Impulse drive

From Trek DB
(Redirected from Impulse engine)
Jump to navigation Jump to search


  • Short for "internally metered pulse drive" (Invasion Novel: First Strike)
  • Main Federation sublight drive system
    • Description guided by both TNG technical manual and general description in Final Frontier, in order to best fit qualities on-screen inconsistent with straightforward Newtonian drive
    • Based on deuterium-fed laser pulse fusion reactor generating high energy electroplasma compatible with internal EPS power systems
      • Early systems occasionally also based on tritium fusion (TNG Novel: A Time to Sow)
      • First generations of impulse fusion reactors produced neutron radiation as a byproduct, requiring extensive radiation shielding (TNG Novel: A Time to Sow)
    • Combination of Newtonian and non-Newtonian propulsion (DS9 Novel: Gamma: Original Sin)
      • Fusion reaction captured by artificial gravitational field, subspace field effects to hypercompress released energy, generating spatial distortions to linearly propel vessel either forward or in reverse
      • Velocity aided and vectored by expulsion of reactants under effect of a subspace field driver coils, increasing reactant mass and reducing vessel mass to increase effectiveness of Newtonian propulsion (TNG Tech Manual)
    • As of 2270s, impulse operation also incorporates low-level warp field to reduce vessel inertial mass (TOS Novel: Ex Machina; TNG Tech Manual)
      • Soon after implementation, led to impulse velocities sometimes being referred to as fractional warp velocities, though this practice was soon dropped (Star Trek: The Motion Picture; TOS Novel: Ex Machina)
    • Maximum impulse velocity limited to 0.25c by policy, to prevent severe relativistic effects from bringing vessels too significantly out of sync with rest-frame activities (TNG Tech Manual)
      • Up to 0.75c in emergency situations (TNG Tech Manual)
  • Impulse operation produces ion exhaust (NF Novel: House of Cards)


  • 2018: Invented by Earth, quickly displacing other engine technologies
  • Late-21st century: First redesigns to incorporate subspace features, increasing potential delta-V


  • Impulse rod (NF Novel: Into the Void)
    • Unclear what this might be