section_path: Versions/V1.1
section_name: V1.1
paragraph_text: V1.1
  
  V1.1 is 60% heavier with 60% more thrust than v1.0. Its nine (more powerful) Merlin 1D engines were rearranged into an "octagonal" pattern that SpaceX called Octaweb. This is designed to simplify and streamline manufacturing. The fuel tanks were 60% longer, making the rocket more susceptible to bending during flight.
  
  The v1.1 first stage offered a total sea-level thrust at liftoff of 5,885 kN (1,323,000 lb), with the engines burning for a nominal 180 seconds. The stage's thrust rose to 6,672 kN (1,500,000 lb) as the booster climbed out of the atmosphere.
  
  The stage separation system was redesigned to reduce the number of attachment points from twelve to three, and the vehicle had upgraded avionics and software.
  
  These improvements increased the payload capability from 9,000 kg (20,000 lb) to 13,150 kg (28,990 lb). SpaceX president Gwynne Shotwell stated the v1.1 had about 30% more payload capacity than published on its price list, with the extra margin reserved for returning stages via powered re-entry.
  
  Development testing of the first stage was completed in July 2013, and it first flew in September 2013.
  
  The second stage igniter propellant lines were later insulated to better support in-space restart following long coast phases for orbital trajectory maneuvers. Four extensible carbon fiber/aluminum honeycomb landing legs were included on later flights where landings were attempted.
  
  SpaceX pricing and payload specifications published for v1.1 as of March 2014 included about 30% more performance than the published price list indicated; SpaceX reserved the additional performance to perform reusability testing. Many engineering changes to support reusability and recovery of the first stage were made for v1.1.