National Security Space Launch


The Launch Enterprise Systems Directorate of the Space and Missile Systems Center, Los Angeles Air Force Base, California, manages the National Security Space Launch program (NSSL, formerly the Evolved Expendable Launch Vehicle or EELV) program.  The program provides the United States assured access to space -- defined as at least two launch systems or families of launch systems -- with three families of launch vehicles: Atlas V, Delta IV, Delta IV Heavy, and Falcon 9 and Falcon Heavy. These launch vehicles provide critical space-lift capability to support Department of Defense and other National Security missions. The NSSL program has successfully launched over 70 National Security Space launches in support of the Air Force, the National Reconnaissance Office and the U.S. Navy. 


The NSSL program procures launch services from the United Launch Alliance and the Space Exploration Technologies Corporation, or SpaceX. ULA is a joint venture between Boeing and Lockheed Martin formed in 2006 and produces the Delta IV and Atlas V launch vehicles.  SpaceX produces the Falcon 9 and Falcon Heavy launch vehicles. SpaceX and ULA also maintain space launch complexes at Cape Canaveral Air Force Station, Florida, and Vandenberg Air Force Base, California. 


Program cost savings are achieved through operability and acquisition improvements. Operability improvements include the use of common components and infrastructure, standard payload interfaces, standardized launch pads, and reduced on-pad processing.  Acquisition improvements include block buys of launch vehicles and competition between certified providers.


Program History:

Buy 1

The Air Force began the EELV program in 1994 to develop multiple launch systems capable of meeting the entire spectrum of National Security Space launch requirements. The Air Force selected four contractors in 1996 to begin the development of evolved expendable launch systems with the intent to down-select to one launch provider. During the mid-to-late-1990s, the U.S. anticipated a very robust commercial launch market that would provide sufficient rate and throughput necessary to provide low-cost and reliable launch systems across a broad industrial base. The robust commercial market forecast led the Air Force to reconsider its acquisition strategy. The EELV acquisition strategy changed from a planned down-select to single contractor and a standard Air Force development program to a dual commercialized approach that leveraged commercial market share and contractor investment. In 1998, the Air Force down-selected to two launch systems, Atlas V and Delta IV.


The Air Force employed a co-investment acquisition strategy to share development costs for new evolved expendable launch vehicles. The U.S. Government provided a fixed non-recurring investment and U.S. commercial launch providers funded the remaining costs required to develop new launch systems that could meet NSS launch requirements. The Air Force used Other Transaction Authority to execute this co-investment by awarding Other Transaction agreements to two launch providers. This acquisition approach enabled the Air Force to have adequate insight during the development phase to ensure the new launch systems would be capable of meeting NSS requirements. Congruent to the OT agreements, the Air Force conducted a competition to split award firm-fixed price launch services to the two launch providers, The Boeing Company using its Delta IV launch vehicle and Lockheed Martin using its Atlas V launch vehicle. Missions were assigned to each launch service at contract award and were scheduled to launch between 2002 and 2006. The new EELV systems, Atlas V and Delta IV, accommodated the large spectrum of launch needs for the space systems that were in parallel development.


When the anticipated commercial launch market did not materialize in the early 2000s, the U.S. Government was left with the majority of launches using the two new launch systems. In addition, the NSS spacecraft undergoing development with launch dates between 2002 and 2006 experienced significant delays (the last of these originally awarded missions launched in 2016). Under the firm-fixed price contracts awarded in 1998, Boeing and Lockheed Martin were losing millions of dollars waiting for those spacecraft and contemplated exiting the business.  The Air Force was forced to adjust the acquisition approach to enable both launch providers to be viable in the face of the low NSS launch rate, yet still meet the NSS-required reliability.



