'All Systems Are Go' For SpaceX's Most Ambitious Astronaut Launch Yet. Watch Live Now

 NASA has given SpaceX the go-ahead to launch its first full crew of 4 astronauts toward the International space laboratory (ISS).

If all goes per plan, the company's Falcon 9 rocket will set forth its historic launchpad at NASA's Kennedy Space Centre in Florida on Sunday night, careen through Earth's atmosphere, and jettison a Crew Dragon spaceship into orbit with the astronauts tucked inside.

"All systems are select tonight's launch at 7:27 pm EST [0027 UTC] of Crew Dragon's first operational mission," SpaceX tweeted on Sunday morning.

You can watch live below:

After 27 hours of flying around Earth, the spaceship is scheduled to sync up with the ISS on Monday and dock to the power at 11 pm ET. 'Resilience', as astronauts named their ship, will stay for 6 months while the crew lives and works in orbit.

The planned flight would constitute NASA's longest human spaceflight ever because the US$150 billion, football field-size laboratory enters its 20th year of continuous human habitation.

"This is that the culmination of years of labor and energy from lots of individuals, and lots of your time, and that we have built I believe what I might call is one in all the safest… launch vehicles and spacecraft ever," Benji Reed, SpaceX's director of crew mission management, said during a Friday press briefing.

The Crew-1 astronauts sit inside the Crew Dragon spacecraft during training. (SpaceX/NASA)

NASA, SpaceX 'ready to go' after months of delays

The mission, called Crew-1, is that the first of six round trips that the agency has contracted from SpaceX. NASA tapped astronauts Mike Hopkins, Victor Glover, Shannon Walker, and Japanese Aerospace Agency (JAXA) astronaut Soichi Noguchi to hold out the historic flight.

In a final launch-readiness review on Friday, NASA gave SpaceX it's an official blessing for Sunday's liftoff.

The launch had been scheduled for Saturday evening, but mission managers decided to delay the flight. NASA cited "onshore winds" and "first-stage booster recovery readiness" because the reasons - the latter refers to the Falcon 9 rocket's booster, which is programmed to land itself on a ship confounded after it releases the Crew Dragon into orbit.

The booster will be reused in future launches, including crewed flights.

This is the fourth time NASA has pushed back the launch of Crew-1 because of numerous hiccups. The mission was originally scheduled to fly in late September.

"We're able to go," Norm Knight, a flight operations manager for NASA, said during the briefing.

"The journey to urge here is one in every of resilience, and it had been a tough journey with lots of stuff happening and COVID affecting the teams."

Crew Dragon Resilience and its Falcon 9 rocket, NASA's Kennedy Space Centre, November 9, 2020. (Spacex)

Final checks for the primary commercial spaceflight system

With the review complete, SpaceX will do its final preparations and keep a detailed eye on the weather. Rain, high winds, or too many puffy clouds could make conditions unsafe for launch.

The skies and seas must even be clear at potential splashdown sites across the ocean, just in case the rocket malfunctions and also the Crew Dragon should speed away.

As of Sunday morning, the Air Force's 45th Weather Squadron projected a 50 percent chance of poor weather delaying launch. NASA and SpaceX are because of the meeting for a weather briefing around 3 pm ET, during which they'll plan to prolong or try again some days later, on Wednesday night.

Technical issues could abort the mission at the last moment. That happened to a Falcon 9 launch on October 2: Just some seconds before liftoff an automatic flight computer shut everything down.

It clad that lacquer from a corrosion-resistance treatment had clogged a little borehole on a safety valve for one amongst the engines. this might have resulted in an excessive amount of fuel entering the engines at the incorrect time, caused an uncontrolled explosion, and damaged the engines, almost like a car backfiring - though with far more power and potential consequences.

SpaceX says it's examined the whole rocket for Crew-1 to create sure no small crevices were clogged with lacquer.

Saturday's launch is that the fruit of a decade-long effort to revive NASA's human spaceflight abilities, which have lain dormant since the Space Shuttles were retired in 2011. Through the Commercial Crew Program, NASA funded the event of the Crew Dragon to fulfill its requirements for flying astronauts.

On Tuesday the agency finally awarded SpaceX its human-spaceflight certification, making the Crew Dragon and Falcon 9 the primary commercial launch system to receive the designation.

"Thank you to NASA for his or her continued support of SpaceX and partnership in achieving this goal," Elon Musk, SpaceX founder and CEO, said during a statement on the certification.

"This may be a great honor that inspires confidence in our endeavor to return to the moon, travel Mars, and ultimately help humanity become multi-planetary."

Nerves 'pile on' as launch approaches

SpaceX proved its ability to securely fly humans and return them to Earth with an illustration flight, called Demo-2, that launched this summer.

That mission launched NASA astronauts Doug Hurley and Bob Behnken within the world's first commercial human spaceflight. the boys spent two months on the ISS before climbing into the Crew Dragon, screaming through Earth's atmosphere, and parachuting into the Gulf of Mexico.

Bob Behnken (left) and Doug Hurley wish their families goodnight from inside the Crew Dragon capsule, May 30, 2020. (SpaceX)

The Crew-1 astronauts are on the brink of whether the identical ordeal, with a full-length ISS shift of half a year.

"The nerves start to essentially pile on as you catch up with to launch," Hopkins told reporters in an exceedingly invoke Monday.

But the astronauts are busy with final preparations at NASA's facilities in the foreland, Florida. They completed a dry run on Thursday, putting on their spacesuits, driving bent on the launchpad, and boarding the Crew Dragon to practice for launch day.

"I think that helps keep the nerves down a bit bit," Hopkins said of the week's preparations. "Because you're just reasonably going like clockwork through the procedure and therefore the timeline."

Michael Lopez-Alegria, a retired astronaut who's flown to space fourfold and is slated to command SpaceX's first all-private flight next year for Axiom Space, said he had "no concerns" about the crew or ship earlier than launch.

"I became inured, almost, to SpaceX launches," Lopez-Alegria told Business Insider.

"They just still make incredible things look routine… But our mission, AX-1 one goes flying with the identical capsule that's visiting get on Crew-1. So we'll be definitely taking note and wishing the crew and teams from NASA and SpaceX all the simplest."