As Hollywood rolls out a blockbuster drama about the 19 firefighters killed after crawling inside their protective emergency shelters during a raging 2013 wildfire, the federal government is wrapping up a real-life bid to improve the nation’s standard-issue fire shelter — by going space-age.

Much of the redesign is being done by a group of NASA engineers, and their work couldn’t come at a more opportune time, with the deadly Wine Country fires just the latest in an escalating trend of wildland blazes tearing up the West.

The engineers were already busy building heat shields for space missions four years ago when they heard of the unprecedented deaths of Arizona’s Granite Mountain Hotshots, portrayed in the new film “Only the Brave.” The NASA engineers immediately decided to volunteer their expertise.

“I saw it on the news,” recalled Mary Beth Wusk, a materials scientist reached by phone at NASA’s Langley Research Center in Hampton, Va. “I called the next day to my team, and they agreed this was something we could potentially look into.”

Four years later, Wusk and her team have created several portable fire shelters that are among those being considered for replacement of the early-2000s model carried by tens of thousands of firefighters nationwide, including California Department of Forestry and Fire Protection crews. Those shelters could well mean the difference between life and death on the fire line.

So lightweight they can be carried on a belt or in a backpack, portable fire shelters are essentially personal tents that are easy to deploy, so firefighters can slip inside quickly and survive an otherwise unsurvivable situation. They’re intended to be an option of last resort for wildland firefighters trapped by flames, and the last time they got a major redesign was in 2003.

The U.S. Forest Service, which is spearheading the redesign, says several promising prototypes emerged in tests conducted this fall. With cost and production capabilities to consider before moving forward, the question remains whether any of the new products are much better than the current one. But the Forest Service hopes to narrow down the choices in the coming months.

The current 2003-model shelter is made of an outer layer of silica cloth laminated to aluminum foil, and an inner layer of aluminum foil laminated to fiberglass. It’s intended to be manageable, weighing just 4.3 pounds, while keeping cool inside and repelling outside heat — which can soar to above 2,000 degrees during a wildfire.

This model has proved resilient to such temperatures for short periods, and is credited with saving dozens of lives while limiting injuries. Four firefighters in Lake County likely staved off more intense burns when they deployed the devices during the devastating 2015 Valley Fire.

The Forest Service, though, acknowledges that the shelters are far from fail-safe — and the calamity of the Granite Mountain Hotshots in the Yarnell Hill Fire in Arizona is Exhibit A on that account. On June 30, 2013, 19 of the 20 members of the team died after climbing into their shelters in what amounted to the biggest loss of U.S. firefighters since the Sept. 11 attacks.

While an investigation into the deaths didn’t reveal any unknown shortcomings with the device, the Forest Service decided to fast-track a scheduled redesign of the shelter in light of the tragedy.

“A lot of advancements have occurred,” Wusk said.

At the time Wusk heard of the Arizona deaths, she and others at NASA had been working to improve the ability of manned and unmanned spacecraft to endure searing temperatures associated with flights in and out of Earth’s atmosphere. They believed the work was transferable to protective materials closer to home, and after reaching out to the Forest Service, they wound up partnering on the project.

NASA’s eventual prototypes for fire shelters were taken to test sites in Canada, where they joined other designs in a rigorous review. Propane torches shot flames at the models for a minute or more. Testing temperatures approached 1,800 degrees, where human survival without a shelter would be maybe 10 seconds.

“The craziest stuff usually blows up,” said Tony Petrilli, leader of the fire shelter project for the Forest Service. “We were getting ideas well out of the box.”

Even the best designs, which generally consisted of materials similar to those used in the current shelter, struggled to be significantly better. In particular, the models didn’t improve much on one fundamental weakness: contact with direct flame.

When the new shelters did show substantial benefits, they were often too flimsy, not breathable or too heavy.

“The laws of physics get in the way,” Petrilli said. “If it wasn’t for those things, it would be a big bulky suitcase, but that doesn’t match up with firefighting. We can’t load firefighters down with an 80-pound pack and expect them to do work.”

A panel of federal and state scientists, firefighters and risk-management specialists is expected to convene within the next few months to discuss the top contending shelters. A final decision on how to move forward is expected next year.

Kurtis Alexander is a San Francisco Chronicle staff writer. Email: kalexander@sfchronicle.com Twitter: @kurtisalexander

Kurtis Alexander is an enterprise reporter for The San Francisco Chronicle, with a focus on natural resources and the environment. He frequently writes about water, wildfire, climate and the American West. His recent work has examined the impacts of drought, threats to public lands and wildlife, and the nation's widening rural-urban divide.

Before joining the Chronicle, Alexander worked as a freelance writer and as a staff reporter for several media organizations, including The Fresno Bee and Bay Area News Group, writing about government, politics and the environment.