Achieving unprecedented feats, it reached the highest orbit since the Apollo program, tested Starlink's laser-based communication system, conducted advanced scientific research, and, most notably, carried out a spacewalk — the first ever by commercial astronauts using privately developed spacesuits.

Launched on September 10th, 2024, Polaris Dawn stands as the most ambitious private spaceflight to date. The mission was crewed by four: Commander Jared Isaacman, founder of Shift4 Payments and a key sponsor of the mission; Pilot Kidd Poteet, a former Air Force pilot; and SpaceX engineers Sarah Gillis and Anna Menon, marking the first time SpaceX employees have flown into orbit.

As the primary objective of the mission, preparations for the spacewalk began immediately after the crew reached orbit. They underwent a pre-breathing process over two days, during which the cabin pressure inside the Dragon spacecraft was gradually reduced from 100 kPa (14.5 psia) to 59.64 kPa (8.65 psia) — similar to the pressure at Mt. Everest Base Camp — while the oxygen proportion in the atmosphere was increased. This process aimed to purge nitrogen from the crew's blood to prevent decompression sickness, also known as "the bends." During this period, Dragon ascended to an altitude of 1408.1 kilometers (875 miles), passing through the South Atlantic Anomaly, an area of the Earth’s inner Van Allen radiation belt. This ascent set a record as the first crew to venture that far into space since the Apollo Program. Notably, Anna and Sarah became the first women to reach such an altitude. During this orbit, they were exposed to significantly higher radiation levels than those experienced by astronauts at the ISS; hundreds or thousands of times greater than those on Earth.

On the day of the spacewalk, September 12th, Dragon reduced its orbit to 737 kilometers (approximately 458 miles), about 322 kilometers (200 miles) higher than the typical orbit for NASA’s ISS spacewalks. During the final stages of pre-breathing, the astronauts breathe 100% oxygen and donned their spacesuits. Inspired by the intravehicular activity (IVA) suits, worn by the astronauts during previous Dragon missions, these spacesuits were specially designed by SpaceX for extravehicular activity (EVA), all geared toward ensuring astronaut safety. It incorporated new materials and added joints to enhance mobility, thermal protections to withstand the extreme temperatures of space, a new helmet design featuring a visor coated with copper indium tin-oxide to protect against solar glare, and a heads-up display. They are connected to a tether which not only kept the astronauts physically connected to the spacecraft but also provided oxygen, power, and the communications links. 

A series of system and leak checks later, the Dragon spacecraft began venting its remaining atmosphere, exposing all four astronauts to the vacuum of space. Only Jared and Sarah (designated EVA1 and EVA2, respectively) were designated to step outside the spacecraft while Kidd and Anna (Support1 and Support2) stood by to assist as needed. After achieving vacuum, Jared manually opened the hatch above him and emerged from the Crew Dragon spacecraft, pausing momentarily at the threshold of space to look back at Earth, marking a historic first for commercial spaceflight.

"Back at home, we all have a lot of work to do, but from here, Earth sure looks like a perfect world," he said.

The astronauts were outside of Dragon for about 30 minutes. During this time, Jared and Sarah performed a series of mobility checks to test the effectiveness of the EVA suits while being tethered to the spacecraft. They were supported by a scaffold, aptly named Skywalker, which helped secure them in place. This setup allowed them to conduct trials of hand and body control as well as vertical movements, while Skywalker held their feet for safety reasons.

Spacewalks are inherently risky, as it involves the spacesuit acting as a mini-spacecraft, tasked with shielding the astronaut from the harsh conditions of space while providing sufficient mobility. The very first spacewalk was performed by Soviet cosmonaut Alexei Leonov during the Voskhod 2 mission on March 18, 1965. His spacewalk, though groundbreaking, lasted only 12 minutes and 9 seconds and was fraught with perilous challenges. Leonov floated from the spacecraft, tethered for safety, but his suit ballooned in the vacuum of space, severely restricting his movement. Additionally, the suit lacked effective thermal control systems, causing his internal temperature to rise by 35 degrees Celsius (95 degrees Fahrenheit), pushing him to the brink of heatstroke. Leonov later described sloshing in sweat inside his suit. The suit became so inflated due to the vacuum that he struggled to re-enter the Voskhod’s airlock and had to bleed off some air from his suit, risking decompression sickness.

Just a few months later, on June 3, 1965, Ed White performed the first American spacewalk during the Gemini IV mission and encountered similar issues with his spacesuit’s thermal management and humidity control, to the extent that his visor fogged up.

