A year ago tomorrow, a failure on the Integral spacecraft meant it fired its thrusters for likely the last time. In the days since, the spacecraft in Earth orbit has continued to shed light on the violent gamma ray universe, and it should soon be working even more efficiently than before, as mission control teams implement an ingenious new way to control the 18-year-old spacecraft.

Jeff Bezos, the richest person in the world, is set to join the astronaut club Tuesday on the first crewed launch by Blue Origin, another key moment in a big month for the fledgling space tourism industry.

The mission comes days after Virgin Galactic founder Richard Branson crossed the final frontier, narrowly besting the Amazon magnate in their battle of the billionaires.

Blue Origin's sights are, however, set higher: both literally in terms of the altitude to which its reusable New Shepard craft will ascend compared to Virgin's spaceplane, but also in its future ambitions.

Blue Origin's maiden crewed flight on Tuesday involves four people who will cross the Karman line, which separates Earth's atmosphere from space, for the very first time.

Here is a brief look at the quartet of soon-to-be astronauts.

The tycoon, Jeff Bezos

Jeff Bezos, 57, will leave behind the planet where he made his vast fortune for a few minutes on a spaceship built by the company he founded in 2000, when he was still merely a single-digit billionaire.