SpaceX is moving toward another private crewed Dragon mission called Polaris Dawn this summer. In addition to testing new ultra-high orbits and assessing the Starlink laser communication net, Polaris Dawn will feature the first flight of SpaceX’s new spacesuits. The spaceflight firm has just unveiled the long-awaited Extravehicular Activity (EVA) suit, which can protect astronauts from the harsh environment of space. The Polaris Dawn crew will use the new EVA suits to venture outside the Dragon capsule for the first time, testing the advanced composite materials, streamlined joint design, and in-helmet heads-up display.
The SpaceX EVA suit looks very similar to the standard flight suits used thus far. We’ve all seen images of the NASA Extravehicular Mobility Unit (EMU) and Russian Orlan, which are considerably bulkier. That’s partially because they were designed decades ago, but they also have different use cases. The SpaceX suits will be tethered to the Dragon spacecraft by an umbilical to provide life support. The EMU and Orlan both have independent life support systems—they’re essentially single-occupant spacecraft that can operate for eight hours at a time.
SpaceX hasn’t offered too many details on the functional limits of its new EVA suit, but it will be put through its paces during the Polaris Dawn mission. SpaceX had hoped to launch Polaris Dawn in 2022, but it has been pushed back repeatedly while development of the EVA suit continued. These sleek suits have a 3D-printed polycarbonate helmet and visors coated with copper and indium tin oxide, which prevent glare and fogging. A HUD inside the helmet provides real-time data on pressure, temperature, and humidity. Most of the suit control is automatic, but there’s a dial to control oxygen levels, which is piped in via the Dragon umbilical.
The suits use a flame-resistant material and a spiral zipper design for added strength. The boots are composed of the same material SpaceX uses in the Dragon capsule’s trunk and Falcon 9 rocket’s interstage. The company says the combination can survive a wide range of temperatures and pressures. They can also be scaled up and down to accommodate various body sizes.
All four members of the Polaris Dawn crew will have to wear the suits as SpaceX will need to depressurize the entire ship to conduct the spacewalk.
Credit: SpaceX
The suit will be pressurized to 5.1 PSI, a bit higher than the 4 PSI used in NASA EMU suits. NASA’s suits have rigid rotator joints, which help astronauts move their limbs without fighting against the pressurization, but they’re essentially useless when unpressurized. That effect is multiplied as pressure increases, too. SpaceX says the new suit uses semi-rigid rotator joints that are much more compact than the EMU’s, and they should be equally usable in both pressurized and non-pressurized states. That will be important because all four members of the Polaris Dawn crew will wear them throughout the five-day mission.
Dragon does not have an airlock, so SpaceX is working on a system to vent and repressurize the capsule during the mission. Two crew members will head out of the airlock at an altitude of 435 miles, spending up to two hours testing the suits. SpaceX has said it may eventually transition all flights to the new EVA suit, making it easier to service spacecraft like the in-development Starship. Billionaire businessman Jared Isaacman, a longtime SpaceX collaborator and commander for Polaris Dawn, has also suggested that SpaceX EVA suits could be used to service the Hubble Space Telescope. We’ll have to see how the test goes this summer before getting too excited. SpaceX has yet to nail down an exact date for the launch.