This study is concerned with the use of Thermoluminescent Detectors (TLDs) in low-dose and slow-rate radiation environments, as encountered by manned or unmanned satellites in space. In the first phase of this work, samples of four types of TLDs (LiF and CaF 2 of small and large size) were exposed to an absorbed dose rate of 10 #Gy/min (1 mrad/min) of 6Β°Co 7 rays at irregular, intermittent intervals for a total of 62 min/day. Irradiations lasted for seven days and were followed by one day of annealing at room temperature, prior to the final measurements. Results show that the larger size TLDs followed the expected linear increases of light output with dose for each day without indication of either fading (due to the relatively long time period between irradiations) or discrepancies (due to the low dose rates in comparison to background and noise), whereas the smaller samples deviated significantly from the linear increase of a projected dose-per-day curve, implying an effective and substantial daily fading process in the slow-rate environment. These latter results, however, need further investigation. Some contributing sources of error in the small LiF dosimeters have been identified, such as the existence of high temperature traps in the 400 Β° 600Β°C temperature range. Conclusions and recommendations are presented.