STP-3

Space Test Program 3 (STP-3) is a flight for the U.S. Space Force and part of a Defense Department strategy to deploy new space capabilities quickly to support changing military needs.

The main satellite for the mission is STPSat-6, which is home to a Laser Communications Relay Demonstration experiment for NASA and the Space and Atmospheric Burst Reporting System-3 platform for the National Nuclear Security Administration.

The NASA laser communications experiment will test the usefulness of a two-way optical relay to ferry data between mission control centers and satellites in space.

The Space and Atmospheric Burst Reporting System platform on the other hand is designed to detect nuclear explosions and then monitor how space is affected.

Several smaller payloads with different scientific and technology testing goals will also share the ride to space.

Image Credit: ULA

This is the workhorse of United Launch Alliance's rocket fleet: Atlas V

A mix of Russian and American technology, Atlas V uses the Russian RD-180 engine on its first stage. It is one of the most versatile rockets in the world with 20 possible configurations, though only 10 have flown.

Stats

Height: 58.3 m (191 ft) with payload fairing, 52.4 m (172 ft) with Starliner.

Diameter: 3.81 m (12.5 ft)

Mass: 590,000 kg (1,300,000 lb)

Stages: 2 (3 with Star 48 upper stage)

Developed in the mid- to late-1990s, it is the fifth and last version of the veteran Atlas rocket, which began flying in 1957.

Lockheed Martin designed and built Atlas V as part of the U.S. government's 1994 plan to create an Evolved Expendable Launch Vehicle program for national security missions.

The two companies with rockets in this program -- Lockheed Martin with Atlas V and Boeing with Delta IV -- merged in 2006, creating an effective U.S. market monopoly with United Launch Alliance.

Pricing of the Atlas V has varied greatly over the years, with a basic Atlas V 401 (no boosters and a single-engine second stage) costing anywhere from the high-$90 millions to $163 million USD in the 2000s and early 2010s.

Sweeping price reductions have occurred since SpaceX began directly competing in the 2010s.

While not the cheapest rocket on the market, the Atlas V's safety and success record are unparalleled -- with a 100% mission success rating.

It will be slowly replaced with the Vulcan rocket over the course of several years in the 2020s.

Atlas V 551

The Atlas V 551 variant uses a five-meter payload fairing (5), five side-mounted solid rocket boosters (5), and a single engine Centaur upper stage (1).

This variant's most notable mission came in January 2006 when it launched the New Horizons probe to Pluto and the Kuiper Belt.

Image: John Kraus for Supercluster

Space Launch Complex 41 (SLC-41) is a significant launch site located at Cape Canaveral Space Force Station (CCSFS) in Florida. Originally built in the 1960s, SLC-41 was designed to support the Titan III and Titan IV rocket programs. Throughout its history, the pad has been used for various missions, including the deployment of military and reconnaissance satellites. A notable launch from SLC-41 was the Cassini spacecraft mission, which began its journey to Saturn in 1997.

In the early 2000s, SLC-41 was repurposed to support the Atlas V rocket, operated by United Launch Alliance (ULA). This transition involved extensive upgrades to the pad’s infrastructure and the installation of new ground support equipment to accommodate the Atlas V. These modifications ensured that SLC-41 could meet the requirements of modern space missions.

Under ULA’s management, SLC-41 has hosted a range of important launches, including the Mars Science Laboratory mission, which successfully landed the Curiosity rover on Mars in August 2012, and the launch of GPS III satellites, enhancing global positioning capabilities. The pad has also supported Boeing's CST-100 Starliner capsule, which is part of NASA’s Commercial Crew Program. The Starliner capsule, designed to transport astronauts to and from the International Space Station, has been launched from SLC-41 to support crewed missions.

Looking to the future, SLC-41 is set to support ULA’s Vulcan Centaur rocket. The Vulcan Centaur is intended to replace the Atlas V and Delta IV rockets, marking a new era in ULA’s launch capabilities with enhanced performance and cost-efficiency. The pad’s infrastructure will be further updated to accommodate this next-generation rocket.