The SpaceX Crew Dragon manned spacecraft will update the possibility of using a jet landing system
Dragon receives long-planned propulsive landing upgrade after years of development
written by Aaron McCrea | October 10, 2024
Translated from English Andrey Klimkovsky
SpaceX announced a new capability for the Dragon spacecraft on September 27 in the unlikely event of a parachute failure. Dragon now has the ability to activate a propulsion landing system using SuperDraco engines, saving the ship and its crew from a rough landing or imminent danger.
SpaceX unveiled the Dragon jet landing concept more than a decade ago. When SpaceX unveiled Dragon 2, it was marketed as capable of jet landing anywhere on Earth and was originally designed to land solely using SuperDraco. However, SpaceX ultimately decided to use parachutes as the primary form of escape for Dragon 2 missions.
A lot has had to change in Dragon 2 since May 30, 2014 to make it the reliable manned spacecraft we know it as today. Now SpaceX has decided to bring back one of the main capabilities that was thought to be left behind during the development process.
Why land a manned capsule using jet propulsion?
Rapid reuse was a top priority in SpaceX's original plans to launch Dragon. SpaceX planned that upon returning from space, Dragon would fire eight SuperDraco engines and propulsively slow down the capsule's speed. When the speed reaches zero, the capsule will land on the retractable landing legs on the designated landing pad. This action could speed up the time it takes to recover Dragon and return it to the launch pad.
Landing on a concrete landing pad on land rather than in the ocean has many advantages, especially when it comes to the long-term reusability and recovery of Dragon capsules. When landing in the ocean, saltwater can corrode the aluminum body and carbon fiber parts that make up the Dragon. A propulsion landing on Earth would prevent invasive corrosion from occurring in the first place, making rapid reuse a much more achievable goal.
Eight SuperDraco engines on #DragonV2 will allow the device to land anywhere with the precision of a helicopter.
SpaceX (@SpaceX) May 30, 2014
Moreover, landing Dragon using jet propulsion would also be safer for the crew when exiting the spacecraft. Getting astronauts out of the capsule is a lengthy process, especially if they were exposed to microgravity for a long time. The movement of ocean waves and the process of extracting the Dragon from the water turned out to be quite lengthy, and landing on a solid surface on land would allow rescue teams to approach the crew inside the Dragon and disembark them much faster.
At the time of Dragon 2's announcement and the reveal of Dragon's propulsion landing capabilities, SpaceX planned to eventually use Dragon to land on the surface of Mars. This mission, called “Red Dragon”, was technically feasible, but SpaceX later abandoned the plans in favor of Starship.
Mars' atmosphere is much less dense and thinner than Earth's, meaning parachutes are much less useful for landing. In the case of Red Dragon, the thin atmosphere of Mars meant that Dragon would have had to land on the surface using jet propulsion without the use of parachutes. With plans for Red Dragon in place and knowing that jet landings would be necessary for future missions to Mars, SpaceX decided to pursue jet landings on Earth as well.
Why plans to land Dragon using jet engines were scrapped
Certifying a spacecraft for flight involves a long and in-depth process before it is allowed to reach orbit. These safety measures exponentially slowed down the Red Dragon mission launched to Mars, even without a crew. When NASA decided not to fund Red Dragon for a possible Mars sample return mission, SpaceX abandoned the Red Dragon concept and focused on further development of Dragon 2 for missions on Earth.
SpaceX began submitting applications to NASA's Commercial Crew Program with a design for a crewed spacecraft with a powerful propulsion system that was planned to also serve as a launch abort system. After Dragon 1 proved capable of reaching the International Space Station (ISS), SpaceX was selected by NASA to produce a crewed spacecraft for the Commercial Crew Program, which eventually became Dragon 2.
Although Dragon 2 and its participation in the Commercial Crew Program differed from Red Dragon, the idea of a jet landing Dragon was not immediately canceled after the contract was awarded to SpaceX. It was originally planned that in the event of problems with the jet landing sequence, precision water landings using two drogue parachutes and four main parachutes would be the backup plan. However, a few months later it was announced that SpaceX had changed its landing system choice and was now focusing on water landings using parachutes rather than land landings using SuperDraco engines.
Dragon 2 was designed for powered landings, with parachutes as a backup. Switched to parachutes as primary due to the difficulty of maintaining safety, but Dragon can still do it.
Elon Musk (@elonmusk) March 9, 2019
With parachutes now serving as the Dragon's primary landing system, the Dragon's jet landing system was no longer the main focus of Dragon 2's development. It was later revealed that NASA wanted a higher “lost crew” reliability rating for the Dragon and felt more comfortable with the parachute landing system than with a jet landing system. NASA also believed that small holes in the Dragon's heat shield for the four retractable landing legs could cause hot spots to quickly form during reentry, potentially leading to the destruction of the vehicle.
Returning to jet landings
In March 2019, SpaceX completed Demonstration Mission-1 (DM-1), during which Crew Dragon (the crewed version of Dragon 2) successfully flew to and from the ISS without any significant problems. After the mission, Elon Musk, when asked about Dragon's jet landing, said it was “subject to NASA review and approval.”
Just over a month after the success of DM-1, Crew Dragon C204 encountered an anomaly during a SuperDraco fire test. This anomaly resulted in a complete loss of the vehicle, likely causing widespread delays to any SpaceX plans to jet-land Dragon. Outside SpaceX, it was speculated that the anomaly marked the end of any plans for a Dragon jet landing.
Today, Crew Dragon is known as an extremely reliable and well-tested vehicle – it has completed 15 successful manned missions to the ISS and other low-Earth orbits and experienced virtually no problems with the parachute landing system. During Crew-9's pre-launch briefing, NASA announced that Dragon now has the ability to activate its SuperDraco engines and perform a jet landing in the event of parachute failure. If a parachute anomaly occurs, the four main parachutes will be cut and Dragon will fire its eight SuperDraco engines to slowly perform a jet splashdown. NASA said such a landing would be “tolerable” for any crew inside Dragon.
@SpaceX's Bill Gerstenmaier says this capability has been implemented before, but this is the first time it has been used on a @NASA mission.
He confirms that this allows Dragon to launch SuperDracos “at the very end” to provide an “acceptable landing” for the crew.
Ryan Cayton (@dpoddolphinpro) September 27, 2024
At a press conference after Crew-9's launch, in response to a question from NSF, SpaceX Director of Dragon Flight Operations Sarah Walker explained that the rules for activating a propulsion landing require that all relevant systems and sensors be operational or it will be disabled. SpaceX used this capability on the Crew-7 Dragon, but it was disabled until the crew returned when a faulty GPS sensor was removed from the system. As of that September 28 press conference, the propulsion landing capability was still active for the Crew-8 mission, which will not return until October 13. She was also active for the recent privately manned mission Polaris Dawn.
