Daily SumUp

After a two-week delay, SpaceX is preparing for its latest launch which will send four astronauts into space to attempt the first private spacewalk. 

The Polaris Dawn mission, the first of three missions bought and captained by billionaire Jared Isaacman, will launch from Florida on Tuesday morning with a crew of four: Isaacman, his colleague Scott Poteet, and two SpaceX employees: Anna Menon and Sarah Gillis. 

The crew will orbit through a radiation belt and attempt to reach the highest Earth orbit, according to the Polaris Dawn website.

"We stand to learn quite a bit from [this mission] about human health, science and research," Isaacman said in a pre-mission briefing on Monday. 

"If we get to Mars one day, we’d love to come back healthy enough to tell people about it". 

This mission is also remarkable, according to Isaacman, because it is the first time that a private company will be doing a extravehicular activity (EVA), aka a spacewalk. They plan to do so at roughly 700 km above the Earth.

What is the plan for the mission?

Astronauts will have five days to fit everything into their mission, but most of the focus will be on the spacewalk. 

The crew has several times where a potential launch could take place around August 26 and they will pick which time is best to minimise the risk of micrometeorite orbital debris caused by previous missions, according to Isaacman.

On the first day once the crew is in orbit, they will test the Dragon capsule to make sure there are no major faults before they reach 1,400 km orbit. 

On that first day, the crew will also pass through the South Atlantic Anomaly, a high radiation zone of the Earth’s magnetic field. 

Research done here will look to understand "the effects of spaceflight and space radiation on human health," according to a statement from the Polarisprogramme.

By day two, the crew will be working on the 40 scientific experiments Polaris Dawn wants to accomplish, Gillis said. 

This includes the launch of several SpaceX satellites that can communicate with each other instead of relying on ground infrastructure to send signals.

To do this spacewalk, SpaceX developed a whole new suit called the EVA that has cameras and heads-up displays that show astronauts information about the status of their suits outside their vehicle.

The suits also have what the company calls "improved thermal management" and a helmet that acts like a sun visor.