After a launch early yesterday on the 10th, the Polaris Dawn crew has been busy as they prepare for the first commercial spacewalk. Currently, the actual spacewalk itself is scheduled for the third day of the mission which is tomorrow September 12th.
Here we’ll see two astronauts stay inside the spacecraft while two actually exit the vehicle and complete the EVA. After reaching its high earth orbit, the crew has officially become the furthest human mission from Earth in over half a century.
Day 1 Activities
A Falcon 9 launched early yesterday morning around 5:23 am ET. There had been a few delays to this mission related to weather but they were able to find a clearing. Not only were they looking for clear weather during the launch timeframe but also about a week in advance when the capsule was set to return. This made the process a bit more complicated but they were eventually able to find clear weather on both ends of the mission.
The launch went well and after about 12 minutes in, the Dragon was deployed to begin making its way to a high Earth orbit.
One of the first official updates we got came late last night when SpaceX tweeted saying, “Achievement unlocked – apogee 1,400.7 km Forward bulkhead Draco firing during burn. This included a very unique video where you could actually see some of the burn taking place. Soon after, they confirmed that the apogee-raising burn was complete and successful.
Later that night they tweeted again saying, “Polaris Dawn and Dragon at 1,400 km above Earth – the farthest humans have traveled since the Apollo program over 50 years ago.” This included a view from an external camera showing the forward hatch of the Dragon spacecraft with Earth in the background.
In order to get to this high orbit, they had stressed before that it would require the maximum performance of both the Falcon 9 and the capsule. As far as why they went to such a high orbit, here they will be orbiting through portions of the Van Allen radiation belt. Besides the EVA, Polaris Dawn will also conduct research with the aim of better understanding the effects of spaceflight and space radiation on human health.
However, the spacecraft wasn’t at this high Earth orbit for very long before SpaceX began to lower the altitude. By this morning Dragon and the Polaris Dawn crew had completed six orbits of Earth at ~1,400 km. Then over the course of about five hours, the vehicle performed four burns to lower itself to an orbit of ~190 x 742 km in preparation for tomorrow’s spacewalk.
Fortunately, besides just frequent updates on the spacecraft itself, SpaceX also provided an in-depth update of what the crew did on day 1. Here they were quoted saying, “The Polaris Dawn crew completed their first day on-orbit, also known as Flight Day 1. After a successful launch by SpaceX’s Falcon 9 rocket to low-Earth orbit from Launch Complex 39A at NASA’s Kennedy Space Center in Florida at 5:23 a.m. ET, the crew took off their spacesuits and began their multi-day mission.”
“Shortly after liftoff, the crew began a two-day pre-breathe protocol in preparation for their anticipated spacewalk on Thursday, September 12 (Flight Day 3). During this time, Dragon’s pressure slowly lowers while oxygen levels inside the cabin increase, helping purge nitrogen from the crew’s bloodstreams. This will help lower the risk of decompression sickness (DCS) during all spacewalk operations.”
“About two hours into Flight Day 1, the crew enjoyed their first on-orbit meals before engaging in the mission’s first science and research block and testing Starlink, which lasted about 3.5 hours” they said.
It’s important to point out that while the EVA is the main mission milestone, the crew is also conducting a number of other tests during the 6-day mission. Focusing back on the Day 1 activities they continued by saying, “Dragon made its first pass through the South Atlantic Anomaly (SAA), a region where Earth’s magnetic field is weaker, allowing more high-energy particles from space to penetrate closer to Earth. Mission control operators and the crew worked closely to monitor and respond to the vehicle’s systems across all high-apogee phases of flight, particularly through the SAA region. By around mid-day the crew had settled in for their first sleep period in space.”
They finished by saying, “Following a healthy systems checkout, the crew and mission control will monitor the spacecraft ahead of the vehicle raising itself to an elliptical orbit of 190 x 1,400 kilometers at the start of Flight Day 2.” By now this has been completed along with the lowering of the orbit as well. At this point and until late tomorrow, the main focus is getting ready for the spacewalk.
