The US military is very dependent on satellites. The existing satellite architecture used has single point failures to existing recognized threats. A concept that could provide a significant part of the solution of how the US as well as other states can overcome such vulnerabilities is discussed. The prescription centers on a new satellite architecture --the 'Multi-tiered Microsatellite Constellation Architecture' (MMCA) -- which reduces risks to space assets by increasing system redundancy, modularity and dispersion through the use of microsatellite constellations in several orbital tiers. An example constellation design is given for each of the five major contemporary military space uses -- early warning, reconnaissance, signals intelligence, military communications and navigation. The scheme is placed in the context of other complimentary elements that are likely to be necessary to enable security of space assets, in particular: protection of space systems; responsive space access; terrestrial alternatives; space surveillance; treaties; and verification means thereof. Since the Chinese anti-satellite (ASAT) test, the response of the US military in part has been to re-double efforts to develop Operationally Responsive Space (ORS). Whilst ORS is a key ingredient, it must be complemented by a more secure satellite architecture. In addition to dealing with satellite vulnerabilities, the talk will discuss issues relating to space-based weapons and their effectiveness.

William Marshall is based in the Small Spacecraft Office at NASA's Ames Research Center in California. He holds a PhD in Physics from the University of Oxford, U.K., where his thesis centred on an experimental proposal to create macroscopic mass quantum superposition states. He conducted two years of his research at the University of California in Santa Barbara. He holds a degree in Physics with Space Science and Technology (MPhys) from the University of Leicester, UK. He has held placements at the European Space Agency, NASA's Jet Propulsion Laboratory, Marshall Space Flight Center and the Parliamentary Office of Science and Technology (POST) in London. Will's work at NASA centers on mission planning, in particular trajectory analysis, and spacecraft testing for a variety of microsatellite missions, focusing on lunar orbiters and landers. He is working on a project on the topic of space traffic management. Will serves on the Governance Group of the Space Security Index research project and also holds positions of non-resident fellow at both the Space Policy Institute (SPI) of the George Washington University and the Belfer Centre for Science and International Affairs, Kennedy School of Government, Harvard University. In these capacities, Will has published on strategic benefits and costs of the deployment of space weapons and more broadly the increasingly important role that space is playing in global security issues. Will is the Global co-Chair of the Space Generation Advisory Council to the United Nations Programme on Space Applications (SGAC), which represents the views of students and young professionals interested in space to the UN and space agencies around the world.