The recently formed Space Development Agency is preparing to buy 150 satellites to continue to form a multi-layered system that will deliver data to weapons systems, extend surveillance and support ground systems with critical information. The large buy of satellites is part of SDA’s “throwing spaghetti against the wall” approach of putting up a high volume of low-cost satellites. “What our architecture is based on is proliferation and spiral development,” Derek Tournear, SDA director, said Tuesday at a Space Foundation event. “When I say ‘proliferation,’ I mean hundreds of satellites. That is what will give you the persistence and the resiliency that you need. The spiral development will give you the rapid capability and rapid fielding.”