An updated version of the Atlas MA - 5 system. Upgrades included
replacments with selected RS-27 components. This provided a sea-level Isp
increase of 4 secs. In addition to this, the side-mounted verniers were
deleted. The roll control and final adjustment functions were integrated
into the vehicle's interstage.
| Applications | Atlas 2 primary
propulsion system |
| First Flown | December 7th, 1991 |
| Flown | 7 til the end of 1993 (49 systems contracted) |
| Dry Mass | 1610 kg |
| Length | 343 cm |
| Maximum Diameter | 119 cm |
| Mounting | all thrust chambers are gimballed |
| Engine Cycle | gas generator |
| Oxidizer | liquid oxygen pump-fed at 505 kg/sec |
| Fuel | RP-1 hydrocarbon pump-fed at 224 kg/sec |
| Mixture Ratio | 2.25:1 |
| Oxidizer Turbopump | each 1903 kW, 6730 rpm, 70 atm discharge
pressure |
| Fuel Turbopump | 1362 kW, 75 atm discharge pressure |
| Thrust | total 2100 kN vacuum, 1890 kN sea level |
| Isp | 295 sec vacuum, 263 sec sea level |
| Time to Full Thrust | 2.0 sec |
| Expansion Ratio | 8:1 |
| Thrust Chamber Length | 249 cm |
| Thrust Chamber Materials | 347 CRES austenitic stainless
steel |
| Thrust Chamber Cooling Method | regenerative, two passes of
fuel through 292 chamber tubes |
| Combustion Chamber Pressure | 48 atm at injector end |
| Combustion Chamber Temperature | 3316 Celsius |
| Combustion Chamber Materials | 347 CRES austenitic stainless
steel |
| Combustion Chamber Cooling | as thrust chamber |
| Combustion Chamber Ignition | hypergolic fluid chamber
enclosed in burst diaphragms |
| Burn Time | 167 sec maximum flight duration |
The RS - 27 powerplant comprises an RS2701A/B main engine, and twin
LR101 - NA - 11 verniers. Introduced in 1974 on the McDonnell Douglas'
Delta 2000 series launcher it replaced the MB - 3 as the main system for
that launcher. It completed it's Delta service on the 6000 model in 1992;
and continues in service as part of the Atlas MA - 5A powerplant.
| Application | Delta 6000 series (RS -
27A; 7000 series) |
| First Flown | January 18th, 1974 on Delta 100/Skynet 2A (RS -
27A debut 1990) |
| Flown | 107 Delta plus 8 Atlas (RS - 27A with 14) to the end
of 1993 |
| Dry Mass | 1027 kg (1091 kg) |
| Length | 363 cm from top of thrust ring (378 cm) |
| Maximum Diameter | 107 cm envelope |
| Mounting | gimballed-mounted for pitch/yaw control with
gimballed verniers for roll control |
| Engine Cycle | gas generator |
| Oxidizer | liquid oxygen at 250 kg/sec |
| Fuel | RP-1 hydrocarbon at 111 kg/sec |
| Mixture Ratio | 2.245:1 |
| Oxidizer Turbopump | 1900 kW, 6784 rpm (7085 rpm at
altitude), 70 atm discharge pressure |
| Fuel Turbopump | 1289 kW, 70 atm discharge pressure |
| Thrust | 971 kN sea level/1023 kN vacuum (890 kN sea
level/1054.2 kN vacuum) |
| Isp | 264 sec sea level/295 sec vacuum (255 sec sea level/302
sec vacuum) |
| Expansion Ratio | 8:1 (12:1) |
| Thrust Chamber Length | 219 cm (234 cm) |
| Thrust Chamber Materials | 347 CRES austenitic stainless
steel |
| Thrust Chamber Cooling | regenerative, two passes of fuel
through 292 tubes |
| Combustion Chamber Pressure | 48 atm at injector end |
| Combustion Chamber Temperature | 3315 Celsius |
| Combustion Chamber Materials | 347 CRES austenitic stainless
steel |
| Combustion Chamber Cooling | same as thrust chamber |
| Combustion Chamber Ignition | hypergolic fluid cartridge
enclosed in burst diaphragms |
| Burn Time | 274 sec |
| Verniers | each LR101-NA-11 at 21.8 kg mass, 4.63/5.30 kN sea
level/vac thrust, 209/246 sec sea level/vac Isp, 1.8 mixture ratio, 5.6
expansion ratio(9.8 cm exit diameter), 283 sec burn time |
A new system under study at Rocketdyne which is a derivative of the MA
and RS systems for ELV applications. The RS-X would employ existing Delta
and Atlas engine hardware on a new thrust chamber assembly to generate a
thrust of 1890 kN.
Rocketdyne is teamed with Aerojet and Pratt & Whitney on the STME, which
could power the next generation of large launch vehicles.
The Rocketdyne Company has just completed the advanced technology
development phase of the pump-fed high performance upper stage engine. Its
performance, mass, and extended space storability make it a candidate for
perigee/apogee stages; as well as transfer vehicles and lunar and Martian
missions.