Van Allen Probes

Van Allen Probes

The Van Allen Probes (formerly known as the Radiation Belt Storm Probes[1] (RBSP)) are two robotic spacecraft being used to study the Van Allen radiation belts that surround Earth. NASA is conducting the Van Allen Probes mission as part of the Living With a Star program.[2] Understanding the radiation belt environment and its variability has important practical applications in the areas of spacecraft operations, spacecraft system design, mission planning and astronaut safety.[3] The probes were launched on August 30, 2012.

Contents

  • Overview 1
    • Milestones 1.1
    • Launch vehicle 1.2
  • Science 2
  • Spacecraft 3
    • Instruments 3.1
  • Scientific results 4
  • See also 5
  • References 6
  • External links 7

Overview

NASA's Goddard Space Flight Center manages the overall Living With a Star program of which RBSP is a project, along with Solar Dynamics Observatory (SDO). The Applied Physics Laboratory is responsible for the overall implementation and instrument management for RBSP. The primary mission is scheduled to last 2 years, with expendables expected to last for 4 years. The spacecraft will also work in close collaboration with the Balloon Array for RBSP Relativistic Electron Losses (BARREL), which can measure particles that break out of the belts and make it all the way to Earth's atmosphere.[4][5]

The Radiation Belt Storm Probes mission is part of NASA’s Living With a Star program, which is managed by Goddard Space Flight Center in Greenbelt. The Johns Hopkins University Applied Physics Laboratory (APL) manages the mission and is building and will operate the Van Allen Probes for NASA.

Milestones

Launch vehicle

On March 16, 2009 United Launch Alliance (ULA) announced that NASA had awarded ULA a contract to launch RSBP using an Atlas V 401 rocket.[8] NASA delayed the launch as it counted down to the four-minute mark early morning on August 23. After bad weather prevented a launch on August 24, and a further precautionary delay to protect the rocket and satellites from Hurricane Isaac, liftoff occurred on August 30, 2012 at 4:05 AM EDT.[9]

Science

RBSP science overview.

The Van Allen radiation belts swell and shrink over time as part of a much larger space weather system driven by energy and material that erupt off the Sun's surface and fill the entire Solar System. Space weather is the source of aurora that shimmer in the night sky, but it also can disrupt satellites, cause power grid failures and disrupt GPS communications. The Van Allen Probes will help scientists to understand this region and to better design spacecraft that can survive the rigors of outer space.[2] The mission is to gain scientific understanding of how populations of relativistic electrons and ions in space form or change in response to changes in solar activity and the solar wind.[2]

The mission's general scientific objectives are to:[2]

  • Discover which processes - singly or in combination - accelerate and transport the particles in the radiation belt, and under what conditions.
  • Understand and quantify the loss of electrons from the radiation belts.
  • Determine the balance between the processes that cause electron acceleration and those that cause losses.
  • Understand how the radiation belts change in the context of geomagnetic storms.

Spacecraft

Artist's rendition of Van Allen Probes A and B in Earth orbit. Credit:NASA

The Van Allen Probes consists of two spin-stabilized spacecraft that were launched with a single Atlas V rocket. The two probes must operate in the harsh conditions they are studying; while other satellites have the luxury of turning off or protecting themselves in the middle of intense space weather, the Van Allen Probes must continue to collect data. The probes have, therefore, been built to withstand the constant bombardment of particles and radiation they will experience in this intense area of space.[2]

Instruments

Because it is vital that the two craft make identical measurements to observe changes in the radiation belts through both space and time, each probe will carry the following:

  1. Energetic Particle, Composition, and Thermal Plasma (ECT) Instrument Suite [1]; The Principal Investigator is Harlan Spence [2] from University of New Hampshire. Key partners in this investigation are LANL, Southwest Research Institute, Aerospace Corporation and LASP
  2. Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS); The Principal Investigator is Craig Kletzing from the University of Iowa.
  3. Electric Field and Waves Instrument (EFW); The Principal Investigator is John Wygant from the University of Minnesota. Key partners in this investigation include the University of California at Berkeley and the University of Colorado at Boulder.
  4. Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE); The Principal Investigator is Lou Lanzerotti [3] from the New Jersey Institute of Technology. Key partners include the Applied Physics Laboratory and Fundamental Technologies, LLC [4].
  5. Relativistic Proton Spectrometer (RPS) from the National Reconnaissance Office

Scientific results

In February 2013, a third temporary Van Allen Radiation Belt was discovered by using data gathered by Van Allen Probes. The said third belt lasted a few weeks.[10]

