Suprathermal and Thermal Ion Composition (STATIC)

Graphic showing the STATIC instrument on the MAVEN spacecraft. STATIC is able to measure the composition and velocity of ions, allowing us to determine escape rates at the present epoch. (Courtesy NASA/GSFC/University of California Berkeley-SSL)

The Suprathermal and Thermal Ion Composition (STATIC) instrument is part of the Particles and Fields (P & F) Package and measures thermal ions to moderate energy escaping ions.

Goals:

Measure the source ion populations near periapsis, the heated ionospheric ions at intermediate altitudes that achieve escape velocity, and the pickup acceleration of these ions in the magnetosheath and solar wind
Allow direct measurements of the Martian sheath plasma, separating shocked solar wind and planetary ions that populate the sheath and plasma sheet

Observations:

Escaping ions and processes
Composition of thermal to energetic ions; energy distributions and pitch angle variations
Ionospheric Ions 0.1-10 eV
Tail Superthermal ions (5-100eV)
Pick-up Ions (100-20,000 eV)
Key ions H⁺, O⁺, O₂⁺, CO₂⁺

MAVEN will measure the drivers, reservoirs, and escape rates to determine the present state of Mars' upper atmosphere and allow determination of the net integrated loss to space through time. (Courtesy MAVEN) — MAVEN will measure the drivers, reservoirs, and escape rates to determine the present state of Mars’ upper atmosphere and allow determination of the net integrated loss to space through time. (Courtesy MAVEN)

Technical details and heritage:

Toroidal Electrostatic Analyzer with Time of Flight section
Mass Range 1-70 AMU, ΔM/M > 4
Energy range ~0.1 eV to 30 keV, ΔE/E~15%
FOV 360^o X 90^o
Angular Resolution 22.5^o x 6^o
Energy Flux < 10⁴ to 10⁹ eV/cm²-s-sr-eV (to 10¹² w/attenuators for low energy beam)
Can be oriented to measure either upwelling/downwelling or horizontal flows
Heritage from Cluster CODIF

Instrument publications:

Altitude dependence of nightside Martian suprathermal electron depletions as revealed by MAVEN observations
(Geophysical Research Letters article—published online November 2015)—Download PDF (3 MB)

MAVEN SupraThermal and Thermal Ion Compostion (STATIC) Instrument
(Space Science Reviews article—published online November 2015)—Download PDF (13 MB)

The STATIC instrument lead is Jim McFadden (SSL). For more about McFadden, visit: http://bit.ly/jpmbio.

MAVEN Science Community Workshop Presentation
(Dec. 2, 2012)