In 2010, the mission study investigated the possibility of a landing on the planet Mercury, but the challenges were also significant in time.
(Illustration: Space.com; NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington; JHU/APL/NASA)
Mercury is devoid of spacecraft companions since NASA’s Messenger mission ended in 2015, and during the next mission bound for the innermost planet launches later this year, it will not come until 2025.
Scientists are passing the time digging through the Messenger data and the planning of what the new mission will bring, of course. But, they’ve also begun to think about what the next step for the smallest planet in the solar system — and to breathe new life into dreams finally in order to put a robot on the surface.
“It really is unprecedented, with two spacecraft observations of Mercury at once,” Nancy Chabot, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory, told Space.com. Chabot was referring to the BepiColombo mission, which consists of a pair of satellites that will be launched in October. “We all know that we are going to have a lot of great data and making many of the discoveries about the planet, but we also know that the mission has been in development for decades.” [10 Strange Facts About Mercury (A Photo Tour)]
Chabot is one of the lead authors of a recently published white paper calls for a detailed study into the feasibility of putting a lander on Mercury. Although such a study was carried out in 2010, no mission ever came of it, because the planet is a challenging target, but new technology can be a Mercury lander more feasible. And lander would fit in with the typical rhythm of planetary exploration: fly-by, orbit, land, rove.
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10 Strange Facts About Mercury (A Photo Tour)
Mercury Photos from NASA s Messenger Probe 2 (April 2011 till 2012)]
But NASA decided the missions in accordance with the reports called decadal surveys that are produced every 10 years by the National Academies of Science. Committees will soon begin work on the following for planetary efforts, which will cover 2023 to 2032. And if they do, Mercury, scientists want that they consider their favorite planet.
“We need to get started with this now for us, a Mercury lander, in the 2030s,” Paul Byrne, a planetary geologist at the North Carolina State University and one of the lead authors of the white paper, told Space.com. “It is our task will be complete if we convince people to one of these studies.”
Why send a lander?
There are lots of questions haunting Mercury scientists, especially in the wake of the Messenger orbiter, which collected data from 2011 to 2015. And that situation will only improve when BepiColombo reaches the planet in 2025, and starts sending more jobs data.
Mercury itself is a strange, wonderful world. “Mercury is a kind of a planet of extremes, you have the hot and cold temperatures, you have the fact that he rotates on its axis three times for every two times it goes around the sun,” Steven Hauck, a planetary scientist at Case Western Reserve University, one of the lead authors on the white paper and an important figure in the mission study completed in 2010, told Space.com. “There are places on earth where you can see a double sunset or double sunrise.” And then there’s the bit where the planet is almost entirely made of core, with thin shells of the mantle and the crust of the environment, a large metal ball.
All that craziness means that while individual scientists have their own preferences for what a mission might look like if they say now, the details are much less important than the feasibility of a mission. That is the reason why the white paper does not specify a particular site or tool suite — or even what the lander’s primary goal would be. [Mercury Photos from NASA s Messenger Probe 2 (April 2011 till 2012)]
“With one of those [mission goals], there is still a great, fascinating science that you could do on the surface of Mercury,” Chabot said. “I think I would be prepared to go with lots of different options, simply because there are so many different science questions that a lander could answer.”
What makes Mercury so difficult
But the missions are not only on scientific merit: the NASA and the other space agencies should be pragmatic about their resources, and that puts Mercury in the disadvantage. “For decades, people have argued that Mercury is just as — if not more — scientifically convincing than Mars, but Mars is much easier to get,” said Byrne. Mars is also easier for a spacecraft to land on and survive, when every step of a Mercury lander would be difficult.
First, how to get there: “You essentially have three rockets to get to Mercury,” Hauck said, a step from the Earth, from the Earth to Mercury and carefully land on the planet (due to the lack of an atmosphere that can slow down a spaceship). Oh, and the whole process takes six or seven years, because of the complex trajectory of a spaceship would have to follow in order to reach the small, inner planet.
And it can’t be easier after landing, given a wide range of threats in the surface — especially the incredible extreme temperatures on the planet. “It is exceptionally hot on the day side and the opposite in the night side,” Hauck said.
But since the last mission study was conducted in 2010, a host of new technologies have become available, or close enough for the researchers to reasonably consider, to use them for a mission in the 2030s. That includes high power rockets such as SpaceX’s Falcon Heavy, which could help with the sending of a mission on its way. And the technology developed to the Parker Solar Probe to fly only 4 million miles (6 million kilometers) above what we consider as the surface of the sun can be flexible enough to allow a lander to survive out of the shadows on Mercury, said Byrne.
The team is hoping that a new detailed mission study to determine whether these factors, plus administrative changes, such as it is no longer necessary to have the costs of the launch itself in a mission plan — maybe a Mercury lander and affordable under NASA’s New Frontiers program, which has led to the Juno, New Horizons and OSIRIS-REx missions. That program caps mission costs at $850 million. [The most enduring Mysteries of Mercury]
The group behind the white paper know that a detailed consideration of study may not return for a favorable outcome. “A Mercury-lander is a challenge, we all know this, we are not naive,” Chabot said. But the group of scientists worry that, without a study of the NASA is simply assumed that a lander is not possible — and in the process, shortchange the scientific merit of the smallest planet.
“We do not know why Mercury is the way it is, only that it is important that we understand,” said Byrne. And landing on the small planet may be the key to solving some of the many mysteries — if only someone can figure out how to do it.
Editor’s note: This story was corrected to make clear that the next decadal survey for planetary science covers 2023-2032.
Original article on Space.com.