'Polaris Dawn' Takes Off in the Wee Hour with Jared Isaacman and team
SpaceX has scheduled a Polaris Dawn launch on a Falcon 9 v1.2 FT Block 5 rocket from Launch Complex 39A at NASA’s Kennedy Space Center in Florida at 3:38 a.m. ET (07:38 UTC) on Tuesday, August 27, 2024. The Crew Dragon C207 Resilience spacecraft on this mission previously flew on the Crew-1 mission to the International Space Station and the Inspiration 4 campaign, the first all-civilian space mission. This will be the fourth flight of the first stage booster, which previously launched Crew-8 and two Starlink missions. Following stage separation, the rocket’s first stage will land on the A Shortfall of Gravitas drone ship stationed in the Atlantic Ocean. There are two additional opportunities in the four-hour window at 5:23 a.m. ET and 7:09 a.m. ET. If needed, booking opportunities will be available on Wednesday, August 28th at the same time.
Entrepreneur Jared Isaacman and three crewmates — including his close friend and former Air Force pilot Scott “Kidd” Poteet, and two SpaceX engineers, Anna Menon and Sarah Gillis — are already preparing for launch. The spacecraft to be used at Polaris will enter an elliptical orbit of 190 x 1,200 km, then be raised to 190 x 1,400 km, then lowered to 190 x 700 km for the spacewalk, and then lowered again for the deorbit and reentry ignition.
During their six-day mission, the crew will reach the highest Earth orbit achieved since the Apollo program and participate in the first commercial astronaut extravehicular activity (EVA) wearing spacesuits developed by SpaceX. They will also conduct 36 research studies and experiments from 31 partners designed to advance human health during long-duration spaceflight, and test Starlink laser-based communications in space.
With Polaris Dawn, Isaacman — the founder of the payments services company Shift4, who is also a jet pilot with long-held dreams of traveling to space — is making it clear that he’s not just interested in duplicating what professional astronauts have experienced. He’s looking to advance space technology by helping to fund the development of new equipment, as well as personally exposing himself to the risks of testing this technology where it matters most: in the void of space.
During the approximately two-hour EVA, mission commander Jared Isaacman and specialist Sarah Gillies will exit the spacecraft separately through the forward hatch. Pilot Kidd Poteet and specialist Anna Menon will remain in the spacecraft, operating the suit's umbilicals and monitoring telemetry. Gillies could become the youngest human to perform a spacewalk. To date, the youngest astronaut to perform an extravehicular activity was Alexei Leonov (at 30 years, 9.5 months). Gillis was born on January 1, 1994, and will be 30 years, 7 months, and 4 weeks old at the time of the EVA.
Chris Trigg is the SpaceX spacesuit design manager and was part of a discussion at X Spaces. The EVA suits are completely different from the original IVA suits. They feature over a dozen layers of MLI, redundancy in seals, vents/valves, a new visor, multiple rotating swivels, a HUD, and a camera. They are very rigid when pressurized, as are all EVA suits. We have rotating joints and seams throughout the suit for mobility, and the main purpose of the operation is to collect data on the suit’s performance. It’s not a Mars suit, but at least the journey toward becoming one has begun. At the press conference, expedition leader Jared Isaacman mentioned that there were two separate nitrogen and oxygen systems for the spacewalk. This means that the nitrogen and oxygen systems on Dragon are doubly redundant, rather than triply redundant: “We have redundancy with the nitrogen re-pressurization system and the oxygen system, including all the seals, valves, and pathways.” One of the challenges was ensuring that we retained all of the functionality of the IVA suit while also adding EVA capability,” Trigg said. To avoid unnecessary bulk inside the spacecraft, the crew will leave their IVA suits behind, requiring only the EVA suits for the entire mission. “We’re using a single suit on the mission, so the crew will wear the suit from pad to touchdown,” Trigg said, adding, “We wanted to make sure that everything the current IVA suit can do, we retained that functionality, but also made it EVA capable.”
Improvements to bring the IVA suit design up to EVA specifications included upgrading the thermal management system, which involved materials sourced from the Falcon 9 rocket’s interstage section itself, as well as the Crew Dragon’s torso. Other improvements included a new visor coating and the addition of information displays and cameras inside the helmet. The new copper-colored visor is treated with the same indium tin oxide coating process that the Inspiration4 dome underwent. (This was the window that allowed the Inspiration4 crew to virtually stick their heads out of the spacecraft.)
“The visor is doing a lot of work,” Trigg explained. “It helps seal the suit and retain pressure; it’s the optical port for the crew to see out; it needs to manage the thermal environment as well — and of course, it also needs to protect, like a pair of sunglasses, from getting too much light and harmful wavelengths into the suit.”