The President issued the National Security Presidential Directive (NSPD-40) in 2004 outlining the National Space Transportation Policy. This directive stated that “the Secretary of Defense shall be the launch agent for the national security sector and shall maintain the capability to develop, evolve, operate, and purchase services for those space transportation systems, infrastructure, and support activities necessary to meet national security requirements.” The directive went on to say, “The Secretary of Defense shall maintain overall management responsibilities for the Evolved Expendable Launch Vehicle program and shall fund the annual fixed costs for both launch services providers…” In response to the NSPD-40 and lack of commercial viability for domestic launch providers, the Air Force changed it acquisition strategy in 2005. The Air Force awarded new contracts for launch services and launch capability to Boeing and Lockheed Martin in 2005 (Boeing and Lockheed Martin entered into a joint venture to create United Launch Alliance in 2006). The launch services contracts funded the activity to produce the launch vehicles and remained firm-fixed price. The launch capability contracts funded the activity to launch the rockets as well as maintain the launch infrastructure and used a cost-reimbursement arrangement. This contract structure provided some stability to the launch providers; however, the Air Force still ordered launch services annually with no long-term commitment.


Phase 1

The Air Force Service Acquisition Executive approved a new acquisition strategy on  Nov. 24, 2011 that restructured the EELV program approach to provide more commitment to industry and meet affordability goals. The acquisition strategy objectives were to maintain mission success, stabilize the industrial base, reduce costs, promote competition within the launch industry, prevent or mitigate any cost or redesign impacts to space vehicles, and sustain assured access to space. The acquisition strategy was amended on Feb. 10, 2013 and allowed the Air Force to procure up to 35 launch vehicle cores (a core is the main rocket body; the Delta IV Heavy consists of three cores) over a five year ordering period, 2013-2017 and provide the associated launch capability from 2013-2019. The Air Force awarded a sole source contract with a requirements type component to United Launch Alliance (ULA) that provided a long-term commitment in exchange for much lower launch service prices and substantial manifest flexibility.  This contract with ULA was deemed to be “Phase 1” of the EELV program.


Phase 1A The February 2013 acquisition amendment also outlined the parameters for re-introducing competition to the EELV Program. The Under Secretary of Defense for Acquisition, Technology and Logistics (USD (AT&L)) amended the EELV Acquisition Strategy on Nov. 3, 2016 that further defined the acquisition and business approach for the competitive component of the approved EELV Phase 1 Acquisition. The competitive component, known as Phase 1A, includes competitive FY15-FY19 launch service procurements for launches in the FY18-FY22 timeframe to allow new EELV providers to on-ramp into the program. This acquisition strategy fosters competition while maintaining focus on mission success in meeting NSS manifest requirements. Phase 1A is the first iteration of competitively procured launch services. The Air Force awarded the first competitive launch service in more than 15 years to SpaceX in April 2016. 


Phase 2


Following Russia’s February 2014 invasion of Crimea, section 1608 of the Carl Levin and Howard P. “Buck” McKeon National Defense Authorization Act for Fiscal Year 2015 (FY 15 NDAA), Public Law 113-291, was enacted to prohibit the Department of Defense (DoD) from procuring launch services that involved the use of rocket engines designed or manufactured in the Russian Federation. The Atlas V launch system uses the Russian-designed and manufactured booster engine (RD-180). Per the fiscal year 2015 National Defense Authorization Act (NDAA) and as amended in 2016 and 2017, the EELV program is transitioning from the use of non-allied engines to the use of domestic alternatives.


The Air Force developed an acquisition strategy to transition off the RD-180 engine, increase competition and reduce the overall cost of launch services.  The end goal of this strategy is to leverage the capabilities of commercial launch providers to develop two domestic launch systems that meet the NSS requirements and are not reliant on non-allied technology.

The Air Force started the transition off the RD-180 engine in 2015, through strategic investments to mature booster propulsion technology. The Air Force awarded ten contracts to industry and academia for booster propulsion technology maturation efforts and advancing American rocket engine industrial capability. The Air Force followed the technology maturation with public-private partnerships for the development of domestic rocket propulsion systems using of OT Agreements. 

To complete the transition from non-allied propulsion systems, the EELV program office intends to partner with industry through OT Agreements to make investments in new or upgraded launch systems that will meet the NSS requirements. The OT Agreements may leverage the booster propulsion technology investments or use the domestic rocket propulsion systems currently in development. This approach provides the opportunity to combine U.S. Government funds with private industry funds in the development of NSS capable launch systems. However, until these upgraded and/or newly developed launch systems are completed and certified for NSS launches (projected in FY22), sufficient access to Atlas V launch services and the corresponding RD-180 engines is necessary to maintain affordable assured access to space. Phase 2 will culminate in competitions for NSS launch services using the newly developed or upgraded domestic launch systems.

