1. Launch Propulsion: SMC/LR Perspectives Presented to
Launch Propulsion Workshop
Caltech Pasadena, CA
Presented by
Lt Col Toby Cavallari
Chief Engineer
Launch and Range Systems Directorate
Space and Missile Systems Center
23 March 2011

2. ELV History (1958 – Present)
In past 50 years, propulsion enabled ballistic and spacelift capabilities
Powered first US ICBMs
Evolved into launch vehicle systems, opening the door to space
Continued with improvements in performance, reliability, and operability
However, more than 40% of all historical launch vehicle failures caused by propulsion subsystem malfunctions (#1 contributor)
Drawing courtesy of Boeing

3. Historical USAF Development & Industrial Base
More than 50 years, USAF has been a key player in rocket development
Today, only several U.S. companies are active

4. EELV Families Two families of launch vehicles (Atlas V and Delta IV)
(401)
(5XX Series)
Delta IV (Med)
Atlas V Family
GTO Capability
(lbs)
8/02
7/03
(4XX Series)
Delta IV
(Med+ 4 series)
(Med+ 5 series)
(Heavy)
3/03
11/02
12/04
Delta IV Family
5,000
10,000
15,000
20,000
25,000
30,000
IOC
Atlas V (Heavy)
PWR
RS-68
Engine
Russian
RD-180 Engine
RL10-A-2 Engine
RL10B-2
GEM-60
SRB

5. Current EELV Propulsion Environment
Escalating engine cost growth
Must ensure engine availability for EELV until 2030
Supplier obsolescence
Reliance on foreign suppliers for EELV mission assurance and sustainment
Payload mass-to-orbit expected to continue on an upward trend
Declining U.S. industry capability in engine development and production
Some specific concerns:
EELV Upper Stage Engines:
50-year-old craftsman-based manufacturing
Currently flying at reduced confidence margins
Running at twice original engine chamber pressure
Requiring highly selective screening per USG standards
Increased mission assurance costs
No further growth opportunity without major redesign
Kerosene Booster Engine:
DoD reliance on Russian designed and built engine
Limiting opportunity for technology transfer to new U.S. engine effort
Also, ITAR restricts U.S. technology transfer into RD-180 program

6. Chamber Pressure (psia)
RL10 Engines
LOX/LH2 engine built by Pratt-Whitney Rocketdyne
Expander cycle
1st RL10 flight in 1963 (RL10A-3 on Centaur)
RL10A-4-2 and RL10B-2 first flown in 2002
Atlas V and Delta IV 2nd stage engines
More than 40% component commonality between Delta and Atlas RL10 variants
RL10A-4-2 (Atlas V)
RL10A-4-2
(Atlas V)
RL10B-2
(Delta IV)
Thrust, vac (lbf)
22,300
24,750
Chamber Pressure (psia)
610
640
Isp, vac (sec)
450.5
464 MR
5.5
6.0
Expansion Ratio 84
285
RL10B-2 (Delta IV)

7. Upper Stage Engine History & Future Paths
Qual. Year
RL10A-1
15k lbf
Pc=300 psia
Isp = 422 s
1961
1963
1967
1991
1998
1999
2000
RL10A-3
Isp = 427 s
1966
1985
1994
A-1 A A A-3-3A A A B A-4-2
A-3-3
A-4-1A
RL10A-3-3A
16.5k lbf
Pc=475 psia
Isp = s
RL10B-2
24.7k lbf
Pc=640 psia
Isp = 464 s
RL10A-4-2
22.3k lbf
Pc=610 psia
Isp = 451 s
(Delta IV)
(Atlas V)
Model
Possible Upper Stage Engine Paths
Converting existing RL10B-2 inventory
No further growth opportunity without major redesign
Fly RL10C on Atlas V
RL10C
RL10A
&
RL10B-2
Next Generation Engine (NGE)
True common, new upper stage engine
Greater designed-in reliability/performance margins
Fly on both Atlas V and Delta IV

