PSF point spread function
PSI physiological strain index
PSK-ir perisulfakinin immunoreactive
PSSC Pico-Satellite Solar Cell Experiment
P3R plants, protocols, procedures and requirements
PuFF Pulmonary Function in Flight
Puls Study of Vegetative Regulation of the Cardiorespiratory System in Weightlessness
PVA polyvinyl alcohol
PVT (^) Psychomotor Vigilance Test
Pro K Dietary Intake Can Predict and Protect Against Changes in Bone Metabolism during Spaceflight and Recovery
QCT quantitative computed tomography
qRT-PCR quantitative real time-polymerase chain reaction
QTCMA Quad Tissue Culture Module Assembly
QUS quantiative ultrasound
Rad Gene Gene Expression of p53-regulated Genes in Mammalian Cultured Cells
After Exposure to a Space Environment
RaDI-N Radi-N Neutron Field Study
Rad Silk Integrated Assessment of Long-term Cosmic Radiation Through
Biological Responses of the Silkworm, Bombyx mori, in Space
RAFT radar fence transponder
RAIDS Remote Atmospheric and Ionospheric Detection System
RAMBO Ram Burn Observations
RANKL receptor activator of NF-B ligand
RASV Recombinant Attenuated Salmonella Vaccine
rbx- 1 ring-box 1
RCS Reaction Control System
Reaction Self Test Psychomotor Vigilance Self Test on the International Space Station
REBR Re-Entry Breakup Recorder
Relaksatsiya Processes of Relaxation in the Ultraviolet Band Spectrum by High-^
Velocity Interaction of Exhaust Products on ISS
Renal Stone
Renal Stone Risk During Spaceflight: Assessment and Countermeasure
Validation
Repository National Aeronautics and Space AdminisRepository tration Biological Specimen
Resist Wall Role of Microtubule-Membrane-Cell Wall Continuum in Gravity
Resistance in Plants
RFII Radio Frequency Impedance Interrogation
Rho Signalling Signalling through Rho GTPases in microgravity