASA’s nearby Perseverance rover.

Ingenuity’s achievements led NASA to ditch plans to send a European Space Agency rover to Mars to transport soil samples cached by Perseverance so that they can be returned to Earth for analysis. The agency now says that in 2028 it will launch a pair of new Ingenuity-style fliers, each enhanced with four wheels and a grasping arm to help collect the samples.

NASA’s Perseverance Rover and Ingenuity helicopter have been exploring the Red Planet since touching down in February 2021. Photo: NASA/JPL-Caltech

Working with colleagues at JPL as well as NASA’s Ames Research Center and the company

AeroVironment Inc.,

Mr. Tzanetos has also drawn up a concept for a larger copter with six rotors instead of Ingenuity’s two. The Mars Science Helicopter, as the craft is known, would be able to carry up to about 10 pounds of instruments.

Then there is Dragonfly, a nuclear-powered helicopter in development at Johns Hopkins University’s Applied Physics Lab (APL) in Laurel, Maryland. In 2027, NASA plans to launch Dragonfly toward Titan, where the atmosphere is four times denser and the gravity seven times weaker than Earth’s. Under those conditions, a modest nudge from Dragonfly’s eight rotors should be enough to send the half-ton science lab soaring through the sky.

“Titan’s just calling out to be flown on,” says APL’s Elizabeth “Zibi” Turtle, a planetary scientist at APL and the principal investigator for the Dragonfly mission.

Plans call for Dragonfly to take to the air once a month for nearly three years, logging up to 10 miles per flight, to explore a landscape dotted with liquid methane lakes, ice boulders and dunes made of grains of tar. Each time it touches down in a new spot, the octocopter will use its suite of instruments to assess the local environment, seeking out carbon compounds of the sort that scientists believe might be precursors of life. If a location seems particularly interesting, Dragonfly will collect surface samples using a pair of drills.

“We want to understand the chemical steps occurring on Titan, ones that may be like the early chemical steps that occurred here on Earth” before the first living things appeared, Dr. Turtle says.

The other moons and small bodies of the solar system lack any significant atmosphere, meaning flight by winged craft is impossible there. Undaunted, aerospace engineers are coming up with flying machines designed for those worlds as well.

While a graduate student at the Massachusetts Institute of Technology in 2021, Oliver Jia-Richards came up with a concept for a glider that would electrically charge the ground and repel itself against it, like two magnets pushing against each other. Now an aerospace engineer at the University of Michigan, Dr. Jia-Richards continues to test components for a levitating glider. He envisions a two-pound, saucer-shaped explorer that could cruise smoothly over rugged terrain in airless settings.

While at MIT, Oliver Jia-Richards came up with a concept for a space glider that would levitate by charging the ground below it.

Photo:

MIT (Rendering)

NASA’s Dr. Landis has conceptualized zero-atmosphere fliers that pack more punch, powered by bursts from a rocket engine. These “hoppers,” capable of covering dozens of miles at a time, might scavenge local resources so they wouldn’t need to carry propellant from Earth. On Pluto, for instance, “we could scoop up nitrogen snow, heat it up and use it to fuel our rocket,” Dr. Landis says.

Venus presents an opposite challenge for flying machines: an extremely dense atmosphere that crushes the surface with pressure equivalent to that 3,000 feet underwater on Earth. And ground temperatures on Venus hover around 900 degrees Fahrenheit. No helicopter, glider or hopper would last long there.

In July, a one-third scale prototype of a balloon probe for use on Venus was tested in Nevada’s Black Rock Desert.

Photo:

NASA/JPL-Caltech

The solution proposed by Paul Byrne, a planetary scientist at Washington University in St. Louis, is to build an altitude-adjustable balloon probe and park it 35 miles above the Venusian surface, where temperatures and pressures are surprisingly Earthlike. The so-called aerobot would feature a high-pressure chamber filled with helium to maintain buoyancy surrounded by a lower-pressure chamber that expands or contracts to change the craft’s altitude, dodging storms and avoiding the heat as needed.

