## 3 Methods and Results
### Experimental Results  
Numerous experiments have been conducted in low orbit aboard the ISS (both within and beyond the confines of the station) and on satellites such as the Foton-M2 to M4. Passive radiation detectors have been predominantly used in these experiments and have been the subject of further analysis both on the ISS and on the ground.  
Table 2 compares the absorbed dose rate measurements obtained from experiments aboard the ISS, such as PADLES [31], BRADOS-1 [32], LIULIN-5 [33], DOSIS and DOSIS3D [34], and the ISS-RAD experiment [35] with predictions made by the Systems Tool Kit (STK) and SPENVIS (AE8-AP8 and CRRES) models.  
Other experiments, summarized in Table 3, show similar results. Note that the shielding in the case of the SATRAM-Timepix experiment is 0.5 mm and that the CRRES simulations can only be carried out with a 2 mm aluminum thickness. In the case of the sensor  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Experiment**} & \multirow{2}{*}{**Period**} & \multirow{2}{*}{**Days**} & \multirow{2}{*}{**Orbit**} & **Measured** & & **SPENVIS** & **SPENVIS** \\  & & & **(km)** & **Dose Rate** & **STK** & **AES-AP8** & **CRRES** \\  & & & **(km)** & **(uGy/Day)** & **(uGy/Day)** & **(uGy/Day)** & **(uGy/Day)** \\ \hline \multirow{2}{*}{PADLES} & June 2008 to & & & & & & \\  & March 2009 & 301 & 352 & 247–360 & 1275 & 455.89 & 6449.32 \\ \hline \multirow{2}{*}{PADLES} & March 2009 & & & & & & \\  & to Sept 2009 & 180 & 350 & 220–329 & 1313 & 366.85 & 5657.53 \\ \hline \multirow{2}{*}{DOSIS} & July 2009 to & & & & & & \\  & June 2011 & & 350 & 195–270 & 1877 & 428.77 & 5928.77 \\ \hline \multirow{2}{*}{DOSIS3D} & 2012 to & & & & & & \\  & October 2001 & & & 208–275 & 1352 & 1635.34 & 7145 \\ \hline \multirow{2}{*}{LIULIN-5} & July 2007 to & & & & & & \\  & Feb 2009 & & 350 & 180–220 & 1048 & 863.56 & 7490.41 \\ \hline \multirow{2}{*}{ISS-RAD} & Jan 2016 to & & & & & & \\  & Jan 2017 & 365 & 411 & 255 & 2444 & 1120.82 & 8813.70 \\ \hline \multirow{2}{*}{ISS-RAD} & Dec 2019 to & & & & & & \\  & Dec 2020 & 358 & 426 & 361 & 2824 & 1284.93 & 8813.70 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Comparison of absorbed dose rate measurements aboard the ISS and in other satellites and predictions from SPENVIS (AE8-AP8 and CRRES) and STK models with 12 mm of aluminum shielding thickness for the same period of time. Based on the results, we can observe a significant difference between the data from the models and those obtained through actual dosimetry.  
aboard the FOTON-M4 mission, the author [36] observes the same radiation value obtained during the same period of time in the Dosis-3D/5 experiment aboard the ISS.  
Missions aboard the MIR space station collected data for several years [30] using TLDs at various locations within the station. Table 4 presents the collected values of dose rate and the comparison using SPENVIS (AE8-AP8 and CRRES) and STK models. The results are comparable to the ones obtained in the ISS, with similar differences between measurements and models for the same orbit and duration.  
Some experiments have been carried out on nanosats such as Timepix [37] or iMERSA-R [38], and on cubesats with experiments such as Lucky7 [39], where active radiation sensors were installed. These missions have demonstrated their ability to detect and accurately determine the flow of protons and electrons. Although the amount of data they carry is not excessively large, it represents an important step toward the design of more reliable and precise detectors to be used in future missions.