Watch ULA Rocket Launch Live Today as it Carries Missile-Detecting Satellite Into Space

The United Launch Alliance (ULA) is preparing to blast a missile-detecting satellite into space today, after technical issues twice forced the aerospace company to amend its plans.

The ULA's new launch attempt has been scheduled for 1:31 p.m. ET on the afternoon of Tuesday, May 18, and anyone can watch the mission as it unfolds online.

The broadcast will go live on YouTube 20 minutes before launch, at 1:31 p.m. ET.

The launch will see an Atlas V 421 rocket lift off from Space Launch Complex-41 in Cape Canaveral Space Force Station, Florida.

It will carry with it the fifth Space Based Infrared System Geosynchronous Earth Orbit (SBIRS GEO Flight 5) missile detection and early warning satellite for the U.S. Space Force's Space and Missile Systems Center.

The launch vehicle will stand 194 feet tall, but within three minutes of takeoff it will jettison its two solid rocket boosters, and after reaching space it will release the booster stage.

The satellite itself will be encapsulated within a two-piece extra extended payload fairing measuring 13.7 feet in diameter.

This will split open 42 minutes and 46 seconds after launch, releasing the Space Based Infrared System into geosynchronous transfer orbit, a highly elliptical earth orbit with an altitude of 499.58 nautical miles (926 kilometers) at its perigee, and 19305.20 nautical miles (35,752 kilometers) at its apogee.

"We take our role in national security very seriously and pride ourselves in being partners in space with the U.S. Space Force," said Gary Wentz, the ULA vice president of Government and Commercial Programs.

"We are launching critical capabilities for the warfighter and understand the need for reliability and consistency. This mission marks our 91st launch in support of national security space."

ULA says the satellites will provide "persistent, infrared surveillance" to the U.S. military, in order to "support missile warning, missile defense, battlespace awareness and technical intelligence," and "greater resiliency ... against growing threats."

The launch of SBIRS GEO Flight 5 had originally been scheduled for liftoff at 1:35 p.m. ET on Monday, May 17, but it was pushed back to 1:42 p.m. "due to a Collision Avoidance period, or COLA, that prohibits an earlier launch time to ensure the launch does not pass too close to an object already in space."

The mission was then scrubbed and rearranged for today, when the team "identified an anomalous system response that could not be resolved within the launch window."

Tory Bruno, the CEO of ULA, said that a temperature sensor on the ground side failed, but by the time they identified and understood the problem, they'd run out of time.

ULA plans to launch a sixth satellite, which would complete the SBIRS constellation, on an unspecified date this year.

A United Launch Alliance Atlas V rocket
A United Launch Alliance Atlas V rocket streaks skyward off Launch Complex 41 from Cape Canaveral Air Force Station on July 30, 2020. The ULA is set to launch SBIRS GEO Flight 5 on Tuesday afternoon. Red Huber/Getty Images