On March 1, 2019, the Evolved Expendable Launch Vehicle program name was officially changed to the National Security Space Launch program.

The 2019 National Defense Authorization Act directed the name change from EELV to NSSL to reflect consideration of both reusable and expendable launch vehicles future solicitations.

The NSSL program is designed to continue to procure affordable National Security Space launch services, maintain assured access to space, and ensure mission success with viable domestic launch service providers. The program is driven to provide launch flexibility that meets warfighter needs while leveraging the robust U.S. commercial launch industry, which has grown significantly during the past five to seven years.


NSSL Launch Vehicles:

ULA Delta IV

ULA’s Delta IV family is capable of carrying over 13,810 kg (30,440 lbm) to Geosynchronous Transfer Orbit (GTO) and can lift over 28,370 kg (62,540 lbm) to Low-Earth Orbit (LEO). The Delta IV Medium, Medium-Plus, and Heavy configurations are evolved from flight-proven Delta II and Delta III systems while incorporating the latest technology into a family of vehicles maximizing the use of common hardware.


The Delta IV Medium and Medium-Plus vehicles use a single Common Booster Core, while the Heavy variant uses three CBCs. The first stage is powered by an Aerojet Rocketdyne RS-68A, a liquid hydrogen/liquid oxygen engine that produces 702,000 lbs of thrust. The Delta Heavy variant uses three of these engines for a combined 2,106,000 lbs of thrust and can lift over 13,810 kg (30,440 lbm) to GTO and over 28,370 kg (62,540 lbm) to LEO. The Delta IV Medium can augment launch performance by adding either two or four solid rocket boosters. The second stage is powered by the Aerojet Rocketdyne RL10B engine. Either a 4-meter or 5-meter fairing encapsulates the payload. Vehicles are defined by the number of solid rocket boosters and the width of the payload fairing. Delta IV's inaugural flight was marked by the successful launch of a commercial satellite on a Medium-Plus in November 2002. The first Delta IV Heavy launch vehicle demonstration was flown in December 2004.


ULA Atlas V

ULA’s Atlas V family of launch vehicles is capable of carrying payloads over 8,900 kg (19,620 lbm) to geosynchronous transfer orbit (GTO) and can lift over 18,850 kg (41,570 lbm) to Low-Earth Orbit (LEO). The Atlas V provides medium and intermediate lift capability and is evolved from flight-proven Atlas IIAS and III programs, maximizing flexibility and reliability. The Atlas family of launch vehicles has and continues to be a national workhorse, logging over 600 total launches (NSS, civil, and commercial) over the last 60 years.

The Atlas V family uses a Russian RD-180 engine to power the first stage common core booster. The RD-180 produces 860,000 lbs of thrust. ULA can add up to five solid rocket boosters to augment performance. The second stage of the launch vehicle is called Centaur and is powered by the Aerojet Rocketdyne RL10C engine. As with the Delta IV, either a 4-meter or 5-meter fairing is used to shroud the payload, and vehicles are defined by the number of solid rocket boosters and the size of the payload fairing. The Atlas V's inaugural flight was marked by the successful launch of a Hotbird-6 commercial satellite in August 2002.

SpaceX Falcon 9 and Falcon Heavy


SpaceX’s Falcon 9 is capable of carrying payloads of over 8,300 kg (18,300 lbm) to geosynchronous transfer orbit and can lift over 22,800 kg (50265 lbm) to Low-Earth Orbit. The Falcon 9 provides medium and intermediate lift capability. The Falcon Heavy is capable of carrying payloads of roughly 63,800 kg (140660 lbm) to Low-Earth Orbit, providing up to heavy lift capability.

The Falcon 9 first stage uses nine Merlin engines to produce a combined 1,710,000 pounds of thrust at lift-off. The second stage is powered by a single, vacuum optimized, Merlin engine which helps to achieve cost reduction through production efficiencies. The Falcon 9 flies with a 5.2-meter composite fairing. The Falcon 9’s inaugural flight was successfully launched in June 2010. The Falcon Heavy consists of three first stage cores with a total of 27 Merlin engines producing roughly 5 million pounds of thrust at lift off.


(Current as of March 2019)