Galactic cosmic-ray energy spectra and expected solar events at the time of future space missions

Galactic cosmic-rays (GCRs) and solar energetic particles (SEPs) affect observations on board long-lived space missions. We developed a parameterization of proton and helium fluxes for various levels of solar modulation during opposite polarity periods. In addition to long-term variations (decades), short-term fluctuations (minutes to days) were considered as well. In particular, we focused on data from experiments carrying magnetic spectrometers in space. The shortest GCR variations we were able to study are of the order of hours. We point out that GCR variations and fluctuations are strongly energy dependent. The detector charging onboard space experiments is also energy dependent. The measurements of energy differential fluxes and their variations are needed in order to evaluate properly the performance of future space missions. We present here the projections for the GCR fluxes and solar events at the time of LISA (Laser Interferometer Space Antenna) Pathfinder (LISA-PF).