See also

References


-- Module:Hatnote -- -- -- -- This module produces hatnote links and links to related articles. It -- -- implements the and meta-templates and includes -- -- helper functions for other Lua hatnote modules. --


local libraryUtil = require('libraryUtil') local checkType = libraryUtil.checkType local mArguments -- lazily initialise Module:Arguments local yesno -- lazily initialise Module:Yesno

local p = {}


-- Helper functions


local function getArgs(frame) -- Fetches the arguments from the parent frame. Whitespace is trimmed and -- blanks are removed. mArguments = require('Module:Arguments') return mArguments.getArgs(frame, {parentOnly = true}) end

local function removeInitialColon(s) -- Removes the initial colon from a string, if present. return s:match('^:?(.*)') end

function p.findNamespaceId(link, removeColon) -- Finds the namespace id (namespace number) of a link or a pagename. This -- function will not work if the link is enclosed in double brackets. Colons -- are trimmed from the start of the link by default. To skip colon -- trimming, set the removeColon parameter to true. checkType('findNamespaceId', 1, link, 'string') checkType('findNamespaceId', 2, removeColon, 'boolean', true) if removeColon ~= false then link = removeInitialColon(link) end local namespace = link:match('^(.-):') if namespace then local nsTable = mw.site.namespaces[namespace] if nsTable then return nsTable.id end end return 0 end

function p.formatPages(...) -- Formats a list of pages using formatLink and returns it as an array. Nil -- values are not allowed. local pages = {...} local ret = {} for i, page in ipairs(pages) do ret[i] = p._formatLink(page) end return ret end

function p.formatPageTables(...) -- Takes a list of page/display tables and returns it as a list of -- formatted links. Nil values are not allowed. local pages = {...} local links = {} for i, t in ipairs(pages) do checkType('formatPageTables', i, t, 'table') local link = t[1] local display = t[2] links[i] = p._formatLink(link, display) end return links end

function p.makeWikitextError(msg, helpLink, addTrackingCategory) -- Formats an error message to be returned to wikitext. If -- addTrackingCategory is not false after being returned from -- Module:Yesno, and if we are not on a talk page, a tracking category -- is added. checkType('makeWikitextError', 1, msg, 'string') checkType('makeWikitextError', 2, helpLink, 'string', true) yesno = require('Module:Yesno') local title = mw.title.getCurrentTitle() -- Make the help link text. local helpText if helpLink then helpText = ' (help)' else helpText = end -- Make the category text. local category if not title.isTalkPage and yesno(addTrackingCategory) ~= false then category = 'Hatnote templates with errors' category = string.format( '%s:%s', mw.site.namespaces[14].name, category ) else category = end return string.format( '%s', msg, helpText, category ) end


-- Format link -- -- Makes a wikilink from the given link and display values. Links are escaped -- with colons if necessary, and links to sections are detected and displayed -- with " § " as a separator rather than the standard MediaWiki "#". Used in -- the template.


function p.formatLink(frame) local args = getArgs(frame) local link = args[1] local display = args[2] if not link then return p.makeWikitextError( 'no link specified', 'Template:Format hatnote link#Errors', args.category ) end return p._formatLink(link, display) end

function p._formatLink(link, display) -- Find whether we need to use the colon trick or not. We need to use the -- colon trick for categories and files, as otherwise category links -- categorise the page and file links display the file. checkType('_formatLink', 1, link, 'string') checkType('_formatLink', 2, display, 'string', true) link = removeInitialColon(link) local namespace = p.findNamespaceId(link, false) local colon if namespace == 6 or namespace == 14 then colon = ':' else colon = end -- Find whether a faux display value has been added with the | magic -- word. if not display then local prePipe, postPipe = link:match('^(.-)|(.*)$') link = prePipe or link display = postPipe end -- Find the display value. if not display then local page, section = link:match('^(.-)#(.*)$') if page then display = page .. ' § ' .. section end end -- Assemble the link. if display then return string.format('%s', colon, link, display) else return string.format('%s%s', colon, link) end end


-- Hatnote -- -- Produces standard hatnote text. Implements the template.


function p.hatnote(frame) local args = getArgs(frame) local s = args[1] local options = {} if not s then return p.makeWikitextError( 'no text specified', 'Template:Hatnote#Errors', args.category ) end options.extraclasses = args.extraclasses options.selfref = args.selfref return p._hatnote(s, options) end

function p._hatnote(s, options) checkType('_hatnote', 1, s, 'string') checkType('_hatnote', 2, options, 'table', true) local classes = {'hatnote'} local extraclasses = options.extraclasses local selfref = options.selfref if type(extraclasses) == 'string' then classes[#classes + 1] = extraclasses end if selfref then classes[#classes + 1] = 'selfref' end return string.format( '
%s
', table.concat(classes, ' '), s )

end

return p-------------------------------------------------------------------------------- -- Module:Hatnote -- -- -- -- This module produces hatnote links and links to related articles. It -- -- implements the and meta-templates and includes -- -- helper functions for other Lua hatnote modules. --


local libraryUtil = require('libraryUtil') local checkType = libraryUtil.checkType local mArguments -- lazily initialise Module:Arguments local yesno -- lazily initialise Module:Yesno

