Several months ago, SpaceX completed the first of three phases of review required by NASA's Safety Review Panel (SRP) to send the Dragon spacecraft to the ISS. The review covered twenty-three hazards, with extra attention paid to the danger of collision - one of the most difficult hazards to mitigate, and generally considered one of the most difficult areas for "visiting vehicles".
The SpaceX propulsion team has completed the first Draco development engine, and it will soon begin testing at their new MMH/NTO vacuum test chamber in Texas. Once completed, the Dragon spacecraft will have a total of 18 Draco thrusters for both attitude control and orbital maneuvering.
SpaceX has completed the full-scale engineering unit of Dragon's heat shield. Shaped like the heat shields that protected the Apollo cpasules during their high-speed returns from the Moon, Dragon's heat shield uses phenolic impregnated carbon ablator (PICA), the highest heat resistance material known. At heat fluxes that would vaporize steel, PICA is barely scathed.