Blue Origin, a private space flight company, just announced that it has successfully launched a rocket that reached the lower reaches of space on Monday, as HNGN previously reported. The feat is not really that amazing, but what transpired next qualified as truly remarkable. The rocket landed back on Earth in an upright position, which constituted what is technically called a vertical takeoff and landing (VTOL). It not only paved the way for the advent of reusable rockets, but it also sparked a spat between Jeff Bezos, Blue Origin's founder, and Elon Musk, SpaceX CEO.

"To be able to do a vertical landing with a fully reusable booster stage is a really big deal," Bezos said in a Space report. "It is the Holy Grail - to get full reuse."

Presently, rocket technologies involve parts falling out of the sky into the ocean upon reentry from space. But Blue Origin achieved a breakthrough with its New Shepard rocket, which maneuvered a vertical landing flawlessly at a West Texas launch site after an impressive flight. Watch the historic feat in the video below:

As the news of the New Shepard's landing got around, Musk congratulated Bezos in a Twitter post. But he seemed unhappy about some details. He disagreed, for instance, that the New Shepard's landing is historic, citing the rocket X-15 as the first reusable suborbital rocket. "Jeff maybe unaware SpaceX suborbital [vertical takeoff and landing] flight began 2013. Orbital water landing 2014. Orbital land landing next," he was quoted in a Space News report.

Bezos did not take Musk's critique sitting down. "SpaceX is only trying to recover their first-stage booster, which is suborbital. The second point that I would make is that the SpaceX first stage does an in-space deceleration burn to make their re-entry environment more benign," Bezos said in the Space report. "So if anything, the Blue Origin booster that we just flew and demonstrated may be the one that flies through the harsher re-entry environment."

There are those who say that Musk is only sore because Blue Origin's landing eclipsed what SpaceX has achieved so far. SpaceX's Grasshopper rocket, which also successfully achieved VTOL, only reached 744-meter altitude before the landing, whereas the New Shepard rocket clocked in an impressive 100-kilometer flight, Popular Science repored. However, the launch was in 2013, which is also impressive in its own right. Watch it in the video below: