SpaceX flight testing in South Texas

[ORAC]

https://x.com/JoeTegtmeyer/status/20...588801191?s=20

Something I haven’t heard discussed very much is how the new @SpaceX Starship V3 has been configured for on-orbit refueling … something that is absolutely essential for Starship to conduct any mission beyond LEO, and arguably a critical capability for any significant operational missions in various earth orbits as well.

According to SpaceX, “Four docking drogues have also been added on the leeward side of the vehicles to enable docking with other Starships, along with propellant feed connections for ship-to-ship propellant transfer.”

So, how will this system work?

SpaceX has adapted its tried and true DragonEye System from the Dragon capsule for Starship operations into housings under each of the four probe and rogue enclosures on the leeward side of the ship. (See images)

These DragonEye navigation sensors support autonomous rendezvous operations and leverage proven flight heritage from the Dragon spacecraft’s successful dockings with the International Space Station. These have undergone dedicated testing to validate their performance in the Starship configuration.

Flight 12 will be the first time a Starship has launched with this system, although it won’t be until later flights when a rendezvous in orbit will be demonstrated.

The DragonEye LIDAR units are integrated into the forward avionics and structural sections of Starship, positioned to provide an unobstructed line of sight during approach maneuvers.

On Starship V3, this aligns with the addition of four docking drogues and associated propellant feed connections located on the leeward side of the vehicle. These features enable secure mating with another Starship, along with the necessary umbilical interfaces for propellant transfer.

The sensor suite is recessed or flush-mounted within protective bays or fairings, similar to its placement on Dragon, ensuring it remains shielded during atmospheric flight while deployable or exposed in orbit.

Here’s how it would work in practice:

Both tanker (chaser) and receiver (target/depot) Starships carry the sensors, allowing flexible role assignment in paired operations.

In the orbital refueling scenario, one Starship assumes the active “chaser” role (typically the tanker), while the other serves as the passive “receiver” (target or depot).

Rendezvous Phase: The chaser employs its DragonEye flash LIDAR sensor to emit laser pulses toward the receiver. Retro-reflectors (corner-cube arrays) on the receiver enhance signal return, enabling precise three-dimensional range, bearing, and relative attitude measurements in real time. This provides centimeter-level accuracy for safe closure from kilometers to meters.

Approach and Alignment: Data from DragonEye is fused with other navigation inputs (e.g., star trackers and RF systems) to guide autonomous thruster firings, ensuring alignment of the docking interfaces.

Docking and Transfer: Once within close proximity, the chaser’s docking probe engages the receiver’s drogue, achieving a hard mate. Propellant transfer then occurs via a pressure-differential system through the integrated umbilicals, with settling thrusters used to manage microgravity fluid dynamics.

Symmetry and Redundancy: Because both vehicles share identical sensors, software, and docking hardware, the system supports bidirectional capability if roles reverse. Post-docking, the connection is released after transfer is complete.

This architecture draws directly from Dragon’s operational success, scaled for Starship’s larger size and cryogenic propellant handling requirements.

I suspect this capability will not only be tested and demonstrated in future Starship flights later this year and throughout 2027, but it may be part of the upcoming @NASAArtemis III test and demo mission to ensure Starship and the HLS lunar lander will be ready for Artemis IV landing on the moon in 2028.

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