They're always watching.

A San Francisco-based startup on Tuesday launched 88 satellites capable of taking images of the earth's surface. The launch puts the company, Planet Labs, within reach of its goal of being able to photograph the surface of the entire world on a daily basis.

According to the Verge, the satellites were sent up aboard a rocket launched by the Indian Space Research Organisation. They'll begin coming online over the next three months to snap images of the world below.

While traditional satellites are about the size of a bus, Planet uses nine-pound satellites only slightly bigger than a brick. This keeps costs down and lets the company build a bigger fleet, covering more surface area.

With the new batch, the company now has 144 satellites orbiting the earth. Planet previously said it would take 100 to 150 of them to be able to photograph the world's entire surface daily, so it's now squarely within that target range. Mike Safyan, Planet's director of launch and regulatory affairs, told the Verge that Planet now has "the biggest fleet of Earth-imaging satellites ... in human history."

The satellites aren't used to take up-close images, like of a license plate or a person's face. Instead, they gather wider scale images, passing over the same location at the same time each day and continually comparing the results. Other companies can purchase that data from Planet and use artificial intelligence to find relationships with data relevant to their particular industries.

A change in a specific element within an image might be found to have a relationship with certain market trends, explains Carissa Christensen, founder of space and satellite analytics firm the Tauri Group. A company might find, for example, that its competitor's prices fall when a certain land mass changes from green to brown, or that congested highways in a specific region correlate with higher sales.

Larger firms like DigitalGlobe already provide space imaging data, but with a focus on larger clients, including the U.S. government. With its cost-effective satellites, Planet could make this kind of data accessible to startups and other smaller companies.

Another San Francisco space startup, Spire, also has a fleet of mini satellites, though its imaging primarily targets the world's oceans. Planet finds itself in a rapidly growing space: As launches become less expensive, the barriers to entry are lower. There's such a backlog of companies trying to get to space, in fact, that the U.S. government is granting waivers to launch with Indian companies--a practice that's usually prohibited. Planet received such a waiver to get its 88 satellites into space sooner.

While Planet has a head start, the increased competition could mean the market--and possibly the skies--becomes crowded. Satellite companies will likely need to find ways to diversify and differentiate their data offerings down the road.

Earlier this month, Planet acquired Terra Bella, a Google-owned satellite imaging company. That firm's seven satellites are capable of taking high-resolution images, so Planet's capabilities will likely grow to fit a wider variety of client needs.

Founded in 2010, Planet has $158 million in funding. Its backers include VC firm Data Collective and early Facebook investor Yuri Milner.