A SpaceX rocket was set to blast off early Tuesday morning on a mission to reach a new milestone in human spaceflight: the first walk in space by private citizens.

A Falcon 9 rocket was schedule to lift off from Kennedy Space Center, carrying mission commander Jared Isaacman, a fintech billionaire, and three other crew members, including two SpaceX employees. They will reach the highest Earth orbit since the Apollo program.

Here’s what to know about the Polaris Dawn mission, which is scheduled to last five days and end with a splashdown off the coast of Florida.

Why is this mission such a big deal?

The crew is expected to carry out the first commercial space walk during its time in orbit, testing a new generation of mobile space suits that SpaceX says will be necessary to colonize the moon and Mars. The sleek Extravehicular Activity suits have been in development for several years and are designed to withstand the rigors of space. The walk is set to be conducted on the mission’s third day.

What spacecraft will carry the Polaris Dawn crew?

The crew will be aboard a SpaceX Crew Dragon capsule. The spacecraft was designed to service the International Space Station and was developed by Elon Musk’s Hawthorne company (which recently announced it was relocating its headquarters to Texas) after it received a $2.6-billion contract from NASA in 2014. On Saturday, NASA announced another Crew Dragon capsule would pick up and return to Earth two astronauts stranded on the space station because of problems with Boeing’s rival Starliner capsule.

How risky is this mission?

All spaceflight is risky, from launch to the upper-stage maneuvers that place a spacecraft in orbit, to the return to Earth, which requires passing through the atmosphere at temperatures exceeding 3,500 degrees. Additionally, a space walk exposes astronauts to the vacuum and hazards of space, which they could not survive without their suits. However, the astronauts will be tethered to the Crew Dragon capsule, and despite the inherent risks of a space walk, there never has been a human casualty during a walk since they were pioneered in the 1960s.

Who funded the mission?

Polaris Dawn is the first flight of the Polaris Program, a private space program funded by Isaacman, a 41-year-old American entrepreneur who founded Shift4 Payments, a Pennsylvania company that processes payments for multiple industries. His net worth is estimated at $1.9 billion. The program involves two more commercial human spaceflights. He has not said how much the mission costs.

What kind of aerospace experience does Isaacman have?

Isaacman is an experienced jet pilot who has flown in air shows and set records for around-the-world flights in 2008 and 2009. He funded and was the commander of Inspiration4, the first all-civilian space mission in September 2021, also carried out by SpaceX on a Crew Dragon capsule.

Who are the other crew members on the mission?

The pilot is Scott “Kidd” Poteet, 50, a retired Air Force lieutenant colonel who has logged 400 hours of combat flight time and has served as an executive at Shift4. The medical officer is Anna Menon, an operations engineer at SpaceX who has worked on the Dragon program. Mission specialist Sarah Gillis also is an operations specialist at SpaceX who oversees the company’s astronaut training program.

This is the first spaceflight for all three. The crew has been training for two years, including skydiving at the U.S. Air Force Academy and experiencing zero-gravity flight, similar to what NASA astronauts go through. They even hiked to the summit of Cotopaxi, a nearly 20,000-foot peak in Ecuador.

How will the space walk be carried out?

The crew will attempt the space walk while the Crew Dragon is roughly 430 miles above Earth, putting it nearly 200 miles higher than the International Space Station. SpaceX says that colonizing the moon and Mars will require the production of thousands, if not millions, of space suits, and that this is the first iteration of one that can do the job.

The form-fitting suits looks little like the bulky suits NASA astronauts have long used to weather the harsh space environment. Those suits include packs that allow astronauts to survive in space without support from a spacecraft. The Polaris Dawn astronauts will receive their life support from long hoses. Due to the lack of an airlock on the Crew Dragon, the 13-foot-wide capsule will be depressurized and exposed to space during the walk. However, only Isaacman and Gillis will “walk” outside the craft.

Are there other scientific goals for the mission?

The Crew Dragon capsule will be launched into a highly elliptical, or oval-shaped, orbit that at 870 miles above Earth will take it through portions of the Van Allen radiation belts, zones of highly charged solar particles with varying radiation levels. Scientific research will be conducted throughout the mission to better understand human health during long-duration spaceflights, such as a flight to Mars. Multiple universities are collaborating on the research, including USC, Johns Hopkins and Cornell.