The EVA suits also feature a connection port for life support functions while the crew is exposed to vacuum, as well as an additional cooling knob to adjust internal temperatures. In addition, technicians paid extra attention to re-evaluating and improving the suits’ joints and mobility capabilities.
“One of the joints we’ve worked on a lot is the joints in the arms, shoulders, and wrists that allow for rotation. They’re unique in that when they’re not pressurized, they remain soft and flexible, so that during the dynamic phases of flight, like launch or reentry, you don’t have rigid metal objects that are attached to the body of the crewmembers. They remain soft. So when you pressurize the suit, they stiffen up and provide the mobility that you need,” Trigg said.
After completing the bulk of their research in the highly elliptical orbit, the crewmembers will reduce their apogee to about 700 kilometers, where they will perform their EVA. Among all the research on the mission, testing and validating the new suits will mark not only a significant milestone for Polaris Dawn and the Polaris Program but also for SpaceX.
On the ISS and certain other space stations and spacecraft, including NASA's now-retired Space Shuttle, egress involves sealing the EVA participants in a decompression chamber, hermetically sealed from the rest of the spacecraft, which then slowly depressurizes to vacuum. This prevents explosive decompression due to differences in life-sustainable air pressure (maintained by life-support systems) and the cold vacuum of space.
Another way astronauts prepare for an EVA is similar to the procedures performed by deep-sea divers or high-altitude pilots — they undergo a pre-breathing protocol designed to purge the body of nitrogen gas, which causes decompression sickness.
However, without a decompression chamber, the entire cabin of the Crew Dragon must be ventilated and exposed to space, making Polaris Dawn’s pre-EVA procedures different from those historically observed aboard the ISS and changing the crew’s pre-breathing routine.
“The difference is that [astronauts aboard the space station] are often breathing 100 percent oxygen for a very prolonged period, or doing a routine of exercises to try to purge the nitrogen from their systems, in which case you have less concern about experiencing decompression sickness,” Isaacman explained. “Now, the problem is that we don’t have a decompression chamber on the Crew Dragon, so we can’t just sit there for hours breathing 100 percent oxygen to get rid of that nitrogen. We have to take a different approach.”
Over several days, the pressure inside Crew Dragon will slowly decrease while the partial pressure of oxygen (PPO2) levels gradually increase. Isaacman compared the pressure change to visiting Denver, which has an altitude of 5,500 feet (1,610 meters). “Over that period of being at an elevation that our bodies believe is higher, we are slowly purging the nitrogen from our systems,” Isaacman explained. “We will then switch to 100 percent O2 in our suits for some time while we are venting the capsule, and then we will perform the entire operation at 100 percent O2. ”
From there, with the entire cabin ventilated and the hatch open, all four astronauts will be exposed to the vacuum; this EVA will not only be the first ever performed by any private citizen, but also the largest ever in terms of participation.
Typically, EVA tasks performed outside the ISS by American astronauts and Roscosmos cosmonauts are performed by two people at a time. In fact, the only three-person EVA ever performed was during the Space Shuttle mission STS-49, which was improvised and only occurred as a result of two previous failed attempts and the hope that three astronauts could complete a task that two could not.
While the Crew Dragon’s design has been tested and qualified for vacuum exposure, the scenarios in which such exposure could occur all fall into the “emergency” category. To make the spacecraft EVA-ready, the interior needed to undergo a major overhaul. As such, SpaceX technicians removed any components or materials that could not withstand prolonged exposure to vacuum and added hand and footholds to the cabin for added stability, including a mobility interface apparatus (essentially a ladder) on the Crew Dragon’s forward hatch. SpaceX engineers named the ladder “Skywalker”; it was designed to provide extra safety as astronauts exit the spacecraft.
The interior of Polaris Dawn’s Crew Dragon also houses a new nitrogen repressurization system for use at the end of the crew’s EVA. SpaceX technician Gillis explained some of the reasons behind the modifications during the May 4 discussion at X, saying, “All of our life support will come from the spacecraft — oxygen tanks inside the spacecraft fed by an umbilical to our suits. The umbilicals also house our electronics; our life support. That’s really our connection to the vehicle. We have to effectively carry all of those consumables — and in order to account for the entire mission duration and make sure we can test [the EVA suit and procedures], the operation will be limited to about two hours from start to finish. And that includes venting the capsule, external operations, and then repressurization.”
She also detailed how the Polaris Dawn EVA will utilize that two-hour window. “Outside the spacecraft, two crew members will go through a matrix of tests, effectively, to get the data that SpaceX expects to see,” she said, adding that the tests will primarily focus on the suit’s performance and mobility in microgravity conditions.
SpaceX also wants to use this opportunity to validate how it trains astronauts for future EVAs.
“We have a validated system on the ground for training, but we’re also equally validating that training method in the microgravity environment to see if there are nuances that we didn’t fully capture in our simulated environment,” Gillis said.
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