Dr. Byrne has been collaborating with a team from the Jet Propulsion Lab and Near Space Corp. in Tillamook, Ore., to develop a one-third scale prototype of the aerobot. In July, it flew successfully over Nevada’s Black Rock Desert. Now Dr. Byrne is working on a proposal for a full-size version, which would resemble a huge silvery peanut, roughly 45 feet wide and 60 feet tall.

An aerobot could fly for months atop the Venusian clouds, engineers suggest, investigating one of the solar system’s greatest puzzles: Why did Venus turn hellish while Earth became lush, though the two planets are so similar in size and composition? Could the same fate lie ahead for our planet? “If it were to fly, we would rewrite the textbooks—for Venus, for Earth and for rocky planets in general,” Dr. Byrne says.

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What discoveries do you expect to come from expanded flight on other worlds in coming years? Join the conversation below.

MIT astronomer Sara Seager wonders if ancient life on Venus might have taken refuge in the clouds, and if it might still be there today. She has helped draw up plans for a mission to find out. It would send a rocket-equipped aerobot to Venus to collect samples of the clouds and return them to Earth for analysis.

A concept for a Venus airship to support a crew of two for 30 days and a permanent outpost that could operate miles above the surface.

Photo:

NASA (Rendering)

Then again, maybe the scientists will go there instead. Giant airships could enable crewed missions to Venus, Dr. Landis says. Looking further ahead, he can imagine aerial cities on the planet, with people living inside oxygen-filled habitats that float atop the dense atmosphere.

“You could do a settlement on Venus probably more easily than almost any other place in the solar system,” he says.

Write to future@wsj.com

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Health

The World Is Likely Sicker Than It Has Been in 100 Years

February 5, 2022 Admin Leave a comment

The world is living through a unique moment: In the past five or six weeks, the Omicron coronavirus variant has likely gotten more people sick than any similar period since the 1917-18 flu pandemic, according to global health experts.

While Omicron infections have peaked in many places, February is likely to see similar case loads as the variant continues to spread before it flames out, causing worker shortages from hospitals to factories and spurring debate about Covid-19 restrictions, particularly since Omicron appears to be causing less serious illness.

In England, more than one in six residents are estimated to have caught the coronavirus since Omicron emerged in late November, surveys and modeling by the Office for National Statistics indicate. In Denmark, about one in five have caught the virus, and in Israel one in nine, authorities estimate.

SHARE YOUR THOUGHTS

How is Omicron affecting labor and the economy in your community? Join the conversation below.

“This is an unbelievably unique moment when so many people get infected by a pathogen at the same time,” said Christopher Murray, the director of the University of Washington’s Institute for Health Metrics and Evaluation, which tracks global health.

Roughly one in five Americans had contracted Omicron by the mid-January peak, a number that could double by the time the surge ends in mid-February, Trevor Bedford, a virologist at the Fred Hutch Cancer Research Center, estimated. “Having ~40% of the population infected by a single pathogen in the span of 8 weeks is remarkable and I can’t think of an obvious modern precedent. Flu seasons generally have perhaps 10% infected in the span of 16 weeks,” he wrote on Twitter.

Unlike previous waves of the pandemic, which infected fewer people and often surged in different parts of the globe at different times, the current wave is largely world-wide, even if parts of Asia still haven’t seen a substantial Omicron outbreak.

Factory workers lined up for Covid-19 boosters in Mexico on Tuesday.

Photo:

JOSE LUIS GONZALEZ/REUTERS

“If you don’t have friends infected right now, you don’t have friends,” Brenda Crabtree, a Mexican infectious-disease specialist, said on Twitter.

Not everyone who gets infected gets sick. The IHME estimates that as many as 80% to 90% of those infected may be asymptomatic, compared with about 40% with the Delta variant of the coronavirus and similar numbers for influenza. But that still likely leaves a record number of sick people in such a short period.

“Even if just 5% of those who got infected are sick, those are still very big numbers,” said Mr. Murray, adding that about 10% of his own university’s hospital—approximately 900 staff—were either out sick or tending to someone sick in mid-January. And influenza, while less prevalent than before the pandemic, is also circulating, adding to the rolls of the ill. The U.S. Centers for Disease Control and Prevention estimates two million Americans have had symptomatic flu so far this season, which began in October.

