After their launch on June 2033, the spacecraft employed by the Arcas Project arrived at Jupiter only eight months later, in February 2034.
At first Lewis & Clark, Smirnova, Marco Polo and Shyust Vertia kept away from the strong radiation belt of the planet. By early March they began moving towards Callisto, entering orbit around the second largest of the Galilean moons on March 15.
The powerful sensory systems of the three human spacecraft scanned the surface of the moon over the following week, creating a surface map that was more detailed than those of the various international probes and allowing the planning staff on Earth to decide on a good position for Arcas Station.
The tidally locked rotation of Callisto narrowed the choice of the location down to the side that faced away from Jupiter, additionally making use of the moon’s mass as additional radiation shielding from the radiation belt of Jupiter. This made it necessary for the Arcas Project to place a number of communication satellites in orbit around Callisto and Jupiter to keep continuous contact with Europa during the mission.
Smirnova placed a constellation of six communication satellites into Callisto orbit. Based on the Meridian series of communication satellites, the satellites of the Jupiter Communication Network were all powered by large solar panels that theoretically were able to power the satellites for longer than radiothermal generators. They were also considerably cheaper to build.
Lewis & Clarke and Marco Polo carried six landers for Callisto, four of them being unmanned cargo landers and the remaining two manned ones. The Quetzal Shyust Vertia carried the remaining cargo in the form of all the things needed to build up Arcos Station.
The initial landing on Callisto happened on March 24, with one of the two crew landers touching down on the moon to test whether or not the selected location was actually suitable and stable.
Over the following week, the second crew lander touched down, with the automated cargo landers delivering the first modules needed for base construction. The first was the fusion reactor, which was activated with the help of several superconducting capacitors build into the reactor module and precharged in orbit. It was a Deuterium-Deuterium reactor to ease fueling the reactor and a tank with fuel for the reactor was within the second module delivered to the surface.
The third module contained the systems needed to create an airlock on the icy surface and to melt the ice beneath the airlock and create the cavity to hold the actual station. The fourth module finally was a system of inflatable and insulated tanks needed to take in large amounts of liquid water, as well as liquid oxygen and hydrogen needed to refuel the landers. A complicated system of filters was employed to deal with any form of contamination, especially as the water proved to contain a good amount of organic material.
Melting the cavity for the station into the ice and pumping the water into the awaiting tanks took close to three weeks, during which the Europa lander with the Europa Explorer was launched from Smirnova into a trajectory that brought it to Europa.
On April 24, the Europa Explorer entered orbit around Europa, while the automated landers began to carry the first actual modules for Arcas Station to Callisto.
Connection to the Europa Explorer was good through the Jupiter Communication Network and the probe landed near Columbus, only about fifty meters away from the probe and the pair of iron and brass spheres. Had the spheres been largely inactive since December 2032, the larger of the two turned active again, observing the Europa Explorer, as its heated container was set onto the surface and began to slowly melt itself through the ice of Europa. It was expected that the smaller heatsource of the Europa Explorer would need up to a month to melt itself through the ice until it reached clear waters.
Meanwhile the construction of Arcas Station continued until the station consisted of twenty different modules, some of them adapted from conventional space station modules to modules originally intended to expand lunar or Mars stations. Each had an increased insulation against the low temperature of the surrounding ice and the station in its entirety was held in place by anchoring points driven deep into the surrounding ice.
Three of the modules were based on the Soviet MOK modules and each contained an aquaponic system spread over three stories on the inside, allowing the station to at least grow most of their own food. Three modules were conventional laboratories intended to be used for work on samples from Callisto itself as well as the Jovian system at large.
On May 10, Arcas Station began it nominal operation, with an international crew of ten, including Ineorm Lor En’ust, a Quetzal from Diego Garcia who held an academic rank in exopsychology. Lewis & Clarke was the first craft to be placed on station duty over Callisto, while the remaining spacecraft prepared to return back to Earth.
The Europa Explorer had finally melted itself through the relatively thin ice of the lineae, dragging a long cable along behind it to ease communication with the lander. The carrier shell for the submarine robot descended further into the sub-Europan ocean as to not force the robot to collide with the ice if it could be avoided.
On June 19, the carrier shell filled with water and allowed the Europa Explorer to begin its work, analyzing the water with its internal laboratory, while the autonomous systems went through a number of pre-mission tests. The shell opened on June 20, releasing the mini submarine for its mission, oversight provided by Arcus Station.
The submarine almost immediately detected sonic disturbances in deeper water, coming from the free ocean beneath the lineae. It also rapidly found two sets of cables and tubes that appeared to be connected to the pair of iron and brass spheres near the landing spot. They led down towards the free ocean and the cameras were able to detect low magnetic fields coming from cables, while the tubes gave off heat.
Being directed to sink deeper down, alongside the cables, the Europa Explorer kept observing and analyzing the water, detecting high amounts of organic materials within the water as well as high concentrations of minerals.
After following the cables to the spheres for about three kilometers downwards, the water pressure only raising to a pressure of about one kilometer depth on Earth due to the low gravity of Europa, the submarine reached the free ocean and was forced into corrections for its course due to turbulences from a cold water current along the ice shelf above. The submarine nearly lost sight of the cables, but was able to recover and sink deeper, past the current and detected an orange glow coming from the deep about four kilometers along the cables.
A slight warm current was encountered a little deeper and the cameras pointed directly downwards filmed how a massive shape was slowly exposed from the blackness of the surrounding water.
Several crew members of Arcus Station and people on Earth later described the scene as being similar to the arrival of the aliens in the Spielberg movie ‘Close Encounters of the Third Kind’.
