Why was a banana floating inside Starship on 6th test flight?

Anyone who watched SpaceX’s sixth test flight of its mighty Starship rocket on Tuesday will have noticed the odd sight of a banana — albeit a fake one — floating in the hold of the spacecraft as it sailed above Earth on its way from the launch site in Boca Chica, Texas, to splashdown in the Indian Ocean.

No, this wasn’t placed there by a sneaky SpaceX engineer as  joke. Rather, the full-size, toy banana acted as a zero-gravity indicator so that the mission team could confirm when the vehicle had reached microgravity conditions high above Earth.

“Bananas have been used for quick visual comparisons for quite some time, and our teammates thought it was time to bring the venerated yellow fruit to Starship,” Kate Tice, a quality engineering manager at SpaceX, said in comments reported by Space.com.

Continuing with the banana theme, SpaceX also slapped a sticker of the popular fruit on the outside of the Starship, highlighting the team’s playful approach to showing off the rocket’s massive scale.

The sixth test flight of Starship — comprising the first-stage Super Heavy booster and upper-stage Starship spacecraft — lifted off successfully, with the booster’s 33 Raptor engines creating a colossal 17 million pounds of thrust as it climbed skyward.

Following a nominal ascent and stage separation, the Super Heavy successfully transitioned to its boostback burn to begin its journey back to the launch site. But unlike the fifth test when the launch tower’s giant mechanical arms successfully secured the booster as it returned home, this time automated health checks of critical hardware on the tower triggered an abort of the catch attempt. As a result, the booster executed a pre-planned divert maneuver that sent it into the Gulf of Mexico.

Starship, meanwhile, completed another successful ascent. It was also able to successfully reignite a single Raptor engine during its journey, part of a vital deorbit process.

The spacecraft, complete with its banana, made it through reentry and executed a flip, landing burn, and soft splashdown in the Indian Ocean, SpaceX said.

Data gathered from the mission will provide SpaceX engineers with vital feedback on the flight hardware, giving them a great opportunity to further refine the system ahead of the seventh test. Eventually, SpaceX wants to use the Starship for crew and cargo flights to the moon, Mars, and beyond.