A new batch of satellites for Amazon’s internet constellation will launch to orbit tonight (May 29), and you can watch it live.
A United Launch Alliance (ULA) Atlas V 551 rocket rolled out to its launch pad yesterday (May 28), ahead of today’s mission to deliver 29 Amazon Leo spacecraft to low Earth orbit (LEO). The rocket is scheduled to lift off from Launch Complex-41 at Cape Canaveral Space Force Station in Florida, during a 29-minute window that opens at 7:33 p.m. EDT (2333 GMT).
It will be the seventh Amazon Leo mission to fly on an Atlas V, and will tie, for the second time, the rocket’s record for heaviest payload launched to orbit — about 18 tons. Overall, this will be the 12th Amazon Leo mission, and it will add the 29 satellites to Amazon’s existing network of 300 already in orbit.
Amazon aims to raise that number more than tenfold. The company currently plans on launching about 3,200 broadband satellites to orbit to compete with SpaceX’s Starlink internet megaconstellation, which currently consists of nearly 10,500 spacecraft.
The Amazon Leo constellation doesn’t need that many, due to its planned infrastructure of relay stations on the ground, but will still require more than 80 launches to reach the number that Amazon is striving for. Those missions are spread across several launch providers, including SpaceX, ULA, Europe’s Arianespace and Amazon’s own sister company, Blue Origin, both of which were founded by billionaire Jeff Bezos.
Starlink has a significant head start in the broadband megaconstellation race, with SpaceX launching fresh batches weekly or even more frequently on its workhorse Falcon 9 rocket while also preparing to launch bigger payloads on the Starship rocket, which is currently under development. But Amazon is picking up the pace.
Today’s launch will be the fourth Amazon Leo mission so far this year. Another group was expected to launch on a Blue Origin New Glenn rocket next month, but that vehicle experienced a catastrophic event last night (May 28) during testing at Blue’s launch pad on Cape Canaveral Space Force, which resulted in a massive explosion and fireball, and complete loss. While the Leo satellites were not aboard the rocket during the incident, it is unclear when Blue Origin will be able to support another New Glenn mission.
For today’s launch, once the Atlas V reaches orbit this evening, the rocket’s second stage will deploy the satellites in groups of three over the course of about 10 minutes, releasing the final two 37 minutes and 41 seconds after liftoff, according to ULA’s flight profile.
The rocket’s “551” configuration indicates that five solid rocket boosters will support the first stage, and that the upper stage sports a 5-meter payload fairing to house the Amazon Leo satellites. It’s one of the Atlas V’s most powerful flight setups, with each solid rocket engine providing 371,550 pounds (1.6 mega-Newtons) of thrust at liftoff on top of the main booster’s RD-180 engine, which produces 860,200 pounds (3.83 mega-Newtons) of power itself.