Luna 2
Luna 2
[Cueball is standing behind while Megan sits at a laptop.] Megan: Huh. Luna 2 , the first artificial object to touch another world, carried a sphere made of steel Soviet flag emblems.
[A patterned sphere is shown blowing up to pieces.] It was designed to blow apart on impact, scattering tiny metal flags and ribbons across the surface of the moon.
[Close-up of Cueball and Megan's faces.] Cueball: So the first physical contact humans had with a heavenly body... Megan: ...was throwing a shrapnel grenade full of flags at it. Cueball: Well, it's on-brand for us, at least.

This comic is referring to Luna 2 , the first man-made object to make contact with the surface of the moon, and consequently, as stated in the comic, the first man-made object to touch another world. On September 13, 1959, it hit the Moon's surface east of Mare Imbrium near the craters Aristides, Archimedes , and Autolycus .
Megan is sitting in front of a computer, and telling Cueball about the Luna 2. She shows a picture of the probe and explains that the probe was designed to explode on impact, thus scattering multiple metal Soviet flags and ribbons on the surface of the Moon. They compare it to throwing a shrapnel grenade with flags in it at the moon (see Trivia ).
In truth, the idea behind the two explosive spheres was rather clever.  The spacecraft arrived at the moon at about 12,000 mph - and with uncontrolled orientation.  But no matter which orientation that these spheres were in as they arrived at the moon, the force of the explosion would cause the commemorative plaques nearest to the direction of motion to be thrown even faster at the moon (and, presumably, be vaporized) - while the ones from the opposite side of the sphere would be slowed down by the force of the explosion and might possibly arrive at the surface intact.
Cueball's observation that it is "on-brand" for humans to litter another world with an explosion of nationalist iconography immediately upon reaching it, is a reference to the vastly numerous historical instances when, upon setting foot on territory for the first time, humans "conquer" it, by planting flags on the first thing they see.  Alternately, it may be "on-brand" for humanity's first interaction with a new object to be striking it with a weapon.
The title text refers to the fact that for the Luna 2 mission it was more important to just get to the moon at all rather than have a sophisticated landing mechanism. This was due to the fact that it happened during the space race between the USA and USSR and both countries tried to reach significant milestones in space exploration. The metaphorical interpretation is that sometimes people get overly excited after an initial breakthrough and dive into projects without thinking them through or considering long term consequences. This often leads to the project failing or barely achieving its aim. This often goes along with the confidence to be able to "wing it" making up a solution on the spot when a problem comes up.
Note that Randall makes a subtle yet strong declaration that he is an engineer, a human, and an Earthling first, and American second, by saying "we" in the title text, regarding this effort to reach the Moon.
[Cueball is standing behind while Megan sits at a laptop.] Megan: Huh. Luna 2 , the first artificial object to touch another world, carried a sphere made of steel Soviet flag emblems.
[A patterned sphere is shown blowing up to pieces.] It was designed to blow apart on impact, scattering tiny metal flags and ribbons across the surface of the moon.
[Close-up of Cueball and Megan's faces.] Cueball: So the first physical contact humans had with a heavenly body... Megan: ...was throwing a shrapnel grenade full of flags at it. Cueball: Well, it's on-brand for us, at least.
