SpaceX launch becomes first commercial crewed spacecraft
On Saturday May 30, 2020, with the launch of their spacecraft, Crew Dragon, private space company, SpaceX, re-launched America’s ability to fly NASA astronauts to space on American vehicles for the first time since 2011. This is the first docking of a crewed U.S. spacecraft since the retirement of NASA’s shuttle fleet. The spacecraft launched from the John F. Kennedy Space Center, located in Merritt Island, Florida
On Sunday, May 31, after a historic nineteen-hour voyage, Crew Dragon, commanded by NASA astronauts Robert Behnken and Doug Hurley, slid into a dock at the International Space Station (ISS). While the spacecraft is designed to dock itself autonomously, Hurley took manual command of the spacecraft to test flight systems. Hurley serves as the Crew Dragon spacecraft commander while Behnken serves as the mission’s joint operations commander. The ISS’s current crew welcomed them aboard at 1:25 p.m. EDT (10:55 p.m. IST).
According to SpaceX’s website, the Dragon spacecraft is capable of carrying up to seven passengers to and from Earth’s orbit, and beyond. It is the only spacecraft currently flying that is capable of returning significant amounts of cargo to Earth, and will soon become the first private spacecraft to take humans to the space station.
The spacecraft measures just under 27 feet, coming in at 26.7. It is 13 feet in diameter, boasts a launch payload mass of 13,228 pounds and a return payload mass of 6,614 pounds.
The Dragon is composed also of the trunk and the capsule. The trunk carries unpressurized cargo and also provides support to the spacecraft during ascent. One half of the trunk is covered in solar panels, providing power during flight and while on station. The trunk remains attached to the Dragon until shortly before reentry into the Earth’s atmosphere.
The pressurized portion of the spacecraft is the capsule, allowing for transport of people as well as environmentally sensitive cargo. The capsule is equipped with Draco thrusters which allow the spacecraft to maneuver while in orbit as well as eight SuperDracos, which are coupled together as a Launch Escape System. The capsule is equipped with a Launch Abort System, a built-in safety system used to quickly separate Dragon from Falcon 9 in the unlikely event of an emergency. The SuperDraco engines propel both the capsule and the trunk away from the launch vehicle during a launch abort scenario. The capsule uses sixteen Draco thrusters to orient the spacecraft during the mission, including different maneuvers, orbit adjustment and altitude control. Each thruster is capable of generating ninety pounds of force in the vacuum of space.
The length of this Demo-2 mission is uncertain, as it could last one to four months, with the exact duration depending on a few factors. According to Space.com, NASA is seeking to maximize their time in orbit, since astronaut time is a precious commodity, while balancing the fact that Demo-2 is a test mission. SpaceX's first full-fledged astronaut mission to the space station, Crew-1, can't blast off until after Demo-2 smoothly returns to Earth. An estimated end date is fall of this year, as the spacecraft’s solar arrays are currently rated for 119 days in space.
When the Demo-2 mission departs the ISS, the procedure is very similar to arrival, only backwards. The entire descent will be about two days. First, the Dragon must slowly exit the “keep-out sphere”, a two-hundred meter radius around the ISS, before conducting phasing burns to lower its orbit.
As the spacecraft gets closer to Earth, it will ditch the “trunk” before it conducts a deorbit burn that will send it plummeting into Earth’s atmosphere. The Crew Dragon will enter the atmosphere at a speed of approximately 17,000 mph where the friction of particles will create a drag force, slowing it down drastically while heating the outside of the capsule to temperatures that rival the heat of the sun. The astronauts won’t feel the heat as they are protected by a heat shield, however, the spacecraft will not look as new after its return as it did before the launch, resembling a toasted marshmallow.
Once the fiery reentry phase is complete, the spacecraft will deploy four Mark 3 parachutes, this aides in slowing the spacecraft down as it descends to a gentle splashdown in the Atlantic Ocean, off the coast of Florida. Once splashdown occurs, a search and recovery crew will be awaiting nearby on SpaceX’s GO Navigator ship to help the Demo-2 crew out of the Crew Dragon as well as hoist the spacecraft out of the water so it can return to Cape Canaveral, where it will be inspected.
There are several criteria NASA and SpaceX use to determine whether this Demo-2 mission is considered a success. According to Space.com, the Crew Dragon must demonstrate that it can successfully separate and deploy into its target orbit after launch, rendezvous and dock/undock at the ISS, and safely bring the astronauts back to Earth. If everything goes according to plan, SpaceX will soon begin regularly ferrying astronauts to the ISS with its Crew Dragon capsule.