The massive object was irregularly formed, but had the general shape of a sphere, illuminated by a near countless number of orange and white lights, though the orange light sources were more numerous. Openings were everywhere within the sphere and it was surrounded by a massive cloud of life. Creatures that were the Europan equivalent of fish swarmed around the sphere, some of them eating from it, while others ate smaller fish.
The Europa Explorer moved closer towards the object, hovering above its surface and taking close up images and videos, showing that the surface of the object was actually coral like and alive as well, with polyp like creatures feeding on a form of plankton.
The lights were also filmed, turning out to be similar to either early 20th century light bulbs or fluorescent lights. Other images showed that the coral growth had been shaped into specific forms, parts of the corals being neatly cut or chiseled away with tools, while insulated cables and tubes were interwoven with the structure. While alive, the structure showed every sign of being artificial.
Warm water flowed through openings within the coral growth, carrying nutriments and alien fish. Eventually the flow of warm water also carried several cephalopod like creatures out into the open water and they stopped as the caught sight of the Europa Explorer. The autonomous system kept the creatures within sight, while they appeared to be wary and their skins exploded into colors, they also made sounds, appearing to talk to each other..
The creatures themselves were about three meters in length and had the general shape of a cuttlefish, with a pair of shell-like protrusions protecting the dorsal and ventral parts of their mantle. Two pairs of fins stuck out left and right along the shells in a V-shape. They had about twelve arms, which split in half in the last ten centimeter of their length and were covered with suckers. Two intelligent eyes, which looked close to those of Earth cuttlefish, observed the submarine. The skin of their mantles flashed in a multitude of colors from chromatophores, while the shells themselves were covered by a variety of patterns, some of them obviously not natural.
The intelligence of the creatures was not questioned, especially as all of them carried belts of some kind slung around their bodies, with a number of tools hanging from them. It was possible to identify hammers, chisels, pliers and knifes. That two of the four creatures grabbed their tools with their arms and appeared to be ready to use them as weapons also spoke for their intelligence.
The Europa Explorer kept its position, retracting its robotic arms completely and the video screens awoke to life, beginning with a simple first contact protocol, using basic geometric shapes and math to try and open up a communication route.
Following a rapid conversation between the creatures, one darted back into the tunnel it had come from, using a pair of water jets. The Europa Explorer stopped its communication attempts and waited about half an hour until the creature reappeared, with several more aliens close behind, one of them mutilated and missing most of its arms.
The submarine began its first contact protocols again and ran through them twice, before waiting, allowing the aliens to converse between each other.
Over the next two weeks it was possible to come up with a way to communicate with each other, using the video screens and audio system of the submarine.
The reactions to images of the Sun, Earth, humans and the other aliens was hard to measure during the early contact, but it became clear that the Europans were initially sceptical about intelligent creatures not living under water. Eventually however they became rather accepting.
The Europans invited the submarine into the sphere, which turned out to be a floating city, on the tenth day after contact. The interior of the floating city was similar in construction to the outer surface, with light fixtures embedded into the walls, while heated tubes were running everywhere. It was possible to look into several large rooms, discovering that the tubes appeared to be used to transport steam and hot water, as they connected to a variety of engines powered by steam.
The Europa Explorer was directed into a room where one wall was covered in a large number of dials, switches, valves and gauges, with a sort of screen in its center, showing a life image of the Columbus probe on the surface of Europa. In response the submarines video display showed a high quality image of the two spheres.
Communication with the Europans became easier and six months after first contact it was possible to piece together information about the aliens, with the aliens being very eager to provide information and cooperate.
Their civilization was based around the floating cities and cities on the ocean ground around natural hydrothermal vents. At first it was unclear how the floating cities worked, but at the center of the city the scientists discovered a blue glow in the water, as well as an unusually high concentration of heavy isotopes of hydrogen, oxygen and other elements. This implied that the floating cities were powered by a form of fusion or fission reactor, through fusion reactors were more likely, even though the actual civilizatory level was closer to the age of steam. There were also observations of several types of robotic systems servicing a variety of system surrounding the center of the city as well as outlying parts of the steam network.
According to the Europans there were about ten thousand floating cities within the ocean, with an additional twenty thousand ocean floor cities, each with a population of at least five thousand Europans or more, making a combined population of at least 150 million Europans.
It also appeared that the Europans were somewhat religious, going as far as claiming that their floating cities were gods and that the fusion reactors in the center of their city was the heart of the god, with the Europeans themselves being the children of the gods. The notion was somewhat understandable as they had apparently backslid from a higher technology level, capable of building self repairing fusion reactors, to the current steam age level.
While they appeared to have developed a theory of evolution and even said to be following the laws of evolution, they believed that they had been created by the gods, with no other explanation possible to explain the total lack of any fossil record for the Europans older than about 150000 years.
Their easiness in accepting the possibility of alien life, especially life outside of water, was eventually explained by their religiousness as well. To them the various gods of the universe had obviously also created intelligent servents after their own, strange image.
On Earth there was a loud discussion on how to act. The Europans appeared to be rather peaceful, friendly and reasonable and their technology level was more advanced than could have been expected from an aquatic race. There were groups that wanted to uplift the Europans to a higher level of technology, while other groups wanted to employ a form of ‘Prime Directive’ and not interfere with the natural development of the aliens. There were also groups that felt that there were already too many aliens on Earth.
Another discussion was on the Europans origin. The lack of a fossil record of their species until 150000 years ago, seemed to imply that they had simply appeared on Europa, indicating an extrasolar origin. Others suggested that the Europans had been genetically engineered by other aliens to create intelligences, with a lower number of people stating that both the Europans and humanity had been created by aliens around the same time. Either way, it was accepted in academic circles that the current Europans had evolved on Europa and were in a sense siblings to humanity for being ‘born’ in the same solar system.