The crew will orbit the planet aboard SpaceX's Crew Dragon capsule every 90 minutes along a customised flight path. Upon conclusion of the three-day journey, Dragon and the Inspiration4 crew will re-enter Earth's atmosphere for a soft water landing off the coast of Florida.
The mission is the second of the six certified, crew missions NASA, and SpaceX will fly as a part of the agency`s Commercial Crew Programme. Crew-1 successfully docked into the ISS in November, last year.
According to a TechCrunch report, the launch also set a record for SpaceX for its Falcon 9 rocket reusability programme, since it was the ninth flight and ninth landing for this particular first-stage booster.
Both men are veterans of the Space Shuttle program, which ended in 2011, and they had been training for five years with SpaceX.
The launch was to be witnessed by US President Donald Trump from Kennedy Space Station in Florida.
According to a Quartz report, Musk has steadily moved away from original posts and retweets to engaging with other Twitter users.
