The technical innovation proposed here is the continued functional evolution and concept refinement of an incremental series of test vehicles that will ultimately provide dedicated, low-cost, reliable, on-demand routine space access for the emerging nano and micro satellite markets. Initial orbital operational capability for delivering 10 kg to a 250 km circular LEO is achieved with a two-stage, pressure-fed "10/250" Nanosat Launch Vehicle (NLV) that will pathfind performance, production, regulatory and operational challenges. This NLV will then be followed by a clustered "20/450" Nano/Micro Satellite Launch Vehicle (NMSLV) that addresses this topic's primary objective of providing a capability to place nano and micro satellites weighing up to 20 kg into 450 km circular LEO. Aggressive leveraging of our team's existing NLV development initiative enables significant hardware development and the start of static fire testing during Phase I, followed by actual flight testing in Phase II for TRL-7 technology evaluations. These tests have incrementally introduced state of the art capabilities like advanced propellants (LOX/propylene) and structures (composite cryogenic tanks). The Phase I effort focuses on the development of the next class of test vehicle a high altitude suborbital single booster stage (the "P-K") that features closed-loop thrust vector control (TVC) and candidate avionics technologies for guidance and navigation, as well as eventual autonomous flight termination systems (AFTS) for range safety, TRDRSS-based telemetry and tracking functions. In addition, it will incorporate features needed to implement the clustered first stage configuration and second stage separation method associated with the 20/450 NMSLV. The Phase II effort will then focus on the further development of an NMSLV-type first stage with two additional core boosters, for a total of three, and the conducting of a high-altitude demonstration flight.