Elon Musk's SpaceX Mars-Colonizing Starship Spacecraft Just Overcame a Big Hurdle

Elon Musk has confirmed Starship prototype SN4 passed a cryogenic proof test on Sunday, a milestone for the project designed to send payloads to Mars.

Taking place at a SpaceX site in Texas, the most recent iteration became the first full-scale Starship prototype to pass the crucial test following a series of setbacks with prior models including the MK1, SN1 and SN3, NasaSpaceFlight.com reported.

The cryogenic proof test—which fills the ship with liquid nitrogen to ensure it is able to survive in flight pressure conditions—was previously successful in the SN2 prototype, but that was not a full-scale build.

The news was announced on Twitter. "SN4 passed cryo proof!" Musk tweeted, later adding that the result had been "kind of softball" but it was "enough to fly!" He praised the work of SpaceX engineers.

The project is envisioned as a "fully reusable transportation system" to carry payloads— and eventually humans—to the Moon, Mars and beyond. It's a "two-stage" vehicle that uses the boosting capabilities of the company's "Super Heavy" rocket.

"Starship will be the world's most powerful launch vehicle ever developed, with the ability to carry in excess of 100 metric tonnes to Earth orbit," Space X says. "Drawing on an extensive history of launch vehicle and engine development programs, SpaceX has been... iterating on the design of Starship with orbital-flight targeted for 2020.

"[The] Starship system uses in-space propellant transfer to enable the delivery of over 100t of useful mass to the surface of the Moon or Mars. This system is designed to ultimately carry as many as 100 people on long-duration, interplanetary flights."

SN4 passed cryo proof! 😅 pic.twitter.com/EJakThZRGF

— Elon Musk (@elonmusk) April 27, 2020

It is unclear if the 2020 target remains feasible, although work at the firm's facilities has continued despite the ongoing COVID-19 outbreak in the U.S. Success of the cryogenic test was likely welcome news for SpaceX, following earlier prototype issues.

As reported by Space.com, the launch of the SN3 prototype failed during the pressure testing on April 2, which Musk later blamed on a "configuration error."

The first full-scale build, the MK1, failed in November last year, while its successor, the SN1, was destroyed after initiation of a pressurization test on February 28, 2020.

According to Musk, who made the headlines last week following the launch of 60 new satellites in the Starlink mission, the next stage in the SN project will potentially take place later this week, consisting of a "static fire" test of the "Raptor" engines.

The CEO said the SN4 will be paired with one Raptor engine, but added the next craft prototype, the SN5, will be attached to three. As noted by NasaSpaceFlight.com, the team is aiming to conduct a "hop" of the craft, launching it up to 150 meters.

In January, Musk tweeted the project's goal is to reach three flights per day on average using Starship tech—bringing humanity closer to his vision of a Mars-based colony. "Helping to pay for this is why I'm accumulating assets on Earth," he noted.

Building 100 Starships/year gets to 1000 in 10 years or 100 megatons/year or maybe around 100k people per Earth-Mars orbital sync

— Elon Musk (@elonmusk) January 17, 2020

Helping to pay for this is why I’m accumulating assets on Earth.

— Elon Musk (@elonmusk) January 17, 2020
Elon Musk
SpaceX founder Elon Musk addresses members of the media during a press conference announcing new developments of the Crew Dragon reusable spacecraft, at SpaceX headquarters in Hawthorne, California on October 10, 2019. PHILIP PACHECO/AFP/Getty