But Rocket Lab’s Electron is a harbinger of a new breed of rocket — small, cheap, able to be launched frequently — that could prove much more important in the future of how companies send swarms of smaller satellites to orbit.

When is the launch and how can I watch it?

Rocket Lab will be streaming the launch on the internet from its launch site in New Zealand.

The launch window stretches for nine days, four hours each day. The first opportunity will be Sunday at 4:50 p.m. New Zealand time. (In the United States, it will still be Saturday, and it will be a late-night show, or 10:50 p.m. Eastern time).

What is the rocket carrying?

There are seven payloads, all small satellites. Those include two ship-tracking satellites for Spire Global; a small climate- and environment-monitoring satellite for GeoOptics; a small probe built by high school students in Irvine, California; and a demonstration version of a drag sail that would pull defunct satellites out of orbit.

Why is the Electron rocket so small?

Just like technology on Earth, satellites are getting smaller and can be launched on smaller rockets. Companies and governments now also see benefits to designing constellations of small satellites to perform tasks that were once handled by one giant, expensive satellite. With this approach, the failure of one satellite can be handled by moving around the remaining satellites. It is also quicker and cheaper to send up a replacement.

What other companies are building small rockets to launch smaller satellites?

There are at least 150 firms working on small rockets, although most probably will never get off the ground.

Some of the most promising are Virgin Orbit, started by billionaire Richard Branson; and Vector Launch and Firefly Aerospace, started by alumni of SpaceX.

Two other promising companies are Relativity Space, which looks to 3D print most of its rocket, and Gilmour Space, based in Australia.

This article originally appeared in The New York Times.

Kenneth Chang © 2018 The New York Times