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The Hubble Constant has been, historically, the most fundamental parameter in observational cosmology. Today, direct measurements of H0 remain a top priority of the cosmology community. In the context of the standard LCDM model, Planck observations of the CMB predict H0 to be 67.8 km/s/Mpc with 1% precision, while astrophysical measurements using traditional standard candles (Cepheids and SN Ia) measure 74 km/s/Mpc with 3% uncertainty. The tension between these values may indicate new physics, so the measurements require independent confirmation. I will describe ongoing work seeking new measurements of H0, including efforts by the Megamaser Cosmology Project (MCP). The MCP combines spectral monitoring of water maser disks in AGN with sensitive VLBI mapping to determine direct geometric distances to the host galaxies. I will also summarize recent work using gravitational lens time delays to measure H0. Each of these methods is capable of determining H0 with a few percent total uncertainty within a couple of years. With new, sensitive telescopes proposed in the coming decade, it may be possible to reach percent-level precision.
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