Chapter 151 spoilers
Speed Time

While Yada and Kurahashi distract the guards, Kimura infiltrates the Control Room and links Ritsu to the system, granting her remote control.
After she deactivates the security controls around the launchpad (for the meantime), a number of students under Kataoka's leadership approaches the rocket. They were able to slip past the staff by "erasing their presence".

After Korosensei inspects the rocket, it's time to decide who will replace the 2 dummies (whom are already wearing astronaut suits) and ride to space.
I think everyone managed to pass a "space aptitude test", but when asked who wants to go, all the boys raise their hands.
Upon reminding them that this is a test flight without a confirmed success, the hands steadily lower.
Itona is interested in this sort of mecha-stuff, but he'll let someone else more suitable go.

For this hijack mission, the consensus is that the combat-oriented Karma and the assassination-excelling Nagisa are good choices, all the moreso given their sense of responsibility shown during the wargame.


8 hours later, countdown begins.
This reminds the them of when Korosensei took them both to Hawaii for the Sonic Ninja movie.

As the rocket takes off (eventually accelerating to Mach 23), Korosensei comes to see them off. He tells them not to over-worry about getting the data on him, and just enjoy this journey.
Hearing him say that, Nagisa voices that Korosensei really is thoroughly using his life to give them chances to learn. He's grateful, but he and the others won't let Korosensei's life end as mere teaching material.
"... I understand. I'm glad."

Chapter 152 spoilers
Outer Space Time

After docking onto the ISS, of the 6 astronauts who came to tend to the vessel, Nagisa and Karma took one of them hostage, with knives and a plastic explosive in hand (both of which turned out to be fake)
Ritsu cuts off communication between the ISS and the Japanese space center, while Nagisa and Karma explain the situation and request a copy of the American team's research data.

Although the astronauts were taken by surprise at first, they cooled down rather quickly. As expected of professionals, some of whom are soldiers as well.
The captain applauds their bravado, but he questions whether the kids seriously think they can take them on.
Also, the bomb isn't a threat to them, because in the first place, they came to the station for the sake of life-risking experiments that might blow them up at any point.

That said, this is a terrible place for any fights to take place, and pointless ones at that. If they want to talk, let go of the hostage first.

---

The astronauts question how the kids intend to return without the help of ground control, to which Nagisa replies that their classmate (Ritsu) will perfectly calculate the return trajectory. If there are any adjustments required mid-flight, their teacher can do it himself (ie fly to the rocket when it's in the atmosphere and tilt it here and there, probably).

Isn't that a bit reckless? After all, their vessel is still in an experimental stage. They're taking their lives a bit too lightly, no?

Funny, because all they've been thinking about lately is "life". After all, they are the students of a classroom that's going to kill their teacher.
If they're going to face off against a life, then they have to do it with their lives. That's the sort of determination they have. It's the same way with the astronauts, no?

The captain is actually impressed at the duo's trust in this plan that their target came up with.
Very well, he'll give them the data.

---

But first, they should at least help with offloading supplies and such. In a sense, they're given a rare experience of working in space.
The data is received, which Ritsu verifies is complete and authentic.

As they depart, Nagisa and Karma reveal that their weapons were fake and apologise for their intrusion. At least they got to kill off some idle time, right?
Confounded at how childish the entire affair became, the astronauts welcome them to come to space again (but legally).
Karma has had enough, but he'll be sure to raise the budget of space development when he becomes somebody great.

---

During the return flight, Ritsu has already made several trajectory calculations, and the spaceship may as well be her own body.
Furthermore, with the numerous sensors equipped on the vessel, Ritsu is able to sense much more things than before.

External temperature, pressure, speed, surroundings...
The breathing, conversations, heart rate, temperatures of the occupants...
She can feel that this mission has allowed her to evolve further, it's great.

For the first time, Ritsu became self-conscious of "emotion". She feels happy; happy that she came to Class E.

Chapter 153 spoilers
Resolve Time

As the spaceship descends, Korosensei comes to fine tune the trajectory, in particular untangle the erroneous parachutes.
The landing site is ... the Class E pool.

Certainly, Karasuma is frustatedly speechless, but Korosensei tells him to just give the excuse that Korosensei threatened the students into doing this hijack. Furthermore, he provides his and Ritsu's observation data of the whole test flight as compensation.


Okuda starts deciphering the experiment data:
- The experiments entailed creating various antimatter lifeforms, place them into capsules and release them into outer space, making observations as they explode.
- The researchers find that the risk of exploding correlates to "size", with the larger they are, the more stable the risk.
- Also, the case of the mouse on the moon might not apply as much to "him" (Korosensei), because its cells were forcibly made to break down more easily (remember, the mouse was there to see what happens when cell division ceases for antimatter lifeforms)
- That is, chances of Korosensei exploding might be lower than first thought.

As for recommendations:
- A chemical solution has been prescribed. If a chemical compound of Silicon is regularly circulated throughout the body (which then does something), the risk of running wild lowers.
- If the requirements are fulfilled, the possibility of exploding should lower to less than 1%
- And within 90 years, when the life span of the cells are up, they are likely to quietly evaporate
- This solution ... is almost the same as what Okuda had made in the past, the one that liquefies Korosensei.

The point is, Korosensei can pretty much be saved, and they already have a solution at hand.
However:

- They have been carrying out the assassination since the 1st Trimester. Isogai questions if it's really OK for them to end it like this today?
- Karasuma tells them even if they do accept these results, the assassination request won't disappear so easily. The fact that Korosensei is dangerous hasn't changed.

And so this is their conclusion:

- So long as the request remains, they will continue the assassination with all their might until March. After all, the assassination is their mission, and their bond.
- But if they can't kill him when the assassination deadline in March is up, then they'll graduate from the assassination and leave things to the country/government. In that case, they'll just be "ordinary students" and the "indebted teacher"

They have spent this one month mulling over what it means to "kill". From that, "resolve" has sprouted.
A resolve to accept responsibility for whatever they may gain or lose, so long as they swing their blades with conviction.

Chapter 154 spoilers
Winter Break Time

I am certain that many readers are unhappy at how Winter Break has been skipped. Korosensei too regrets that Class E had to spend that time mulling over his life and death, such that they didn't celebrate anything either.

So this chapter is a slice-of-life tale where Korosensei makes up for that loss by celebrating all the festivities with Class E at the classroom. Christmas, New Years, Setsubun, etc.

After clearing out all the events around the New Year's holiday period, it's time to move on to some important matters: school entrance exams.
It's time for them to study properly for those, and after the exams and results have come out, he will once more conduct one-on-one interviews about what sort of future they want to choose.

No matter what the fate of the Earth will be, Class E's assassination will end upon graduation. It's time for them to gaze at their own futures.

It is now February. The day until their graduation, and the deadline for the assassination, is 38 days away.