ESA Space Environments & Effects

The space environment and effect section's website is split into this website and a general ESA website. General information on space environments and their effect in general and a section overview can be found there.


More detailed information of the section's activities can be found here.

 

Highlights

Soft Proton Fluxes in and around Earth’s Magnetotail

Analysis of 10 keV to 1 MeV proton environment (“soft protons”) in Earth’s neighbourhood beyond the radiation belts has been recently published in IEEE TPS. Soft protons are particularly interesting for X-ray space telescopes, since they pass through X-ray optics and cause background increase in the telescope instruments – affecting observations performed by Chandra and XMM-Newton. The second L-class (large) mission in ESA’s Cosmic Vision programme will be a large X-ray telescope named Athena, planned to operate at the L2 Lagrange point of the Sun-Earth system. There, the spacecraft would encounter protons accelerated both in the heliosphere and in the tail of Earth’s magnetosphere. Twin NASA Artemis spacecraft have measured proton fluxes in Earth’s magnetotail at the distance of the Moon’s orbit (about 60 Earth radii) – these data serve as proxy for proton rates in the still more distant environment near the L2 point (about 235 Earth radii).

 

In the first plot below, the proton spectrum measured by Artemis in Earth’s magnetotail is compared to the spectrum measured by NASA ACE spacecraft at the Sun-Earth L1 Lagrange point, which sees only protons of heliospheric origin. The spectra show proton fluxes which are not exceeded 90% of time, in a 9 month period in 2010 and 2011. Above 100 keV, the spectra show good agreement, indicating that heliospheric proton fluxes were dominant. However, protons in 30 to 80 keV energy range are most critical as background for the instruments of Athena. At these lower energies the Artemis data show an increase in flux contributed by the Earth’s magnetotail.

 

The second plot shows the background spectra in Athena instruments, derived using Monte Carlo simulations from the source proton flux as measured by Artemis in the magnetotail. Athena space telescope will use magnetic deflectors, not included in our simulation, to further suppress the proton fluxes in order to achieve the low background required for the most demanding astrophysical observations.

90% worst-case spectra for solar (from ACE) and solar + Earth magnetotail (from Artemis) proton flux.
90% worst-case spectra for solar (from ACE) and solar + Earth magnetotail (from Artemis) proton flux.
Estimate of soft-proton background in Athena X-ray detectors without magnetic diverters.
Estimate of soft-proton background in Athena X-ray detectors without magnetic diverters.

FORecasting Solar Particle Events and Flares

The prototype FORSPEF (FORecasting Solar Particle Events and Flares) System is now available!


This system, initially developed at the behest of the launcher directorate at ESA, is operated by the Space Research and Technology Group of the Institute for Astronomy, Astrophysics, Space Applications & Remote Sensing (IAASARS), National Observatory of Athens (NOA) with funding from ESA's Technology Research Programme (ESA Contract No. 4000109641/13/NL/AK). The system combines solar flare forecasting with an historical Solar Particle Event (SPE) catalogue in order to give long-term predictions of possible radiation flux enhancements of solar origin in the near-Earth environment.

 

 

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Rosetta SREM Solar Particle Event

Following the arrival of the Rosetta spacecraft at the comet  67/P Churyumov-Gerasimenko on 6 August, the first solar particle event to reach the spacecraft at the comet location has been observed by the on-board ESA Standard Radiation Environment Monitor (SREM). The diagram below shows the timeline of radiation counts between 1st September and 3 September as observed by three of the SREM energy channels TC3, S12 and TC2, sensitive to protons of energies above 12, 27 and 49 MeV respectively. The solar event in question took place on 1 September and originated from the far side of the Sun, just beyond the northeastern limb, and hence was not visible at Earth. However it was seen by the NASA Stereo spacecraft based behind the Sun.The present location of the Rosetta and the comet 67/P is currently such that there is a good heliospheric magnetic connection between the Earth and Rosetta. This translates to good correlation of the observations between the SREM unit on Rosetta and another one on the Earth-orbiting INTEGRAL spacecraft, the counts for which are also shown for comparison.

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Rosetta SREM Awakes

Following the recent emergence of the ESA Rosetta mission from its 2.5-year deep-space hibernation, the first new data from the on-board Standard Radiation Environment Monitor (SREM) instrument have been received, The attached figure shows the charged particle count rates observed in two energy channels of the SREM: TC3, which is sensitive to protons from roughly 27 MeV energy upward, and TC2 from 49 MeV on. The counts observed give an indication of the Galactic Cosmic Ray (GCR) environment encountered by Rosetta at its current location at 4.4 AU distance from the Sun. These new measurements take place during a solar maximum period and are a factor ~2 lower than in February 2011 which was during the previous solar minimum. This is as expected by the variation of the GCR fluxes over the 11-year solar cycle. Similar behaviour can be observed by another SREM unit on the ESA Integral spacecraft ("IREM") at 1 AU, showing the good agreement between the different SREM units. The spikes seen in the Integral diagram result from the periodical passage of the spacecraft through the Earth's radiation belts, while the periods in between correspond to the interplanetary space.

