On Sunday, April 26, SpaceX proved that four is the company’s lucky number as the long-awaited cryogenic proof test for Starship SN4 occurred, and for the first time in the Starship history, the test resulted in success.

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

— Elon Musk (@elonmusk) April 27, 2020

The cryogenic proof test is a key assessment for SpaceX to hurdle over, and for Starship to be a success. For SN4’s predecessors, Mark 1, SN1, and SN3, all suffered a catastrophic anomaly during this test.

Starship SN3 destroyed in its cryogenic proof test. (Labpadre)

After the success of SN4, Elon Musk, CEO of SpaceX, tweeted that SN4 will perform a static fire “later this week” and a short 150 meter hop in May after regulatory approval. SpaceX was aiming for Wednesday, April 29 to conduct the static fire, however, the date was pushed back to Friday, May 1. What is interesting, however, Musk confirmed that the SN4 will conduct the static fire and 150 meter hop with only one raptor engine, when previously speculated to have three raptor engines installed. Not to worry though, Musk later confirmed that Starship SN5, SN4’s successor, will be fitted with three raptor engines.

Just one. SN5 will get three.

— Elon Musk (@elonmusk) April 27, 2020

Raptor Engine spotted heading to Boca Chica launchpad to be installed onto Starship SN4. (Labpadre)

In addition to the triple raptor engines, Starship SN5 will be fitted with aero flaps for the much anticipated 20 kilometer hop. The aero flaps will possibly look similar to Starship Mark 1.

Flaps, actuator & static aero are undergoing redesign for mass reduction & simplicity

— Elon Musk (@elonmusk) April 17, 2020

Starship Mark 1 (Darrell Etherington)

You can watch Starship SN4’s cryogenic proof test below.