Will there be any other benefits to the mission?

The crew will test SpaceX’s Starlink communications system — which provides satellite-based high-speed internet to residential customers — for space communications. There also is a philanthropic component. The three-day Inspiration4 mission raised more than $250 million for cancer research at St. Jude Children’s Research Hospital. This flight is also raising money for the same cause.

What do we know about the two other Polaris Program flights?

Those flights also are expected to be led by Isaacman. For the final flight, SpaceX would like to switch from its workhouse Falcon 9 rocket to its giant Starship rocket, which is taller and with more thrust than the Saturn V that propelled the Apollo astronauts to the moon. But the rocket is still in its development phase, so whether that is possible will be determined by the success of future Starship test flights.

Up to now, Kamala Harris’ presidential campaign has been careful about rolling out its policy initiatives, and — at least in political terms — for good reason.

Policy details at this stage of a campaign do little but give opponents and pundits grist for nitpicking. Most voters aren’t very interested in the details of what a given legislative venture will look like once it goes through the Capitol Hill meat grinder. Political journalists, for their part, seem to be chiefly interested in teasing out holes in the proposal.

For Harris’ campaign, this looks like a lose-lose proposition. After grousing incessantly that Harris hadn’t offered policy specifics since becoming the evident Democratic nominee on July 21, the press has moved on to questioning her intentions, sometimes by seizing on misrepresentations of her actual proposals.

That has been happening since Friday, when Harris issued her first policy “agenda.” This was largely devoted to lowering the cost of housing, food, medical services and child-raising for families, and generated a swell of quibbles in the press and the punditocracy. As it happens, however, Harris is right about the burden of those costs, and right about the best ways to address them.

At this point in an election cycle, presidential campaigns are all about themes and impressions. Harris plainly is setting out a theme of help for an American middle class that has rightly felt neglected by government for decades. Donald Trump’s theme is … what, beyond whining about how he’s treated?

Harris’ professed desire to lower food prices led to a spurt of news articles and columns asserting that she was proposing “price controls.”

It’s hard to know where that idea came from; it peaked even before Harris’ policy brief was issued Friday, when the hand-wringers discovered that she was contemplating nothing of the kind.

Some commentators, abetted by the right-wing peanut gallery, may simply have extrapolated from indications that she was targeting price gouging, but that’s on them, not her. (The Murdoch-owned New York Post strained so hard to tag her policies as “Kamunism” that one almost fears that it gave itself a hernia.)

The Harris campaign in its formal statement proposed “the first-ever federal ban on price gouging on food and groceries.”

Some commentators pointed out that the average net profit margin for supermarkets is about 1%. They argued that this rules out any indication that Americans had been the victim of gouging by retailers.

Is that so?

It’s true that retail grocery profit margins are in the very low single digits. They always have been. But food retailing is a high-volume business, so margins below 2% can translate into annual profits of — to take just two examples — $1.3 billion (at Albertsons) and $2.2 billion (at Kroger).

That doesn’t mean that the grocers can’t gouge shoppers. After all, they did so during the pandemic.

How do we know this? From their own financial disclosures, which show that Albertsons and Kroger jacked up prices well beyond any increases in their costs.

The pretax profit margin at Albertsons rose from 0.96% in 2019 to 1.62% in 2020 and 2.92% in 2021; it fell back to 2.01% in 2023, once the pandemic appeared to move to the rearview mirror. At Kroger, the margin went from 1.62% in 2019 to 2.54% the following year. It dipped to 1.49% in 2021, but rose again to 1.96% in 2022 and 1.89% last year.

Nothing can explain the pandemic-era spike in profits better than these companies raising prices faster than their costs. In other words, gouging.

The Federal Trade Commission said so, without using the term. It found that food and beverage retailer revenues rose to 7% over total costs during the pandemic, well beyond “their recent peak of 5.6 percent in 2015.” That trend, the FTC reported, “casts doubt on assertions that rising prices at the grocery store are simply moving in lockstep with retailers’ own rising costs.”

