Atlas 5-551 – Spaceflight Now

ULA’s Atlas 5 rocket launches its heaviest payload ever with fifth Amazon Leo mission

April 3, 2026 Will Robinson-Smith

Liftoff from pad 41 at Cape Canaveral Space Force Station happened Saturday at 1:46 a.m. EDT (0546 UTC).

ULA Atlas 5 launch puts Amazon’s 180th broadband satellite in low Earth orbit

December 15, 2025 Will Robinson-Smith

Liftoff from Space Launch Complex 41 at Cape Canaveral Space Force Station occurred at 3:28 a.m. EST (0828 UTC), as the RD-180 engine on the booster roared to lift alongside five solid rocket boosters.

ULA launches ViaSat-3 following valve replacement on Atlas 5 rocket

November 13, 2025 Will Robinson-Smith

The mission was the second of three planned spacecraft that Viasat plans to operate in geostationary orbit. United Launch Alliance launched from pad 41 at Cape Canaveral Space Force Station at 10:04 p.m. EST (0304 UTC).

Issue with Atlas 5 booster liquid oxygen vent valve causes second scrub of ViaSat-3 F2 launch

November 6, 2025 Spaceflight Now

United Launch Alliance scrubbed a second launch attempt for an Atlas 5 rocket carrying the ViaSat-3 F2 satellite. A new launch date hasn’t been announced.

Atlas booster valve issue scrubs launch of ViaSat-3 F2 satellite

November 5, 2025 Will Robinson-Smith

The mission is the second of three planned spacecraft that Viasat plans to operate in geostationary orbit. United Launch Alliance is targeting liftoff from pad 41 at Cape Canaveral Space Force Station no earlier than Thursday, Nov. 6, at 10:16 p.m. EST (0316 UTC).

ViaSat-3 F2 satellite arrives in Florida ahead of late October launch

October 1, 2025 Will Robinson-Smith

The spacecraft will launch onboard a United Launch Alliance Atlas 5 551 rocket from Cape Canaveral Space Force Station. It’s built on Boeing’s 702MP+ satellite bus.

ULA launches third batch of Amazon’s Project Kuiper satellites from Cape Canaveral

September 25, 2025 Will Robinson-Smith

This is the third time that United Launch Alliance will launch these broadband satellites, but it’s the fifth batch heading to orbit overall for the constellation. Liftoff is scheduled for 8:09 a.m. EDT (1230 UTC).

ULA launches Kuiper 2 mission on Atlas 5 rocket from Cape Canaveral

June 22, 2025 Will Robinson-Smith

The 27 Kuiper satellites will head to low Earth orbit on an Atlas 5 rocket flying in a 551 configuration, using five solid rocket boosters. ULA launched its rocket at 6:54 a.m. EDT (1054 UTC) on Monday, June 23.

Atlas 5 booster engine issue causes scrub of Monday’s Kuiper 2 launch

June 15, 2025 Will Robinson-Smith

The 27 Kuiper satellites will head to low Earth orbit on an Atlas 5 rocket flying in a 551 configuration, using five solid rocket boosters. ULA has not announced a new launch date following the scrub.

ULA launches first production Amazon Kuiper satellites on Atlas 5 rocket from Cape Canaveral

April 28, 2025 Will Robinson-Smith

The rescheduled mission comes following the April 9 scrub due to poor weather and a period on the Eastern Range marked by a noted lack of orbital launches. Liftoff from pad 41 at Cape Canaveral Space Force Station is targeting Monday, April 28, at 7 p.m. EDT (2300 UTC).