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7KLVUHSRUWLVDYDLODEOHLQHOHFWURQLFIRUPDWKWWSZZZVWLQDVDJRYDQGKWWSQWUVQDVDJRY
Reflections on Centaur Upper Stage Integration 

by the NASA Lewis (Glenn) Research Center 

Scott R. Graham 

National Aeronautics and Space Administration 

Glenn Research Center 

Cleveland, Ohio 44135 

Abstract 

The NASA Glenn (then Lewis) Research Center (GRC) led 

several expendable launch vehicle (ELV) projects from 1963 

to 1998, most notably the Centaur upper stage. These major, 

comprehensive projects included system management, system 

development, integration (both payload and stage), and launch 

operations. The integration role that GRC pioneered was truly 

unique and highly successful. Its philosophy, scope, and 

content were not just invaluable to the missions and vehicles it 

supported, but also had significant Agency-wide benefits. An 

overview of the NASA Lewis Research Center (now the 

NASA Glenn Research Center) philosophy on ELV integration is provided, focusing on Atlas/Centaur, Titan/Centaur, 

and Shuttle/Centaur vehicles and programs. The necessity of 

having a stable, highly technically competent in-house staff is 

discussed. Significant depth of technical penetration of 

contractor work is another critical component. Functioning as 

a cohesive team was more than a concept: GRC senior 

management, NASA Headquarters, contractors, payload users, 

and all staff worked together. The scope, content, and history 

of launch vehicle integration at GRC are broadly discussed. 

Payload integration is compared to stage development 

integration in terms of engineering and organization. Finally, 

the transition from buying launch vehicles to buying launch 

services is discussed, and thoughts on future possibilities of 

employing the successful GRC experience in integrating ELV 

systems like Centaur are explored. 

Nomenclature 

AC Atlas/Centaur 

ADDJUST Automatic Determination and Dissemination 

of Just Updated Steering Terms 

CISS Centaur Integrated Support System 

CRRES Combined Release and Radiation Effects 

Satellite 

ELV expendable launch vehicle 

EOS Earth Observing System 

ERB Engineering Review Board 

FLTSATCOM Fleet Satellite Communications 

GFE government-furnished equipment 

GOES Geosynchronous Operational Environmental 

Satellite 

GRC Glenn Research Center 

HQ Headquarters 

IUS inertial upper stage 

IV&V independent verification and validation 

JSC Johnson Space Center 

KSC Kennedy Space Center 

LeRC Lewis Research Center 

LH2 liquid hydrogen 

LOX liquid oxygen 

RF radiofrequency 

RTG radioisotope thermoelectric generator 

SC Shuttle/Centaur 

SEP solar electric propulsion 

SOHO Solar and Heliospheric Observatory 

ULA United Launch Alliance 

1.0 Introduction 

The NASA Glenn (then Lewis) Research Center (GRC) led 

and managed several expendable launch vehicle (ELV) 

projects from 1963 to 1998, most notably the Centaur upper 

stage. These major, comprehensive projects included system 

management, system development, integration (both payload 

and stage), and launch operations. The integration role that 

GRC pioneered was truly unique and highly successful. Its 

philosophy, scope, and content were not just invaluable to the 

mission and vehicles it supported, but also had significant 

Agency-wide benefits that might also be useful to future 

NASA activities. 

NASA’s Centaur upper stage was the first of a new generation of space vehicles that pioneered the use of liquid hydrogen as a fuel for space flight rocket engines. The Centaur 

upper stage was developed by NASA Lewis Research Center, 

now Glenn Research Center1

 in Cleveland, Ohio. The Centaur 

became the world’s first high-energy upper stage, burning 

liquid hydrogen (LH2) and liquid oxygen (LOX) to place 

payloads in geosynchronous orbits or provide escape velocity 

for interplanetary space probes. In combination with the 

1

 On March 1, 1999 NASA’s Lewis Research Center (LeRC or 

Lewis) in Cleveland, Ohio, was officially renamed the John H. 

Glenn Research Center at Lewis Field (GRC or Glenn). 

Because of the historical nature of this paper both center 

names, Lewis (LeRC) and Glenn (GRC), are used interchangeably herein. 

NASA/TM—2015-218742 1 

 
RL10 rocket engine (currently manufactured by Aerojet 

Rocketdyne), the Centaur became (and still is today) the 

highest performing upper stage and one of the most prominent 

launch vehicles in America’s exploration of space. Centaur 

has launched over 200 payloads, most notably the Surveyor 

landers to the Moon (a precursor to the Apollo lunar landings), 

the Pioneer and Voyager spacecraft to the outer planets, the 

Viking landers and the Curiosity rover to the surface of Mars, 

Cassini to the rings of Saturn, and the New Horizons probe to 

Pluto. Centaur has also launched dozens of communication 

satellites into geosynchronous orbit. 

The Centaur upper stage was developed and manufactured 

by General Dynamics Convair Aerospace Division (later 

renamed to Space Systems Division) under the direction of 

NASA’s LeRC. The Centaur Program started in 1958 with its 

first successful flight (AC-2) on November 27, 1963, from 

Cape Canaveral Air Force Station in Florida. Since then the 

vehicle has undergone numerous evolutionary upgrades and 

modifications to improve its performance, operability, and 

reliability. Centaur has flown as the upper stage for both the 

Atlas and Titan launch vehicles, and continues flying today as 

the upper stage for the Atlas V. Last year (November 2013) 

marked the 50th anniversary of the first successful flight of 

Centaur. In the early 1980s, NASA embarked upon a large 

effort to modify Centaur to safely fly as a high-energy upper 

stage inside the space shuttle cargo bay for NASA missions 

such as Galileo and Ulysses, and certain Department of 

Defense missions. This program, known as Shuttle/Centaur, 

was cancelled in 1986 shortly after the Space Shuttle Challenger accident, just a few months prior to the planned first 

launch in May 1986. The Centaur G-prime upper stage 

developed for the Shuttle/Centaur program later flew as a new 

upper stage for Titan IV. 

This paper will reflect on NASA GRC’s unique and highly 

successful role in managing and integrating ELVs, with 

emphasis on the Centaur upper stage development and 

integration with Atlas, Titan, and the space shuttle. 

2.0 LeRC Philosophy on Centaur/ELV 

Integration 

LeRC’s management philosophy for launch vehicle integration was centered on having a robust and highly competent inhouse technical staff working in partnership with contractor 

personnel and the launch organizations. A true governmentindustry team was developed in which each organization 

supported, stimulated, and challenged the other to produce a 

whole that was greater than the sum of the parts. The government-industry team was highly experienced and dedicated to 

mission success, with considerable pride and confidence that 

served to maintain a high level of morale and motivation. 

Figure 1.—Centaur Program organization showing

LeRC-managed contracts (circa 1980). 

With its acknowledged technical leadership, LeRC evolved 

into a position of manager and system integrator of associate 

contractors, supplying the guidance subsystem and RL10 

engines as government-furnished equipment (GFE) to General 

Dynamics Convair as the prime integrating contractor. This 

mode of operation was well conceived and highly successful 

for many years, up until LeRC’s ELV program transitioned 

into procuring launch services from industry. Up until that 

transition, LeRC managed separate contracts with General 

Dynamics Convair (multiple contracts), Teledyne (Centaur 

digital computer), Honeywell (Centaur guidance), Pratt & 

Whitney (Centaur RL10 engines), and Rocketdyne (Atlas 

MA-5 engines). These associate contractors delivered flightqualified hardware to LeRC that was then furnished to General 

Dynamics in San Diego. Figure 1 shows the Centaur program 

organization in 1980 including the LeRC-managed contracts. 

