Super Heavy Block 3 the Booster of the Future

Date:
Mon, 18 May 2026 18:27:46 +0000

Description:
The first stage of Starship, the Super Heavy booster, has already undergone many changes during The post Super Heavy Block 3 the Booster of the Future appeared first on NASASpaceFlight.com .

FULL STORY ======================================================================

The first stage of Starship, the Super Heavy booster, has already undergone many changes during its development. This most recent design change, from Block 1/2 boosters to Block 3, is by far the biggest leap. This new design we are about to cover is a clean-sheet design built from the ground up, informed by lessons learned over the last seven years.





Block 3 Super Heavy Booster

One of the most visual changes is the integrated hotstage truss, a big improvement over the old add-on hotstage ring that SpaceX used for Boosters 9 through 16.

This new design uses an N1 rocket-style hotstage truss system, which is more open, and instead of a separate surface for the ship exhaust to hit, the exhaust hits the boosters forward dome. The forward dome also has added steel plating for additional protection from the ships exhaust plume.

Just below the hotstage truss is another obvious change: the three newer, larger grid fins.

These grid fins are now spaced in a T formation and are 50% larger than the Block 1 and 2 grid fins. The two grid fins opposite each other now have lift/catch points, while the third grid is a rudder fin.

The rudder fin is also angled on the internal grid to allow air to pass through at a better angle; otherwise, the airflow could cause the booster to pitch up when not desired.



Deleting the fourth fin saves weight and is no longer needed, as it would be completely out of the airflow with the boosters newer glide-back profile.

Other changes include the raceway, which has been redesigned and now extends only about halfway down the booster before going internal and splitting off
to one of the taller chines. The new raceway also includes the Flight Termination System (FTS) charges, which deletes the separate FTS raceways
seen on Block 1 and 2 boosters.

Ship 39

Also, the chines on the raceway side are taller and closer together, and the chines opposite the raceway on the rudder fin side are shorter and farther apart. Being farther apart on the rudder fin side can give the chines a
little more lift during the new glide back maneuver.

Inside these chines are the upgraded avionics, COPVs, and batteries. The
large steel CO2 tanks have been deleted since the engine shielding cavities were deleted as well.



These COPVs, or composite overwrapped pressure vessels, contain all the needed gases for the booster, gaseous methane and oxygen for spin start and igniters, nitrogen for actuating pneumatic valves, and pressurization gas for the new side landing tank. With all the requirements, SpaceX has nearly doubled the amount of COPVs located on the booster.

As for the tanks themselves, the methane tank is now shorter, and the LOX tank is now longer. But the methane tank capacity was offset by the new transfer tube. This transfer tube is nearly the size of a Falcon 9, measuring at 50 meters tall and 3 meters wide.

With this new transfer tube and the updated engine plumbing, SpaceX can
ignite all 33 Raptor 3 engines simultaneously. This will also allow for simultaneous ignition of the inner ring of 10 engines during boost-back
burns. Installing the redesigned fuel transfer tube into the first next generation Super Heavy booster.

Roughly the same size as the first stage of a Falcon 9 rocket, the new transfer tube is responsible for channeling cryogenic fuel from Super Heavy's main tank to its 33 Raptor pic.twitter.com/oL5cMoR3CU

SpaceX (@SpaceX) July 9, 2025



The aft section is where SpaceX has made the most changes. First off, the Quick Disconnect is now split into two, with Oxygen ports on one and methane ports on the other. Making this split helps with interior plumbing and
reduces complexity by using a single QD on the launch mount itself. Also, it helps so that the main fill/drain ports can be larger without causing issues with a single QD.

Inside the newly designed aft sits a brand-new propellant distribution system, which includes a separate LOX landing tank that feeds all 13 inner engines. This is part of the Block 3 boosters new landing burn startup and gives SpaceX the ability to start any of the inner 13 engines, should one fail, for redundancy. Aft shot of Booster 19 Rolls out to Masseys for Cryo

On the aft section, there are a large number of pipes going around the outside of the booster aft with many junction boxes. These are all of the commodities needed for the Raptor 3 engines, as well as the autogenous pressurization manifolds for pressurizing the main propellant tanks.

In these conduits are power and data cables, spin start, and igniter gases. All of these used to be in manifolds and conduits inside the primary engine shielding under the aft dome.

Looking at the engines, almost all of the engine shielding has been deleted. With Raptor 3, by deleting several flanges and addressing heat issues, SpaceX eliminated the cumbersome engine shielding and switched to protection only around the main propellant valves, thrust vector control actuators, and primary inlets.



Now the engines themselves are no longer attached to a dome, but rather to a steel plate that carries the thrust of all 33 Raptor 3 engines. This plate also has a taper down, which causes the engines themselves to protrude out
the bottom more than in the past. To protect the new aft plate, SpaceX has introduced a new metallic tile to cover the exposed steel of the thrust
plate.

This new design also introduced a new engine setup; its still 33 engines,
but the inner ring of 10 has been rotated to prevent any one engine from hitting the top of the ridge on the pad deflector. And the center three engines are no longer all 120 degrees apart; they are now clocked
108-108-144. This also prevents any one engine from hitting the ridge cap. This is an effort to increase the life span of the launch pad.

Block 3 of Super Heavy Booster is an important step forward in the Starship program towards better reliability and a more capable vehicle.

Featured Image: Booster 19 Rolling back after first full stack (Credit: Max Evans for NSF)



The post Super Heavy Block 3 the Booster of the Future appeared first on NASASpaceFlight.com .



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Link to news story: https://www.nasaspaceflight.com/2026/05/super-heavy-block-3-booster-future/


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