Nearly two decades after its launch from Cape Canaveral, Florida, the Cassini Mission to Saturn will come to an end with a dramatic flourish. The spacecraft will dive into the planet’s atmosphere on Friday for its planned self-destruction, burning up and ultimately disintegrating.
The idea behind the suicidal plunge is to protect the moons Titan and Enceladus—both of which, Cassini has revealed, are capable of supporting life. If the spacecraft were left spinning without fuel through the Saturn system, it could accidentally collide with one of the moons and expose it to any microbes that might remain on board.
“I'm exhilarated about this. Cassini was made for Saturn, and Saturn is where it's going to stay,” Curt Niebur, a program scientist at NASA headquarters, told Newsweek. “The team was able to come up with this utterly brilliant idea for how to end the mission, to squeeze out an end to the mission that gives us new science right to the very last minute.”
Still, “there is a certain melancholy among the team,” Niebur says. “While it's an exciting end, it's still an ending.” RIP.
The end of the mission might have a funereal air to it, but passionate space enthusiasts need not despair. There is plenty more exploration coming up after the death of Cassini. There are missions planned to planets and their moons, to the sun and the Earth’s moon and to asteroids, along with new telescopes and satellites launching.
It’s possible that NASA will return to the Saturn system in the coming years, depending on which mission is named the winner of the next round of the New Frontiers competition. This round of the contest, which is for missions that cost up to about $1 billion, asked for proposals on one of six themes that would take them to the surface of a comet or the moon to collect samples; to the ocean worlds of Titan and/or Enceladus (both moons of Saturn); to Saturn with a probe; to Jupiter’s Trojan asteroids; or to Venus.
Regardless of whether we return to the Saturn system, Niebur says the Cassini mission will have a lasting impact. “Cassini's discoveries on Enceladus and Titan really help cement this paradigm shift about ocean worlds,” Niebur says. “It was really Cassini that made it exquisitely clear to us that these are not special, unique, rare places. These ocean worlds are relatively common in our solar system and, by extension, in [the] universe at large.” Cassini has had a profound effect on scientists’ understanding of how common these potentially habitable worlds are.
Although NASA has been working toward the Europa Clipper mission for years, beginning before Cassini reached Saturn, Cassini helped shape the future mission’s strategy and determine which instruments will be put on the spacecraft. So even though it will take its final dive on Friday, the mission’s influence will live on.
Here is a partial list of missions and events to look forward to:
NASA’s InSight mission is scheduled to launch on May 5, 2018, and to land on Mars on November 26 of the same year. The lander will drill deep into the planet’s surface to study its structure, which in turn will help scientists understand its evolution as a rocky planet.
The Parker Solar Probe, billed as “a NASA mission to touch the sun,” is scheduled to launch between July 31 and August 19, 2018. The probe, which will come within 4 million miles of the sun’s surface, will study solar activity and help scientists learn how to better predict space-weather events.
The James Webb Space Telescope, a collaboration between NASA, the ESA and the Canadian Space Agency (CSA), is scheduled to launch in October 2018. The highly anticipated “scientific successor” to the Hubble Space Telescope is larger and will be able to see objects much farther away (which, in space, means further back in time) as it peers at the universe in the infrared.
The ESA plans to launch its Solar Orbiter (SolO) mission in October 2018. Dedicated to solar and heliospheric physics, it will help scientists understand how planets developed and life emerged, as well as the origins and fundamental physics of the universe.
NASA’s Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer, or OSIRIS-REx, which launched on September 8, 2016, is scheduled to reach the near-Earth asteroid Bennu in 2018. The first U.S. mission to bring an asteroid sample back to Earth, it’s scheduled to return with more than two ounces of material in 2023.
The New Horizons spacecraft is planning a flyby of Kuiper Belt object 2014 MU69 on January 1, 2019, about three and a half years after its historic flyby of Pluto. If all goes according to plan, the spacecraft will get much closer to MU69 than it did to Pluto. Niebur explains that MU69 might actually be two bodies orbiting very closely to one another. “It’s going to be a very exciting flyby,” he says, “another one of those never-seen-this-before” moments.
NASA’s Mars 2020 rover is scheduled to launch in summer 2020. The mission will investigate the rocks of the red planet for evidence of past life, focusing on a region where the ancient environment may have supported microbial life. A new system will collect soil and rock samples to be deposited in sample tubes at certain surface locations for potential retrieval. It will be a big year for international Mars exploration, with the ESA planning to launch its ExoMars rover and the United Arab Emirates planning to launch Hope. China announced earlier this year that it aims to launch a Mars mission around 2020.
The Lucy mission, one of two selected by NASA in January as part of the Discovery Program, is scheduled to launch in October 2021. After reaching a main asteroid belt in 2025, the robotic spacecraft will continue on to its main target and become the first to study six Jupiter Trojan asteroids, thought to be relics from an earlier era of the solar system, from 2027 to 2033.
The other mission NASA selected for January is Psyche, scheduled to launch in 2022. It will explore 16 Psyche, a unique metal asteroid that could be the exposed nickel-iron core of an early planet. As with Lucy, the mission will aim to answer questions about the early solar system. It might also provide some stunning images. “We think it's the metallic core of another planetoid, and impact blew everything else off of it and left this solid metal sphere,” Niebur says, adding, “Some of the surface features on it could be really wicked.” Imagine a ball of molten iron, he explains, and as it’s hit, “stuff splashes out of it and freezes in weird shapes.”
The ESA’s best-acronymed mission, the Jupiter Icy Moons Explorer (JUICE), is scheduled to launch in 2022 and to arrive at Jupiter in 2030. It will study the planet as well as three of its largest moons: Ganymede, Callisto and Europa.
NASA is planning a Europa Clipper mission to the smallest of Jupiter’s four Galilean moons that will launch sometime in the 2020s. The reconnaissance of the icy moon—which appears to have liquid water underneath its icy crust—will help scientists investigate whether it could harbor conditions suitable for life. The spacecraft will perform a series of 45 close flybys so that it can withstand the high radiation in that region.