February 10, 2020 – A United Launch Alliance (ULA) Atlas V rocket carrying Solar Orbiter, an international cooperative mission between the European Space Agency (ESA) and NASA, lifted off from Space Launch Complex-41on February 9 at 9:03 p.m. MST. This marks the 82nd successful launch of an Atlas V rocket and 137th launch for ULA.
Solar Orbiter will work closely with NASA’s Parker Solar Probe, launched by ULA on a Delta IV Heavy rocket in 2018. Together, both spacecraft will provide a never-before-seen global view of the sun.
Thanks to its unique — and difficult to achieve — orbit, Solar Orbiter will also provide the first-ever pictures of the Sun’s polar regions, offering key insights into the poorly-understood magnetic environment there, which helps drive the Sun’s 11-year solar cycle and its periodic outpouring of solar storms.
“The ULA team is extremely honored to launch Solar Orbiter, enabling more discovery of our sun,” said Gary Wentz, ULA vice president of Government and Commercial Programs. “Thank you to our NASA and international mission partners for the outstanding teamwork.”
Solar Orbiter’s trajectory includes 22 close approaches to the Sun, bringing the spacecraft within the orbit of Mercury to study the Sun and its influence on space.
“As humans, we have always been familiar with the importance of the Sun to life on Earth, observing it and investigating how it works in detail, but we have also long known it has the potential to disrupt everyday life should we be in the firing line of a powerful solar storm,” said Günther Hasinger, ESA director of Science. “By the end of our Solar Orbiter mission, we will know more about the hidden force responsible for the Sun’s changing behavior and its influence on our home planet than ever before.”
Solar Orbiter will spend about three months in its commissioning phase, during which the mission team will run checks on the spacecraft’s 10 scientific instruments to ensure they are working properly. It will take Solar Orbiter about two years to reach its primary science orbit.
Solar Orbiter combines two main modes of study. In-situ instruments will measure the environment around the spacecraft, detecting such things as electric and magnetic fields and passing particles and waves. The remote-sensing instruments will image the Sun from afar, along with its atmosphere and its outflow of material, collecting data that will help scientists understand the Sun’s inner workings.
During the mission’s cruise phase, which lasts until November 2021, the spacecraft’s in-situ instruments will gather scientific data about the environment around the spacecraft, while the remote-sensing telescopes will focus on calibration to prepare for science operations near the Sun. The cruise phase includes three gravity assists that Solar Orbiter will use to draw its orbit closer to the Sun: two past Venus in December 2020 and August 2021, and one past Earth in November 2021.
Following its Earth gravity assist, Solar Orbiter will begin the primary phase of its mission – leading up to its first close pass by the Sun in 2022 – at about a third the distance from the Sun to Earth. Throughout its mission, Solar Orbiter will use successive Venus gravity assists to draw its orbit closer to the Sun and lift it out of the ecliptic plane.
Solar Orbiter’s unique orbit will bring the spacecraft out of the plane that roughly aligns with the Sun’s equator where Earth and the other planets orbit. Spacecraft launched from Earth naturally stay in this plane, which means that telescopes on Earth and telescopes on satellites have limited views of the Sun’s north and south poles.
A previous ESA-NASA mission, Ulysses, launched in 1990, achieved an inclined orbit giving scientists their first measurements of the space around the Sun in this critical region. Unlike Ulysses, Solar Orbiter carries cameras that will provide the first-ever images of the Sun’s poles. This vital information will help scientists fill in the gaps in models of the Sun’s magnetic field, which drives the Sun’s activity.
Solar Orbiter launched on an Atlas V 411 configuration vehicle including a 4-meter payload fairing (PLF) and standing 189 ft. tall. The Atlas booster for this mission was powered by the RD AMROSS RD-180 engine. Aerojet Rocketdyne provided the one AJ-60A SRB and RL10A-4-2 engine for the Centaur upper stage. NASA’s Launch Services Program at the agency’s Kennedy Space Center in Florida selected ULA’s
Atlas V vehicle for this mission and is responsible for management and oversight of the Atlas V launch services.
ULA’s next launch is the AEHF-6 mission for the U.S. Space Force in March 2020.