The first three Able series of space probes were also called Thor-Able because they were launched on Thor booster rockets.

• Pioneer 0 (Thor-Able 1) called the Able 1 probe. (Pioneer)
• Pioneer 1 (Thor-Able 2) called the Able 2 probe. (Pioneer I)
• Pioneer 2 (Thor-Able 3) called the Able 3 probe. (Pioneer II)

These Able series of space probes were also called Atlas-Able (Pioneer P series) because they were launched on Atlas launchers.

• Pioneer P-1 (Atlas-Able 4A) called the Able 4A probe. (Pioneer W)
• Pioneer P-2 (Atlas-Able 6) called the Able 6 probe. (Pioneer 5, or Pioneer V)
• Pioneer P-3 (Atlas-Able 4B or Atlas-Able 4) called the Able 4 or Able 4B probe. (Pioneer X)
• Pioneer P-30 (Atlas-Able 5A) called the Able 5A probe. (Pioneer Y)
• Pioneer P-31 (Atlas-Able 5B) called the Able 5B probe. (Pioneer Z)

See also

• Pioneer program