Last Thursday, a shiny new SpaceX Falcon 9 rocket sat perched atop NASA’s historic Pad 39A, at Florida’s Kennedy Space Center, waiting to briefly fire its engines. The exercise was part of a routine prelaunch test. What wasn’t routine was the presence of a Crew Dragon capsule atop the slick black-and-white Falcon. The domed capsule, which can accommodate up to seven passengers, represents the next big step in SpaceX’s evolution and in NASA’s dependency on a commercial space industry.

As the rocket’s nine Merlin engines roared to life for a few seconds, exhaust plumes billowed around the launchpad. The test simulated all of the events of an actual launch, though with the rocket secured to the pad. A static test fire typically occurs one to two weeks before a scheduled take-off. Although just a practice run, it is getting extra scrutiny because it signals the impending return of crewed space launches to American soil. And it means new hardware: the launch pad features a black-and-white astronaut walkway, called a crew access arm, which was installed last summer. A few hours after the test fire, SpaceX tweeted that it was a success.

The rocket SpaceX tested on Thursday could lift off as soon as next month as part of a test flight called Demo Mission-1, or DM-1, which will see an upgraded version of the Dragon cargo craft (called Crew Dragon) fly to and dock with the International Space Station. When SpaceX first designed its Dragon capsules, the intent was for them to ferry humans. To date, however, every SpaceX Dragon capsule has carried only cargo to and from the ISS. The upgraded version, debuting on DM-1, will feature new crew life-support systems, seats, control panels, and a propulsion system that can be used to keep the crew safe during a launch emergency. Despite these upgrades, DM-1 also won’t carry people; its purpose is to prove that the spacecraft is ready to transport NASA astronauts to and from the ISS—a first for a private company and the first crew-ready flight of a US vehicle since the final flight of the space shuttle Atlantis eight years ago.

In the years after America’s storied shuttle program ended in 2011, NASA selected two companies to provide its future space taxis: SpaceX and Boeing. The companies have spent the past five years developing vehicles capable of carrying crew under a contract worth $6.8 billion. Their vehicles—SpaceX’s Crew Dragon and Boeing’s CST-100 Starliner—will be the agency’s primary means of ferrying astronauts to space. (Currently NASA and others around the world depend on Russian rockets to send crew to and from the ISS). It’s not a cheap agreement, as each seat costs NASA about $80 million. This year, both SpaceX and Boeing hope to finally launch humans.

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The current estimated date for the launch of DM-1 is February 23, but additional reviews could push it to the end of the month or later. One item of special interest to NASA is the way SpaceX fuels its rockets. Anytime a Falcon flies, SpaceX quickly fuels the vehicle with super-chilled propellant about 30 minutes before launch, with the payload already attached to the rocket. This process is called “load and go” fueling and saves SpaceX time between launches while also boosting performance. (When fuel is kept at a colder temperature, more of it can fit in the tanks, which translates into increased lifting capability.) Many experts within the industry have criticized it as unsafe, arguing that fueling should be completed before astronauts climb aboard. But NASA reviewed SpaceX’s procedures and deemed the practice safe, with a caveat. NASA is requesting “additional verification and demonstration” of the fueling procedure, which means that SpaceX will need to fly seven Falcons and demonstrate that it can safely load propellant each time before SpaceX is allowed to fly people. To date, SpaceX has flown four of those missions.

Following Thursday’s test, the mission must undergo a final review process by both SpaceX and NASA. When the flight does take off, the Crew Dragon will autonomously dock with the space station—another first for SpaceX, as the cargo version is attached using a robotic arm that's controlled by an astronaut on the station. Upon its return to earth, the craft will splash down in the Atlantic Ocean. Assuming all goes as planned, two astronauts could fly to the space station as soon as this summer.

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