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Langmuir Probe (LAP)

NSSDCA ID: 2004-006A-12

Mission Name: Rosetta
Principal Investigator:Dr. Anders Eriksson


The Langmuir Probe (LAP) is designed for detailed study of the plasma around the comet to address structure and dynamics of comet outgassing, relation of coma structures to comet surface properties, plasma structures and boundary layerswaves and fields in the coma, and possibly tail processes. The LAP is part of the Rosetta Plasma Consortium (RPC) which consists of four additional instruments: the Ion and Electron Sensor (IES), the Fluxgate Magnetometer (MAG), the Ion Composition Analyser (ICA), and the Mutual Impedance Probe (MIP). The scientific objectives of the RPC instruments are to study inner coma structure, dynamics, and aeronomy, characterize the development of cometary activity and the formation and evolution of the plasma tail, and investigate solar-wind and asteroid interaction.

The LAP consists of two 5 cm diameter spherical titanium probes mounted on booms which protrude several meters from the main body of the spacecraft. The probes are separated from each other by a few meters. The LAP will measure electron number density, electron temperature, and plasma drift velocity, density variations, and waves. The probe separation will also enable the measurement of plasma flow velocity and electric fields below 10 kHz. Onboard control is provided by the Plasma Interface Unit (PIU), a common interface to the spacecraft for the RPC experiments. The LAP sensors have a total mass of 0.454 kg; the LAP electronics, which are shared with the PIU, MAG, and MIP, have a mass of 3.291 kg.

Alternate Names

  • LAP
  • Rosetta/LAP
  • urn:esa:psa:context:instrument:ro.rpclap

Facts in Brief

Mass: 0.454 kg
Power (avg): 1.4 W


  • Planetary Science: Small Bodies
  • Planetary Science: Fields and Particles

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. Anders ErikssonPrincipal InvestigatorSwedish Institute for Space

Selected References

  • Trotignon, J. G., et al., The Rosetta Plasma Consortium: Technical realization and scientific aims, Adv. Space Res., 24, No. 9, 1149-1158, June 1999.
  • Carr, C., et al., RPC: The Rosetta Plasma Consortium, Space Sci. Rev., 128, 629-647, doi:10.1007/s11214-006-9136-4, 2007.
  • Eriksson, A. I., et al., RPC-LAP: The Rosetta Langmuir Probe Instrument, Space Sci. Rev., 128, 729-744, doi:10.1007/s11214-006-9003-3, 2007.

Other Related Data/Information

Image of EASEP

Rosetta RPC

RPC Home Page (Rosetta Plasma Consortium)

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