What is Polaris Dawn Mission
After several months of delay, the Polaris Dawn mission was launched on September 10. Its objective was to complete a private commercial spacewalk in space. Four people participated in the mission. Its funding and command is with Jared Isaacman. He is a billionaire businessman. The responsibility of pilot was performed by Lieutenant Colonel Scott Poteat. Joining as mission specialists are Sarah Gillis and Anna Menon, who are operations engineers at SpaceX.
EVA vs SEVA
EVA or Extravehicular Activity means that an astronaut left his spacecraft in space. He came out of it completely and returned to the spacecraft after completing his work. During this time he walks in space outside the spacecraft. During EVA, tasks like satellite maintenance are usually completed.
In comparison, in ‘Stand-up Extravehicular Activity’ or SEVA, the astronaut does not completely exit the spacecraft. Some part of his body remains attached to the spacecraft. This is what happened in the Polaris Dawn mission. Jared Isaacman and Sarah Gillis didn’t give up spacecraft entirely.
Space.com’s report also states that during the private commercial spacewalk, both the astronauts did not walk outside the spacecraft. He was in stand up position. Interestingly, this was the 20th Stand-up Extravehicular Activity (SEVA) in the history of space. The difference between EVA and SEVA first came to light in 1966, when the Gemini spacecraft reached space. Then NASA astronaut Michael Collins took some pictures out of the spacecraft.
SEVA was repeated once again on Thursday. During this time, Isaacman and Gillis never completely left the Dragon capsule. He kept at least some part of his body inside at all times. Even before this mission, SEVA was done in the year 2008. Two Chinese astronauts came out of the spacecraft a little to wave the national flag of their country. Nonetheless, the Polaris Dawn mission’s SEVA lasted approximately 1 hour and 46 minutes.
