Atlas LV-3B

An Atlas D LV-3B launchingMercury-Atlas 6[1][a]
Function	Crewedexpendable launch system
Manufacturer	Convair
Country of origin	United States
Size
Height	28.7 metres (94.3 ft)
Diameter	3.0 metres (10.0 ft) width over boost fairing 4.9 metres (16 ft)
Mass	120,000 kilograms (260,000 lb)
Stages	1+1⁄2
Capacity
Payload toLEO
Mass	1,360 kilograms (3,000 lb)[2]
Launch history
Status	Retired
Launch sites	CCAFSLC-14
Total launches	9
Success(es)	7
Failure	2
First flight	29 July 1960
Last flight	15 May 1963
Boosters
No. boosters	1
Powered by	2Rocketdyne XLR-89-5
Maximum thrust	1,517.4 kilonewtons (341,130 lbf)
Burn time	135 seconds
Propellant	RP-1/LOX
First stage
Diameter	3.0 metres (10.0 ft)
Powered by	1Rocketdyne XLR-105-5
Maximum thrust	363.22 kilonewtons (81,655 lbf)
Burn time	5 minutes
Propellant	RP-1/LOX
[edit on Wikidata]

TheAtlas LV-3B,Atlas D Mercury Launch Vehicle orMercury-Atlas Launch Vehicle, was ahuman-ratedexpendable launch system used as part of the United StatesProject Mercury to sendastronauts intolow Earth orbit. Manufactured by American aircraft manufacturing companyConvair, it was derived from theSM-65D Atlas missile, and was a member of theAtlas family of rockets.^[3]

The Atlas D missile was the natural choice for Project Mercury since it was the only launch vehicle in the US arsenal that could put the spacecraft into orbit and also had many flights from which to gather data. But its reliability was far from perfect, and Atlas launches ending in explosions were an all-too common sight at Cape Canaveral. The Atlas had also been originally designed as a weapon system, thus its design and reliability did not need to necessarily be 100% perfect. As such, significant steps had to be taken to human-rate the missile and make it safe and reliable unless NASA wished to spend several years developing a dedicated launch vehicle for crewed programs or else wait for the next-generationTitan II ICBM to become operational. Atlas' stage-and-a-half configuration was seen as preferable to the two stage Titan in that all engines were ignited at liftoff, making it easier to test for hardware problems during pre-launch checks.^[4]

Shortly after being chosen for the program in early 1959, the Mercury astronauts were taken to watch the second D-series Atlas test, which exploded a minute into launch. This was the fifth straight complete or partial Atlas failure and the booster was at this point nowhere near reliable enough to carry a nuclear warhead or an uncrewed satellite, let alone a human passenger. Plans to human-rate Atlas were effectively still on the drawing board and Convair estimated that 75% reliability would be achieved by early 1961 and 85% reliability by the end of the year. Despite the Atlas' developmental problems, NASA had the benefit of conducting Project Mercury simultaneously with the Atlas R&D program which gave plenty of test flights to draw data from as well as test modified equipment for Mercury.^[3]

• Project Mercury

• Lists of rocket launches

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• Use dmy dates from March 2021
• Use American English from March 2021
• All Wikipedia articles written in American English