A Covid-19 testing site at a New Delhi hospital last month.

Photo:

ANUSHREE FADNAVIS/REUTERS

The impact on labor markets is threefold: Those who get sick, those who have to stay home to tend to sick family members, and those who are asymptomatic but test positive and have to stay home because of workplace and government guidelines.

As a result, unprecedented numbers of people who can’t work remotely are absent, which is hitting hospitals, airlines, schools and sporting events. In Brazil, up to one-fifth of healthcare staff called in sick last week in Rio de Janeiro state, which has also been hit by a flu outbreak. Between 10% and 13% of factory employees in Mexico have called in sick in recent weeks, according to estimates from Coparmex, the country’s largest industry chamber of commerce. “Some manufacturing firms have had up to 20% of the workforce out,” said Ricardo Barbosa, head of the labor committee at the chamber. “We’ve never seen anything like this.”

The scale and speed of Omicron’s spread make it comparable only to the 1917-1918 influenza pandemic, in terms of the percentage of the global population infected with the same virus in such a short period, said Dr. William Schaffner, a professor of infectious diseases at the University of Vanderbilt medical school.

“Obviously there have been other influenza pandemics that have occurred which we would think of as being close to this, but I think we’re playing in the major leagues here,” he said.

In January, there were more than 84 million positive Covid-19 cases world-wide, almost exactly the number of positive Covid-19 results during all of 2020, the year the pandemic got under way, according to numbers from Our World in Data. Fortunately, widespread vaccination, previous infection and better treatments kept the Covid-19-related death toll relatively low during the month, at 217,442.

Commuters in London and Copenhagen (below) rode trains after Covid-19 restrictions were eased in recent weeks in the U.K. and Denmark.

Photo:

Victoria Jones/PA Wire/Zuma Press

Given that testing only captures a fraction of likely cases, however, as many as 95 million people a day around the world were likely catching Omicron in the early part of January, six times higher than the pandemic’s previous peak, according to IHME estimates. It forecasts a sharp decline in new infections over the next few weeks, with the global surge ending by mid-March.

In the first half of December, about three million people across the U.S. said they were at home from work either sick themselves or taking care of a sick family member, according to numbers tracked by the Census Bureau.

The workplace strains and the evidence that Omicron is less severe than earlier variants are prompting more governments to ease Covid-19 guidelines. The U.S. and U.K. have both reduced the isolation period for positive cases to five days from 10. Israel decided that students exposed to a confirmed case no longer need to miss in-person classes. In Dubai, authorities last week told healthcare workers exposed to the coronavirus that they don’t need to isolate if fully vaccinated and have no symptoms, state-backed media reported.

Some governments are going further, encouraged by the idea that the wave of current infections will add to immunity from vaccines and set the stage for a significant decline in infections in coming months, ushering in a new stage where Covid-19 becomes endemic like a seasonal flu. Denmark and France this week said they would scrap many Covid-19 restrictions.

The World Health Organization warned against easing restrictions too quickly. “We’re concerned that a narrative has taken hold in some countries that because of vaccines, and because of Omicron’s high transmissibility and lower severity, preventing transmission is no longer possible and no longer necessary,” WHO Director-General

Tedros Adhanom Ghebreyesus

said on Tuesday. “Nothing could be further from the truth. More transmission means more disease.”

Amid a surge in cases, some countries are handing out second booster shots. In Israel, early data suggest a fourth vaccine dose can increase antibodies against Covid-19, but not enough to prevent infections from Omicron. WSJ explains. Photo composite: Eve Hartley/WSJ

Caroline Ball, an accountant in London, says she knows about 15 families currently infected with the virus—more than she has known of at any one time in the past two years. During two weeks in mid-January, her husband and three young sons tested positive for the virus days apart. Their symptoms ranged from fever and fatigue to no sign of illness at all.

“Especially with Omicron and the boys being at school, it did feel like our time was going to come,” she said. Children under 12 aren’t routinely eligible for Covid-19 vaccines in the U.K.

