Geoff Brumfiel

Updated at 5:40 p.m. ET

Satellite imagery of a space launch center in northern Iran suggests a second attempt to launch a satellite has failed.

The imagery, taken Wednesday by San Francisco-based company Planet and shared with NPR, shows burn scars on a newly painted launchpad at the Imam Khomeini Space Center. The burns appeared after days of activity at the site, which suggested Iran had been preparing for a launch.

At a Russian base on the Baltic Sea, construction is underway to house a new generation of nuclear-capable missiles.

Tentlike structures have popped up to shelter the mobile missile system, known as Iskander, which is capable of firing weapons with both conventional and nuclear warheads. Recent satellite imagery of the territory, known as Kaliningrad, also shows that old buildings on the base are being demolished.

The U.S. Department of Energy has started making a new, low-yield nuclear weapon designed to counter Russia.

The National Nuclear Security Administration says production of the weapon, known as the W76-2, has begun at its Pantex Plant in the Texas Panhandle. The fact that the weapon was under production was first shared in an e-mail to the Exchange Monitor, an industry trade magazine, and independently confirmed by NPR.

Big, important scientific breakthroughs are built of small, incremental experiments. And the partial government shutdown is already interfering with some of that research.

Scientists often depend on the government for grant funding, expertise and — in some cases — even regulatory approval. With the shutdown, some researchers are missing those key elements of scientific collaboration. Here's how some scientists say the shutdown is affecting their work.

Carbon dioxide emissions in the U.S. are on the rise again after several years of decline, and a booming economy is the cause.

That's according to a report out today from the Rhodium Group, an independent research firm that tracks CO2 emissions in the U.S.

Updated at 8:35 p.m. ET

Shoot it down. Jam it. Use a missile or maybe a net.

There's no shortage of ideas about how to stop a drone, but as the past few days at London's Gatwick Airport show, the reality is far more difficult.

From Wednesday night to Friday morning, flights in and out of Gatwick were halted after a small drone, or perhaps multiple drones, were spotted over the airfield. Hundreds of flights were canceled and thousands of passengers saw their holiday travel plans grounded.

For years, the world has imposed strict sanctions on North Korea in an attempt to stop its development of nuclear weapons. Officials from nations across the globe have seized shipments of raw materials, shut down shell companies and interdicted ships smuggling equipment.

But despite these efforts, last year North Korea tested the most powerful weapons known to humanity: a nuclear device far larger than any it had tested before, and an intercontinental ballistic missile that put much of the world, including the U.S., within range.

Updated Dec. 12 at 4:20 p.m. ET

North Korea appears to be expanding a missile base in a remote, mountainous part of the country, according to new commercial satellite imagery studied by independent researchers.

After meeting with North Korea's leader Kim Jong Un in Singapore this past June, President Trump was effusive.

"Our conversation was open, honest, direct and very, very productive," he said. "We produced something that is beautiful."

But after five months of canceled meetings and muted statements of dissatisfaction by both countries, experts say there is no sign of progress toward the Singapore goal of so-called "denuclearization" of the North.

Commercial satellite imagery has revealed the location and layout of a previously undisclosed North Korean missile base, including deep underground tunnels designed to house the weapons.

The Trump administration is imposing major sanctions on Iran, effectively ending America's participation in a nuclear deal it helped forge in 2015.

Effective Nov. 5, Iran will see sweeping sanctions imposed on its banking, shipping and petroleum sectors. The move will "put a vise on Iran's ability to conduct economic activities internationally," says Corey Hinderstein, a vice president at the nonprofit Nuclear Threat Initiative.

President Trump's national security adviser, John Bolton, is in Moscow for a second day Tuesday, to discuss the U.S. intent to withdraw from the Intermediate-Range Nuclear Forces Treaty. The end of the 31-year old treaty is a sign that world powers may be returning to an arms race mentality.

But it's not the only one.

Aric Toler isn't exactly sure what to call himself.

"Digital researcher, digital investigator, digital something probably works," Toler says.

Toler, 30, is part of an Internet research organization known as Bellingcat. Formed in 2014, the group first got attention for its meticulous documentation of the ongoing conflict in Ukraine. Toler used posts to Russia's equivalent of Facebook, VK, to track Russian soldiers as they slipped in and out of eastern Ukraine — where they covertly aided local rebels.

Donna Strickland seemed genuinely surprised to learn that she was only the third woman to ever win the Nobel Prize in physics.

"Is that all, really?" a flummoxed Strickland asked during a press conference announcing the prize. "I thought there might have been more."

It's a terrifying weapon: a nuclear-powered cruise missile that can fly anywhere on the planet, possibly spewing radioactivity as it goes. In March, Russian President Vladimir Putin announced that his nation had successfully tested just such a machine.

But new satellite imagery of a remote Russian test site suggests that the missile may not be working as well as claimed.

North Korea announced today that it will permanently close a major missile test site. Kim Jong Un, the North's leader, said the site would be dismantled in the presence of international inspectors.

A Swiss laboratory likely involved in analyzing samples from a March chemical attack in Salisbury, England, has reportedly been targeted by Russian agents.

Experts have been left scratching their heads over one of the most concrete concessions President Trump says he received from North Korean leader Kim Jong Un during Tuesday's summit in Singapore.

At a press conference after their meeting, Trump said Kim had agreed to destroy "a major missile engine testing site."

Updated: 10:45 a.m. ET

North Korea closed its nuclear test site in spectacular fashion Thursday, blasting the site in what one observer described as a "huge explosion."

NASA and the U.S. Department of Energy say they have successfully tested a new type of nuclear reactor that could one day provide juice to colonies on other worlds. The reactor can power several homes and appears able to operate in harsh environments.

Former weapons inspectors say an apparent trove of information on Iran's nuclear weapons program will increase pressure for more intrusive inspections of its atomic sites.

On Monday, the Israeli government disclosed it had obtained thousands of pages of documents and nearly 200 CDs' worth of data on Iran's nuclear program.

As chemical weapons inspectors wait to investigate an alleged strike near the Syrian capital of Damascus, former inspectors say the challenges the current team faces are daunting.

The inspectors arrived in Syria on April 14, on a mission to investigate a suspected chemical attack in the Damascus suburb of Douma seven days earlier. Unconfirmed reports from the scene suggest that dozens may have died.

The type of nerve agent used to poison a former Russian spy and his daughter in the U.K. was developed in a top-secret laboratory in Moscow and was once a closely held secret of the Russian government.

Sergei Skripal and his daughter, Yulia, were found slumped on a bench in the city of Salisbury on March 4. Experts quickly assessed that Skripal — a former Russian intelligence official accused of spying for the British — had been poisoned with a nerve agent.

On Monday, British Prime Minister Theresa May named the agent in a speech before Parliament.