The Atlas LV-3B, Atlas D Mercury Launch Vehicle or Mercury-Atlas Launch Vehicle, was a human-rated expendable launch system used as part of the United States Project Mercury to send astronauts into low Earth orbit. Manufactured by American aircraft manufacturing company Convair, it was derived from the SM-65D Atlas missile, and was a member of the Atlas family of rockets.[3]
 | |
| Function | Crewed expendable 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 to LEO | |
| Mass | 1,360 kilograms (3,000 lb)[2] |
| Launch history | |
| Status | Retired |
| Launch sites | CCAFS LC-14 |
| Total launches | 9 |
| Success(es) | 7 |
| Failure(s) | 2 |
| First flight | 29 July 1960 |
| Last flight | 15 May 1963 |
| Boosters | |
| No. boosters | 1 |
| Powered by | 2 Rocketdyne 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 | 1 Rocketdyne XLR-105-5 |
| Maximum thrust | 363.22 kilonewtons (81,655 lbf) |
| Burn time | 5 minutes |
| Propellant | RP-1/LOX |
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-generation Titan 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]
Launch outcomes
editLaunch History
edit| Flight | Crew member | Mission name | Date | Outcome |
|---|---|---|---|---|
| 1 | Uncrewed | Mercury Atlas-3 | Tuesday, April 25, 1961 | Failure |
| First flight of the Atlas LV-3B. Was an uncrewed test flight. Resulted in failure. The cause remains disputed. | ||||
| 2 | Uncrewed | Mercury Atlas-4 | Wednesday, September 13, 1961
10:04 AM EDT[6] |
Success |
| Second uncrewed test flight. The launch was successful. | ||||
| 3 | Uncrewed | Mercury Atlas-5 | Wednesday Nov 29th, 1961
10:07 AM EST[6] |
Success |
| Final uncrewed test flight. Launch was successful. | ||||
| 4 | John Glenn | Mercury Atlas-6 | Tuesday, February 20, 1962
9:47 AM EST[7] |
Success |
| First crewed flight of the Atlas LV-3B. Successfully launched John Glenn to become the first American to orbit the Earth. First flight of John Glenn. | ||||
| 5 | Scott Carpenter[8] | Mercury Atlas-7 | Thursday, May 24, 1962
8:45 AM EDT[7] |
Success |
| Second crewed flight of the Atlas LV-3B. First flight of Scott Carpenter. | ||||
| 6 | Wally Schirra[9] | Mercury Atlas-8 | Wednesday, October 3, 1962
8:15 AM EDT[7] |
Success |
| Third crewed flight of the Atlas LV-3B. First flight of Wally Schirra. | ||||
| 7 | Gordon Cooper[10] | Mercury Atlas-9 | Wednesday, May 15, 1963
9:04 AM EDT[7] |
Success |
| Final flight of the Atlas LV-3B. Final crewed flight of the Atlas LV-3B. First flight of Gordon Cooper. | ||||
| 8 | Alan Shepard | Mercury-Atlas 10 | October 1963[11] | Cancelled |
| Was to be second flight of Alan Shepard. Was to be final flight of the Atlas LV-3B. Was cancelled because it was determined to be too risky.[12] | ||||
See also
editNotes
editReferences
edit- ^ "Atlas LV-3B / Mercury". www.astronautix.com. Archived from the original on 27 December 2016. Retrieved 8 July 2021.
- ^ Wade, Mark. "Atlas LV-3B / Mercury". Encyclopedia Astronautica. Archived from the original on 11 November 2011. Retrieved 24 November 2011.
- ^ a b "ch5". history.nasa.gov. Retrieved 8 July 2021.
- ^ Limited, Alamy. "Stock Photo – The Mercury Atlas rocket (officially designated the Atlas LV-3 B) was an Atlas D missile modified for Project Mercury launches". Alamy. Retrieved 8 July 2021.
{{cite web}}:|last=has generic name (help) - ^ "1961-1969 Launch Schedule". Space Launch Schedule. Retrieved 22 February 2021.
- ^ a b "1961-1969 Launch Schedule (Page 2)". Space Launch Schedule. Retrieved 22 February 2021.
- ^ a b c d "1961-1969 Launch Schedule (Page 3)". Space Launch Schedule. 22 February 2021. Retrieved 22 February 2021.
- ^ "May 24, 1962: NASA Astronaut Scott Carpenter Departs From Earth Aboard Mercury-Atlas 7". spacecoastdaily.com. Retrieved 22 February 2021.
- ^ KSC, Lynda Warnock. "NASA – Mercury-Atlas 8 (25)". www.nasa.gov. Retrieved 22 February 2021.
- ^ "Mercury-Atlas 9 (Faith 7)". Supercluster. Retrieved 22 February 2021.
- ^ "Cancelled spaceflight mission: Mercury 10". www.spacefacts.de. Retrieved 3 March 2021.
- ^ "Mercury MA-10". www.astronautix.com. Archived from the original on 28 December 2016. Retrieved 3 March 2021.