Hospitals have been most affected by the surge, with more patients and fewer staff. Staff out sick with Covid-19 in English hospitals peaked in early January at almost 50,000, before the government reduced the isolation period for positive cases to five days with two negative test results, according to data from the National Health Service. More than a third of staff at one of Argentina’s largest public hospitals, Hospital General Durand, were out sick or looking after sick family members, hospital officials say.

São Paulo, Brazil’s largest city, hired several hundred new health workers to cope with staff absences. A local judge filed an injunction in mid-January preventing emergency-care health workers in São Paulo from going on strike after they planned walkouts this week over staff shortages.

“Everyone is exhausted…the biggest risk is that we get to a point where the system collapses,” said Victor Vilela Dourado, an anesthetist from São Paulo and head of the city’s doctors union.

In São Paulo, more than 600 bank branches temporarily closed in recent weeks because of lack of staff, according to the banking association. About 20% of workers at Brazilian bars and restaurants across the country have been sent home since December, according to the local industry association. Argentina’s state-run airline Aerolineas Argentinas said one-tenth of its 11,000 employees were out sick in mid-January, causing scores of flights to be canceled.

Health workers demanded better work conditions in a demonstration in São Paulo last month.

Photo:

CARLA CARNIEL/REUTERS

The virus has also hit the world of sports. About 21 Premier League games have been called off because of Covid-19 infections in the U.K. in the past month, far more than the six total games postponed in the 2020-21 season. Argentina’s soccer season is getting under way late because so many players are testing positive. India was forced out of the Women’s Asian Cup soccer tournament after a dozen Covid-19 cases among players.

New Delhi banker Abhishek Sharma is one of millions world-wide now faced with backed-up healthcare services. He kept trying to contact his family’s longtime pediatrician Sameer Maqsood after the banker’s 8-year-old came down with flulike symptoms. But the doctor wasn’t answering his phone or responding to texts. In desperation, Mr. Sharma drove to the doctor’s clinic in east Delhi and found a long line of sick children waiting. The doctor said he was forced to ignore his phone for the first time in two decades because of so many patients.

“Looks like everyone is falling sick,” the banker quoted Dr. Maqsood as saying.

People waited for Covid-19 testing outside a hospital in Buenos Aires in January.

Photo:

AGUSTIN MARCARIAN/REUTERS

—Luciana Magalhaes in São Paulo, Silvina Friedlewsky in Buenos Aires and Dov Lieber in Tel Aviv contributed to this article.

Write to David Luhnow at david.luhnow@wsj.com, Joanna Sugden at joanna.sugden@wsj.com and Rajesh Roy at rajesh.roy@wsj.com

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Science

The Beauty of Buying a Ski Home in Idaho? Nobody Knows a Thing About It

September 30, 2021 Admin Leave a comment

Schweitzer Mountain has 2,900 acres, great snow and stunning lake views; it’s Idaho’s largest ski terrain area.

Most people have never heard of it.

“We have no lift lines. It’s low-key, it isn’t pretentious and there’s a strong sense of community,” says David Thompson, a retired surgeon from Houston who bought a ski-in, ski-out house there with views of Lake Pend Oreille in 2009 for $850,000.

It isn’t easy to get to Schweitzer—the closest major airport is in Spokane, Wash., about a two-hour drive, including a steep road with sharp switchbacks. The two fastest routes from Idaho’s capital, Boise, are 10-12 hours and involve going through either Washington or Montana.

There aren’t many shops and hotels right at the mountain’s base, and cell and internet service can be spotty in the area. Residents have to pick up their mail in the village.

This coming season, the base village of Schweitzer will look very different with the addition of an angled, contemporary, glass and steel hotel and restaurant, designed by hip Portland firm Skylab Architecture.

Schweitzer

Schweitzer is in the midst of a dramatic transformation, aiming to become a destination resort. Last season it added seven runs and two lifts.

Schweitzer

Locals say Schweitzer’s terrain is varied and the mountain is typically uncrowded, with no lift lines most days.

Schweitzer

But Schweitzer is in the midst of a dramatic transformation, aiming to become a destination resort. Last season it added seven runs and two lifts and joined the Ikon Pass, a 47-mountain destination ticket that gives members access to elite ski areas around the world, including Aspen, Colo., Jackson Hole, Wyo., Utah’s Deer Valley, Vermont’s Killington and Zermatt in Switzerland.

