This chapter explores a core question in astrobiology: what is the future of life on Earth and beyond? The first part describes the cessation of habitable conditions in Earth’s distant future (about a billion years hereafter), and the myriad risks that apparently confront humanity on shorter timescales, ranging from wars and artificial intelligence to asteroid impacts and massive volcanoes. The second segment outlines the possibility of humans migrating to other worlds in the solar system, and the numerous technological and logistical challenges expected to arise during this endeavour. The even more daunting notion of interstellar travel is also touched upon, and the propulsion systems and spacecraft advanced in this regard are sketched. The textbook comes to a close by taking stock of the fates that might await humankind.

Space tourism began in 2001 when an American investment manager paid the Russian space agency US$20 million to travel to the International Space Station on a Soyuz rocket. In 2021, three US-based companies began launching tourists on their own rockets: Virgin Galactic, Blue Origin and SpaceX. The emergence of Space tourism raises difficult issues. One such issue is the environmental effects of launches on the atmosphere and the corresponding implications for climate change. Space tourism also raises difficult questions of international law, including, where does space begin? Who gets to call themselves an ‘astronaut’? Do states have a duty to rescue tourists stranded in space?

More than six decades after Sputnik, most rocket bodies used for space launches are still abandoned in orbit. In 2020, over 60 per cent of all launches to low Earth orbit resulted in at least one rocket body being abandoned in orbit. If that orbit has a sufficiently low perigee, drag from gas in the tenuous, uppermost regions of the atmosphere will gradually reduce the rocket body’s altitude and cause it to re-enter the denser, lower atmosphere in an uncontrolled way. This can occur at any point under its flight path, creating dangers for people on the surface and in aeroplanes. Moreover, many uncontrolled re-entries occur near the equator due to the trajectories of many of the abandoned rocket bodies. As a result, the cumulative risk from rocket body re-entries is higher in the states of the global South, as compared to the major spacefaring states. Yet launch providers have access to technologies and mission designs today that could eliminate the need for most uncontrolled re-entries, albeit at increased financial cost.