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EPT first results

The Energetic Particle Telescope (EPT) is an instrument designed for high-fidelity measurements of the charged particle radiation environment in space. The first EPT flight unit was launched to a polar orbit onboard the Proba-V spacecraft on 7 May, 2013 and following the commissioning phase the first EPT results have been obtained. These results show a good coverage of the near-Earth radiation environment as well as sporadic enhancements caused by Solar Particle Events (SPE). Data from the EPT will help to improve the present radiation environment models, and to cross-calibrate results obtained from a number of coarser in-orbit radiation monitoring devices, such as the ESA Standard Radiation Environment Monitor (SREM).

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JUpiter Icy moons Explorer

The JUpiter Icy moons Explorer, previously known as Laplace, was recently chosen as the first “large”-class Science mission of the ESA Cosmic Vision 2015-2025 programme. The mission will encounter the highly severe radiation environment of Jupiter, against which special shielding and design countermeasures will need to be taken. The Jovian plasma and micrometeorite environments are also unique and need to be carefully considered. To aid the formulation and eventual design activities of the mission, various capabilities have been developed under various space environments and effects contracts.

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March Solar Proton Event

Following a quiet period in February, March has brought increased solar activity and with it the largest solar energetic particle event of cycle 24 so far. A cluster of sunspots designated sunspot 1429 appeared at on the Eastern limb of the solar disk, on the 2nd of March. This produced an M3 class solar flare, which was followed in the morning of the 5th of March with an X1.1 class solar flare and an impressive associated CME visible on the LASCO C2 images at 04:00:05.

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10 Years of Proba-1 SREM data

The Project for On-Board Autonomy (Proba) is a technology demonstration mission of the European Space Agency, funded within the frame of ESA’s General Support Technology Programme (GSTP). It is managed by ESA’s Control and Data Systems Division within the Department of Electrical Engineering, part of the Directorate for Technical and Operational Support at ESA/ESTEC.

A Standard Radiation Monitor (SREM) was include as a payload on Proba-1, with the first data provided on the 29th October, 2001.

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SEPEM release

The SEPEM (Solar Energetic Particle Environment Modelling) Application Server is now open for registration. The server allows users to plot and download data from Solar Energetic Particle Events and to create statistical models for long-term predictions of the SEP environment. This includes well known methodologies such as ESP and JPL as well as new models using virtual timelines.

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The 2011 Draconid meteor shower

On 8 October 2011, the Earth will cross a stream of dust particles that have been ejected from the comet 21/P Giacobini-Zinner more than a century ago.


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First Solar Particle Event of Solar Cycle 24

The first Solar Particle Events of the new Solar Cycle 24 have taken place. While the event on 14 August 2010 was rather small in amplitude, it was detected by ESA's Standard Radiation Environment Monitor (SREM) units flying on Herschel, Planck and INTEGRAL missions. The images below show the energetic proton fluxes at Herschel and Planck as derived from the raw SREM counts by the Singular Value Decomposition method developed at ISARS/NOA (GR).

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First SREM data from Herschel/Planck

After their successful launch yesterday (14 May 2009), the first SREM data have been received from both the Herschel and Planck spacecraft.

The SREM instruments on the two spacecraft were switched on at slightly different times, but clearly show very similar count rates in all channels.



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GIOVE-B

The GIOVE-B satellite, is the second Galileo in-orbit validation element preparing the way for the deployment of the Galileo satellie system. It carries a radiation monitor known as SREM, designed by the Paul Scherrer Institute and built by Oerlikon Space, both in Switzerland.

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DEBIE-2

DEBIE-2 impact detector launched to ISS onboard Columbus. The in-situ impact detector DEBIE-2 is one of the payloads of the European Technology Exposure Facility (EUTEF). DEBIE-2 will measure the sub-mm size populations of meteoroids and space debris particles in space.

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Rosetta Fly By

ESA's Rosetta satellite had an Earth swing-by on 13 November 2007. The closest distance was 5300km from the Earth surface. One of the onboard instruments of the Rosetta satellite is the SREM radiation monitor, which measured the presence of the Radiation belts during the swing-by.

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CHAMP/SWARM Modelling Using SPIS

The CHAllenging Mini-satellite Payload (CHAMP) satellite is a small German satellite mission for geoscientific and atmospheric research.

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Solar Wind Shock simulation

Solar energetic particle (SEP) events represent one of the most severe hazards in space environment.

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