UNITED24 - Make a charitable donation in support of Ukraine!


EELV Evolved Expendable Launch Vehicle


The purpose of the EELV program is to support the National Mission Model (excluding crew-read or cargo return missions), reduce overall system recurring costs, and maintain or improve the reliability, operability, and capability of current medium through heavy lift systems (ie Titan II, Delta, Atlas, and Titan IV). The EELV system may include, but is not limited to launch vehicles, launch facilities, support equipment, and payload integration in support of the Department of Defense, the Intelligence Community, the National Aeronautics and Space Administration, and the Departments of Transportation and Commerce.

The EELV system will be used to deploy Government payloads. The EELV system consists of the Launch Vehicle (LV) Segment and the Ground Segment. The EELV system includes all equipment, facilities, and launch base infrastructure necessary to launch a payload, place it in the required delivery orbit, provide specified environments, provide EELV system maintenance, and perform any necessary recovery/refurbishment operations.

The Launch Vehicle Segment consists of the means for transporting the payload from the launch site to the delivery orbit, through completion of the contamination and collision avoidance maneuver (CCAM) and stage disposal. It includes, but is not limited to, production, assembly, propulsion, guidance and control, electrical power, tracking and telemetry, communication, ordnance, flight termination, payload separation, structural elements, payload fairing, software, and appropriate vehicle/ground and vehicle/payload interfaces that are necessary to meet mission requirements. The payload and its unique Airborne Support Equipment (ASE), though transported by the EELV, are not considered as part of the EELV system.

The Ground Segment consists of all existing, modified or new construction, facilities, and the equipment, software, and utilities necessary to support the planning, storage, integration, check-out, processing, launch, telemetry, tracking and control through CCAM, and recovery/refurbishment (if any) for the EELV system.

The EELV system shall meet all non-tradable performance requirements simultaneously. All performance requirements specified are tradable except for the following: reliability; lift capability; launch rates; orbital parameter, attitude and rate accuracies; all payload environments and accommodations (including CCAM); and any required by law. These include, but are not limited to the following.

The EELV system shall provide a sufficient range of lift capability to accommodate the Government portion of the National Mission Model. The EELV MLV and HLV shall have the capability to inject into geosynchronous transfer orbits on either the ascending or descending leg. The EELV MLV shall have the capability to fly directly to 12-hour, highly elliptical, critically-inclined orbits and the capability to perform short duration upper stage burns for circularizing low altitude orbits. This is a non-tradable requirement. Vehicle sizing shall be based on performance estimation techniques which shall provide a 99% assurance of the vehicle fully meeting mass to orbit requirements while considering possible uncertainties in EELV and environmental parameters, such as propellant loading, Isp, and atmospheric density.

The EELV system shall accommodate the Transition Schedule included in the RFP.

The system shall have sufficient throughput to support the range of Government requirements. This is a non-tradable requirement. The system shall also be resilient enough to recover from a downing event or other delays which may cause the system not to meet the launch rate requirements.

The EELV system (ground and launch vehicle segments) shall launch within 7 calendar days of the scheduled launch time. Attributable delays include EELV equipment-caused delays, processing delays and weather delays. The schedule shall be considered firm 90 days prior to the scheduled launch date.

The EELV shall be capable of repeatedly responding to priority requests for launches within a minimal time (MLV goal of 30 calendar days, HLV goal of 60 calendar days) from the date of launch request, assuming the availability of a processed payload ready for mating with the EELV.

The system shall be capable of holding in a mission ready status for a minimum of 30 days. Mission ready means the system can move from the mission ready hold state to launch within 24 hours of notification. The system shall be capable of maintaining a ready-to-launch status with propellants loaded for at least two hours.

The system shall be capable of performing a fail-safe abort such that the payload and launch system are protected following a launch abort anytime prior to launch commit.

The system shall be capable of recycling, following a fueled vehicle hold, to enable launch within the launch window on the next calendar day. The system shall also be capable of performing recycling on at least two successive days.

The EELV must accommodate the Government payloads in RFP Annex C- I and shall provide standard interfaces and services (such as mechanical interfaces, power, environmental conditioning, etc.). This is a non-tradable requirement. The Payload Database Document may be used for reference information regarding current payloads. Current or new payloads having unique interface/services needs (such as special power conditioning) shall provide appropriate payload ASE/services. The weight of the ASE shall be considered payload weight.

The envelope shall be sufficient to provide a minimum of one inch clearance between the payload and the fairing under worst case dynamic conditions and shall accommodate the maximum static payload envelopes. This is a non-tradable requirement.

The LV shall be capable of accommodating the mass properties of the Government payloads in the National Mission Model. This is a non-tradable requirement. The Payload Database Document may be used for reference information regarding current payloads.

Payload Substitution. To maximize operational flexibility and reduce costs, EELV shall accommodate payload substitution (with another payload normally assigned for launch on the same size LV) prior to payload mate, up to five days before a scheduled launch. The EELV system shall facilitate rapid payload substitution so that schedule delays are minimized or avoided. Payload substitution should not drive additional launch processing other than activities normally required for payload mating.

Design reliability, including hardware, software, and firmware, from launch commit through CCAM shall be at least 98% for the LV. This is a non-tradable requirement.

Performance margin shall be defined in the Contractor prepared system specification. The Government has an objective of a 15 percent performance margin. Design margin and verification of chosen design margin values shall be defined in the Contractor prepared system specification and Requirements Verification Matrix, respectively.

The EELV plans to reduce annual launch costs by at least one quarter and as much as half, compared to current spacelift systems. The cost target (covering development, procurement, integration and maintenance) is specified in the Operational Requirements Document (ORD) statement by US Space Command Commander-in-Chief of Gen. Joseph Ashy, which characterizes EELV as: "... a family of vehicles that is technically achievable and costs us 25 percent less (threshold) than current systems with an objective of 50 percent reduction in the annual cost of spacelift. . . .[ln] responsivenesS schedule dependability and supportability, we are willing to examine the trade between cost and improvements."(2)


1. Department of the Air Force Office of the Assistant Secretary for Acquisition, "Request for Proposal (RFP) F04701-95-R-0009, Evolved Expendable Launch Vehicle (EELV) SPD Annex C," 17 May 1995.

2. "EELV Target: Cut Current Launch Costs by 25 Percent to 50 Percent," Inside The Air Force, 21 April 1995, page 3.

Join the GlobalSecurity.org mailing list

Page last modified: 21-07-2011 00:46:24 ZULU