On Wednesday, the Californian company SpaceX will launch a mission to the International Space Station (ISS). This is something the firm has done several times before, transporting cargo to an exquisite laboratory. But on this occasion, the company will transport people.
This is one of those defining moments in the history of space flight.
When NASA astronauts Doug Hurley and Bob Behnken take off on top of their Falcon-9 rocket inside their Crew Dragon capsule, it will be the first time that humans have left US territory to reach orbit low terrestrial in almost nine years.
But more than that, there is a shift towards the commercialization of human space transportation – from companies that sell “taxi” trips to government and anyone else who wants to buy the service.
This page details the key phases of the mission sequence.
The launch will take place from Complex 39A at the Kennedy Space Center. It is the famous Florida pad from where the Apollo 11 moon walkers and the very first shuttle, Columbia, also began their missions.
The timing is precise. The Falcon must leave the ground at 4:33 pm EDT (20:33 GMT / 21:33 BST), otherwise the astronauts will not be able to catch the ISS passing over the head at 27,000 km / h (17,000 mph).
Falcon-9 is a two-stage rocket. Its lower segment will fire for 2.5 minutes before stopping and separating. This will leave the second stage to burn for an additional six minutes to put Dragon into orbit. Once detached, the capsule will then make the rest of the journey to the ISS using its own thrusters.
The second stage of the rocket will be ordered to burn into the atmosphere. The lower segment of the booster aims to hit a drone ship in the Atlantic. It is a SpaceX specialty that distinguishes its Falcon from all the other orbital rockets used today.
It sounds remarkable, but NASA astronauts haven’t used a whole new spacecraft design for 39 years. Not since John Young and Bob Crippen boarded the Columbia orbiter. Their shuttle had dials, switches and a joystick. Dragon is all touch screen.
It’s an automated ship, so it’s making its own way to the ISS, but Hurley and Behnken must practice manual flight if something goes wrong.
Dragon Capsule was designed to handle all imagined scenarios, including a rocket failure on the pad or in flight. If this happens, the ship will use a powerful, integrated propulsion system to push itself to a safe distance. SpaceX repeated this possibility both on the ground and in the air.
This mission is expected to see Dragon reach the ISS after approximately 19 hours of flight time. The capsule will align with the bow of the space station and approach at a relative speed of a few centimeters per second. Once attached, the hooks form an airtight seal.
The length of Hurley and Behnken’s stay aboard the ISS 420 km high has not yet been determined.
It should last more than a few months but should not exceed 120 days. Engineers say the Dragon’s solar cells are degrading in orbit, and NASA is sure to bring the crew home before the equipment’s performance is compromised.
The descent to Earth will not be rushed. Astronauts are planning a two-day free flight to further test on-board systems and procedures. When the desorbite burn is finally called, Dragon will be protected from falling into the atmosphere by a heat shield. Four large parachutes will slow the spacecraft for a slight splash in the Atlantic, just off the coast of the United States.
SpaceX teams have repeated the capsule recovery process several times.