This website is dedicated to hosting the most comprehensive, single, archive of the in-situ Helios 1 & 2 data along with previously unavailable documentation on the different instruments, their operation, the datasets, and the early data processing.

Dr. Chadi Salem (Space Sciences Laboratory/University of California Berkeley) has been funded by NASA, under a two-year NASA HDEE grant (grant NNX14AQ89G, 10/1/14 – 9/30/16) to work on aggregating, analyzing, evaluating, documenting and archiving the available Helios 1 & 2 in-situ data.  The work and team effort put forward under this project and the development of this single Helios archive was done in very close collaboration with colleagues at the University of Koln (Germany), the University of Kiel (Germany), the Imperial College in London (UK), the LPC2E and University of Orléans (France) and at the Paris Observatory (France).

Up to date, there has been no comprehensive public repository of all Helios in-situ data.  Most of the highest resolution data could be obtained from a variety of places, although with very little documentation, especially on calibration.  Analysis of this data set requires overcoming a number of technical and instrumental issues, knowledge and expertise of which is only possessed by the original PI’s of the Helios experiments.  Therefore, there was a sense of urgency to revisiting and reanalyzing this valuable, unique, dataset, and to establishing its long-term preservation now before detailed knowledge is lost.  Hence this project and this single archive of all in-situ Helios data.