Recently, officials in California announced that the Camp Fire, the deadliest wildfire in the state's history, had been fully contained. The achievement was made possible through the hard work of firefighters on the ground, with some help from above: a swarm of tiny, orbiting satellites that represent the next phase of the Space Age.

The satellites are operated by Planet Labs, a company in San Francisco that runs the world's largest fleet of Earth-observing satellites. Its craft number around 140. All of them carry cameras and telescopes. In size, most rival a loaf of bread.

As a group, the satellites can view the same spot on the ground once or even twice a day. Until now, commercial satellites could observe a location only weekly or monthly, if at all. The quicker pace enables the close monitoring of rapid environmental change, including fires, floods, volcanic eruptions, earthquakes, hurricanes and the effects of such events on urban areas.

"You can't fix what you can't see," said Will Marshall, the company's chief executive.

The Camp Fire started Nov. 8. The next day, a Planet Labs team in Sacramento began streaming surveillance data to the war room where state officials coordinated the response. They used the satellite imagery to help map the fast-moving flames and determine whether individual buildings were intact, damaged or destroyed. Mark Ghilarducci, director of the office, described the images as "a gold mine" for managers and emergency teams.

"It's situational awareness," said Brittany Zajic, head of disaster response for Planet Labs. "The damage assessments were done neighborhood by neighborhood."

The Planet Labs fleet is part of a larger trend toward miniaturization. Satellites are shrinking in size and expanding in ambition. Made smaller, the craft are less expensive and more accessible to a wider group of interests, and they enable, among other advances, the ability to observe Earth's environment more completely and regularly than ever.

The debut of the iPhone in 2007 signaled to a new generation of satellite-makers that their creations, too, could shrink. Early models were called PhoneSats because their electronic cores were made of smartphones. The satellites cost just $7,000 apiece.

Today, relatively small rockets send aloft satellites the size of handbags, knapsacks and pizza boxes. The spacecraft teem with tiny sensors, circuits, lenses, motors, batteries and antennas. Last year, a single launch in India cast into orbit 104 satellites, shattering the previous world record for deployment.

The spacecraft came from India, Israel, Kazakhstan, the Netherlands, Switzerland and the United Arab Emirates, as well as from two U.S. companies, including Planet Labs. Ghana entered the Space Age last year with a satellite the size of a can of beans. Outer space is being democratized.

Typically, the new spacecraft cost so little to build and send aloft that universities and even high schools are getting into the act. On Nov. 10, students from six high schools in Irvine, Calif., cheered as their tiny craft was carried into orbit. Its mission is to study Venus.

Even NASA, a founding member of the big-is-better club, has joined the new wave. In May, it fired a pair of briefcase-size craft, known together as Mars Cube One, toward Mars — the first miniaturized probes to fly beyond Earth orbit.

Not every space mission can use tiny satellites. Miniaturization may not work for orbiting telescopes used in astronomy, nor for high-powered satellites that beam television signals to rooftop antennas and home viewers.

But the appeal of miniaturization is likely to grow: a large mission becomes less vulnerable to total failure if it can be subdivided into many tiny parts.