SpaceX and Tesla CEO Elon Musk, who claims to be living in a modest $50,000, 37-square-metre prefab guest house in Boca Chica, Texas, has bought a $250,000 ticket to space from fellow billionaire Richard Branson's Virgin Galactic.

The Wall Street Journal reports that Musk had bought a ticket for his space ride before Branson touched the edge of space on Sunday.

"It is unclear how far up the waiting list Musk is for a seat. Virgin Galactic said its tickets have sold for $250,000 each, and the company has collected $80 million in sales and deposits," the report said on Monday.

Elon Musk

Musk and Branson are good friends

In an interview with Sunday Times, Branson said: "Elon's a friend and maybe I'll travel on one of his ships one day.

In a pre-flight tweet, Branson said: "Thanks for being so typically supportive and such a good friend, Elon. Great to be opening up space for all - safe travels and see you at Spaceport America!".

Musk responded: "Will see you there to wish you the best". Virgin Galactic has already sold nearly 600 tickets for a ride on its SpaceShipTwo. With the historic flight to the edge of space, Branson has opened the doors for all humans to visit space.

Branson's feat on Sunday

Branson on Sunday touched the edge of space with three employees, including one of Indian-origin, and landed safely back to Earth, on board his company Virgin Galactic's VSS Unity. It was the 22nd test flight of VSS Unity and the first test flight with a full crew in the cabin.

It was an "experience of a lifetime", said the 70-year-old billionaire. The flight climbed nearly 86 kilometres above the Earth's surface.

Richard Branson: Legalise all drugs and prostitution

Besides Branson, the flight included Beth Moses, Chief Astronaut Instructor, Colin Bennett, lead Operations Engineer, and Indian-origin Sirisha Bandla, Vice President of Government Affairs at Virgin Galactic.

Virgin Galactic aims to fly two more flights, then start regular commercial operations from early 2022. The ultimate goal is to conduct 400 flights per year. The company has already sold nearly 600 tickets, with each ticket costing nearly $250,000.

After Branson, Amazon Founder Jeff Bezos is expected to take off in his own space tourism Blue Origin rocket on July 20. Bezos will fly with his brother Mark and two others.