Boeing and SpaceX once were racing to be the first to carry NASA astronauts to the International Space Station in a privately built spacecraft. That race ended in 2020, with SpaceX emerging as the victor. After technical problems in 2019 and 2021, Boeing finally sent an uncrewed Starliner to the space station in 2022. After even more delays prompted by problems with the capsule, it is scheduled to fly a crew of astronauts to the orbital outpost this spring, expanding the number of spacecraft capable of carrying humans into orbit.

Europe’s final Ariane 5 rocket completed its last mission in July 2023, and problems with other rockets have left the continent’s space program reliant on SpaceX and others for trips to space. The Ariane 6 rocket could lift off on a demonstration flight that aims to restore Europe’s ability to reach space on its own after a series of delays. Other customers are also waiting to fly on the rocket.

It’s the scientific start to summer in the Northern Hemisphere, when this half of the world tilts toward the sun. Read more about the importance of the solstice for life on Earth.

Even as the Northern Hemisphere experiences the heat of summer, our planet is at aphelion, the farthest it will get from the sun during its elliptical orbit. Read more about aphelion, and what it’s like on other worlds in our solar system.