The experience, depth of technical penetration, and familiarity of the LeRC project staff with the Atlas/Centaur vehicle 

was a major strength of the program. This supplied both a 

“corporate memory” and person-to-person familiarity with 

their counterparts among the contractors (Ref. 1). As an 

example of this technical penetration and government-industry 

partnership, LeRC assigned a highly competent engineer to be 

the system engineer for the RL10 rocket engine and worked 

on a day-to-day basis with his counterparts at Pratt & Whitney 

and General Dynamics. This government-industry engineering 

counterpart arrangement was repeated for most every major 

system and subsystem (hydraulic, pneumatic, guidance, 

computer, avionic, structure, thermal, etc....). This not only 

provided a tightly coupled government-industry team, but also 

provided the government with significant technical penetration 

into all aspects of the designs and hardware. It also served as a 

NASA/TM—2015-218742 2 
check-and-balance system to assure mission success. Many 

times the LeRC system engineer was more knowledgeable 

about a particular issue, component, or design feature than his 

industry counterpart. Responsibilities of the GRC launch 

vehicle systems engineers, assigned as a technical specialist 

for a particular system or subsystem, included (Ref. 2)

x Mission integration interfaces 

x Problem solving 

x Evaluation and qualification testing 

x Factory acceptance 

x “Tiger Team” product reviews 

x Flight readiness status 

x Launch support 

x Flight data reduction analysis 

x Flight report 

x Contract support 

x Liaison with contractor and Kennedy Space Center 

(KSC) counterparts 

Atlas/Centaur is an extremely complex vehicle with minimal redundancy, and flight success required an unusual degree 

of both care and familiarity on the part of all system and 

subsystem engineers (Ref. 3). Flight failures were often not 

caused by gross design flaws but by things being forgotten or 

“slipping through the crack” (Ref. 4).

“The technical penetration by the Lewis project team 

was more than just monitoring and directing the contractors to ensure that they do a good job. When competence in government meets competence in industry, 

a synergism occurs: the whole is greater than the sum 

of the parts. Each party stimulates and challenges the 

other to a higher level of care and diligence than 

would otherwise be obtained. The success of Atlas/Centaur could not have been achieved by either 

government or industry alone.” (Ref. 3) 

LeRC’s philosophy for Centaur mission success was also 

built on a foundation of extensive ground testing in the 

relevant environment—from components, to subsystems, 

systems, to the complete vehicle. Types of testing conducted 

included engine hot fire tests, separation, vibration, structural, 

etc... LeRC’s emphasis on ground testing, coupled with an 

experienced technical staff and unique test facilities were 

critical to the successful development and operation of the 

Centaur (Ref. 5). Figure 2 shows a Centaur upper stage being 

lowered into position for testing at LeRC. 

As problems arose, LeRC’s program philosophy was to 

maintain close contact with the contractor’s engineering and 

quality personnel for awareness and resolution. Engineering 

Review Boards (ERBs) were often conducted by both the 

Figure 2.—A Centaur stage being readied for testing. 

Figure 3.—LeRC Launch Vehicles Division

organization (circa 1980).

contractor and LeRC. Sometimes joint NASA-industry ERBs 

were conducted for particular problems. A very formal, welldocumented process existed for conducting business and 

reviews. Both industry and LeRC management were kept well 

informed of current status, problems, and problem resolution 

activities. Senior management was tightly engaged with the 

systems engineering and quality assurance personnel, to 

ensure no surprises. The engineering and project management 

organizations at GRC were within the same Directorate, not 

matrixed. This “stove-piped” organization was effective in 

focusing experienced engineers on solving problems in a 

timely fashion. Figure 3 shows the LeRC Launch Vehicles 

Division organization in 1980. Lower level organization 

“sections” are not shown. Launch vehicle staffing levels at 

GRC fluctuated around 100 to 150 people for the majority of 

the years. (There was a ramp up to near 250 people in the 

early 1980s for Shuttle/Centaur development.) In the early 

NASA/TM—2015-218742 3 
1980s, GRC began augmenting its civil servant staff with onsite engineering support contractors. Throughout GRC’s 

leadership of launch vehicles and Centaur, the Center 

maintained and staffed a resident office at General Dynamics 

in San Diego and later at Lockheed Martin in Denver. GRC 

also maintained an on-site presence at other associate 

contractor locations. Likewise, the major contractors maintained a local representative in Cleveland, near GRC. GRC 

staff also cochaired technical working groups and panels in 

key areas along with their contractor counterparts. GRC staff 

sometimes shared operational work responsibilities with 

contractor staff during critical launch preparation periods. 

Functioning as a cohesive team was more than a concept—

where GRC upper management, NASA Headquarters (HQ), 

contractors, payload users, and all staff worked together as a 

team, not as government versus contractor. 

LeRC’s approach to launch vehicle integration and mission 

success rejected the approach of contracting out all technical 

and engineering matters to industry. LeRC’s approach was 

much more than simply providing contract management, 

oversight, and insight. LeRC’s deep technical penetration into 

all aspects of the vehicle, an engineering staff comparable to 

the contractor’s staff, and working in close partnership and 

collaboration with industry, helped ensure a highly successful 

program for many decades. Attention to detail was paramount. 

The LeRC team brought hands-on experience coupled with 

equal-to or superior analytic tools and testing facilities 

compared with the contractors. LeRC’s trajectory optimization, mission design, and coupled loads analysis tools are but a 

few examples of LeRC’s superior tools. The Center’s largescale vacuum chambers for hot fire engine and stage testing 

(at altitude conditions) of Centaur during its early development were crucial to the success of the program. 

GRC’s philosophy for Centaur flight software was to design 

and structure it to be very flexible and “robust.” It could 

compensate for very large in-flight dispersions or even for 

some hardware anomalies. For example, it could initiate main 

engine restart sequences, recover from very high tumble rates 

after Centaur engine shutdown, and retarget in flight. The 

software was able to respond to many hardware dispersions or 

anomalies. Three examples of this philosophy are briefly 

explained here. First, if a Centaur main engine failed to start, 

software initiated a main engine restart sequence. This 

software capability was actually invoked on the first Titan/Centaur flight, a test flight where the Centaur engines 

failed to start after separation from Titan. The software 

initiated an engine restart sequence, but the engines still failed 

to start for hardware reasons. Second, in the event of very high 

Centaur/payload tumble rates after Centaur engine shutdown 

(i.e., during coasting) special software initiated commands to 

recover control of the vehicle, even if it meant that the vehicle 

rotated through 360° before control was regained. It had been 

shown analytically that this approach was preferable to 

running out of attitude control propellant trying to null the 

high rate quickly and then returning to the proper attitude. And 

finally, if on-board guidance and navigation calculations 

indicated that the desired target was unreachable because of 

some anomaly earlier in flight, a new target would actually be 

computed in flight using an onboard algorithm. This retarget 

would result in a compromised mission, (e.g., a lower orbital 

altitude), but such a mission was preferable to losing the 

spacecraft by running out of propellant before reaching orbit 

trying to achieve the original nominal target. 

