Lawrence Berkeley National Laboratory

We examine the constraints that satellite-acquired Type Ia and IIP supernova apparent magnitude versus redshift data will place on cosmological model parameters in models with and without a constant ortime-variable cosmological constant lambda. High-quality data which could be acquired in the near future will result in tight constraints on these parameters. For example, if all other parameters of aspatially-flat model with a constant lambda are known, the supernova data should constrain the non-relativistic matter density parameter omega to better than 1 (2, 0.5) at 1 sigma with neutral (worst case, best case) assumptions about data quality.