Table:
Launch date | Operator | Name | Sample origin | Samples returned | Recovery date | Mission result
June 14, 1969 |  | Luna E-8-5 No.402 | The Moon |  | - | Failure / Launch failure
July 13, 1969 |  | Luna 15 | The Moon |  | - | Failure / Crash-landed on the Moon
23 September 1969 |  | Cosmos 300 | The Moon |  | - | Failure / Failed to leave Earth orbit
22 October 1969 |  | Cosmos 305 | The Moon |  | - | Failure / Failed to leave Earth orbit
6 February 1970 |  | Luna E-8-5 No.405 | The Moon |  | - | Failure / Launch failure
September 12, 1970 |  | Luna 16 | The Moon | 101 grams (3.6 oz) / of lunar rock | September 24, 1970 | Success
September 2, 1971 |  | Luna 18 | The Moon |  | - | Failure / Crash-landed on the Moon
February 14, 1972 |  | Luna 20 | The Moon | 55 grams (1.9 oz) / of lunar rock | February 25, 1972 | Success
November 2, 1974 |  | Luna 23 | The Moon |  | - | Failure / Drilling device damaged on Moon landing / Mission abandoned
October 16, 1975 |  | Luna E-8-5M No.412 | The Moon |  | - | Failure / Launch failure
August 9, 1976 |  | Luna 24 | The Moon | 170 grams (6.0 oz) / of lunar rock | August 22, 1976 | Success
1979 (planned) / (canceled 1977) |  | Mars 79 ("Mars 5M") | Mars | - | - | Canceled in 1977 / Planned to return 500 grams (18 oz)
February 7, 1999 |  | Stardust | 81P/Wild / (Comet coma) | Over 1 million / comet particles | January 15, 2006 | Success
August 8, 2001 |  | Genesis | Solar wind | Solar wind particles | September 8, 2004 | Partial success / Return capsule damaged after failed parachute deployment / Some usable samples recovered
May 9, 2003 |  | Hayabusa | 25143 Itokawa / (Asteroid surface) | 1,500 grains / of asteroid particles | June 13, 2010 | Partial success / Planned to return several hundred milligrams
November 8, 2011 |  | Fobos-Grunt | Phobos / (Mars satellite soil) |  | - | Failure / Failed to leave Earth orbit / Crashed into the southern Pacific Ocean / Returned none of the 200 grams (7.1 oz) planned
July 2014 / (planned, earliest) |  | Hayabusa 2 | Planned for / (162173) 1999 JU3 / (Asteroid surface) | - | 2020 (planned) | 
2016 / (planned) |  | OSIRIS-REx | Planned for / 101955 Bennu / (Asteroid regolith) | - | 2023 (planned) | Planned to return between 60 g to 2 kg (2.1 oz to 4.4 lb)
2017 / (planned) |  | Chang'e 5 | The Moon | - | 2017 (planned) | Planned to return at least 2 kilograms (4.4 lb)
2020-2022 / (proposed) |  | MarcoPolo-R | Near-Earth object / (Asteroid surface) | - | To be determined | To return samples from a yet to be determined near-Earth object
2020/2021 / (planned) |  | Luna-Grunt | The Moon | - | 2021 (planned) | Planned to return up to 1 kilogram (2.2 lb)
Mid-2020s / (proposed) |  | MEJI / MSR | Mars | - | To be determined | To be determined
Mid-2020s / (proposed) |  | Mars-Grunt | Mars | - | To be determined | Intended to return about 200 grams (7.1 oz)
By 2030 |  | Chinese Mars sample return mission | Mars | - | To be determined | To be determined
To be determined | (private) | OpenLuna | The Moon | - | To be determined | Intended to return about 200 kilograms (440 lb)

Question: what was the name of the mission previous to cosmos 300?
Answer: Luna 15

Question: what year was the first success?
Answer: 1970

Question: what was the average amount of missions that were successful?
Answer: 4

Question: how many missions have returned samples?
Answer: 6

Question: how many missions had launch failures?
Answer: 3

Question: other than cosmos 300, name a mission that failed to leave earth's orbit.
Answer: Cosmos 305

Question: how many mission failures were there for the cosmos 305?
Answer: 1