Polaris Dawn sets new altitude record in space

BWhen astronaut Pete Conrad, commander of NASA's Gemini 11 mission, fired his spacecraft's engines to climb to a record orbital altitude of 850 miles on September 14, 1966, he couldn't contain his enthusiasm.

“Yippee!” exclaimed the former naval aviator. “This is the biggest thrill of my life. I have India on my left window and Borneo right under our noses.”

Conrad died in 1999, but his altitude record stood for 25 years. Until now. Yesterday, September 10, it was broken when the four crew members of the all-civilian Polaris Dawn mission flew their SpaceX Crew Dragon spacecraft to a new altitude of 870 miles, traveling farther from Earth than any human has ever traveled on a non-lunar journey.

“Achievement unlocked,” SpaceX posted on X, using the language of video games.

The new milestone was not only a record, but also scientific. Earth is surrounded by two bands of radiation called the Van Allen Belts, which stretch from a depth of 400 miles to a height of 36,000 miles above the planet. The belts crackle with energy, subjecting a spacecraft – or astronaut – to a potentially destructive bombardment of 20,000 highly charged electrons per second per cubic centimeter. One of Polaris Dawn's goals is to study both the Dragon and crew in this dangerous environment to determine if either suffers any ill effects, as trips to the Moon and Mars require surfing the Van Allen surf. Mission commander Jared Isaacman – the billionaire founder of online payments company Shift4, which is funding Polaris Dawn – and the three other astronauts are not taking too many risks: During their five-day mission, they will stay at their highest altitude for less than a day, but that should be enough to collect at least some data from a series of over 40 medical experiments the astronauts will conduct.

“Some of our research will be looking closely at this radiation environment and studying how drugs work in this type of radiation and whether you can develop diagnostic technologies like X-rays in this environment,” Anna Menon, crew member and medical officer, told TIME. “These insights will help us a lot as we look to longer missions. [flights] such as missions to Mars.”

The astronauts will undergo medical tests not only in space but also after they return to Earth. The spacecraft itself, flying its third mission, will also undergo similar examinations. The Dragon is not designed to leave Earth orbit, but SpaceX's next manned vehicle, Starship, is being developed for lunar and Mars missions; what engineers learn about the Dragon's radiation exposure could inform the design of shielding for any successor ships.

Even bigger things are coming this week. On Thursday, Sept. 12, Isaacman and crew member Sarah Gillis are scheduled to embark on the first extravehicular activity (EVA), or spacewalk, by civilian astronauts—an exercise that will be risky not only for them but also for Menon and crew member Scott Poteet, who will remain on the spacecraft. Unlike the International Space Station, which has an airlock to keep the entire outpost pressurized as astronauts head into space, Dragon has nothing more than a hatch that opens to vacuum. That means the vacuum inside the ship will match the vacuum outside, requiring all four astronauts to wear newly developed, extra-tough spacesuits. SpaceX designed the suits not just for EVAs, but also for exploring the surface of other worlds. This first flight of the new suits will help determine whether they are indeed suitable for those later missions.

“There is obviously a lot to learn that has to happen through this initial development, [including] “How the suit works and what agility, dexterity, tactility and all those important suit metrics we need to look at,” Gillis says.

“The smart engineers at SpaceX built an EVA suit in less than a year,” Isaacman adds. “NASA has been working on it for some time, and the costs typically run into the billions. I can assure you that SpaceX and Polaris are not investing anywhere near that much.”

The cost savings are important. NASA's budget request for its Artemis moon program for fiscal year 2025 is just $7.8 billion. That compares to the nearly $29 billion (adjusted for inflation) cost of the Apollo program in 1966. Savings on the suits could make a big difference if pockets aren't nearly as deep as they were three generations ago.

Polaris Dawn will return to Earth no later than September 15, but that won't be all for the Polaris program. Isaacman plans two more flights in the Polaris series – another in a Dragon and the last on the Starship's maiden mission. He named the program after our North Star, which is actually made up of three stars, and wants to honor that nickname with his own trio of cosmic voyages.