Northrop powers Atlas V launch

United Launch Alliance launched 29 Amazon Leo internet satellites on an Atlas V rocket from Cape Canaveral on April 27. (ulalaunch.com) (aboutamazon.com) The mission, called LA-06 by Amazon and Amazon Leo 6 by ULA, lifted off at 8:53:30 p.m. EDT from Space Launch Complex 41. Amazon said the launch brought its deployed satellite total to 270. (aboutamazon.com) (spaceflightnow.com) Atlas V flew in its 551 configuration, which means one main booster, five side-mounted solid rocket boosters, and a 5-meter payload fairing. ULA says each solid booster adds 371,550 pounds of thrust at liftoff. (ulalaunch.com) Those strap-on motors are the extra kick at the pad: they burn hard for the first minutes of flight, then fall away after the rocket is moving fast enough on its own. For LA-06, the five boosters supplied roughly 1.86 million pounds of added thrust combined. (ulalaunch.com) Amazon said Atlas V released the satellites at about 289 miles, or 465 kilometers, above Earth. The company said its team in Redmond, Washington, then took over and began initial contact and health checks before raising the satellites to an operating altitude of 392 miles, or 630 kilometers. (aboutamazon.com) The payload also tied Atlas V’s heaviest haul, at about 18 tons, according to launch coverage from Florida. That matters because Amazon is packing more spacecraft per mission as it races to build out a network of more than 3,000 satellites. (spaceflightnow.com) (aboutamazon.com) ULA also used a compressed countdown flow for this mission, rolling the rocket to the pad the same morning as launch instead of at least a day earlier. Spaceflight Now reported the flight came 23 days and 19 hours after the prior Atlas V launch, setting a new turnaround record at pad 41. (spaceflightnow.com) Amazon says ULA is scheduled to keep launching Leo satellites on Atlas V before shifting more of the campaign to Vulcan, with Ariane 6, New Glenn, and Falcon 9 also booked. The LA-06 flight was Amazon’s sixth Atlas V mission and tenth launch overall for the constellation. (aboutamazon.com) (ulalaunch.com) Northrop Grumman’s role sits inside that launch stack rather than the payload itself: the company builds the GEM 63 solid boosters used on Atlas V missions like this one. ULA’s mission page confirms five boosters flew on LA-06, the maximum-booster Atlas V variant. (ulalaunch.com) (northropgrumman.com) For Amazon, the launch added another 29 spacecraft to a constellation still far smaller than SpaceX’s Starlink, but moving faster than it was a year ago. For ULA and Northrop, it was another proof point that Atlas V’s old hardware can still carry some of the heaviest commercial broadband missions on the market. (aboutamazon.com) (spaceflightnow.com)