USA TODAY When the Dragon spacecraft launched Tuesday atop a Falcon 9 rocket, the vehicle carried the private astronauts further into space than humans have reached in more than half a century. Two days after launching, Isaacman and his crew further made history: Becoming the first nonprofessional astronauts to open the hatch of their vehicle and expose themselves to the vacuum of space. While the daring mission has concluded, it's only the first of three spaceflights planned under the larger Polaris Program. SpaceX Dragon splashes down off Florida coast The Polaris Dawn astronauts landed Sunday in waters off the Florida coast in the same SpaceX Dragon that took them to space five days prior. Once it completed a deorbit burn and re-entered Earth's atmosphere, the Dragon cruised over Florida before deploying four parachutes for the water landing in Dry Tortugas, a small island located 70 miles west of Key West in the Gulf of Mexico. After the predawn landing, a recovery team approached the vehicle to retrieve it and its crew. The capsule was then lifted from the water and onto the recovery vessel. SpaceX officials took great strides to ensure that the weather forecast looked clear for the crew's return to Earth. Most crewed space launches send astronauts to dock at the International Space Station, where their return to Earth can safely be delayed and rescheduled as needed, as most recently became the case for the Boeing Starliner astronauts. The space station is well-provisioned, and even uncrewed spacecraft routinely launch on resupply missions. But in the case of the Polaris Dawn mission, the crew members were entirely reliant on the oxygen and supplies they had stored on the spacecraft, which was only enough for about a week, Isaacman previously explained on social media site X. For that reason, SpaceX waited for several days for weather conditions to improve to ensure the Dragon would have a safe trip back into Earth's atmosphere. What Polaris Dawn astronauts accomplished Isaacman, founder of internet company Shift4 Payment, commissioned the mission along with SpaceX and served as mission commander. Under Isaacman's leadership were pilot Scott “Kidd” Poteet, a retired United States Air Force lieutenant colonel; and SpaceX employees Sarah Gillis and Anna Menon, who served as mission specialists. Menon, who read a children's book she co-authored while on the mission, was also the crew's medical officer. The four astronauts' five days in space represented a new chapter of space exploration as companies like SpaceX increasingly seek to conduct ventures that were once almost exclusively the realm of space agencies like NASA. And Polaris Dawn was a mission that pushed boundaries beginning on day one. The launch sent the spacecraft ascending to 870 miles above Earth's surface, a height higher than any crewed vehicle has traveled since NASA's Apollo era came to an end in the 1970s. For Menon and Gillis, they are now not only the the first SpaceX employees to travel to space, but have traveled higher than any other women in history. The Dragon then reached a cruising altitude of 435 miles above Earth while the astronauts prepped for the next milestone: a historic spacewalk. On Thursday, Isaacman and Gillis exited the Dragon capsule to take in the endless black expanse of outer space. But because all four crewmembers were exposed to the vacuum of space, they are all considered to be part of the first-ever spacewalk conducted by anyone other than government astronauts. The spacewalk was intended to test the capabilities and mobility of SpaceX's new suits, which the company designed to protect astronauts against radiation and extreme temperatures. Along the journey, the crew tested a new laser-based satellite communication system using Starlink. They also conducted nearly 40 scientific experiments – many of which aim to understand the human body's reaction to long spaceflights as NASA and other space agencies set their sights on destinations like Mars.