Kosmos 300

Kosmos 300 (Russian: Космос 300 meaning Cosmos 300) (Ye-8-5 series) was the fourth Soviet attempt at an uncrewed lunar sample return. It was probably similar in design to the later Luna 16 spacecraft. It was launched, on a Proton rocket, on September 23, 1969.^[3] The mission was a failure. The engines on the Block D upper stage failed due to an oxidizer leak, leaving the spacecraft to burn up in Earth's atmosphere.^[4]

Kosmos 300

A Ye-8-5 model in the Museum of Cosmonautics, Moscow.
Mission type	Lunar sample-return
Operator	Soviet space program
COSPAR ID	1969-080A
SATCAT no.	4104
Mission duration	4 days
Spacecraft properties
Spacecraft type	Ye-8-5
Manufacturer	GSMZ Lavochkin
Launch mass	5,600 kg (12,300 lb)[1]
Start of mission
Launch date	September 23, 1969, 14:07:00 (1969-09-23UTC14:07Z) UTC[2]
Rocket	Proton-K/D
Launch site	Baikonur 81/24
End of mission
Disposal	Launch failure
Decay date	September 27, 1969
Orbital parameters
Reference system	Geocentric[2]
Perigee altitude	184 km (114 mi)
Apogee altitude	189 km (117 mi)
Inclination	51.5°
Period	88.2 min
Luna programme ← Luna 15 Kosmos 305 → Kosmos (satellites) ← Kosmos 299 Kosmos 301 →