Woah! Per the norm for Inagaki, things are progressing straight to the action! I thought it was great that the secondary leaders are all immediately stepping up to do what they can: Tsukasa being the calming force that is insightful (and completely accurate with his tunneling estimate), Ryuusui being a rational leader that rallies the crew, and Chrome working hard to exceed what people expected.
Of course Gen being able to read the situation immediately and act out as needed is always great. I mean, even his "lie" about being fooled about Taiju and Senku is legit and forces Xeno to ponder about the validity since it is a white lie.
The biggest twist is definitely at the end though. I have a hard time imagining anything other than a missile launcher. It's too small for a spaceship of course, but this probably becomes the prototype for the future launcher when they go to space. It makes sense that they need an equivalent to Kaseki on Xeno's side, and I like how his personality so far so hopefully we get him explaining the remainder of the work in the next chapter.
If they already can make bullets, making a missile isn't all that different. Plus, if he was working for NASA, Xeno knows how to not only build all of the rocket propulsion but the most important part of the remote control system (and not something elementary like how Senku uses a remote control car).