Two months ago in June, 2023, Elon Musk said on a Twitter Space, that SpaceX had recently decided to switch to a “hot-staging” approach where the Starship upper stage will ignite its engines while still attached to the Super Heavy booster. There will be a large payload-to-orbit advantage with hot-staging that is conservatively about a 10% increase.” The actual hot staging ring was shown as was being prepared for attachment.
Hot-staging has been used on Russian launch vehicles for decades. The engines of one stage are ignited while still attached to its lower stage. Musk said that, for Starship, most of the 33 Raptor engines on the Super Heavy booster would be turned off, but a few still firing, when the engines on the Starship upper stage are ignited. Doing so, he said, avoids the loss of thrust during traditional stage separation, where the lower stage shuts down first.
Vented interstage and heat shield installed atop Booster 9. Starship and Super Heavy are being upgraded to use a separation method called hot-staging, where Starship’s second stage engines will ignite to push the ship away from the booster pic.twitter.com/UbMpciGJqd
— SpaceX (@SpaceX) August 18, 2023
Great video showing SpaceX's new hot staging ring finally with its inner bulkhead! Video Credit: LabPadre https://t.co/yPU92cvMYZ
— Space Intelligence (@SpaceIntel101) August 17, 2023
Felix Schlang at What About It gives all of the technical details on the SpaceX hot staging.
The water deluge system to protect the launch pad is also ready.
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
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[ ‘water deluge system’
later on to routine with launches, reducing water pressure (openings diameters) and water bowl rim height towards ocean side (following NASA procedure with controlled channeling exhaust on e.g. Space Shuttle platform)? ]
Building 2 stage Estes Rockets as a kid, occasional launches would “Hot Stage” when the second stage wouldn’t release soon enough from the first stage. Wasn’t pretty.
I built Estes 2-3 stage rockets and recall that the booster engines had a zero second delay between engine off and firing a fireball up the rocket tube to ignite the next state. EVERY Estes multistage rocket was a hot stage rocket.
Should work, even if it doesn’t ,it will the next time. I’d say there is at least a 50% chance the next launch gets to the Pacific.
Will they still get all of the potential gain if they throttle down the booster?