local p = {}


-- Helper functions


local function getArgs(frame) -- Fetches the arguments from the parent frame. Whitespace is trimmed and -- blanks are removed. mArguments = require('Module:Arguments') return mArguments.getArgs(frame, {parentOnly = true}) end

local function removeInitialColon(s) -- Removes the initial colon from a string, if present. return s:match('^:?(.*)') end

function p.findNamespaceId(link, removeColon) -- Finds the namespace id (namespace number) of a link or a pagename. This -- function will not work if the link is enclosed in double brackets. Colons -- are trimmed from the start of the link by default. To skip colon -- trimming, set the removeColon parameter to true. checkType('findNamespaceId', 1, link, 'string') checkType('findNamespaceId', 2, removeColon, 'boolean', true) if removeColon ~= false then link = removeInitialColon(link) end local namespace = link:match('^(.-):') if namespace then local nsTable = mw.site.namespaces[namespace] if nsTable then return nsTable.id end end return 0 end

function p.formatPages(...) -- Formats a list of pages using formatLink and returns it as an array. Nil -- values are not allowed. local pages = {...} local ret = {} for i, page in ipairs(pages) do ret[i] = p._formatLink(page) end return ret end

function p.formatPageTables(...) -- Takes a list of page/display tables and returns it as a list of -- formatted links. Nil values are not allowed. local pages = {...} local links = {} for i, t in ipairs(pages) do checkType('formatPageTables', i, t, 'table') local link = t[1] local display = t[2] links[i] = p._formatLink(link, display) end return links end

function p.makeWikitextError(msg, helpLink, addTrackingCategory) -- Formats an error message to be returned to wikitext. If -- addTrackingCategory is not false after being returned from -- Module:Yesno, and if we are not on a talk page, a tracking category -- is added. checkType('makeWikitextError', 1, msg, 'string') checkType('makeWikitextError', 2, helpLink, 'string', true) yesno = require('Module:Yesno') local title = mw.title.getCurrentTitle() -- Make the help link text. local helpText if helpLink then helpText = ' (help)' else helpText = end -- Make the category text. local category if not title.isTalkPage and yesno(addTrackingCategory) ~= false then category = 'Hatnote templates with errors' category = string.format( '%s:%s', mw.site.namespaces[14].name, category ) else category = end return string.format( '%s', msg, helpText, category ) end


-- Format link -- -- Makes a wikilink from the given link and display values. Links are escaped -- with colons if necessary, and links to sections are detected and displayed -- with " § " as a separator rather than the standard MediaWiki "#". Used in -- the template.


function p.formatLink(frame) local args = getArgs(frame) local link = args[1] local display = args[2] if not link then return p.makeWikitextError( 'no link specified', 'Template:Format hatnote link#Errors', args.category ) end return p._formatLink(link, display) end

function p._formatLink(link, display) -- Find whether we need to use the colon trick or not. We need to use the -- colon trick for categories and files, as otherwise category links -- categorise the page and file links display the file. checkType('_formatLink', 1, link, 'string') checkType('_formatLink', 2, display, 'string', true) link = removeInitialColon(link) local namespace = p.findNamespaceId(link, false) local colon if namespace == 6 or namespace == 14 then colon = ':' else colon = end -- Find whether a faux display value has been added with the | magic -- word. if not display then local prePipe, postPipe = link:match('^(.-)|(.*)$') link = prePipe or link display = postPipe end -- Find the display value. if not display then local page, section = link:match('^(.-)#(.*)$') if page then display = page .. ' § ' .. section end end -- Assemble the link. if display then return string.format('%s', colon, link, display) else return string.format('%s%s', colon, link) end end


-- Hatnote -- -- Produces standard hatnote text. Implements the template.


function p.hatnote(frame) local args = getArgs(frame) local s = args[1] local options = {} if not s then return p.makeWikitextError( 'no text specified', 'Template:Hatnote#Errors', args.category ) end options.extraclasses = args.extraclasses options.selfref = args.selfref return p._hatnote(s, options) end

function p._hatnote(s, options) checkType('_hatnote', 1, s, 'string') checkType('_hatnote', 2, options, 'table', true) local classes = {'hatnote'} local extraclasses = options.extraclasses local selfref = options.selfref if type(extraclasses) == 'string' then classes[#classes + 1] = extraclasses end if selfref then classes[#classes + 1] = 'selfref' end return string.format( '
%s
', table.concat(classes, ' '), s )

end

return p
  1. ^
  2. ^ a b c d e
  3. ^ Radiation Belt Storm Probes (RBSP)
  4. ^
  5. ^ Balloon Array for RBSP Relativistic Electron Losses
  6. ^
  7. ^
  8. ^
  9. ^
  10. ^ "Ephemeral third ring of radiation makes appearance around Earth" Nature.com. Retrieved: 2 March 2013.

External links

  • NASA Van Allen Probes mission page
  • Johns Hopkins APL Van Allen Probes mission page
  • The Van Allen Probes on Twitter
  • Hi-res spherical panoramas in the clean room before encapsulation for launch