3.0 Scope and Content of Integration 

As the NASA lead Center for management of intermediateand large-class ELVs (such as Atlas/Centaur and 

Titan/Centaur), GRC was responsible for ensuring that the 

total launch vehicle and mission integration tasks and 

activities were properly coordinated and conducted in support 

of the mission (Ref. 6). These integration tasks and activities 

included the following: 

x Integrated launch vehicle performance and trajectory 

analyses 

x Integrated launch vehicle loads analyses 

x Integrated launch vehicle thermal analyses 

x Integrated guidance accuracy analyses 

x Launch vehicle guidance and flight control integration 

x Integrated launch vehicle radiofrequency (RF) analyses 

x Integrated launch vehicle range and pad safety analyses, 

including flight termination 

x Integrated launch vehicle range planning and data 

acquisition 

x Integrated launch vehicle operations support 

x Overall launch vehicle schedule integration 

x Launch vehicle systems trade studies 

A standardized integration panel structure was utilized for 

each mission. For most missions there were three panels: 

Mission Integration, Mission Design, and Ground Operations. 

For planetary or deep-space missions, a radioisotope thermoelectric generator (RTG) panel was frequently required. All the 

panels were cochaired by GRC launch vehicle personnel. The 

ground operations panel was cochaired by KSC and GRC. 

Each panel had well-documented responsibilities. These 

panels were sometimes referred to as working groups. As 

shown in Figure 4, these panels were typically established 

about 3 years prior to launch (L-3 Years) for each mission. 

NASA/TM—2015-218742 4 
Figure 4.—Typical mission integration process (circa 1996). 

The Mission Integration Panel, sometimes referred to as the 

Systems Integration Panel, was responsible for the overall 

management of the integration process, which included the 

following: 

x Systems safety 

x Systems effectiveness 

x Scheduling and planning 

x Action item review and status 

x Initiation/formation of working groups 

x Resolution of integration disagreements 

x Mechanical, electrical, and environmental interface 

requirements definition (flight and ground) 

Mission Integration Panel products included 

x Integration schedules 

x Safety documentation 

x Interface control documents and drawings, electrical and 

mechanical 

x Postflight reports 

x Flight certification assessment 

The Mission Design Panel was responsible for all aspects of 

mission design and operations between the launch vehicle and 

the payload/spacecraft, including 

x Assuring that all phases of mission design were consistent with performance, trajectory, guidance, and 

launch period requirements of the mission 

x Providing a means for continual compilation, interchange, review, and evaluation of relative data 

x Interpreting performance and guidance accuracy requirements and verifying that they were satisfied 

x Developing appropriate trajectory strategies to meet 

tracking and data acquisition constraints 

x Verifying nominal and contingency trajectory timelines 

and flight profiles 

x Supporting and providing inputs to interface control 

documents and other documents 

x Coordinating performance improvement studies and 

analyses 

x Developing and issuing performance tracking reports 

x Identifying and analyzing problems and determining 

possible courses of action and recommended solutions 

The Ground Operation Panel was responsible for defining 

facility interfaces and services as well as defining and 

integrating ground operations including payload encapsulation 

and scheduling of launch operations from the time the launch 

vehicle and payload arrived at KSC through launch. Additional responsibilities included 

x Coordinating the preparation of all ground operation 

procedures 

x Verifying that all spacecraft ground support equipment 

is provided with proper services 

x Coordinating the preparation and approval of various 

spacecraft and launch vehicle program requirement documents 

x Reviewing and updating launch site schedules 

x Coordinating and communicating requirements among 

payload, launch vehicle, and NASA organizations 

x Coordinating launch site badging and security 

x Coordinating tracking and data acquisition requirements 

and services 

x Monitoring range safety activities leading up to range 

approval of mission flight plans 

For planetary or deep-space missions, the RTG panel was 

responsible for compiling and publishing a RTG safety data 

book in support of the environmental impact statement and 

safety analysis report. This included definition of launch 

vehicle accident scenarios, the resulting vehicle response, 

probability of occurrence, definition of environments resulting 

from accident scenarios, and identification of accident 

mitigation techniques to reduce the severity of accident 

environments. 

4.0 Payload Integration Versus Stage 

Development Integration 

There were two different aspects of launch vehicle integration at GRC: payload/spacecraft integration and vehicle 

development integration. GRC managed over 119 launches 

and integrated 80 different payloads or spacecraft with the 

Centaur upper stage. Beyond early development test flights, 

every launch vehicle (Atlas/Centaur and Titan/Centaur) 

NASA/TM—2015-218742 5 
managed by GRC had a payload or spacecraft that was 

integrated with the launch vehicle by GRC personnel working 

in collaboration with the payload provider and the launch 

vehicle contractor. Payloads included commercial spacecraft, 

such as the Intelsat series of communication satellites, military 

satellites such as Fleet Satellite Communications 

(FLTSATCOM) for the Department of Defense, and many 

NASA planetary and solar system spacecraft, such as the 

Surveyor and Mariner series, Pioneer, Viking, Voyager, 

Cassini, and the Solar and Heliospheric Observatory (SOHO). 

Figure 5 shows the launch of Surveyor 1 on AC-10 in 

May 1966. 

The nature of payload integration was very analytical and 

closely coupled with the mission design, vehicle performance, 

and the trajectory. Payload integration included making sure 

the spacecraft physically fit (including fitting within a 

dynamic payload envelope) and interfaced properly with the 

launch vehicle and launch site ground support equipment and 

that the spacecraft would survive the environments induced by 

the launch vehicle during launch, such as temperatures, 

pressures, g-forces, loads, vibration, and acoustic noise levels. 

Payload integration also included making sure the payload 

requirements for services from the launch vehicle or the 

launch pad were understood and provided. Typical payload 

services included providing access to the payload (if required) 

after it was encapsulated inside the payload fairing; environmental control (thermal conditioning, purge gas); prelaunch 

electrical power, data, and command; and other services 

provided to the spacecraft via umbilical connections from the 

launch pad tower to the payload. GRC payload integrators and 

mission integration managers were intimately familiar with the 

spacecraft requirements, interfaces, and environmental design 

limits and worked to ensure the launch vehicle environments 

were compatible with the environments the spacecraft was 

designed to withstand, with adequate margin. 

In contrast to the 80 payloads that were integrated by GRC, 

integration of launch vehicle stages happened infrequently. 

For Centaur, there were only four substantially different 

versions developed for launch on three booster families over a 

35-year period. These different Centaur configurations are 

commonly referred to as the Atlas/Centaur configuration, the 

Titan IIIE/Centaur configuration, and two Shuttle/Centaur 

configurations—the Centaur G and Centaur G-prime configurations. 

A new Centaur configuration was a major undertaking that 

involved all the contractors and NASA. It was during these 

vehicle redesign efforts that the value and benefit of the joint 

industry-GRC partnership and collaboration really shined, as it 

did from the very beginning during the initial design and 

development of the Centaur upper stage. 

Figure 5.—Surveyor 1 launch on AC-10 (May 1966).