The resort village, with a year-round population of about 65, currently looks like a giant construction site, as the resort embarks on a multiphase rollout of residential development. An angled, contemporary glass-and-steel hotel and restaurant, designed by hip Portland, Ore., firm Skylab Architecture, is rising amid the more traditional alpine condos and lodges. The skeletons of new modern houses and townhouses bolstered by steel rods now inundate the steep slopes.

Demand for real estate is so high that there are currently no houses on the market for sale and only two condos—a stark difference from the 40-50 units for sale in the wider area at any given time in the past, says Patrick Werry, an agent with Century 21 Riverstone. Home prices have risen 40% over the past year in this resort village of about 700 homes.

Last year Schweitzer joined the Ikon pass, a 47-mountain destination ticket that gives members access to elite ski areas around the world, including Aspen, Colo., Jackson Hole, Wyo., Utah’s Deer Valley, Vermont’s Killington and Zermatt in Switzerland.

Photo:

Schweitzer

“Everyone is trying to get on the bandwagon,” says Craig Mearns of M2 Construction, which has a three-year waiting list to even start building a custom house. Its latest spec project sold out in a month, even when prices increased from $550,000 to $950,000 for a unit.

What’s happening at Schweitzer is happening all over Idaho. The state is in the midst of a ski renaissance. As its resorts expand their ski terrain and add amenities, demand for homes is booming.

“Idaho is attracting people who want a smaller resort experience—the feel that other Western resorts used to offer but don’t anymore,” says Thomas Wright, president of Summit Sotheby’s International Realty.

Idaho’s ski resorts are scattered across the state and their characters are as different as the terrain that surrounds them, from the arid, celebrity-infused Sun Valley, to the insular, pine-tree dense village of Tamarack, north of Boise. All the way east is the wilder, remote Grand Targhee, in the Teton Range, located in Alta, Wyo., just on the border with Idaho. But the appeal of all these places is the same: low-key, uncrowded skiing with consistent snow.

At Tamarack, the insular, pine-tree dense village north of Boise, the snow is consistently powdery, there are almost never lift lines and there’s lots of backcountry skiing. Opened in 2004, then shut in 2008 due to bankruptcy, Tamarack is in the midst of a resurgence. The resort’s lifts currently service about 1,000 acres of skiable terrain. VIDEO: Todd Meier for The Wall Street Journal

Real-estate agents say the demand for ski resort homes is an offshoot of the demand for homes in Idaho overall, a movement fueled by the pandemic, with people looking for properties with more space and, in some cases, more lax Covid restrictions. (Idaho is currently in a hospital resource crisis because of its high rate of Covid.)

Idaho’s home prices have grown 42% in the past two years—twice the national average and the highest of all the states, according to Nik Shah, CEO of Home LLC., a down payment assistance provider.

“Most of my friends are like ‘Idaho, what’s there?’ My response is, ‘exactly—it’s because you don’t know about it,’ ” says Harmon Kong, a 57-year-old investment adviser from Lake Forest, Calif.

Mr. Kong and his wife, Lea Kong, fell hard last year for Tamarack and bought two places: a ski-in ski-out, three-bedroom, three-bathroom penthouse condo in the fall of 2020 for $1.8 million, and three-bedroom, three-bathroom chalet nearby for $1.28 million.

Harmon Kong, an investment advisor from Lake Forest, Calif., and his wife Lea Kong fell hard last year for Tamarack and bought a three-bedroom, three-bathroom penthouse ski-in ski-out condo there in the fall of 2020.

Kyle Green for The Wall Street Journal

The living room area as seen from the upstairs in the condo owned by Harmon and Lea Kong at Tamarack.

Kyle Green for The Wall Street Journal

The kitchen area of the condo owned by Harmon and Lea Kong in Tamarack.

Kyle Green for The Wall Street Journal

The main bedroom of the condo owned by Harmon and Lea Kong in Tamarack.

Kyle Green for The Wall Street Journal

Tamarack has applied to the U.S. Forest Service for permits to add seven to nine new lifts, including a gondola, and more than double its size by adding 3,300 new acres of ski terrain and a new summit lodge.

