Total Impulse
1847.0Ns
Burn Time
2.80s
Avg Thrust
661.0N
Max Thrust
2342.0N
Thrust Profile (N)
2.80s Burn WindowEngineered by Contrail Rockets, the K678-BG is a 75mm solid rocket motor designed for high-power rocketry (HPR). As an official K-class motor, it delivers a total impulse of 1847.0 Ns over a 2.80 second burn window.
With an average thrust of 661.0 N and a peak of 2342.0 N, it features a regressive thrust curve optimal for heavy rockets requiring high off-the-pad acceleration.
Technical Specifications
Tripoli Rocketry Association, Inc.Diameter 75 mm
Length 1016 mm
Hardware Single Use
Delays (s) P
Specific Impulse 324.6 s
Peak Thrust 1163.38 N
Peak Time T+ 0.006s
T/W Ratio 16.64
Propellant Standard
Profile regressive
Type hybrid
Sparky No
Mass Budget
4050g TotalCasing (Dry)
3470.0g
85.7%
Propellant
580.0g
14.3%
Live Sizing
Flight Envelope
Design wings in your spreadsheet
AeroSheet loads airfoils directly into Google Sheets. Polars, 3D splines, Fusion 360 export, without leaving your spreadsheet.
Comparable K-Class Alternatives
Veenie Kit
Need a custom engineering simulator?
The 3D engine on this page is built by Veenie Aerospace. We build bespoke, browser-native digital twins, aerodynamic simulators, and AI physics tools for UAV startups and defense contractors.