Virgin Galactic is poised on Saturday for its last spaceflight before heading into a two-year pause on commercial operations to upgrade its fleet, as the company seeks to finally turn a profit.

The "Galactic 07" mission is scheduled to begin at around 8:30 am Mountain Time (1430 GMT) from the company's base in Spaceport, New Mexico, a spokesman said.

A huge carrier plane takes off from a runway, gains altitude for around 50 minutes, and then releases from under its wings a spaceplane that soars at supersonic speed to the edge of space, where passengers can enjoy a few minutes of weightlessness and admire the Earth's curve.

On board will be two pilots and four private astronauts. One of them is Tuva Atasever, a Turkish space agency astronaut whose seat was contracted through another space company, Axiom, while the names of the other three will likely be disclosed afterwards.

It will be the seventh commercial flight for the company founded in 2004 by British tycoon Richard Branson, in an emerging suborbital tourism market where its main competitor is Blue Origin, owned by Amazon billionaire Jeff Bezos.

It will also be the final flight for its current spaceplane called VSS Unity, which it intends to replace with two next-generation "Delta class" ships, currently under construction in Arizona, with test flights due in 2025 before commercial operations in 2026.

The future of the company is at stake as it seeks at long last to get into the black. Virgin is burning through cash, losing more than $100 million in each of the past two quarters, with its reserves standing at $867 million at the end of March.

It also laid off 185 people, or 18 percent of its workforce, late last year. Its shares are currently trading at 85 cents, down from $55 in 2021, the year Branson himself flew, garnering global headlines.

While similar in appearance to Unity, the Delta ships will carry six passengers, compared to the current four. Seat prices will be set at $600,000 and up to 125 flights are projected per year, the company says, hoping to turn around its fortunes.

Some are skeptical, however.

"Virgin Galactic investors can look forward to owning a stock generating essentially zero revenue for the next 18 to 30 months -- and that's if everything goes as planned, and the Delta program doesn't get delayed," The Motley Fool wrote in a note to investors this week.

Blue Origin, which launches on a small suborbital rocket, resumed crewed flights in May after its own hiatus of nearly two years, though it experienced an anomaly with one of the three landing parachutes failing to fully inflate, which could delay the next mission.