One of the more curious aspects of the 10th flight of SpaceX’s Starship rocket on Tuesday was the striking orange discoloration of the second stage. This could be observed on video taken from a buoy near the landing site as the vehicle made a soft landing in the Indian Ocean.

This color—so different from the silvery skin and black tiles that cover Starship’s upper stage—led to all sorts of speculation. Had heating damaged the stainless steel skin? Had the vehicle’s tiles been shucked off, leaving behind some sort of orange adhesive material? Was this actually NASA’s Space Launch System in disguise?

The answer to this question was rather important, as SpaceX founder Elon Musk had said before this flight that gathering data about the performance of this heat shield was the most important aspect of the mission.

We got some answers on Thursday. During the afternoon, the company posted some new high-resolution photos, taken by a drone in the vicinity of the landing location. They offered a clear view of the Starship vehicle with its heat shield intact, albeit with a rust-colored tint.

Musk provided some clarity on this discoloration on Thursday evening, writing on the social media site X, “Worth noting that the heat shield tiles almost entirely stayed attached, so the latest upgrades are looking good! The red color is from some metallic test tiles that oxidized and the white is from insulation of areas where we deliberately removed tiles.”

The new images and information from Musk suggest that SpaceX is making progress on developing a heat shield for Starship. This really is the key technology to make an upper stage rapidly reusable—NASA’s space shuttle orbiters were reusable but required a standing army to refurbish the vehicle between flights. To unlock Starship’s potential, SpaceX wants to be able to refly Starships within 24 hours.