With new improvements and equipment, the spacecraft for the Polaris Dawn mission, launched on August 27, will be unlike any Dragon spacecraft that has flown before.
SpaceX’s Crew Dragon capsule for the Polaris Dawn mission features numerous changes for the first private spacewalk, which will occur after the launch on August 27. The Dragon spacecraft for Polaris Dawn will fly higher than any crewed spacecraft since the Apollo missions, reaching an altitude of 700 km above Earth, according to Space.
The Dragon will carry four astronauts into orbit, including mission commander billionaire Jared Isaacman, who previously flew on the Inspiration4 mission in September 2021, pilot Scott “Kidd” Poteet, a retired U.S. Air Force lieutenant colonel, and mission specialists Sarah Gillis and Anna Menon, both engineers at SpaceX.
Space suit for the Polaris Dawn mission. (Photo: SpaceX).
The spacewalk for the Polaris Dawn mission will involve opening the hatch of the Dragon, which features a new motorized hatch without a wind latch. This differs from the spacewalk procedures on the International Space Station (ISS) and NASA’s retired space shuttle, where wind latches kept the remainder of the spacecraft isolated from the vacuum of space.
The absence of a wind latch on the Dragon means all four Polaris Dawn astronauts will wear their space suits during the spacewalk. They will also be unable to filter nitrogen from the systems and avoid decompression sickness using breathing procedures like those on the ISS. Instead, the spacecraft will gradually lower its internal pressure while increasing the partial pressure of oxygen, helping to eliminate nitrogen. The four astronauts will then use pure oxygen in their suits during the spacewalk.
Starlink Equipment
Polaris Dawn will utilize a new communication system based on laser transmission provided by SpaceX’s Starlink broadband satellites. According to Isaacman, there is a laser device mounted on the vehicle’s body that will communicate with other Starlink satellites via a beam of light. He shared that laser communication is very challenging because the Dragon and Starlink satellites move independently at speeds approaching 28,200 km/h, transmitting information from a spacecraft to Earth and then to another spacecraft.
At times, Starlink may take on part of the communication mission instead of the data relay and tracking satellite system used by ISS astronauts and the U.S. military.
Spacewalk Suit
The new spacewalk suit (EVA) from SpaceX features several modifications to suit the vacuum of space. A new thermal management system keeps astronauts at a stable temperature, utilizing materials found in the Dragon and the interstage of the SpaceX Falcon 9 rocket.
The visor is coated with copper to protect against radiation, using tin oxide similar to the dome window from the Inspiration4 mission. Additionally, displays and cameras inside the helmet allow for information projection directly in front of the astronaut’s eyes. Other changes include more flexible joints, life support systems, and cooling handles for temperature regulation inside the suit.
Mobility Support
Since spacewalking involves movement in a frictionless environment, SpaceX has developed mobility support equipment to allow astronauts to move safely. According to Gillis, there is a new structure to grip onto the outside of the Dragon’s hatch. Moreover, there are hand and foot placements inside and outside the spacecraft, tailored for astronauts wearing their suits. This design prevents them from floating around.
Isaacman noted that spacewalks during the Gemini program in the 1960s allowed NASA astronauts to understand the proper procedures for this activity. After testing equipment such as handheld controllers, NASA quickly realized that astronauts could easily overheat without handholds on the spacecraft.
