Atlas V for Commercial Passenger Transportation Jeff A. Patton1 and Joshua B. Hopkins2 Lockheed Martin Space Systems Company, P.O. Box 179, Denver Colorado 80433 The Atlas and Centaur Programs have enjoyed a rich history as a trusted vehicle for a large number of critical space exploration missions as well as the Mercury manned spaceflight program. The Atlas expendable launch vehicle has matured well beyond the early days of manned spaceflight and is uniquely poised to provide a near-term transportation solution for the emerging space tourism market. This paper addresses the attributes of the Atlas expendable launch vehicle that make it distinctively qualified to be a highly reliable, robust earth-to-orbit transportation solution for commercial passengers. The paper will detail the Atlas expendable launch vehicle system compliance to Human Rating requirements defined by the Federal Aviation Administration (FAA) and NASA Standard 8705.2A “Human-Rating Requirements for Space Systems” as well as the anticipated safety expectations of passengers and insurers. In addition, the paper will compare and contrast various approaches to achieving safety, some of which may drive highly complex, unreliable, and costly design solutions. Atlas has the unique capability to demonstrate the implementation of Human Rating requirements by validating designs on numerous unmanned launches. The Atlas high flight rate of unmanned missions quickly builds sufficient history to rely on flight demonstrated reliability, rather than analytically predicted reliability. Demonstrating these systems has the benefit of increasing reliability through commonality with commercial and government launches, in addition to continuing vehicle characterization due to the experience gained from higher flight and production rates. The Atlas expendable launch vehicle family is a mature system with demonstrated design robustness and processes discipline that provides a highly reliable, robust solution for commercial passenger transportation needs. I. Introduction HE key to the success of commercial space travel is a safe, reliable and affordable transportation system. This T is especially true for orbital missions, where a failure would devastate this fragile emerging industry for years to come. The Atlas V launch vehicle has demonstrated that it would be the Earth-To-Orbit launch vehicle of choice due to its unsurpassed record of mission success. The Atlas V Program was successful on its maiden launch attempt, and has realized a 100% success record on all 8 Atlas V launches. The overall Atlas Program has demonstrated 79 consecutive successes since 1993, including 100% mission success record for all Atlas II, III, and V flights. The Atlas Program approach to human rating is simple. Human rating should utilize a common-sense approach to ensuring 100% mission success and passenger abort survival. This includes maximizing the synergy between the passenger capsule and the launch vehicle, such that neither system levies unattainable requirements on the other. Finally, human rating requires maximizing reliability, applying redundancy where practical, providing system health monitoring and an emergency detection system, and ensuring all mission phases provide survivable abort modes. Many believe that existing expendable launch vehicles can not be human rated due to inherent limitations to their design and operations because they were not initially designed to be human rated. The results of on-going analysis dispel this belief. Atlas is the only existing launch vehicle that can meet or exceed the identified requirements for providing commercial passenger transportation. Atlas has the added benefit of incorporating and demonstrating system upgrades prior to flying the first passengers. This is crucial, as leveraging the synergy with on-going 1 Manager, Business Development and Advanced Programs, Lockheed Martin Space Systems Company, P.O. Box 179, MS T9115, Denver Colorado 80433, AIAA Member. 2 Senior Systems Engineer, Advanced Design and Technology Integration, Lockheed Martin Space Systems Company, P.O. Box 179, MS L3005, Denver Colorado 80433, AIAA Senior Member. 