Centaur was born out of the necessity to have a highperformance upper stage for the Atlas booster to launch the 

Surveyor robotic landers to the Moon as a precursor to the 

Apollo human landing missions. Centaur was the world’s first 

high-energy upper stage—the first to use LH2 and LOX as 

propellants, leveraging the remarkable and legendary RL10 

rocket engine as its propulsion system and ultra-lightweight, 

very thin, pressure stabilized, stainless steel propellant tanks; 

that were separated by a common bulkhead. Atlas was 

originally developed by the United States Air Force as an 

intercontinental ballistic missile. Derivatives of Atlas were 

later used by the Air Force and then NASA for launching 

payloads (and eventually humans) into space. The Atlas 

booster used a refined kerosene RP-1 fuel and liquid oxygen 

as its oxidizer. NASA used Atlas as a booster for its Agena 

upper stage and for the Mercury-Atlas human missions (after 

the two Mercury Redstone launches of Alan Shepard and 

Virgil “Gus” Grissom). Atlas was used to launch John Glenn 

and the Friendship 7 Mercury capsule on his historic journey 

in February 1962. Three more Mercury-Atlas missions 

followed. GRC pioneered the use of LH2 as a high-energy 

propellant and led the development of the RL10 rocket engine 

with Pratt & Whitney and the Centaur upper stage with 

General Dynamics Convair. Atlas became the first booster for 

Centaur, and GRC led the integration of Centaur onto Atlas. 

The first successful Atlas/Centaur launch (AC-2) was in 

NASA/TM—2015-218742 6 
November 1963. Last year, in November 2013, many 

members of the GRC Centaur team gathered in Cleveland with 

their industry and payload partners and NASA senior managers to celebrate the 50th anniversary of the first successful 

Atlas/Centaur launch. Atlas and Centaur continue to fly today 

as the Atlas V ELV. It is not the scope of this paper to reflect 

in any more detail on the early development history of Atlas, 

Centaur, and the RL10 rocket engine. Those efforts are well 

described in the Taming Liquid Hydrogen historical book 

(Ref. 7).

Examples of GRC’s contributions to the Atlas/Centaur 

integrated vehicle configuration included performing structural dynamic tests of the full-scale Atlas/Centaur with a dynamic 

Surveyor spacecraft model at LeRC’s E Stand at Plum Brook 

Station in the 1960s. These tests verified the dynamic models 

for loads, pogo, and autopilot stability analysis. Also in the 

1960s GRC developed the Atlas vehicle ground wind damper 

and the linear-shaped charge for the separation system that 

separated Centaur from Atlas. GRC was also instrumental in 

the development of a new Atlas/Centaur nose fairing and 

fairing jettison system, which were tested at LeRC’s Space 

Power Facility at Plum Brook, the world’s largest vacuum 

chamber. In the 1970s GRC led the development of a computer-controlled Centaur tank pressurization and vent system as 

well as the computer-controlled launch set (CCLS), the 

ground-based computer system used to monitor, calibrate, test, 

and display system status and redlines prior to launch. Another 

significant GRC accomplishment was the development, in 

close collaboration with General Dynamics, of a new launchday wind-monitoring and vehicle-steering system in 1973 

known as Automatic Determination and Dissemination of Just 

Updated Steering Terms (ADDJUST). The premise of 

ADDJUST was to use high-altitude wind data from weather 

balloons launched just prior to launch to provide up-to-date 

vehicle guidance and steering (pitch and yaw) parameters to 

the Centaur flight control computer 15-minutes before launch 

to steer the vehicle through the winds to minimize loads on the 

vehicle during ascent. The ADDJUST system dramatically 

reduced the number of launch scrubs due to upper-atmosphere 

winds and increased the number of days available for 

launch—especially during the winter season of high-upperatmosphere winds in Florida. 

The Titan IIIE/Centaur D-1T configuration, developed in 

the early 1970s, had triple the payload capability of Atlas/Centaur. The development of Titan/Centaur was driven by 

the need to launch the heavy Viking landers to Mars in 1975. 

After its maiden test flight in February 1974 (which ended in 

failure when the Centaur RL10 engines failed to start), Titan 

IIIE/Centaur flew successfully six times, launching Viking 1 

Figure 6.—Titan IIIE/Centaur launch of Voyager 2 (1977).

and 2, Voyager 1 and 2, and Helios 1 and 2. The last Titan 

IIIE/Centaur launch was Voyager 1 in September 1977.2

Integrating Centaur with Titan proved to be a significant 

technical challenge. It required integrating together two 

vehicles, each with their own major aerospace company—

General Dynamic’s Centaur with Martin Marietta’s Titan. 

Further complicating matters was the Air Force’s ownership 

and control of Titan IIIE and the Complex 41 launch pad and 

other Titan facilities at Cape Canaveral. GRC stepped up to 

lead the integration of Titan/Centaur, working in partnership 

with General Dynamics, Martin Marietta, KSC, and the Air 

Force. Figure 6 shows the launch of Voyager 2 in 1977. 

GRC’s contributions to integrating Centaur with Titan IIIE 

included 

x Leading the integration efforts with the aerospace contractors, KSC and the Air Force 

x Development of the Titan Stage 1 oxidizer pogo suppression accumulator system 

x Integrating the ADDJUST system into Titan/Centaur. (All 

seven Titan IIIE/Centaur launches used ADDJUST.) 

2

 Voyager 2 was launched 16 days before Voyager 1. 

NASA/TM—2015-218742 7 

 
x Development of a new payload shroud (Centaur Standard Shroud) for Titan/Centaur, including performing 

shroud jettison tests, including thermal vacuum tests, at 

Plum Brook 

x Development of the Centaur guidance system to guide, 

steer, and control Titan, using the Centaur digital computer and avionics systems 

x Development of a Centaur thermal radiation shield to 

enable in-space coasts for much longer periods (up to 

5 h) than Atlas/Centaur. (Although developed and 

demonstrated on Helios, this capability was never needed or used for a mission.) 

Another challenge in integrating Centuar with Titan IIIE 

was the lack of clear and effective technical communication 

between the two major aerospace companies involved. The 

LeRC integration manager directed that a common database 

and set of definitions be established, documented, and 

maintained as the governing interface control drawings for the 

integration activity. This was no minor task because the two 

companies had differing cultures and design processes.8 In 

addition he directed that a complete structural and structuraldynamics analyses be conducted for the combined vehicle. 

This effort underscored the nature of the integration problems 

because the two companies did not use a common set of 

definitions for such analyses. The different cultures of Atlas 

and Titan programs proved a challenge for LeRC project 

managers. Air Force personnel were rotated every few years, a 

practice that prevented them from forming close personal 

relationships with their counterparts at Martin Marietta. In 

contrast, years of working together had produced a seamless 

relationship between LeRC and General Dynamics people 

(Ref. 9).

The final major new Centaur configuration led and integrated by GRC was Shuttle/Centaur. In the early 1980s, NASA 

embarked upon a large effort to modify Centaur to fly safely 

as a high-energy upper stage inside the space shuttle cargo bay 

for NASA missions such as Galileo and Ulysses as well as 

certain Department of Defense missions. It is important to 

note that Shuttle/Centaur was very political in nature and that 

it began at around the time of the first space shuttle launch in 

1981. At the beginning, Shuttle/Centaur was a political “hot 

potato” with the Agency cancelling it only to have Congress 

reinstate it. To better understand this, it is important to 

understand the environment of the late 1970s and early 

1980s—the dawn of the space shuttle era and a tumultuous 

time for ELVs and Centaur. 

