The Athena rocket was a smaller expendable launch system manufactured by Lockheed Martin. There are two different variants of the rocket; the Athena I and Athena II. The Athena I is the slightly smaller rocket compared to the Athena II. The Athena I stands 18.9 meters tall (62 feet). While the Athena II is 28.2 meters tall (93 feet). Both the Athena I and Athena II have a diameter of 2.36 meters (7.7 feet). The Athena I has a payload capacity of 820kg (1,810lbs) to low earth orbit. The Athena I uses 2 stages. Stage I of the Athena I uses a Castor-120 that produces 1,900kN of thrust (430,000lbs), while the second stage uses Orbus 21D upper stage that creates 189.2kN of thrust (42,500lbs). The first flight for the Athena I was in August of 1995. The Athena I was launched a total of 4 times which of 3 were a success. The Athena II has a payload capacity of 1896kg (4,350lbs). Moreover, The Athena II uses 3 stages. The first stage and second stage uses a Castor-120 that produces 1,900kN of thrust (430,000lbs). The third stage uses a Orbus 21D that also creates 189.2kN of thrust (42,500lbs). The Athena II was launched 3 times and had only 2 successes. The Athena I and II are able to launch from multifarious launch sites: Kodiak, Cape Canaveral, and Vandenberg. The last launch of the Athena was on September of 2001.