8. Upper Stage Next Generation Engine (NGE)
Objectives
Modern manufacturing techniques
Greater designed-in reliability and performance margins
More sustainable
Lower life cycle cost
Achieve a truly common LOX/Hydrogen upper stage engine
Incorporates National Security Space & NASA requirements
Interagency partnership opportunity
Captures emerging commercial needs
Creates open competition
Bolster U.S. liquid propulsion industrial base capability
Leverage advanced design tools matured by AFRL/NASA technology investment
e.g. AFRL Upper Stage Engine Technology (USET)
SMC/Aerospace and NASA currently assessing benefits of using the NGE for
Evolved Expendable Launch Vehicle (EELV) missions
NASA’s Cryogenic Propulsion Stage for space exploration

9. Potential Partnership Areas
Opportunities for joint propulsion development programs
Overcome emerging National Security Space challenges and declining budgets
Lay groundwork for interagency cooperation and commercial partnerships
Take advantage of NASA’s commitment to advanced tech development and emerging commercial needs
National Propulsion Strategy for upper stage engine (e.g. NGE) and high- thrust kerosene booster engine
Common engine - not common vehicle architectures
Improved funding stability
Accelerated development schedule
Shared testing and ground certification costs
Optimal use of national test facilities
Revitalize declining industrial base capability
New engine has many cross-cutting mission benefits & capabilities
Military, civil, and commercial

10. Backup Charts

11. Chamber Pressure (psia)
RD-180 Engine
Atlas V Common Core Booster (first stage) engine
LOX/kerosene engine built by NPO Energomash, Russia
Oxygen-Rich Staged Combustion (ORSC) cycle
First flown in 2002
Full Power Level (100% PL)
Min. Power Level (47% PL)
Thrust, vac (lbf)
933,400
438,700
Thrust, sea level (lbf)
860,200
365,500
Chamber Pressure (psia)
3722
1755
Isp, vac (sec)
339.3
335.5
Isp, sea level (sec)
312.7
279.5 MR
2.72 (+/- 7%)
Expansion Ratio
36.87

12. Chamber Pressure (psia)
RS-68 Engine
Delta IV Common Booster Core (CBC) engine
LOX/LH2 engine built by Pratt & Whitney Rocketdyne
Largest LOX/LH2 engine
Used existing technologies to minimize cost and risk
Gas Generator (GG) cycle
First flown in 2002
RS-68A upgrade certification underway
Full Power Level (102% PL)
Min. Power Level (57% PL)
Thrust, vac (lbf)
751,000
432,000
Thrust, sea level (lbf)
656,000
337,000
Chamber Pressure (psia)
1420
815
Isp, vac (sec)
409
Isp, sea level (sec)
357 MR
6.0
Expansion Ratio
21.6

13. Atlas V Solid Rocket Booster (SRB)
Strap-On Solid Motors
Atlas V Solid Rocket Booster (SRB)
Delta IV GEM-60
Atlas V
(500 Series)
(0-5 SRBs)
(400 Series)
(0-3 SRBs)
SRB
GEM-60
SRB Characteristics
Diameter (in) 62
Length (ft) 67
Gross Weight (lb) 102,396
Burn Time (sec) 88
Total Impulse, Vacuum (lbf-sec) 26,190,000
Isp, Vacuum (sec)
Average Thrust, Vacuum (lbf) 270,420
Max Thrust, Vacuum (lbf) 380,000
MEOP (psi) 1600
GEM-60 Characteristics
Diameter (in) 60
Length (ft) 53
Gross Weight (lb) 74,700
Burn Time (sec) 90.8
Total Impulse, Vacuum (lbf-sec) 17,950,000
Isp, Vacuum (sec) 274
Average Thrust, Vacuum (lbf) 197,540
Max Thrust, Vacuum (lbf) 300,000
MEOP (psi) 1294