Kyle Green for The Wall Street Journal

Mr. Kong was used to skiing at Heavenly Ski Resort in Lake Tahoe, Calif., which he likens to Disneyland because of the crowds. At Tamarack, he says the snow is routinely powdery, there are hardly ever lift lines and there’s lots of backcountry skiing.

Opened in 2004, then shut in 2008 due to bankruptcy, Tamarack is in the midst of a resurgence. The resort’s lifts currently service about 1,000 acres of skiable terrain and it has applied to the U.S. Forest Service for permits to add seven to nine new lifts, including a gondola, and more than double its size by adding 3,300 new acres of ski terrain and a new summit lodge.

Building is underway on ambitious, multiphase residential development projects, which will result in 2,043 residential units, including about 1,000 hotel rooms and a mix of condos, estate homes, townhomes, cottages and chalets. Tamarack is in the process of starting a charter school. The average sold price for a home in Tamarack, which has about 450 homes in all, has grown 80% over the past two years, according to the Mountain Central Association of Realtors.

To attract more skiers, this past year Tamarack joined the Indy Pass, which includes small, independent resorts around North America. The resort’s president Scott Turlington is aiming for 500,000 skier visits over the next couple of seasons (up from 120,000 last season), which he acknowledges might make him persona non grata among some of the current homeowners. “If I do my job properly I won’t be the most popular person,” he says.

Ski Magazine readers voted Sun Valley the country’s top ski resort in Western North America in 2021, in part because of its comparably short lift lines. However, last year it became a partner in the Epic pass, a move that could bring more skiers. Sun Valley has been growing its ski operations. Last season it added 380 acres of skiable terrain on Bald Mountain and a new high-speed chairlift. VIDEO: Sun Valley Resort

Still, Mr. Turlington says, “We want to maintain our rugged individualism and independent spirit. It’s a very different feeling here than at one of the top resorts.”

The top ski resort in Idaho is Sun Valley. In fact, Ski Magazine readers voted Sun Valley the top ski resort in Western North America in 2021, in part because of its comparably short lift lines. It’s located in an arid, high-altitude and desert-like environment and its famed Sun Valley Lodge has walls lined with photos of celebrities like Marilyn Monroe, Ernest Hemingway and Tom Hanks. Business moguls and world leaders convene there every summer for the annual Allen & Company conference.

Sun Valley has also been growing its ski operations. Last season, it added 380 acres of skiable terrain on Bald Mountain and a new high-speed chairlift. It became a partner in the Epic Pass, which includes mountain resorts like Colorado’s Vail, Utah’s Park City and Whistler in Canada, a move to bring more skiers to the mountains.

Sun Valley Resort’s vice president and general manager Pete Sonntag says the resort has no plans to expand further for now. “Our goal is never about competing for the most skiers. It’s about improving the guest experience,” he says, adding, “The remote location will keep it from feeling overrun.”

But, like many resort towns, the issue of development and affordable housing is a hot topic right now. “There’s a huge concern about people getting priced out,” says Katherine Rixon, a real-estate agent with Keller Williams Sun Valley. Property values have appreciated so much that many owners of rental properties are cashing out of the market, leaving their tenants having to find a new place to live in an already tight rental environment. And at the same time, rental rates have doubled in the past year. There are a number of government and nonprofit groups working on increasing housing for the workforce, she says.

The number of sold homes was up 71% in August compared with a year earlier, the median price was up 20%, and the number of homes for sale down 56%. A three-bedroom, three-bathroom townhouse Ms. Rixon sold at Sun Valley last year for $2 million just resold for $3.6 million.

“People here complain when there’s four people in the lift line,” says Jean-Pierre Veillet, a real-estate developer. He moved with his family this summer from Portland, Ore., to Bellevue, about half an hour from Sun Valley’s main town of Ketchum, in part because his 15-year-old son Oliver is a ski racer and was attending a boarding school in the area.

Jean-Pierre Veillet and Summer Veillet bought a four-bedroom, two-bathroom, 3,000 square foot house with a library, a three-car garage and a barn on 10 acres for $1.3 million in March.