After spending three days on-orbit, the world's first civilian mission of SpaceX's Inspiration4 returned to Earth on Sunday.

The crew, onboard the Dragon spacecraft re-entered Earth's atmosphere for a soft water landing off the coast of Florida at 7.06 p.m. EDT (4.36 a.m. Sunday India time).

"Happy. Healthy. Home. Welcome back to Earth," Inspiration4 shared in a tweet.

"Splashdown! Welcome back to planet Earth," added SpaceX on the microblogging site.

The mission lifted off to orbit aboard SpaceX's Falcon 9 rocket and Dragon spacecraft on Wednesday (India time Thursday). It was commanded by tech entrepreneur Jared Isaacman and joined by Medical Officer Haley Arceneaux, a physician assistant at St Jude Children's Research Hospital and pediatric cancer survivor; Mission Specialist Chris Sembroski, an Air Force veteran and aerospace data engineer; and Mission Pilot Dr Sian Proctor, a geoscientist, entrepreneur, and trained pilot.

The fully automated Dragon capsule reached an unusually high altitude of 585 kilometres, surpassing the International Space Station by 160 kilometres. The Dragon's dome window, inspired by the Cupola on the ISSl provided the crew with incredible views of Earth.

"The Dragon performed a series of departure phasing burns to leave the circular orbit of 575 kilometres and then jettisoned its trunk ahead of de-orbit burns. After re-entering the Earth's atmosphere, the spacecraft deployed its two drogue and four main parachutes in preparation for the soft water landing," the company said on its website.

"We loved space but it's great to be home!" Isaacman wrote on Twitter.

"The absolute most incredible experience of my life. Can't wait to share more with you all! Red heart," added Arceneaux.

"What an amazing adventure! I'm so glad to be home on earth and to be back with my family. There is so much to share! What an amazing @inspiration4x team! Thanks @SpaceX!a Sembroski said.

Inspiration4, which was aimed at inspiring humanity as well as to raise money for St. Jude, surpassed "the 200m goal", Isaacman shared in his tweet.

Tech billionaire and SpaceX CEO Elon Musk also committed $50M for the hospital, he wrote on twitter. "Count me in for $50M," he tweeted.