With the development of the space shuttle, which began in 

1972, it became NASA’s official policy to terminate the use of 

all ELVs as soon as the space shuttle became available. As a 

result, for several years before the first space shuttle flight in 

1981, the Atlas/Centaur program and the GRC-industry team 

was living and operating in a phase-out environment—an 

environment of near-term termination. In 1979 it appeared that 

AC-60, scheduled to launch in 1981, would be the very last 

Atlas/Centaur launch and the final Centaur mission. Around 

that time, the launch vehicle staff at GRC was reduced and 

planning was initiated to carry out the remaining launches in 

an orderly fashion and begin to phase-out all other engineering 

and sustaining activities (Ref. 10). However in 1980, concern 

with space shuttle delays resulted in Intelsat requesting four 

more Atlas/Centaur launches that promised to extend the life 

of Atlas/Centaur for at least 4 years. The program continued 

along with no long-range prospects and only being able to 

manage one or two missions at a time as they came to be. An 

attitude that NASA would allow the possible coexistence of 

ELVs with the space shuttle started to emerge with a recommendation by the Atlas/Centaur Review Board in February 

1981 that this become NASA policy (Ref. 11) During this 

same time period, the Europeans entered the ELV market with 

their brand new Ariane launch vehicle. Ariane soon became a 

viable and competitive launch vehicle in the international 

market, creating additional pressures on the United States 

launch vehicle industry to remain competitive in a market they 

once dominated. This was the beginning of a shift towards 

recognizing the need for a robust, competitive, commercial 

space transportation industry, and the move towards commercializing ELVs in the United States began. This also marked 

the beginning of a shift within NASA from managing and 

buying ELVs (like Delta and Atlas/Centaur) to procuring 

launch services from industry. It would take several more 

years for this transition to occur, and GRC was at the forefront 

of making it happen. This transition from launch vehicles to 

launch services will be discussed in Section 5.0 of this paper. 

During this same time period (early 1981), as the space 

shuttle began to fly, it became apparent that the space shuttle 

needed a capability to launch payloads beyond low Earth 

orbit. The idea to redesign Centaur to fit inside the space 

shuttle was a radical idea that had been considered and studied 

in the 1970s, with a large integration study authorized by 

NASA HQ in 1979. The Shuttle/Centaur Program began in 

1981 (albeit with low funding and an “on-again/off-again” 

first couple of years) and was hailed as the “convergence of 

piloted and robotic spacecraft and the next step in launch 

vehicle evolution. In an era of cost cutting and declining space 

budgets, the combination of the shuttle with the world’s most 

powerful upper stage promised to give the United States a 

system of extraordinary power and versatility” (Ref. 12). 

There was also at the time a competing upper stage concept 

for the shuttle, the Air Force’s solid propellant inertial upper 

stage (IUS) built by Boeing. A bitter political debate ensued 

between IUS camps (including Marshall Space Flight Center 

and its powerful delegation) and Centaur camps. 

Unfortunately, Shuttle/Centaur was fraught with controversy and Agency and inter-center politics. Centaur was managed 

as shuttle payload, as opposed to an element of the Space 

NASA/TM—2015-218742 8 
Transportation System. The mass of a fully tanked Centaur 

with its payload stretched the abort landing capabilities of the 

shuttle orbiter. This necessitated designing a complex 

propellant dump system to quickly dump the liquid hydrogen 

and liquid oxygen from the Centaur in the event of an 

emergency abort landing to reduce mass. There were numerous safety concerns associated with flying hydrogen and 

oxygen inside the cargo bay of the shuttle in close proximity 

to the crew and their only ride home—especially with these 

propellants stored inside the Centaur’s balloon-like pressurestabilized tanks. In spite of those safety concerns, all the 

required safety precautions were addressed and all necessary 

emergency systems and redundancy plans were in place. In 

January 1986, Shuttle/Centaur SC-1 and SC-2 were only 

4 months from launch (scheduled to launch 6 days apart in 

May 1986) and ready to be installed inside the Space Shuttle 

Challenger cargo bay for the Ulysses mission (SC-1) to the 

Sun and Space Shuttle Atlantis for the Galileo mission (SC-2) 

to Jupiter. However on January 28, 1986, the Space Shuttle 

Challenger tragically and catastrophically failed during launch 

and everything changed. The Agency became very risk 

adverse. The shuttle program was shut down for almost 

3 years. The Shuttle/Centaur program was not officially 

terminated until June 19, 1986, but its uncertainty and fate 

were largely known soon after the Challenger accident. 

Figure 7 shows artist concepts of Centaur G-prime being 

deployed from the Shuttle cargo bay with the Galileo spacecraft payload. 

GRC comanaged the development of Shuttle/Centaur with 

the Air Force. Although there was low-level, “on-again, offagain” activity and funding in 1981 and 1982, the program did 

not have significant funding and stability until 1983—only 

3 years before the firmly scheduled first launch in May 1986. 

Meeting this schedule was critical for the program. The 

Galileo mission to Jupiter had to be launched within a 21-day 

window that month, or be delayed for over a year. GRC 

created the Shuttle/Centaur Project Office and hired additional 

staff. Launch vehicle staffing at GRC doubled to around 250 

people in the mid-1980s during the peak of Shuttle/Centaur 

development. The Air Force maintained an on-site staff at 

GRC and was an integral, vital part of the Shuttle/Centaur 

Project Office. Together GRC and the Air Force comanaged 

the program including the integration of Centaur design and 

configuration changes to adapt the vehicle for the space shuttle 

platform and to ensure that Centaur addressed all human space 

flight requirements. 

There were two versions or configurations of Centaur 

developed for the shuttle: Centaur G and Centaur G-prime. 

The G-prime version was 30 ft long to accommodate 30-ft 

long payloads. The G version was 20 ft long and could 

accommodate payloads up to 40 ft long. This was a result of 

different requirements for NASA missions versus Air Force 

missions. NASA’s requirements were for a larger upper stage 

Figure 7.—Artist concept of Shuttle/Centaur (with Galileo 

spacecraft) deployment from shuttle.

with the energy to achieve interplanetary velocity requirements. The Air Force requirements were for larger/longer 

payloads (40 ft) for Earth orbital missions. Both versions of 

Centaur were cradled inside the shuttle cargo bay in a device 

known as the Centaur Integrated Support System (CISS). The 

CISS was a major new systems development activity for the 

program. The CISS provided all of the mechanical, electrical, 

and fluid interfaces between the Centaur and the shuttle. The 

CISS not only supported the Centaur during space shuttle 

flights, it also provided the means to control and deploy the 

Centaur. With the cargo bay doors open, the CISS would 

rotate (pivot) the Centaur up and out of the cargo bay and then 

release it. The CISS was designed to be reusable and returned 

to Earth inside the shuttle cargo bay. Both versions of Centaur 

NASA/TM—2015-218742 9 
Figure 8.—Shuttle/Centaur G-prime processing at Kennedy 

Space Center (CISS also shown at right). 

with the payload/spacecraft and the CISS filled the entire 

cargo bay of the space shuttle. The two space shuttle orbiters 

designated to carry Centaur, Challenger and Atlantis, also had 

to be modified for Centaur. These modifications included 

provisions for filling and draining the Centaur propellant 

tanks, venting the tanks, and dumping the tanks in the event of 

an abort landing. Figure 8 shows the first Centaur G-prime 

vehicle being processed for launch at KSC. The CISS can be 

seen in the at the bottom of the lower photograph. 

