We’re used to expendable boosters on space missions, but what about an expendable crew? That is essentially the long-term plan of Objective Europa, a group led by Kristian von Bengtson, founder of Copenhagen Suborbitals, that's contemplating the challenges of sending astronauts to Jupiter's moon Europa to look for life. The only catch is that the trip is one-way with no hope of return at the end of the mission.

Made up of like-minded scientists, architects, designers, and former NASA specialists, including diver Pierre-Yves Cousteau and architect Bjarke Ingels, Objective Europa was set up to answer one question: "Is a crewed mission to Jovian moon Europa possible?"

The work is still at the most preliminary stage and the organizers state that they aren't trying to raise funds. At the moment, they are soliciting ideas and crowdsourcing research to look into the feasibility of a manned mission decades from now. They haven't ruled out a robotic mission, but they've made it quite clear that they want to send astronauts to Europa, even if this means sending them with no chance of ever coming back.

Concept image of a submarine on Europa (Image: Evan Twyford)

This is different from the Mars One idea of sending volunteers to the Red Planet as colonists without a return ticket, and paying for their upkeep by featuring the settlers on a reality show. Objective Europa appears to be purely self-sacrifice in the name of science.

For now, Objective Europa is restricting itself to discussing the ethics of the mission and conceptualizing manned submarines for exploring the Europan ocean and subsurface bases inside the ice crust. Once this "Phase I" is passed, the group will move on to prototyping, technology trials and manned tests before going on to detailed mission planning for an expedition that may not take place for another 50 years.

The main reason for this extraordinary project is to look for life elsewhere in the Solar System. Especially after recent findings on Mars, Europa looks to be the most logical candidate for finding life in our Solar System. The group also wants to bring a number of other questions to the public's attention, such as: Are we alone in the universe? What is the value of self-sacrifice? How do we capture the pioneer spirit of previous centuries? But the presence of life on Europa is the big one.

Sketches of exploration machines for Europa (Image: Objective Europa)

At first glance, Europa seems as unlikely a place as any in the Solar System to find life. The fourth largest of Jupiter’s moons, its atmosphere is to all intents a hard vacuum at about the same pressure as that of the Moon. The surface temperature drops to −170 °C (103 K, -275°F) and the surface is an endless expanse of ice.

When the first NASA probes flew by in the 1970s, this bleak picture began to change. Europa exhibited a number of suspiciously odd features. For instance, it’s one of the smoothest bodies in the Solar System, criss-crossed with lines and bearing the scars of very few impact craters. It also reflects light much more than most moons with an albedo of 0.24. From all of this, scientists deduce that Europa is tectonically active and, based on estimates of comet impacts, its surface is only about 20 to 180 million years old.

On another moon, this would make it a volcanic hell like it's Jovian stablemate Io, but Europa is covered entirely by ice. This means that something else is going on. Furthermore, Europa has its own very faint magnetic field induced by passing through Jupiter’s gigantic one. This has led scientists to believe that below the ice on Europa’s surface is a salty ocean kept from freezing as the result of heating due to tidal forces.

Liquid water is an absolute necessity for life as we know it to exist, and its possible presence on Europa is a very promising sign, though it isn't proof. However, scientists point to life forms known as extremophiles on Earth that can exist in environments that would be fatal to most others. They contend that this means that life could exist in a wider range of temperatures and chemical balances than previously thought. The theory is that if there are volcanic vents on Europa, similar to those in the deep oceans on Earth, they could provide heat and nutrient chemicals to allow at least microbes to live.

Unfortunately, there are also arguments against life being present on Europa. It may be that there isn't really any water, but rather that the ice may extend to the crust and the features seen may be due to “warm” ice circulating. Also the water may be too salty for any life to develop or there may not be enough energy in the right concentrations. Also, the ocean may be 100 km (60 mi) deep. On Earth, this depth would produce a pressure of 9,580 atmospheres, so if Europa does have thermal vents, they may be so deep that the pressure disintegrates any living matter.

If Objective Europa gets off the ground, so to speak, to answer these questions, it will face a number of daunting challenges beside getting someone to go on a one-way mission. Leaving aside the problems of the 600 day passage to Europa that would involve logistics that makes a manned Mars mission look like a row across the pond, Europa itself is a very nasty place.

Sketch of a possible subsurface base on Europa (Image: James Wise)

Along with the extreme cold and airlessness, the moon orbits inside Jupiter's radiation belt, which is about 10 times as strong as Earth's Van Allen radiation belts, and Europa’s tiny magnetic field is no protection. The astronauts would be exposed to 5400 mSv (540 rem) of radiation per day, which is a fatal dose. Also, Europa’s gravity is little more than that of our own Moon, so muscle and bone degradation would be a problem.

Assuming that the explorers could overcome these problems, there’s the question of how to look for signs of life. There is a very remote chance that some parts of the ice crust are only 200 m (650 ft) thick, but it’s more likely to be as much as 30 km (19 mi). Boring through that would be hard enough on Earth, but in pressure suits at the end of an interplanetary supply line, even a couple of hundred meters is a major challenge.

The video below is a teaser for the project.

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