Karun Thanjavur (UVIC) ALTAIR: Calibrated balloon-borne light sources for precision spectro-photometry. Observational systematic uncertainties are currently the dominant limitations facing ground and space based surveys to constrain the properties of Dark Energy and associated cosmological parameters. The largest (and growing) fraction of these uncertainties are due to spectro-photometric flux calibration, in particular from the current practice of using standard stars alone for these calibrations. Assessment of observational systematics in Dark Energy experiments such as CFHT-SNLS3 have repeatedly highlighted the necessity for photometric calibration precision to better than the current 1-2% barrier in order to fully utilize the statistical benefits of the rapidly expanding sample sizes from ongoing and future massive surveys such as DES, LSST and WFIRST. In this context we present ALTAIR, a stratospheric balloon borne, NIST- and NRC-INMS-calibrated set of small, optical, monochromatic light sources as the highest precision standard source to fully characterize the telescope and detector, while measuring the atmospheric transmission simultaneously with the science observations. In this presentation, I will motivate our efforts, summarize ongoing laboratory measurements as well as field trials including 13 successful flights to date, and discuss plans for upcoming science flights at Mt. Hopkins and Pan-STARRS in 2015. In closing, I will summarize future plans for microwave calibrations of the South Pole CMB observatory, and a nanosat designed by UTIAS-SFL to carry the calibration laser source in near earth orbit.