SpaceX and NASA plan to launch astronauts on the Crew Dragon spaceship again next month, with at least 4 major changes

• NASA and SpaceX just completed their first astronaut mission together.
• SpaceX's Crew Dragon spaceship launched, docked to the space station, and returned to Earth according to plan.
• But the demonstration mission revealed a few changes to be made before the next crew launches in September.
• NASA and SpaceX plan to upgrade the spaceship's solar panels, purge the capsule of toxic fumes immediately upon landing, and shoo away spectator boats more effectively.

SpaceX's Crew Dragon spaceship splashed into the Gulf of Mexico on Sunday, bringing NASA astronauts Bob Behnken and Doug Hurley back to Earth to finish the world's first commercial crewed spaceflight.

The two-month ordeal required the Crew Dragon and its astronauts to rocket into space, dock to the International Space Station, then survive a scorching hot plummet through Earth's atmosphere.

Now NASA and SpaceX are preparing to do it all again.

Behnken and Hurley's mission, called Demo-2, was a demonstration meant to show NASA that SpaceX can safely fly people to and from space, and to expose any oversights or unforeseen complications that come with that complicated task. NASA has contracted six more round-trip astronaut flights from SpaceX, the first from US soil since the Space Shuttle program ended in 2011.

The next mission, called Crew-1, is scheduled to launch in September, after NASA officially certifies Crew Dragon for human spaceflight.

That means NASA and SpaceX have just a few weeks to comb through data from Demo-2, evaluate any shortcomings, and fix them.

"It did not seem like this was the first NASA SpaceX mission with astronauts on board," Michael Hopkins, a NASA astronaut who's slated to fly on the Crew-1 mission, said in a press briefing on Sunday. "It seemed to go extremely smooth, but we also realize there's a lot of work to go."

The other Crew-1 astronauts — Shannon Walker, Victor Glover, and Soichi Noguchi of the Japan Aerospace Exploration Agency — nodded in agreement.

Gwynne Shotwell, SpaceX's president and CEO, said even SpaceX leadership was a bit taken aback by how much the mission went according to plan.

"I think we're surprised — minorly surprised, but obviously incredibly pleased — that this went as smoothly as it did," she said. "There's no question that we learned some things along the way that we will want to roll into the Crew-1 flight."

Already, NASA and SpaceX have identified a few changes to make.

NASA and the Coast Guard may get more stern with spectators

One serious kink to iron out has to do with what happens after Crew Dragon splashes down. This time, onlookers on private boats crowded the toasted spaceship.

"The boats just made a beeline for it," NASA Administrator Jim Bridenstine said in Sunday's briefing.

Shotwell added, "it became a little bit too close to the Dragon capsule."

In a statement to CBS, the US Coast Guard said it warned boaters multiple times with radio alerts and physical warnings, yet lacked an order to legally enforce a hazard zone.

"Numerous boaters ignored the Coast Guard crews' requests and decided to encroach the area, putting themselves and those involved in the operation in potential danger," the statement said.

If bystander boats get that close to the capsule, it can be dangerous for both the astronauts and those on the boats. That's because toxic fumes can shroud a spaceship that's just plowed through Earth's atmosphere. After a recovery team pulled the Crew Dragon out of the water, that's exactly what they found.

"That just can't happen like it did before," Hurley said of the boaters in a press conference on Tuesday.

Recovery teams must purge toxic fumes from the spacecraft

Before the astronauts exited the spaceship, recovery team members went around to its thrusters with instruments that "sniff" for any lingering vapors. They found low levels of a poisonous gas called nitrogen tetroxide.

The gas was sparse enough that the recovery team could have opened the hatch and gotten the crew out, but they decided to be safe and purge the capsule's service section — the compartment below the astronauts' cabin that holds maneuvering systems and electronics.

"I think we'll probably do that sooner next time," Shotwell said.

Behnken and Hurley waited patiently inside the capsule until the purge was complete, but the gas would be a bigger problem if future astronauts were injured upon arrival.

It wasn't immediately clear why the gas was present or whether it indicated a problem with the spaceship.

"We think there may be some mechanism where it's getting trapped into the service section, kind of from thruster firings during entry," Steve Stich, who manages NASA's Commercial Crew Program, said on Sunday. "We've got to go look through the data — this is maybe a little bit of speculation on my part. I think we'll go figure out a way to handle it better on the next flight, perhaps starting with a purge as soon as we get on the vehicle."

That would enable the recovery team to open the capsule faster — an adjustment that would come in handy if any astronauts inside were in need of medical attention.

The Crew Dragon needs solar panel upgrades to last in space

NASA plans to keep future astronaut crews on the space station for the standard six months, during which time they'll conduct spacewalks, do science experiments, and work on station maintenance.

The Crew Dragon ship that Behnken and Hurley flew probably wouldn't last that long: The solar panels that power the vehicle could degrade quickly in space. The panels' estimated lifetime limited Demo-2 to 110 days in orbit — roughly four months.

"We're looking to have upgrades there to make sure that the vehicle survives," Shotwell said, though she added that "the solar arrays on this particular mission did better than we anticipated."

Backup generators and better WiFi

A few smaller areas for improvement came up throughout the mission as well.

For one, the backup generator on the ship that pulled the Crew Dragon capsule out of the ocean — SpaceX's GO Navigator — stopped working before the vessel set sail on Sunday. If the main generator had failed, that could have left the ship without power.

"We did mobilize another [generator], but it wasn't going to get to port in time for the vehicle to set sea and make sure it got to Bob and Doug," Shotwell said.

It wasn't a major issue, since other boats flanked that ship with their own generators. Still, Shotwell added, the GO Navigator will bring two backups next time.

"That's just one example. Kind of a small thing that we'll want to do going forward," Shotwell said.

Other small things might include checking the spaceship's WiFi and the astronauts' iPads. In an exchange with mission control as the astronauts orbited Earth ahead of their landing, Behnken asked for help troubleshooting an internet connectivity issue on his tablet.

Additionally, Behnken said on Tuesday, he and Hurley will have some suggestions "to make things a little bit more comfortable or a little bit more efficient inside the vehicle."

He didn't offer specifics, but did describe violent jolts throughout the landing process that felt "very much like getting hit in the back of the chair with a baseball bat."

Dave Mosher contributed reporting.