There were many design changes and modifications 

required for Centaur G and G-prime. The launch environment 

of the space shuttle was totally different than that of Atlas and 

Titan. Significant human rating requirements had to be 

addressed. The RL10 rocket engine had to be able to transition 

to the new Centaur design and shuttle environments with 

minimal changes. This included accommodating space shuttle 

environments, operating constraints, launch loads, different 

propellant mixture ratios, prelaunch cooling replaced with 

multirevolution/on-orbit chill-down, and accommodating new 

Centaur interfaces for the propulsion system. 

Other Centaur design changes included 

x New propellant tank diameters and lengths 

x New conical transition to the LH2 tank 

x New propellant fill, drain, and dump system 

x New separation disconnects to separate the Centaur from 

the CISS and the shuttle 

x New aft adapter and separation ring 

x New forward adapter 

x New S-band transmitter and RF system compatible with 

the Tracking and Data Relay Satellite System 

x Added system and component redundancies 

x New propellant isolation prevalves 

x Ability to handle multiday on-orbit operations 

From a vehicle design and integration standpoint, these 

technical design changes and interfaces were minor compared 

to the multitude of organizational interfaces. The organizational interfaces for Shuttle/Centaur included mission 

management, the Air Force, payload customers, NASA HQ, 

JSC, KSC, and finally the industrial contractors. The complexity of all these organizational interfaces was further compounded because most of these interfaces were 

“authoritative,” meaning they had the power to influence or 

stop the progress of the overall mission (Ref. 13). Relationships and interfaces with JSC were particularly challenging. 

Part of the problem was that GRC was given leadership 

responsibility of a key element of the Space Transportation 

System, rather than MSFC. GRC was an outsider in the NASA 

world of human spaceflight. Another issue, as mentioned 

earlier, was that Centaur ultimately was managed as, and 

treated by JSC as, a shuttle payload, rather than an element of 

the shuttle program. Centaur had to be designed to meet the 

NASA/TM—2015-218742 10 
requirements and criteria of a shuttle payload, which were 

vastly different than an element. 

At the time the Shuttle/Centaur program was canceled in 

1986 approximately a billion dollars had been spent, and two 

sets of flight articles (Centaur G-prime and CISS for SC-1 and 

SC-2), two G vehicles (approximately 50 percent complete), 

and one ground-test article were produced. The space shuttle 

did not return to flight until September 1988. The Galileo 

mission to Jupiter was eventually launched in October 1989 

using the less powerful IUS inside Space Shuttle Atlantis. The 

European Ulysses spacecraft was not launched until October 

1990, also using the IUS, from Space Shuttle Discovery. A 

modified version of the Centaur G-prime ended up flying 16 

times from 1994 to 2003 as the upper stage on the Air Force’s 

Titan IV. This marked the return of Titan/Centaur, 17 years 

after the Voyager launches. Ironically, NASA decided to 

launch the Cassini mission to Saturn on a Titan IV/Centaur 

G-prime in 1997. The Cassini spacecraft was the last ELV 

payload integrated, managed, and launched by GRC. 

During the four main years of the Shuttle/Centaur program 

(1983 to 1986), GRC continued to manage and launch 

Atlas/Centaur. The Shuttle/Centaur Project Office existed in 

parallel with the Atlas/Centaur Project Office. Both project 

offices received launch vehicle engineering support from the 

Space Transportation Engineering Division, led by 

Steve Szabo. The two project offices and the engineering 

division were all within the Space Directorate at GRC. Total 

launch vehicle staffing at GRC during this period reached 

nearly 250 people. 

Separate from the major Centaur stage configuration changes (Atlas, Titan, Shuttle), GRC also co-led with industry other 

aspects of Centaur stage development and subsequent changes 

to the Centaur stage to improve performance and operability. 

In the 1960s, GRC led and performed structural tests for the 

Centaur equipment module, performed zero-gravity drop 

tower tests to better understand propellant behavior in low 

gravity, and developed a capacitance probe propellant 

utilization system to measure the propellant in the Centaur 

tanks. GRC engineers also developed a balanced thrust vent 

system to enable venting of the propellant tanks during inspace coast phases. In the 1970s, GRC was instrumental in the 

development of the Teledyne flight computer and flight 

software, the Honeywell guidance system, and a digital 

autopilot. In the 1980s, GRC led the elimination of the 

jettisonable insulation panels on the Centaur liquid hydrogen 

tank. The panels were replaced with fixed foam insulation. 

Also in the 1980s specifically for the AC-62 “stretched” Atlas 

G configuration (1984), GRC both eliminated the hydrogenperoxide-powered boost pumps that increased propellant inlet 

pressures for the RL10 engines and performed numerous 

RL10 engine performance improvements, including engine 

thrust and specific impulse increases. For example, a silver 

Figure 9.—AC-62 during prelaunch test at Launch

Complex 36B (photographed by the author).

throat insert was added to the RL10 engine to increase 

expansion ratio and specific impulse. GRC also led the 

development of a new hydrazine-based reaction control 

system for AC-62. The previous system used hydrogen 

peroxide. Unfortunately, with all these changes to Atlas and 

Centaur in 1984, the AC-62 launch was a failure due to a 

Centaur oxygen leak in the intermediate bulkhead that was 

believed to have occurred during Centaur’s separation from 

Atlas. Figure 9 shows the AC-62 vehicle during a prelaunch 

test at Launch Complex 36B at Cape Canaveral Air Force 

Station. 

GRC’s launch vehicle development efforts and accomplishments were not limited to the Centaur stage. The same 

roles, responsibilities, expertise, and philosophy that GRC 

brought to Centaur applied equally to the Atlas booster and its 

MA-5 propulsion system. GRC personnel had the same 

relationship and partnership with the industry contractors for 

Atlas (General Dynamics) and MA-5 (Rocketdyne), as they 

did with Centaur. Some of the Atlas launch vehicle developments and configuration changes that GRC led included 

x Structural strength testing at GRC’s Plum Brook E-stand 

of a full-scale Atlas D tank to demonstrate buckling 

strength capability and bending strength (in the 1960s) 

NASA/TM—2015-218742 11 
x Development of the SLV-3C Atlas with stretched propellant tanks (in 1966) 

x Development of the stretched Atlas G for AC-62 (in 

1984). Atlas G was 81 inches longer than the previous 

Atlas configuration 

x Development of the Atlas H configuration for DoD 

launches from Vandenberg Air Force Base 

x Development of numerous Atlas MA-5 propulsion 

system upgrades (1963 to 1989), including booster and 

sustainer engine thrust increase, elimination of the vernier roll-control engines, and a computerized Atlas propellant loading system 

5.0 Other LeRC ELV Leadership 

Accomplishments 

The Challenger accident in 1986 changed everything. 

NASA realized putting all its eggs into the space shuttle 

basket was a mistake; the country became too dependent on 

the space shuttle at a time when foreign countries (i.e., 

Europe’s Ariane) were taking over the ELV market and 

commercial space business. Further, NASA realized that 

risking human lives on space missions that did not require 

humans was unwise. In December 1986, President Reagan 

issued a directive stipulating that NASA would no longer 

launch satellites for private companies or foreign governments, unless they required a human presence in space or 

involved national security. This decision took the shuttle out 

of competition with ELVs for revenue-generating business 

(Ref. 14). The idea of maintaining a “mixed fleet” of ELVs of 

various sizes and payload capabilities emerged in 1987 when 

NASA’s Mixed Fleet Study was completed. GRC chaired the 

procurement development team for this study. Soon after this, 

in 1988, the concept of buying launch services instead of 

launch vehicles emerged. GRC was at the forefront of this 

transition. 

