Sunrise sets off Atlas V sky spectacle

An Atlas V rocket produced a magical light show early Wednesday during a successful flight from Cape Canaveral that captivated – and worried – many launch observers who said they'd never seen anything like it.

Thank a tropical storm, which delayed the mission's first launch attempt two days, and a technical glitch during Wednesday's countdown, for setting the stage.

A problem during fueling pushed the liftoff with a Navy communications satellite back 19 minutes, to 6:18 a.m., about 45 minutes before sunrise.

That turned out to be perfect timing for the United Launch Alliance rocket to catch the morning's first rays of light, barely visible on the horizon, as it climbed from Cape Canaveral Air Force Station on a southeastern shot over the Atlantic Ocean.

Story continues below:

The 21-story Atlas V painted a white streak through the dark sky starting several hundred miles down range. Then an egg-shaped glow appeared to surround the rocket's exhaust trail and spread outward, a strange and somewhat eerie scene that led some, remembering SpaceX's failed launch in June, to fear the mission was in trouble.

It was not, nor was any unusual weather responsible for the striking visual effects.

"Simply put, it was due to the sun's angle at time of launch," explained Col. Shannon Klug, commander of the Air Force's 45th Space Wing Weather Squadron. "The sunrise highlighted the normal expansion of the exhaust plume which expands as the atmospheric pressure decreases with altitude. The rays of the sun caught the expanding gasses just right and...magic!"

"It had to do with the angle of the rising sun, and how it reflected off of the plume and moisture in the air," agreed Tim Sedlock of the National Weather Service in Melbourne. "Pretty simple, actually."

Story continues below:

It may have helped that the Atlas V was flying in its most powerful configuration, blasting off with 2.5 million pounds of thrust generated by a main engine and five solid rocket motors.

Viewers from Florida's Gulf Coast and as far south as Miami marveled at the sight and shared pictures on social media.

"I've been watching launches since I worked at the space center in the mid-80s, and that one was a favorite," Sebastian resident Doug Gabbert told FLORIDA TODAY. "The exhaust plume with first light hitting it was awesome, although it scared me at first."

Not to worry.

Less than three hours after launching the Atlas V, on its 56th flight without a major failure, delivered the fourth satellite in the Navy's $7.6 billion Mobile User Objective System program to an orbit that will place it more than 22,000 miles over the equator.

The roughly 15,000-pound satellite built by Lockheed Martin completes a constellation intended to give special operations forces and other mobile troops from every service the ability to make secure calls to commanders from the field, and to send messages and video, wherever they are located.

Based on commercial cell phone technology, the MUOS satellites are described as cell phone towers in the sky providing nearly global coverage, almost to the North and South poles.

Once the system is fully operational, such "narrowband" communications will no longer be limited to the area covered by a single satellite's view, but could make connections around the world, for example between the Middle East and Washington, D.C.

"Any one person can talk to almost any other person on the globe," said Col. James Ross, manager of the Army program developing Manpack radios compatible with MUOS satellites. "It extends the range greatly of our warfighters on the ground."

Story continues below:

But that "beyond line-of-sight" capability, and the opportunity to upgrade field radios with smart phone-like features, is behind schedule and may not be broadly available until 2017.

Challenges integrating the new system's software with a set of four ground stations and Army-developed radios mean most of the MUOS constellation's capacity – 90 percent, according to the U.S. Government Accountability Office – is not yet being tapped.

The new satellites, however, solidify and expand the reach of older satellites that already are the Department of Defense's most widely used space-based communications system, even though they account for a small amount of that bandwidth.

"This system, narrowband, is critical for warfighting missions," said Capt. Joe Kan, the Navy's MUOS program manager.

A fifth MUOS satellite is expected to be launched next year to provide a spare in orbit.

ULA's next Cape launch is planned Oct. 2, with an Atlas V performing a commercial launch of a Mexican communications satellite.

Contact Dean at 321-242-3668 or jdean@floridatoday.com. And follow on Twitter at @flatoday_jdean and on Facebook at facebook.com/jamesdeanspace