1 American Institute of Aeronautics and Astronautics commercial and government satellite launch missions significantly increases our understanding and characterization of system performance, and ultimately enhances our demonstrated reliability. We believe that analytically predicted reliability estimates will not be sufficient to convince prospective passengers of their personal safety, and that a demonstrated track record over a substantial number of flights will be required for a commercially viable service. II. Baseline Passenger Vehicle Definition The Atlas V Program has been involved in human transportation studies beginning with the Orbital Space Plane (OSP) Program, and continuing during early Crew Exploration Vehicle (CEV) studies. The Lessons Learned from those experiences has formed the basis for changes to the Atlas launch vehicle to provide passenger transportation to Earth orbit. Over the past two years, Lockheed Martin has been refining concepts for a capsule-based commercial transportation system. The study established a baseline capsule-shaped vehicle, which is less complex and less expensive than a winged vehicle, and easier to integrate onto a launch vehicle. The capsule shape draws on Lockheed Martin’s experience building reentry vehicles for Genesis, Stardust, and several Mars missions. The passenger transfer vehicle has a gross mass of approximately 20,000 lbs and is capable of carrying several passengers to a low Earth circular orbit of 265 nmi at a 41 deg inclination. The capsule includes an Abort/Orbital Maneuvering System mounted below the heat shield to provide the required delta V and impulse for either launch aborts or the final orbital maneuvering system function. The Atlas V 401 launch vehicle was selected for its low cost and high intrinsic reliability. However, an Atlas V 402 (with two Centaur engines) could also be used for higher performance. An expanded view of the entire launch stack is depicted in Figure 1. Figure 1. With Minor Modifications, the Atlas V/401 Launch Vehicle Can Support Passenger Transportation to Space. Performance for this configuration was determined using TRAJEX simulations which are anchored to actual flight data. All simulations indicate that the flight environments are well within our current experience. Figure 2 and Figure 3 depict the maximum dynamic pressure and acceleration curves, respectively. A unique benefit of the Atlas BOOSTER ENGINE CUTOFF (242.06 secs) CENTAUR MAIN ENGINE CUTOFF 2 (4393.39 secs) CENTAUR MAIN ENGINE START 2 (4360.49 secs) CENTAUR MAIN ENGINE CUTOFF 1 (1093.21 secs) CENTAUR MAIN ENGINE START 1 (258.06 secs) Figure 2. This Atlas V/401 Passenger Transfer Vehicle Acceleration Profile Demonstrates That the System Can Meet Passenger Requirements. 2 American Institute of Aeronautics and Astronautics is that the peak acceleration, shown in figure 3, can be tailored using the throttle capability of the RD-180 engine. An Atlas 401 vehicle is well suited for this mission as it utilizes only two engines (one RD-180 on the Common Core BoosterTM and one RL10 on the Centaur Upper Stage). This flight proven configuration is the simplest, most reliable system currently available to safely fly a commercial passenger vehicle to low Earth orbit (LEO). MAX Q (94.58 secs) BEGIN CLOSED LOOP GUIDANCE (143.88 secs) START ZERO ALPHA FLIGHT (40.36 secs) ATLAS/CENTAUR SEPARATION (248.06 secs) BOOSTER ENGINE START PITCHOVER CUTOFF (242.06 secs) (18.64 secs) Figure 3. The Atlas V/401 Launch Vehicle Provides a Benign Maximum Dynamic Pressure Environment While Minimizing Ascent Loads and Enhancing Abort Conditions. III. Atlas/Mercury Manrating History The Atlas ICBM was selected to launch the first American into orbit during the Mercury Program. The early days of launch vehicle development were fraught with challenges as engineers struggled to design a vehicle that could perform reliably, and have the necessary systems on-board to ensure the safety of the astronaut. The first two unmanned Atlas/Mercury vehicles resulted in failure (Vehicle 10D on 9/9/59 and Vehicle 50D on 7/29/60). It wasn’t until February 21, 1961 that the program realized its first success (Vehicle 67D). Prior to the first manned mission, the Program suffered 3 failures in 6 launch attempts. “Manrating” for Mercury followed a simple, common sense approach that concentrated in two areas: hardware and people. Hardware changes to the baseline Atlas ICBM focused on improving vehicle redundancy, propellant utilization and control, and structural factors of safety. These changes were based on flight data and on one single critical factor: time: time to sense a system problem, time to evaluate the impact of that problem, and ultimately, time to execute an abort. The involvement of design, test, production and operations people, working hand in hand with the astronauts, was the single most important activity to ensure a successful mission. Hardware for manned missions was uniquely identified, and required meticulous data keeping on each component. There were exhaustive data reviews of the components, subsystems and systems. Everyone realized that the results had real life or death ramifications. Finally, an “Abort Sensing and Implementation System (“ASIS”) was developed to sense the development of any possible catastrophic failure of the booster, accomplishing what is currently commonly referred to