Atlas V rocket is launched from Cape Canaveral
Makes room for Spacex rocket to fly on Thursday
The most powerful variant of an Atlas V rocket shot off its Cape Canaveral pad like a laser beam early Tuesday, taking several payloads on a mission overseen by the Space Force.
The joint strike force of an RD-180 main engine and five solid rocket boosters generated more than two million pounds of thrust at 5:19 a.m., pushing Atlas past the lightning suppression towers at Launch Complex 41 faster than other rockets in its class. It marked United Launch Alliance’s third Florida mission of the year.
The rocket’s second stage was then expected to spend a whopping seven hours delivering the Space Test Program-3 mission, or STP-3, to a geosynchronous orbit some 22,200 miles above Earth.
“STP-3 will exceed ULA’S longest duration mission to date,” said Gary Wentz, vice president of government and commercial programs at ULA. “This will become the longest mission with seven hours and 10 minutes until separation of the payload, and then eight hours and eight minutes until the end of the mission.”
STP-3’S launch was delayed twice due to propellant system issues at the pad, but teams were able to clear the work in two days.
Upper-level winds then moved to the forefront early Tuesday and forced launch engineers to push into the twohour
window that opened at 4:04 a.m. ET.
The mission took several payloads to orbit, including a NASA experiment to test data transmission using lasers. The agency says laser-based communications outstrip legacy radio systems as they deliver more data while using smaller, lighter hardware.
The National Nuclear Security Administration, a Department of Energy agency, also boosted a payload designed to detect nuclear detonations high in the atmosphere.
The Space Force had several payloads of its own, but not all were discussed publicly.
Next launch: Spacex
Next up, a Spacex Falcon 9 rocket was slated to launch a NASA science payload from nearby Kennedy Space Center at 1 a.m. Thursday.
The 230-foot rocket will boost the Imaging X-ray Polarimetry Explorer, or IXPE, spacecraft from pad 39A and kick off its mission to study X-rays from extreme sources like black holes and dead stars. IXPE is the first observatory dedicated to studying polarized X-rays.
Weather for the attempt, according to Space Force forecasters, stood at 80% “go” as of Tuesday. Conditions downrange for a drone ship recovery and upper-level winds, however, could pose problems.
A system moving into Florida “will also be over the booster recovery area, increasing wind speeds and rain chances,” the 45th Weather Squadron said in its pre-launch report. “Finally, upper-level winds over the Space Coast will be near 100 knots at 35,000 feet, slightly increasing the risk for wind shear issues.”
If upper-level winds are too powerful, a rocket already traveling hundreds of miles per hour could be torn apart by the forces.