AEHF stands for Advanced Extremely High Frequency and is a satellite fleet developed and operated by the U.S. Air Force Space Command.

Six satellites are planned for the constellation upon its completion, all of which will operate in Geostationary Orbit (GEO).

The AEHF satellites are tasked with relaying secure communications for the Armed Forces of the United States, the British Armed Forces, Canadian Forces, and the Royal Netherlands Armed Forces.

AEHF replaces a older military system and is a joint service communications system that will provide survivable, global, secure, protected, and jam-resistant communications for high-priority military ground, sea, and air assets.

Lockheed Martin and Northrop Grumman built the AEHF satellites, which weigh 6,168 kg (13,598 lb) each, were constructed on an A2100M satellite bus, and carry a designed 14 year operational life.

The first AEHF satellite was launched on 14 August 2010.

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: home to United Launch Alliance’s Atlas V rocket.

The pad hosted its first launch on December 21st, 1965 and is currently being upgraded to serve ULA's Vulcan rocket beginning in 2021. Vulcan and Atlas V will share the pad for several years.

From the 1960s to the 1990s, SLC-41 was used for the U.S. Air Force’s Titan III and Titan IV rockets.

It has been the launch site of many notable payloads, including:

• the Helios probes to study the Sun,
• the Viking missions to Mars,
• the Voyager interstellar probes,
• the Mars Reconnaissance Orbiter,
• New Horizons to Pluto and the Kuiper Belt, and
• Juno to Jupiter

The pad will soon start launching humans into space on Boeing's Starliner capsule beginning no earlier than 2021.

Cape Canaveral

SLC-41 is located on Cape Canaveral, the primary launch center for the United States.

The Cape has four currently-active launch pads for the Atlas V, Delta IV Heavy, Falcon 9, and Minotaur rockets.

Located on Florida’s east coast, Cape Canaveral provides a wide range of access to space for missions to the Space Station, Geostationary Earth Orbit, the Moon, inter-planetary targets, polar trajectories, and more.

The Cape is ideally suited for reaching all locations in space the U.S. needs access to while launching exclusively out over the open Atlantic Ocean so as not to endanger anyone on the ground.

NASA's Kennedy Space Center, which occupies neighboring Merritt Island, and Cape Canaveral are often confused with each other or referred to as a single place.  They are in fact separate government installations and launch sites.

Cape Canaveral has hosted numerous history-making rocket launches:

• first U.S. Earth satellite in 1958,
• first U.S. astronaut in 1961,
• first U.S. astronaut in orbit in 1962,
• first two-person U.S. spacecraft 1965, and
• first U.S. uncrewed lunar landing in 1966