BACC "Thumper" Solid Fuel Booster

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BACC "Thumper" Solid Fuel Booster
Part image
Solid rocket booster by
Rockomax Conglomerate

Radial size Small, Radial mounted
Cost (total) 850.00 Funds
(dry) 358.00 Funds
Mass (total) 7.65 t
(dry) 1.50 t
Drag 0.2-0.3
Max. Temp. 2200 K
Volume  ?
Impact Tolerance 7 m/s
Research General rocketry.png General Rocketry
Unlock cost 2 800 Funds
Since version 0.16
Part configuration solidBoosterBACC.cfg
Solid rocket booster
Maximum thrust (1 atm) 250.00 kN
(vacuum) 300.00 kN
Isp (1 atm) 175 s
(vacuum) 210 s
Fuel consumption 19.42 Units of fuel/s

Thrust vectoring No
Fuel 820.0 Units of fuel
Burn time (1 atm) 35.2 s
(vacuum) 42.2 s
Testing Environments
On the surface No
In the ocean No
On the launchpad Yes
In the atmosphere Yes
Sub orbital Yes
In an orbit Yes
On an escape No
Docked No
Test by staging Yes
Manually testable Yes

The BACC "Thumper" Solid Fuel Booster is a large solid rocket booster used to provide a short burst of additional thrust to a rocket. It comes as a single unit. The engine and fuel tank are one single part which means that it isn't possible increase the burn time for it by adding more fuel tanks.

The Thumper is larger than the RT-10 "Hammer" Solid Fuel Booster, and smaller than the S1 SRB-KD25k "Kickback" Solid Fuel Booster.

Product description

Filled with a new, even more volatile fuel, the BACC offers semi-reliable performance at a good price.

Rockomax Conglomerate


Thumpers are one-shot rocket boosters often used to help get the massive bulk of a large multi-stage rocket off the ground. They burn at a constant thrust until they run out of fuel and then cease to work. It should be noted that more boosters doesn't reduce the need for liquid fuel, as one must also take into account thrust-to-weight ratios. Thrust can be regulated with tweakables.

The minimum thrust required for the Thumper to lift its own weight off Kerbin's surface is about 30%, or about 75 kN.

Its thrust-to-mass ratio is high enough to make it a popular choice on first stages. Early in the game, it is possible to make an effective first stage out of just the Thumper.



  • New model and texture
  • Thrust increased from 300 to 315. Dry mass reduced from 1.75 to 1.5.
  • Thrust decreased from 550 to 300.
  • Other small performance tweaks.
  • Thrust increased from 400 to 550.
  • Initial Release