L5 Consortium Meeting 2014

The first L5 consortium meeting was held in Sac Peak, New Mexico in April 2010 to discuss L5 missions, especially the Earth-Affecting Solar Causes Observatory (EASCO) mission concept. The EASCO mission was studied at NASA/GSFC as a 10-instrument mission as an enhanced combination of SOHO and STEREO instruments. Since then there have been several developments in instrument and mission concepts in the US and elsewhere. We also have Solar Orbiter and Solar Probe Plus underway, so we need to think beyond these missions to address open questions in heliophysics using future missions from L5 and L4.

The SOHO and STEREO spacecraft were close to quadrature from the beginning of 2010 to the beginning of 2012, and demonstrated the importance of observations from off the Sun-Earth line. In particular, STEREO-behind and STEREO ahead were in the vicinity of Sun-Earth L5 and L4 respectively. Locating a mission at Sun-Earth L5 has several key benefits for solar physics and space weather, including: (1) off the Sun-Earth line view is critical in observing Earth-arriving parts of CMEs without the Thomson surface problem, (2) L5 coronagraphic observations can provide near-Sun true speed of CMEs, which is an important input to models that forecast Earth-arrival time of CMEs, (3) backside and frontside CMEs can be readily distinguished even without inner coronal imagers, (4) preceding CMEs in the path of Earth-affecting CMEs can be identified for a better estimate of the travel time, (5) CIRs reach the L5 point a few days before they arrive at Earth, and hence provide significant lead time before CIR arrival, (6) L5 observations can provide advance knowledge of CME and CIR source regions (coronal holes) rotating to Earth view, and (7) magnetograms obtained from L5 can improve the surface magnetic field distribution used as input to MHD models that predict the background solar wind.

The second L5 consortium meeting will take place in the Laboratory for Atmospheric and Space Physics (LASP), University of Colorado, Boulder during December 2-4, 2014 to discuss the current efforts and pathways towards an L5 mission or missions.

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L5 consortium consists of a group of scientists interested in developing mission concepts and instruments that can eventually be placed at Sun-Earth L5 to study heliophysics.

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Room A200, Engineering Building, LASP
University of Colorado, Boulder, CO

Local Airports

Denver International Airport (DEN) (this is the best option):

  • Roughly 43 miles from meeting location
  • Taxis cost around $90.00 one way
  • Super Shuttle and Execucar services available

A few other nearby airports are:

  • Cheyenne Regional Airport (CYS): ~93 miles
  • Colorado Springs Airport (COS): ~104 miles
  • Laramie Regional Airport (LAR): ~140 miles
  • Eagle County Regional Airport (EGE): ~143 miles

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    If you would still like to attend, please contact Nat Gopalswamy via email at

    Click here to see current list of the workshop attendees (opens in a new tab).

    Click here for a list of submitted abstracts (opens in a new tab).

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    Please click here to view the latest agenda for the meeting (opens in a new tab).

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    The following publications may be useful:

    Akioka et al. 2005, AdvSpcRes: The L5 mission for space weather forecasting

    Simunac et al. 2009, Sol Phys: In situ observations of solar wind stream interface evolution

    Webb et al. 2010, Space Research Today: Using STEREO-B as an L5 space weather pathfinder mission

    Gopalswamy et al. November 2010, EASCO white paper submitted to the Solar and Space Physics Decadal Survey

    Vourlidas et al. 2010, Decadal Survery White Paper: Mission to the Sun-Earth L5 Lagrangian Point: an optimal platform for Heliophysics & space weather research

    Gopalswamy et al. 2011, SPIE: Eath-Affecting Solar Causes Observatory (EASCO): a mission at the Sun-Earth L5

    Gopalswamy et al. 2011, J Atm. Sol. Terr. Phys,: Earth-Affecting Solar Causes Observatory (EASCO): a potential international Liwing with a Star Mission from Sun-Earth L5

    Turner and Li 2011, Spc. Weath.: Using spacecraft measurements ahead of Earth in the Parker spiral to improve terrestrial space weather forecasts

    Gopalswamy et al. 2013, Spc Weath.: Testing the empirical shock arrival model using quadrature observations

    Posner et al. 2014, Spc Weath.: The main pillar: assessment of space weather observational asset performance supporting nowcasting, forecasting, and research to operations

    Please send us any relevant publications to include in this list.

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    A few nearby hotels are listed below:

    Courtyard Inn, Boulder (The link opens in a new tab.)

    Best Western Plus Boulder Inn (The link opens in a new tab.)

    From Denver Airport (DEN)
    Faster (with Toll) Directions from Denver Airport (DEN)
    • Follow signs to exit airport
    • Take the ramp onto Peña Blvd
    • Merge onto I-70 W 4.6 mi
    • Slight right at I-270 W (signs for I-270 W/Ft Collins)
    • Continue onto US-36 W
    • Merge onto Co-157 N/Foothills Pkwy exit toward CU Stadium
    • Turn left at Foothills/Colorado onto Colorado Ave
    • Take third right onto Innovation Dr (destination will be on right)
    • Follow signs to exit airport
    • Take the ramp onto Peña Blvd
    • Take exit 6B toward Boulder/Ft.Collins (toll road)
    • Merge onto E-470 N (toll road)
    • Continue onto Northwest Pkwy (partial toll road)
    • Continue onto Storage Tek Dr
    • Take the ramp onto US-36 W
    • Merge onto Co-157 N/Foothills Pkwy Exit toward Cu Stadium
    • Take Left at Foothills/Colorado onto Colorado Ave
    • Take third right onto Innovation Dr (destination will be on right)
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    There are several restaurants within about 1.5 miles from the meeting location.

    LASP website provides the following lists of restaurants:

    Fine Dining: a list of fine dining restaurants.

    Casual Dining: a list of casual to mid range restaurants.

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    Local Organizing Committee

    Nat Gopalswamy
    NASA Goddard Space Flight Center
    Phone: 301-286-5885
    Fax: 301-286-1433

    Curt de Koning
    Phone: 303-497-4490

    Xinlin Li
    Phone: 303-492-3514

    Andrew Jones
    Phone: 303-735-0914

    Vince Guarino
    Phone: 303-735-6745

    For questions regarding conference registration and this website: please contact, Phone:301-286-8312.