Solar Orbiter is a European Space Agency heliophysics (study of the Sun) spacecraft, with cooperation from NASA, that is tasked with studying the inner-most region of our solar system's Heliosphere.

The Heliosphere is the large, bubble-like region of space which surrounds and is created by the Sun. It terminates billions of kilometers away from the Sun well beyond the orbits of the 13 known/classified planets in our solar system.

The Heliosphere's end - which both Voyager 1 and 2 crossed in 2012 and 2018, respectively - marks the transition to interstellar space.

While the Voyagers explore the region immediately beyond the Heliosphere, Solar Orbiter will investigate the region's inner-most part - with particular focus on the Sun's polar regions - in the hope of helping scientists better understand how the solar wind is created and propelled outward from the Sun.

The solar wind is the constantly outward-moving stream of charged particles in the heliosphere.

After launch, Solar Orbiter will spend 3.5 years getting into its primary science orbit. This will involve repeated flybys for gravity assists and trajectory-altering maneuvers with Venus.

As such, Solar Orbiter only has a 20-day launch window in February 2020 in order to intercept Venus while alignment between Earth and our inner-sister is right.

If Solar Orbiter should miss the February 2020 launch window, liftoff will have to wait until October 2020 - the next time the two planets' orbits align.

During its primary seven year mission, Solar Orbiter will enter a 41.8 million x 119.6 million km orbit of the Sun, completing one trip around our star once every 150 days.

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

The rocket is a mix of Russian and American technology, using the Russian RD-180 as the rocket's first stage engine, and 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 major 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 initiative to create an Evolved Expendable Launch Vehicle (EELV) program for national security missions.

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

For years, the U.S. government paid ULA over $800 million annually -- not for rockets or launches but for ULA to maintain their facilities to be ready to launch EELV missions.

Therefore, 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 and cost-per-launch figure reductions have occurred since SpaceX began directly competing against ULA in the 2010s.

The Atlas V’s 411 variant costs a minimum of $115 million USD.

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

Atlas V 411

This mission will use the Atlas V 411 variant - with a four-meter payload fairing (4), one side-mounted solid rocket booster (1), and a single engine Centaur upper stage (1).

This is the most flown variant of the Atlas V rocket.

Image: ULA

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