The Northern Capital vetoed the idea of detonating it in advance and continued to implement the original plan, but the original plan was not foolproof.

The exact time of Callisto's arrival can be calculated, as can the detailed orbits of Phobos and Deimos, but with Europa's current orbit, it will not be able to fly to Earth at all, and it will definitely have to change direction near Mars.

At that time, it is impossible to determine where Callisto will approach Mars and what its orbital altitude will be, so the distance and position relationship between the satellite and Callisto will not be determined.

If you want to hit Europa, the timing is very important, too early is equivalent to reminding the aliens, too late and suddenness, which is equivalent to giving Ganymede a chance to calmly avoid, so when to detonate is the key to the success of the plan, the position of the satellite and Ganymede cannot be too far away when detonating, and the flight speed of the fragments must be fast enough.

However, although the planetary engine is strong, the quality of Europa is not low, and its steering and acceleration and deceleration are very troublesome, as long as the speed of the pieces is fast enough, it is not impossible to hit Callisto.

If not, the Mars project would not have to continue, just declare it a failure, and return to Earth to wait for a decisive battle with aliens.

After resolving the differences in plans, the Mars program has entered the fast lane, and the first problem that the Fourth Fleet needs to solve is the placement of the super engine.

The impact of the undisturbed super engine on the mission is too serious to be done, and in order to prevent the impact of the nuclear explosion from destroying the engine, the fleet has come up with an unexpected solution: build a shelf!

To put it simply, it is to find a few giant steel cones 100 meters long, the head of which is fixed at a designated position on the surface of the satellite, and the tail of the cone is fixed on the super battleship, which is equivalent to using a shelf to fix the super engine on the satellite.

The depth at which the steel cone is inserted into the satellite, the length left on the outside and the angle at which it is inserted into the ground are carefully calculated, and when the nuclear bomb explodes, the steel cone acts as a buffer between the fragments and the engine, and the steel cone will be inserted deep into the fragments due to inertia, thus completing the fixation of the super engine.

The super engine has a very high weight, and if it is placed on the earth, it will definitely not be able to do so, even the gravitational pull of the moon can bend the steel cone, and only a small celestial body with a low gravitational force such as Phobos can use this method to fix the spacecraft.

On April 6, 2028, the last superengine was fixed to the surface of the satellite.

The successful fixation of the super engine cleared the last obstacle of the Mars project, and the next task was to wait for Ganymede to arrive.

In order to prevent aliens from discovering the super engine, Ye Han also led the soldiers to cover the engine with a camouflage net, camouflaging all the super engines as a hill on the surface of the satellite.

This was not a temporary initiative of Ye Han and others, but a task arranged before the fleet set off.

Ye Han was very skeptical of the effect of the camouflage net, but something was better than nothing.

It took only two days for the Marines to lay out all the camouflage nets, and by that time there was still more than a month before Europa's arrival, and all but a few people in the Fourth Fleet had been injected with hibernation.

At this time, Yushan has completed all the tasks and can leave Mars at any time to return, but first, the distance between the earth and Mars is still relatively far, and secondly, Ganymede is coming, Ye Han solicited the opinions of all officers and soldiers, and applied to stay on Mars temporarily to participate in the follow-up tasks of the Mars plan.

After careful consideration, the Qiongzhou base agreed to Ye Han's suggestion.

The Qiongzhou base doesn't know what to do if the marines are left behind, but they are not in a hurry to come back at this time, it is best if there is no need, what if there is a need but no one can be found?

On May 20, 2028, with only three days left on Mars, the fleet will wake everyone up and wait for Callisto to arrive.

Callisto is getting closer and closer, and its position can be seen with the naked eye, although all the ships of the Fourth Fleet are painted black, but in order to prevent the fleet from being exposed, all the ships are hidden behind the satellites, and only the monitoring equipment installed on the satellites is used to observe Callisto Zero, and all the ships are constantly moving their positions under the unified command of the flagship to ensure that all the ships can be blocked by the satellites.

At 4 a.m. on May 23, Callisto was only two hours away from Mars, and the Fourth Fleet was on standby, with everyone on the bridge of the flagship Nanzhou performing their duties, and Wang Tianyu reporting on the orbital parameters of Callisto every few moments.

That's right, it's Wang Tianyu, not only him, but Ling Yu is also there.

Originally, the Fourth Fleet could not have a few of them, but because of the failure of the Third Fleet, Ling Yu and others strongly requested to join the Fourth Fleet, find a way to send a military order, and even wrote a blood letter, so they won the opportunity to command the Fourth Fleet.

This is also the fact that there are many objective factors in the defeat of the Third Fleet, otherwise the blood of the whole body will be dry, and the Fourth Fleet will not be able to take the turn of these few people.

Of course, the Third Fleet's long-distance sailing experience also added a lot of points to Ling Yu and the others...... There are not many senior commanders with experience in long-distance voyages.

Time passed slowly after a long wait, and when Callisto was only half an hour away from Mars, Wang Tianyu finally got the orbit analysis results: "Report, Commander, the orbit analysis results are out, Callisto will arrive on Mars in 27 minutes, with an orbital altitude of 12,000 kilometers." ”

"What? Only 28,000 km? Are you sure? Ling Yu was shocked, his eyes staring at the home screen in a daze, "What do the aliens want to do?" ”

He was not questioning the results of the orbital analysis, but was shocked by the madness of the aliens.

28,000 kilometers is a very long distance for a man-made vehicle, but it is too close for Mars or Europa.

Although Ling Yu had limited astronomical knowledge and didn't know what would happen if the two planets were too close together, the distance was less than four times the diameter of Europa, which was too close.

Xu Moliang's expression was so serious that it almost froze: "Judging from Callisto's current orbit, it really wants to use Mars to slow down ......"

Ling Yu's eyes never left the home screen, there was a real-time map of the situation near Mars, and at the moment Ganymede was flying in front of Mars, and Deimos happened to be behind Mars, and the closest distance between the two was expected to be no less than 50,000 kilometers, even if Huoimos was blown up immediately, the resulting fragments would not be able to catch up with Ganymede.

The relative speed between Ganymede and Deimos is as high as more than 80 kilometers per second, and although the power of the super engine is good, it can't catch up with the boulder pushing tens of millions of tons of boulders to death, unless the boulder is thrown away and the super engine is directly used to catch the tail of Europa.

But in that case, even if you catch up, it won't be useful, and the super engine will tickle Europa at best.

However, there is no way to go, Phobos is not in a good position, but Phobos happens to be on the other side of Mars!