Atlas V 551 to launch STP-3

  • Launch Vehicle: Atlas V 551
  • Mission: STP-3 (Space Test Program 3)
  • Date / Time: NET July 2021 at *To Be Determined*
  • Launch Site: SLC-41, Cape Canaveral Space Force Station, Florida, USA

Launch Vehicle:

ULA’s Atlas V rocket is a workhorse for the U.S. military, intelligence community and scientific researchers. The rocket will fly in the 551 vehicle configuration with a five-meter fairing, five solid rocket boosters, and a single-engine Centaur upper stage. Developed as a modular vehicle, each Atlas V is tailored to the needs of its passenger by adding as many as five side-mounted solid rocket boosters for increased lift performance and a variety of available payload fairings in various diameters and lengths to protect satellites during atmospheric ascent. The high-energy Centaur upper stage, which has been used to send spacecraft to every planet in our solar system, is incorporated into Atlas V to deliver the payloads to their intended destinations.

Mission Overview:

A United Launch Alliance (ULA) Atlas V 551 rocket will launch the Space Test Program (STP)-3 mission for the U.S. Space Force. Liftoff will occur from Space Launch Complex-41 at Cape Canaveral Space Force Station, Florida.

The Atlas V booster that launched the SBIRS GEO 5 payload | Photo: ULA


This will be 145th mission for United Launch Alliance and our 92nd in service to U.S. national security. It is the 88th Atlas V launch and the 12th in the 551 configuration, which has launched missions to Pluto and Jupiter.

The STP-3 mission consists of the STPSat-6 satellite that hosts the National Nuclear Security Administration’s Space and Atmospheric Burst Reporting System-3 (SABRS-3) package and NASA’s Laser Communications Relay Demonstration (LCRD) experiment. The launch also includes a propulsive secondary payload adapter carrying additional small science and technology missions.

Launch Trajectory

Currently Unknown

Launch Site

Space Launch Complex 41 (SLC-41), previously Launch Complex 41 (LC-41), is an active launch site at Cape Canaveral Space Force Station. As of 2020, the site is used by United Launch Alliance (ULA) for Atlas V launches. Previously, it had been used by the USAF for Titan III and Titan IV launches.

SLC-41 launch pad on Cape Canaveral Space Force Station, Florida, USA
Bird eye view of SLC-41 at Cape Canaveral SFS, Florida, USA | image: Google Earth

Watch Live

Live Stream to be added when closer to launch.