Up until this time, NASA bought ELVs and was responsible 

for integrating them with payloads and launching them. For 

example, with Atlas/Centaur, GRC had separate contracts with 

General Dynamics for the Atlas and Centaur vehicles, Pratt & 

Whitney for the RL10 engines, Rocketdyne for the Atlas MA5 engines, Teledyne for the Centaur flight computer, and 

Honeywell for the Centaur guidance system. GRC was 

responsible for taking delivery of all of these hardware 

elements and integrating them together with General Dynamics into the final integrated vehicle. Pratt & Whitney, Rocketdyne, Teledyne, and Honeywell were not subcontractors to 

General Dynamics. They were referred to as associate 

contractors. Their contracts were with GRC and they delivered 

their products to GRC. GRC then transferred these deliverables as GFE to General Dynamics, who performed the overall 

vehicle integration and tests. GRC was also responsible for 

integrating the payload and supporting KSC in launching the 

rockets from Air-Force-owned launch pads. GRC also owned 

the RL10 test stands at Pratt & Whitney. NASA was responsible for the launch and the mission success. If there was a 

failure, NASA was responsible for the failure reviews. If a 

private company or another government agency wanted to 

launch their satellite on Atlas/Centaur, they had to approach 

GRC to procure and integrate the vehicle and manage the 

launch. This was the era of ELVs, from 1963 to 1989. 

In 1987 the transition to launch services began. NASA 

would no longer buy vehicles, but would contract with 

commercial launch vehicle providers to buy their service to 

launch a particular payload into space. The launch vehicle 

provider became responsible for everything. In the case of 

Atlas/Centaur; Rocketdyne, Pratt & Whitney, Honeywell, and 

Teledyne became subcontractors to General Dynamics. All of 

the NASA-owned property, equipment, and other assets was 

turned over to industry as part of a barter agreement in 

exchange for launching the Combined Release and Radiation 

Effects Satellite (CRRES) on AC-69. This barter agreement 

was an element (condition) of the Geosynchronous Operational Environmental Satellite (GOES) launch services contract 

negotiation. GOES became NASA’s first commercial launch 

services contract and represented a milestone in the effort to 

commercialize the launch vehicle industry (Ref. 15). AC-68, 

launched on September 25, 1989, carrying a FLTSATCOM 

satellite, was the last GRC-managed and -integrated mission 

of the “launch vehicle” era. GRC had managed 112 launches 

over a 26-year period. From this point forward, NASA would 

purchase launch services rather than launch vehicles. Staffing 

levels at GRC for launch services support dropped to 50 to 70 

people. In July 1990, the first commercial launch of a NASA 

mission occurred with the launch of CRRES on AC-69. The 

new era of commercial space and launch services had begun. 

The barter agreement paved the way for the commercialization 

of Atlas/Centaur. It continues to this day with Centaur still 

flying as the upper stage of Atlas, now referred to as Atlas V. 

A very similar upper stage flies atop the Delta 4 launch 

vehicle. Today there are many other commercial launch 

providers, including Orbital Science, SpaceX, and United 

Launch Alliance (ULA, a Boeing/Lockheed Martin joint 

venture). Ariane continues to fly for Europe, as do ELVs from 

other foreign countries including Japan and Russia. In 2012 

ULA celebrated the 200th flight of Centaur. ULA is currently 

developing the next generation of Centaur. It is perhaps ironic 

and remarkable to note that while Centaur still flies today, the 

space shuttle (which almost caused the termination of Centaur 

and ELVs) does not. 

During the 1990s, the first decade of launch services, GRC 

was responsible for procuring launch services for intermediate 

and large ELVs (i.e., Atlas/Centaur and Titan). Although these 

were launch services, GRC still maintained some responsibilities including independent verification and validation (IV&V), 

NASA/TM—2015-218742 12 
leading-edge integration, independent analyses, mission design 

analyses, flight readiness assessments, supported spacecraft 

integration, and any NASA mission unique or peculiar requirements. For example, the Earth Observing System (EOS) AM-1 

spacecraft had several mission-peculiar requirements that drove 

significant modifications to the baseline vehicle, including a 

new extended payload fairing, unique payload adapter and 

separation system, and a strengthened Centaur equipment 

module for the heavy and larger EOS payload. The EOS AM-1 

spacecraft was originally designed to launch on the much more 

powerful Titan launch vehicle. When the change was made for 

budgetary reasons to launch on Atlas/Centaur, the spacecraft 

had to be downsized, but it still ended up being an unusually 

large and heavy payload for Atlas/Centaur. GRC performed all 

of the IV&V analyses of the new designs, the structural test 

program, and the combined spacecraft/launch vehicle environment. EOS AM-1 was launched in December 1999 from a new 

Atlas launch complex (SLC-3E) at Vandenberg Air Force Base. 

This was the very first launch of an Atlas with a Centaur upper 

stage from Vandenberg. Other missions that GRC supported 

during this decade included CRRES (AC-69), Mars Observer 

(Titan III), GOES (AC-73, AC-77), SOHO (AC-121), and 

Cassini (Titan IV/Centaur). 

In managing ELV launch services, GRC employed a variety 

of matrixed analysis capabilities to verify and validate mission 

planning and launch preparations. Typical activities included 

loads analyses, dynamics analyses, stability and control 

analyses, flight software IV&V, guidance analyses, and 

trajectory/performance analyses. These independent analyses 

in critical or high-risk areas, using independently derived 

mathematical models, were then compared with the contractor’s results. In 1998, a NASA “Zero Base Review” directed 

that all NASA ELV programs be transferred to KSC. This 

included GRC’s responsibilities for intermediate- and largeclass ELV launch services (i.e., Atlas/Centaur and Titan), as 

well as Goddard Space Flight Center’s responsibility for small 

and medium class ELV launch services (i.e., Delta). This 

marked the end of GRC’s long, 35-year association with 

Centaur and ELVs. 

GRC led the creation of a new contractual means for the 

government to launch spacecraft. The transition from “launch 

vehicle” to “launch services,” where NASA contracts with 

industry following 30+ years of maturation of ELVs, enabled 

the government to streamline and pursue a cost-effective way to 

launch spacecraft by purchasing a service rather than the actual 

hardware. GRC pioneered the commercial launch services 

culture and was the first to implement the new national space 

policy on commercialization through innovative contracting 

provisions that have become the standard for NASA and DoD. 

GRC’s pioneering launch services methods enabled NASA to 

retain technical insight while keeping costs low. 