The Spacewalk
The Dragon spacecraft doesn’t have an airlock. This means when they do open the hatch, even though only two astronauts will be exiting the vehicle, all four will need to be in their EVA spacesuits and ready. In total, the spacewalk is set to last about two hours. During the operation, Mission Commander Jared Isaacman and Mission Specialist Sarah Gillis will separately exit the Dragon spacecraft through its forward hatch. The other two astronauts will remain seated, managing spacesuit umbilicals and monitoring telemetry on Dragon’s interior displays.
Last month Issacman said in a quote, “The EVA probably makes up the majority of the development for Polaris Dawn. You’re throwing away all of the safety of your vehicle. Your suit becomes your spaceship.” He also pointed out, “After more than two years of training, we are excited to embark on this mission. We are incredibly thankful for this opportunity and to the thousands of SpaceX engineers who have contributed to this endeavor. Throughout our mission, we will aim to inspire humankind to look up and imagine what we can achieve here on Earth and in the worlds beyond our own” he said.
At the end of the day, there is risk involved in a mission like this. Even the SpaceX vice president for build and flight reliability said, “EVA is a risky adventure, but we’ve done all the preparations.” He went on to mention, “I think it’s really a tribute to this team that they advance the state of the art, and we’re going to do it as safely as we can.”
For a while now, SpaceX has been very busy testing its new spacesuit as the mission approaches. This will not only be the first commercial spacewalk, but also the first spacewalk using the SpaceX-designed extravehicular activity (EVA) spacesuits, upgraded from the current intravehicular (IVA) suit.
Evolved from the IVA suit, the EVA suit looks similar but provides greater mobility, a state-of-the-art helmet heads-up display (HUD) and camera, new thermal management textiles, and materials borrowed from Falcon’s interstage and Dragon’s trunk. SpaceX points out that all of these enhancements to the EVA suit are part of a scalable design, allowing teams to produce and scale to different body types as SpaceX seeks to create greater accessibility to space for all of humanity.
In the months leading up to this launch, there was a lot of work to get the crew comfortable and knowledgeable with the suits. They said in a statement, “The Polaris Dawn crew recently completed a series of spacesuit acceptance tests in preparation for the mission’s extravehicular activity, or spacewalk, marking the final significant developmental and test milestone for SpaceX’s newly-developed EVA spacesuit.
These tests marked the first time the Polaris Dawn crew wore the spacesuit in a vacuum environment, which provided some necessary knowledge and familiarity. Some examples include an understanding of how the spacesuit performs in a vacuum, a collection of spacesuit and biometric data to assess the overall system’s performance in a flight-like environment, and even insight into the various thermal states expected throughout the spacewalk, among others.
After day 3 and the completion of the EVA, the crew will move on to a few other mission milestones before returning. On the fourth day, they plan to complete a Starlink demonstration. Specifically, the Polaris Dawn crew has mentioned possibly transmitting a message down to Earth using SpaceX’s constellation of internet satellites. They will be the first crew to test Starlink laser-based communications in space, which SpaceX believes will provide valuable data for future space communications systems necessary for missions to the Moon, Mars and beyond.
On Day 5, the crew will be busy preparing for the journey back home and eventual landing. This leads to day 6 when they are set to return to Earth. That will include deorbit burns, Earth reentry, and eventually a splashdown off the coast of Florida. I mentioned earlier that before launching they had to ensure the weather looked good on the return date as well. Normally when sending a crew to the ISS for example that’s not nearly as relevant because they can simply just stay at the station longer until the conditions are safe.
For Polaris Dawn, they have a limited amount of fuel and time in space which means they basically have to return at a set time. This makes it extra important that the weather on that set day is clear to help aid the recovery and landing process.
Conclusion
The Polaris Dawn crew is now only one day away from the first commercial EVA. Not long from now they will open the hatch and two astronauts will exit the vehicle. Before then, the crew is continuing to prepare in addition to completing other science experiments.