"Mars may be a fixer upper of a planet, but it has great potential," SpaceX founder Elon Musk said.
Almost 6,000 pounds of cargo and experiments are en route to the space station after a bright Thursday evening launch from Kennedy Space Center.
SpaceX CEO Elon Musk in February said the Starship could launch from Texas for less than $10 million per flight within two or three years.
A SpaceX Dragon spacecraft scheduled to send supplies to the International Space Station this week remains grounded after an issue was identified during fueling.
Some 5,000 Starlink terminals, which are designed to provide high-speed broadband internet, have been delivered to aid Ukraine in its ongoing conflict with Russia.
The four crew members will have 10 days to conduct research at the International Space Station.
A former decorated NASA astronaut and an international crew of paying customers will become the first to dock at the International Space Station as an all-private mission flying in SpaceX's Crew Dragon spacecraft next month.
International astronaut crew will share paella and other Spanish dishes on the space station.