Even beyond the food sector, as I reported earlier, corporate profiteering was unmistakably a significant contributor to inflation over the last few years. That was the conclusion of a team at the Federal Reserve Bank of Kansas City, who reported that markup growth “could account for more than half of 2021 inflation.” The annualized inflation rate reached 5.8% that year.

Notwithstanding the ginned-up controversy over Harris’ anti-gouging initiatives, it’s proper to note that price gouging and its country cousin, price-fixing, have traditionally been a bipartisan concern.

In 2020, Donald Trump issued an executive order to prevent gouging on health and medical resources, which makes his claim that Harris’ initiatives on prices are tantamount to “communism” seem more than a teensy bit hypocritical.

In the food sector, Republicans and Democrats in Congress last year took aim at price-fixing in the meat packing business. In 2022, StarKist pleaded guilty to price-fixing on tuna and paid a $100-million fine; Bumble Bee had also pleaded guilty and its former chief executive was sentenced to a prison term.

One linchpin of Harris’ attack on food prices is closer scrutiny of consolidation in the food industry. “Vice President Harris will … direct her Administration to crack down on unfair mergers and acquisitions that give big food corporations the power to jack up food and grocery prices,” the campaign stated.

If you’re an executive of Kroger and Albertsons, you can probably figure out that she’s talking about you. Those grocery giants are trying to push through a gargantuan $24.6-billion merger that, like all such mergers, will almost certainly produce higher prices at the checkout conveyor. The Harris campaign telegraphed that she will give the Federal Trade Commission more authority to chase bad actors in the food sector. The FTC already has sued to block the merger, and it’s a fair supposition that under a President Harris the agency won’t be backing off.

On housing, Harris is proposing $25,000 in down-payment assistance for first-time home buyers, with special attention for first-generation buyers. Her campaign didn’t specify how that assistance would be delivered, but did project that more than 4 million first-time buyers would be eligible over four years.

This proposal generated cavils in the chattering classes that it would drive home prices up to absorb the $25,000 grant, putatively keeping homes out of the reach of the beneficiaries.

A couple of points are germane here. One is that government-sponsored down-payment assistance programs are in place in all 50 states and the District of Columbia. The difference in Harris’ proposal is that it would be federalized and somewhat more generous than many state programs.

Pundits who claim that the proposal would drive prices higher must not know much about how the housing market works. First, fewer than one-third of home buyers are first-time buyers.

Sellers who assume that all their bidders are sitting on $25,000 in government cash risk pricing their homes out of a market in which two-thirds are using their own resources.

Budget hawks at the Committee for a Responsible Federal Budget, which was founded with money from a hedge fund billionaire, fretted that the down-payment proposal would raise the federal deficit by $100 billion over 10 years, at least.

To put this in perspective, consider the biggest federal giveaway to homeowners, the mortgage interest deduction from federal income tax.

This deduction costs the Treasury about $30 billion a year; if the increase in the standard deduction enacted in the Republicans’ Tax Cuts and Jobs Act of 2017 expires as scheduled next year, the cost of the mortgage deduction will soar to $84 billion in 2026, according to the congressional Joint Committee on Taxation.

Unlike the down-payment assistance contemplated by Harris, the deduction on home mortgage interest and points is heavily skewed toward the wealthy.

More than 63% of its claimants in tax year 2018, the most recent for which the IRS provides statistics, had incomes higher than $100,000; the $123 billion of deductible interest and points they reported to the IRS was 73% of the total.

More to the point, the mortgage interest deduction is a lousy tool for spurring home ownership, which supposedly is the goal of such tax breaks. That’s because it is “targeted at the wealthy, who are almost always homeowners,” as Harvard economists Edward L. Glaeser and Jesse Shapiro observed in 2003.

For middle- and low-income Americans, on the other hand, the No. 1 obstacle to home ownership is the down payment. Helping those households buy a house is tantamount to the government putting its money where its mouth is.

During an impromptu encounter with the press Sunday, Harris rightly described her initiatives as investments, not spending. Consider her remarks about the child tax credit, on which she proposes to restore to the level of up to $3,600 per child enacted in the Biden administration’s American Rescue Plan, and to raise to $6,000 for the first year of a child’s life.

“The return on investment in terms of what that will do and what it will pay for will be tremendous,” she said.

