Exploitation of Space Ionizing Radiation Monitoring System in Exploitation of Space Ionizing Radiation Monitoring System in RussianRussian Federal Space AgencyFederal Space Agency

STRUCTURE OF THE MONITORING SYSTEMSTRUCTURE OF THE MONITORING SYSTEM

The Monitoring System includes two parts: the ground-based segment and the engineering monitoring system (space-born segment), - and deals with scientific station and ground-based facilities.

The main features of the engineering monitoring system are:

• measurements of space ionizing irradiation exposure on electronic components;

• registration of the effects in electronic components, not particles;

• low size and mass;• necessity to place on all spacecrafts;• specific orbit measurements.

The base component of space-born segment is a set of TID sensors. These sensors operate on MNOSFET dosimetry principle, which has following advantages:•output electrical signal is proportional to

TID;•real-time monitoring of TID;•low size and power;•work volume is analogous to TID sensitive

area in MOS devices.Specification:• Output range: 100-100.000 rad;• Frequency output: 1-200 kHz;• Analog output: 0.5-5 V;• RS-485 interface;• Power supply: 27 V.

Fig.1. The structure of the Monitoring System

FLIGHT DATA ANALYSISFLIGHT DATA ANALYSIS

Fig.2. The flight data for 26 TID sensors onboard 13 spacecraft at the circular orbit ~20000 km from October 2008 to October 2011

Anomalous increasing dose rate is observed in: •October 2008: in ~ 3 times; October 2010: in ~ 6 times; February 2011: in ~ 4 times; March 2011:

in ~ 15 times; September 2011: in ~ 4 times (Figures 3 - 6). It can be explained by a sharp increase of 2 MeV electrons GEO, that is confirmed by GOES measurement. The flight data are in agreement (at October 2008, October 2010, February and March 2011) and are in consistence (at September 2011) with International Space Station and Ground–level measurement.

•April 2010: in ~ 100 times. The increase of dose rate on MEO cannot be explained only by an increase of electron and proton fluence. According to GOES, International Space Station and ground-level measurements, the increase of dose rate on MEO was more substantial. However, this data can be explained by the compression of Van Allen Belts and, as a result, by increasing particle fluence on MEO.

The Russian Federal Space Agency Monitoring System of space ionizing radiation exposure on electronic components was developed and operates successfully. The total ionizing dose flight data were received by MNOSFET TID sensors which were set onboard in several spacecrafts. The dose rate increasing in October 2008, October 2010,

February, March and September 2011 is in agreement with other monitoring system data and with ground-level measurements. The Monitoring System provides user the space weather forecasts. The main cause of failure events of the space avionic at the geostationary orbit is electron exposure.

FLIGHT DATA FROM FLIGHT DATA FROM JUNE TO OCTOBER 2011JUNE TO OCTOBER 2011

Fig.3. The flight data from June to October 2011

Fig.4. GOES electron flux (E >2 MeV) from June to October 2011

Fig.5. The International Space Station average dose rate flight data from June to October 2011

Figure 6. Ground-level measurements of cosmic ray variations (Moscow Neutron Monitor) from June to October 2011, a.u./min

V.S. Anashin1, G.A.Protopopov1, S.V. Balashov2, S.P. Gaidash3, Y.A. Milovamov4, N.V. Sergeecheva5

1Institute of Space Device Engineering (Moscow, Russia); npk1-niikp@mail.ru; 2Information Satellite Systems” Reshetnev Company, (Zheleznogorsk, Russia); 3Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation (IZMIRAN) (Troitsk, Russia); 4Russian Federal Space Agency; 5S.P.Korolev Rocket and Space Corporation “ENERGIA” (Korolev, Russia)

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09.2008 02.2009 07.2009 12.2009 05.2010 09.2010 02.2011 07.2011 12.2011

Date

Dose, a.u

. .

ANOMALIES ANALYSISANOMALIES ANALYSIS

GROUND-BASED SPACE WEATHER GROUND-BASED SPACE WEATHER FORECAST STATIONFORECAST STATION

Fig.7. Example of solar proton increasing forecast

Fig.8. Example of high energy electron (E>2 MeV) fluence forecast

Available to user forecasts:● Protons increasing ● Geomagnetic and solar activity● Electron fluence ● Proton alert

Table 1. The data of anomalies (failure events) of the space avionics at the geostationary orbit

“Electron” – the high energy electron (E>2 MeV) at the geostationary orbit;“Proton” – the protons (E>2 MeV) at the geostationary orbit;“TID sensors” – the flight data at the circular orbit ~20000 km

  - a danger level

- exceeding of the danger level

For electrons: 1000 electrons/cm2-s-srFor protons: 10 protons/cm2-s-srFor TID sensors: average dose rate (~ 3.5E-04 a.u./s for 2011 year, electrons bring the main dose contribution)

Conclusion: the cause of failure events is the exposure of electrons