6.0 Thoughts on the Future 

It is hard to imagine today a program or project being 

managed and integrated like Centaur was. Times have 

changed, the environment is different, the industry has 

matured, and the roles of government and industry have 

evolved. A trusting, collaborative relationship between 

government and industry, like Centaur enjoyed, may be a relic 

of the past, but it is nevertheless something to strive for. The 

basic tenets of GRC’s launch vehicle management philosophy 

are sound and relevant today: strong leadership; highly 

competent staff with deep technical knowledge, experience, 

and tools; well-defined roles and responsibilities, processes, 

and procedures; and a profound drive for mission success. The 

government’s role needs to be more than just insight and 

oversight of the contractor. The “deep technical knowledge” 

of the staff needs to be allowed access to the contractor’s 

design, development, production, and operations. This 

penetration need not be adversarial but rather in a spirit of 

collaboration, teamwork, and mutual trust for the common 

good of the mission—a “win-win” situation. This proposition 

will lead to much debate and many questions. Is this expensive, bureaucratic, unnecessary overkill? Shouldn’t the 

government step back and stay out of industry’s way? Isn’t 

this “old school” and contrary to commercialization? Does the 

government (NASA) even have the personnel with deep 

technical knowledge and experience anymore? These are all 

valid questions that need to be thoughtfully considered by 

leaders, stakeholders, and customers. 

What is the next Centaur? There are many launch vehicles 

and space transportation systems flying successfully today. 

SpaceX, with their Falcon launch vehicles and Dragon 

capsule, is one example. NASA’s Space Launch System heavy 

lift booster and Orion Multi-Purpose Crew Vehicle are well 

into their development. Future in-space transportation systems 

likely will be higher performing than Centaur or any other 

chemical propulsion stage or spacecraft. Nuclear thermal 

propulsion with its high specific impulse and high thrust or 

solar electric propulsion (SEP) with its very high specific 

impulse (and low thrust) are being considered for future solar 

system missions and destinations, such as Mars and for the 

Asteroid Redirect Mission. The lessons learned from Centaur, 

and there are many, should be heeded as well as the techniques and philosophy employed by GRC. 

GRC is leading the development of SEP and in-space SEP 

transfer stages/spacecraft development. As revolutionary as 

Centaur was in the 1960s in terms of high-energy performance 

and new capability development to enable new missions, SEP 

is this generation’s Centaur. Hopefully some of the management and integration tenets for Centaur will be applied to SEP 

and other future space transportation systems. 

NASA/TM—2015-218742 13 
7.0 Conclusion 

The success and longevity of Centaur can be attributed to 

GRC’s strong leadership, technical competency, and management philosophy for launch vehicle integration. Although this 

paper is about GRC’s role, one should not undervalue the role 

of General Dynamics and the other industry partners that 

equally share in the success of Centaur. It was a true team 

effort and collaboration. Although GRC managed and led the 

launch vehicle integration, as well as the development of the 

Centaur upper stage, the work was largely done by a team of 

industry partners under contract to GRC. However, GRC did 

far more than just manage the contracts and provide oversight 

and insight. The GRC launch vehicle team worked side-byside with their industry counterparts on almost all aspects of 

Centaur development and integration, including the major 

configuration changes described in this paper. The GRC team 

had longevity, continuity, and the corporate knowledge of 

launch vehicles and Centaur. GRC’s knowledge of every 

detail of Centaur, down to individual components such as 

valves and fasteners, sometimes exceeded that of industry. 

Both GRC and industry personnel had immense pride in 

Centaur and their contributions to its success. Each launch 

culminated a multiyear “intimate relationship” life cycle with 

that particular vehicle. Each vehicle had its own unique 

history, pedigree, and problems to overcome that the team 

lived and breathed every day. It was exhilarating when the 

launch was successful and devastating when the launch ended 

in failure. Centaur continues to be the workhorse, high-energy 

upper stage for the nation. Go Atlas. Go Centaur. 

References 

1. NASA Lewis Research Center, “Report of the Atlas/Centaur Review Board,” chaired by Dr. Bruce T. 

Lundin, NASA Glenn History Collection, Centaur Collection, NASA Glenn Research Center, Cleveland, OH, 

1981, p. 5 (unpublished 1981 internal NASA report to 

NASA Headquarters). 

2. NASA Lewis Research Center, “Launch Vehicles 

Division Presentation to the Space Directorate,” NASA 

Glenn Research Center Internal Presentation Charts, 

Cleveland, OH, 1980 (unpublished). 

3. NASA Lewis Research Center, “Report of the Atlas/Centaur Review Board,” chaired by Dr. Bruce T. 

Lundin, NASA Glenn History Collection, Centaur 

Collection, NASA Glenn Research Center, Cleveland, 

OH, 1981, p. 6 (unpublished 1981 internal NASA report 

to NASA Headquarters). 

4. NASA Lewis Research Center, “Report of the Atlas/Centaur Review Board,” chaired by Dr. Bruce T. 

Lundin, NASA Glenn History Collection, Centaur Collection, NASA Glenn Research Center, Cleveland, OH, 

1981, p. 7 (unpublished 1981 internal NASA report to 

NASA Headquarters). 

5. Dawson, Virginia P., and Bowles, Mark D., “Taming 

Liquid Hydrogen: The Centaur Upper Stage Rocket 

௅ ́1$6$/SP—2004-4230, 2004, pp. 71-75. 

6. NASA Lewis Research Center, “NASA Center Roles in 

Management of Intermediate and Large Class ELVs,” 

NASA Lewis Research Center Internal Presentation 

Charts, Cleveland, OH, 1988 (unpublished). 

7. Dawson, Virginia P., and Bowles, Mark D., “Taming 

Liquid Hydrogen: The Centaur Upper Stage Rocket 

௅ ́1$6$/SP—2004-4230, 2004. 

8. Dawson, Virginia P., and Bowles, Mark D., “Taming 

Liquid Hydrogen: The Centaur Upper Stage Rocket 

௅ ́1$6A/SP—2004-4230, 2004, p. 143 

9. Dawson, Virginia P., and Bowles, Mark D., “Taming 

Liquid Hydrogen: The Centaur Upper Stage Rocket 

௅ ́1$6$SP—2004-4230, 2004, p. 144. 

10. NASA Lewis Research Center, “Report of the Atlas/Centaur Review Board,” chaired by Dr. Bruce T. 

Lundin, NASA Glenn History Collection, Centaur Collection, NASA Glenn Research Center, Cleveland, OH, 

1981, p. 3 (unpublished 1981 internal NASA report to 

NASA Headquarters). 

11. NASA Lewis Research Center, “Report of the Atlas/Centaur Review Board,” chaired by Dr. Bruce T. 

Lundin, NASA Glenn History Collection, Centaur Collection, NASA Glenn Research Center, Cleveland, OH, 

1981, p. 2 (unpublished 1981 internal NASA report to 

NASA Headquarters). 

12. Dawson, Virginia P., and Bowles, Mark D., “Taming 

Liquid Hydrogen: The Centaur Upper Stage Rocket 

௅ ́1$6$/SP—2004-4230, 2004, p. 167. 

13. Dawson, Virginia P., and Bowles, Mark D., “Taming 

Liquid Hydrogen: The Centaur Upper Stage Rocket 

௅ ́1$6$SP—2004-4230, 2004, p. 196. 

14. Dawson, Virginia P., and Bowles, Mark D., “Taming 

Liquid Hydrogen: The Centaur Upper Stage Rocket 

௅ ́1$6$/SP—2004-4230, 2004, p. 233. 

15. Dawson, Virginia P., and Bowles, Mark D., “Taming 

Liquid Hydrogen: The Centaur Upper Stage Rocket 

௅ ́1$6$/SP—2004-4230, 2004, p. 237. 

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