She’s right: In 2021, when the higher credit was enacted, the credit reduced the child poverty rate by about 30%, keeping as many as 3.7 million children out of poverty by the end of that year. When the enhancements expired in January 2022 and the credit fell to $2,000, the child poverty rate spiked to 17% from 12.1%, plunging those 3.7 million children back under the poverty line.

This is the program that Sen. JD Vance, the GOP candidate for vice president, claims to love. But when a raise in the program came up for a vote in the Senate earlier this month, Vance didn’t even bother to show up to vote.

A century-old orange grove in Tarzana appears to be on its way to becoming the site of luxury homes, a transformation that would mark the end of commercial citrus farming in the San Fernando Valley, where the crop was once a mainstay.

At 14 acres, Bothwell Ranch represents less than one-thousandth of what once was, before the orchards and ranches of the Valley gave way to vast tracts of housing and commercial buildings to serve residents. Citrus production amid the multimillion-dollar homes is far from viable, and the parcel of land is now owned by a developer who intends to fill most of it with houses.

Los Angeles city planning officials held a public hearing Wednesday to collect comments before deciding whether to give the owners the green light to build 21 two-story homes while preserving a third of the site on Oakdale Avenue as a publicly owned orange grove managed by the Mountains Recreation and Conservation Authority for educational purposes.

City officials are still gathering information about the planned development, but Henry Chu, the city zoning administrator for the project, said Wednesday that he is inclined to approve it within a few weeks.

While hard to imagine today, Los Angeles was the top agricultural county in the nation for most of the first half of the 20th century, according to Rachel Surls, co-author of “From Cows to Concrete: The Rise and Fall of Farming in Los Angeles.” Citrus crops were as integral to that success as they were to the branding and selling of Southern California as a bucolic, desirable place to live.

“The Los Angeles Chamber of Commerce, different citrus marketers and organizations such as Sunkist oranges were very much a part of basically making Los Angeles look like this golden, almost tropical, agricultural paradise where people could come and get a whole new start,” Surls explained. “That positioning of Los Angeles as a place where citrus grew was really, really key to the growth of Los Angeles.”

With history in mind, City Councilman Bob Blumenfield announced in 2022 that after years of negotiations a deal had been reached between the site’s new owners, Borstein Enterprises, and the Mountains Recreation and Conservation Authority to preserve a third of it.

“While I wish there was a way to save the entire Bothwell Ranch, with this partnership we can save a large amount of it to be run by one of the best land preservation organizations in the country,” Blumenfield said.

The Bothwell Ranch gets its name from Lindley Bothwell, who purchased the farmland in 1926 after earning a degree in agriculture from Oregon State University, Blumenfield said. At the time, the citrus orchard was about 6 years old and totaled 100 acres. The Bothwell family sold off pieces of the land over the years but maintained a farming operation for decades until Ann Bothwell died in 2016. The ranch survived even as other ranches were driven out by rising land value during the housing boom after World War II.

It is now likely to be replaced by a development called Oakdale Estates. The owners have said they intend for the houses to include environmentally sustainable features such as “cool” roofs that reduce heat reflection into the atmosphere and a new street with a system that captures and filters rainwater before reusing it to irrigate landscaping that will include some citrus trees.

Two rows of citrus trees are expected to line Oakdale Avenue on the west side of the site as a homage to the land’s past, according to plans for the development. Designs for the residences call for modern farmhouses and Spanish architecture, meant to embrace the heritage of the San Fernando Valley.

A critic of the project, Jeff Bornstein, said at Wednesday’s city meeting that the development should be reduced in scope to preserve more of the orchard.

“We have very little that marks our heritage of the past in the west San Fernando Valley,” he said. “We need to save a lot more of these” trees.

The citrus trees planted in the 1980s are past their prime fruit-bearing years and suffer from the effects of under-watering, a representative for the developer said.

When seen in aerial photographs, the ranch looks like a lush green anachronism — plucked from the agrarian past and neatly but nonsensically deposited into a suburban jewel box of red roofs and turquoise pools and tennis courts.

“We’re overrun,” as the late Bothwell matriarch told a reporter in 1998 with a sigh. “But you can’t stand in the middle of Ventura Boulevard and say, ‘Stop!’”

Times staff writer Julia Wick contributed to this report.