These pioneering spacewalks taught invaluable lessons that led to significant advancements in astronaut training, communication, and spacesuit design. This evolution enabled NASA to conduct extensive 6+ hour EVAs for servicing the ISS. While the Polaris mission's venture into space echoed the feats of the Soviet Union and the United States during the mid-1960s space race, it marked a significant milestone. The spacesuits used were commercially designed, costing a fraction of those developed by governments with mighty resources. SpaceX emphasizes that these are version 1.0 of the suits, as they envision one day to enable a broader population to walk in space, on the Moon and Mars, heralding a new era in human space exploration.

Traditionally, the International Space Station (ISS), Dragon, and all US spacecraft have relied on the Tracking and Data Relay Satellite System (TDRSS) for communication with mission control on Earth. This system comprises 10 satellites positioned in geosynchronous orbit, over 35,000 kilometers (21,747 miles) above Earth's surface. However, TDRSS is aging, with limitations on bandwidth and capacity, and is costly to maintain.

In contrast to the geosynchronous satellite systems, Starlink's laser-based communications network comprises hundreds of satellites in Low Earth Orbit (LEO), providing broader coverage along with faster and higher bandwidth transmissions. Typically designed for terrestrial use, the network was adapted for the Polaris Dawn mission through a system known as "Plug and Plaser" housed in the trunk of the Crew Dragon. This enabled seamless communication with the Starlink satellites, complemented by a router installed within the Dragon’s cabin.

Access to Starlink’s high bandwidth services allowed the Polaris Dawn crew to access high-speed, low-latency internet while in orbit, a significant technological leap forward. For the first time, astronauts could Facetime their family members directly from space. Adding a cultural dimension to the mission, Sarah performed the first violin concert in space. As a classically trained violinist, she played “Rey’s Theme” from Star Wars: The Force Awakens by John Williams. It was not only symbolic but also a technical demonstration, as her performance was recorded and transmitted back to Earth via Starlink. 

“It was so special to have a violin up here and just kind of a traditional wooden instrument floating in a very modern spacecraft,” said Sarah Gillis on Everyday Astronaut’s Spacewalk Podcast.

To make this happen, the violin underwent extensive testing to verify if it could withstand the extreme conditions of space. This involved a rigorous qualification process where the violin was placed in a vacuum chamber to determine what substances might off-gas from it, which could potentially contaminate the Dragon’s atmosphere. This certification process was not straightforward but was crucial to ensuring the safety and functionality of the instrument in a zero-gravity environment.

“We faced a lot of challenges,” said Sarah Gillis regarding her violin’s certification process. She added, “We had a flight unit that we put through a full [testing] cycle as well that actually failed at two high temperatures [test].”

SpaceX was able to certify the violin for flight and it performed flawlessly during the mission. The violin performance was part of a broader initiative named “Harmony of Resilience,” synchronized with orchestra bands all around the world. It symbolized unity, hope, and resilience, particularly aimed at inspiring children while fundraising for St. Jude Children’s Research Hospital and El Sistema USA, a music education program.

The unique mission parameters of Polaris Dawn facilitated crucial research in collaboration with NASA, the Translational Research Institute for Space Health (TRISH), and various research laboratories and universities. Flying at altitudes exceeding 1400 kilometers, the crew was exposed to higher levels of radiation compared to those experienced at the ISS. This presented a unique opportunity to study the effects of increased space radiation on human biological systems.

One of the focal points of the mission's research was the use of smart-contact lenses to monitor intraocular pressure and cornea dimensions, helping to investigate the effects of Space Associated Neuro-Ocular Syndrome (SANS). SANS comprises a series of health conditions affecting astronauts’ eyes and brains during and after prolonged space missions. The crew had also undergone MRI scans before the flight and the researchers aim to compare these scans with the ones which will be taken after the flight to study changes in the crew’s brains, caused by long-term exposure to space conditions.

Wrapping up their research on day five, the Polaris Dawn crew prepared for their return to Earth. Due to continuously unfavorable weather at the usual landing sites, which had already caused a two-week launch delay, a new splashdown site off the coast of Dry Tortugas, Florida, was selected.

"We are mission complete," Jared said after the spacecraft landed. Photos of the crew's return and exit from the Dragon spacecraft were captured by the mission's official photographer, our friend John Kraus.

Polaris Dawn is the first of three missions pioneered by Jared Isaacman and SpaceX aimed at advancing human spaceflight technologies necessary for long-duration, deep-space missions while also raising funds and awareness for St. Jude Children’s Research Hospital. Named after the Polaris Constellation, more commonly known as the North Star, which has served as a guiding light throughout human history for global navigation, this initiative underscores a significant era in space exploration. 

The final flight of the Polaris program will culminate with one of the first crewed spaceflight missions of SpaceX’s Starship, which will set the stage for humans to return to the moon and push forward to Mars.