archive: SETI [ASTRO] ASPERA-3 Instrument To Image Atmopsheric Composition

SETI [ASTRO] ASPERA-3 Instrument To Image Atmopsheric Composition

Larry Klaes ( )
Tue, 22 Dec 1998 14:04:00 -0500

>X-Authentication-Warning: majordom set sender
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>Date: Tue, 22 Dec 1998 16:17:50 GMT
>From: Ron Baalke <>
>Subject: [ASTRO] ASPERA-3 Instrument To Image Atmopsheric Composition Of Mars
>Reply-To: Ron Baalke <>
>Southwest Research Institute (SwRI)
>San Antonio, Texas
>ASPERA-3 instrument to image atmospheric composition of Mars
>SwRI named co-investigator of European Space Agency program
>San Antonio, December 9, 1998 -- NASA has provided $5.3 million to
>Southwest Research Institute (SwRI) to build components of an ion and
>electron measuring instrument that will study the interactions between the
>solar wind and the atmosphere of Mars. The instrument will fly aboard the
>European Space Agency (ESA) Mars Express spacecraft in June 2003. The
>Swedish Institute of Space Physics in Kiruna, Sweden, is taking the ESA
>lead in collaboration with researchers from Finland, Italy, England,
>Germany, and France. SwRI is a co-investigator and the lead U.S.
>SwRI engineers will build part of the analyzer of space plasmas and
>energetic atoms (ASPERA-3) instrument -- one of a suite of instruments
>aboard Mars Express that will examine the present and past states of the
>martian atmosphere. Whether water on the planet might have sometime
>sustained life will also be addressed.
>"The fact that Earth can maintain life is a unique condition in the solar
>system," says Dr. David Winningham, ASPERA-3 co-investigator and an
>Institute scientist in the SwRI Instrumentation and Space Research Division.
>"Mars Express could tell researchers what variables are needed to first
>create, then preserve over geological time, oceans and atmospheres."
>Magnetic and gravity fields help maintain an atmosphere on Earth. When the
>solar wind, the supersonic stream of charged particles flowing out from the
>Sun, interacts with the planet, ion and electron particles become ionized
>and remain trapped in the magnetic field, enabling Earth to sustain an
>active, living atmosphere. The Earth's magnetic field acts as an invisible
>force that reflects away some of the harmful components, such as cosmic
>rays, brought by the solar wind.
>On Mars, interactions with the solar wind also ionize particles, but they
>fly away because the planet lacks a magnetic field and a strong
>gravitational field. Over time, the release of particles continuously
>erodes the martian atmosphere. By examining the ionic composition with
>the Mars Express instruments, researchers will be able to determine whether
>particles, especially water particles, continue to fly away. After combining
>the data with theory, researchers can estimate the length of time
>atmospheric changes have been occurring. The spacecraft will also help
>researchers determine which component, if any, was missing from the martian
>atmosphere that allowed the planet to eventually become geologically
>The ASPERA-3 instrument will measure the ion and electron particles of the
>planet's atmosphere. An additional neutral atom imager will return a
>volumetric image of the martian atmosphere to help characterize its present
>state -- how particles are flying away in a volumetric sense, for example --
>and how the atmosphere has evolved. Data will also help determine if the
>changes contributed to the dehydration of Mars and the loss of its oceans
>and atmosphere, says Winningham.
>SwRI has provided a family of imaging instruments, with different
>adaptations for varying conditions, for a number of NASA and ESA missions.
>The plasma experiment for planetary exploration (PEPE) instrument was
>launched aboard Deep Space One in October 1998, and the Cassini plasma
>spectrometer (CAPS) was launched aboard Cassini in October 1997. Similar
>instruments will also fly aboard the ESA missions Astrid 2 on December 10,
>MUNIN in late 1999, and Rosetta in 2003.
>For more information about Mars Express and the ASPERA-3 instrument, visit
>the NASA web page at .
>For more information about Mars Express, contact:
>Maria Martinez
>Communications Department
>Southwest Research Institute
>P.O. Drawer 28510
>San Antonio, Texas 78228-0510
>Phone (210) 522-3305 Fax (210) 522-3547