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US Space Force blasts missile-warning satellite into orbit around Earth

An Atlas V rocket carrying a missile-warning satellite lifted off from Cape Canaveral Space Force Station in Florida on May 18, 2021.
An Atlas V rocket carrying a missile-warning satellite lifted off from Cape Canaveral Space Force Station in Florida on May 18, 2021. (Image credit: United Launch Alliance)

The U.S. Space Force launched a giant rocket Tuesday (May 18) carrying a satellite that will circle Earth's equator and alert the ground of any incoming missiles, according to news reports. 

The 191-foot-tall (58 meters) Atlas V rocket, built by United Launch Alliance (ULA), lifted off at 1:37 p.m. EDT from Cape Canaveral Space Force Station in Florida. The giant rocket was carrying a military defense payload, called the Space Based Infrared System Geosynchronous Earth Orbit (SBIRS GEO-5) satellite. 

The launch was supposed to happen on Monday (May 17), but it was delayed because of a faulty temperature sensor in the rocket's liquid oxygen system, Space.com reported.

The rocket blasted the satellite into an orbit between 575 and 22,216 miles (925 and 35,723 kilometers) above Earth's surface. From there, it will maneuver into a geosynchronous orbit of about 22,300 miles (35,900 km) above the equator, Space.com reported. When an object is in geosynchronous orbit, it circles the planet at the same rate that the planet revolves around its axis, which for Earth is 23 hours, 56 minutes and 4 seconds.

The newly launched Lockheed Martin satellite will keep an ever-watchful eye on the same strip of the planet, using infrared sensors to watch out for hot plumes produced by missile launches, SpaceFlight Now reported.

"For early missile warning, SBIRS infrared detection capabilities serve as a tip of the spear, or bell ringer, that a launch has occurred and something is coming," said Tom McCormick, vice president of Lockheed Martin Space's OPIR Mission Area, as reported by CBS News. "SBIRS data informs many of our country's other defensive systems, which together form a protective missile kill chain to defend our nation and our armed forces." 

There are currently four other SBIRS Geo satellites circling the equator, and at least two additional infrared instruments onboard spy satellites run by the National Reconnaissance Office that are in elliptical orbits over the poles, SpaceFlight Now reported.

Originally published on Live Science.

Jeanna Bryner

Jeanna is the editor-in-chief of Live Science. Prior to this role, she served as the site's managing editor, and before that a reporter for both Live Science and Space.com. Previously she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a Master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a science journalism degree from New York University.