Pressing ahead with Ares I – Davis

by Chris Bergin

Danny Davis, manager of the Upper Stage of the new Ares I Crew Launch Vehicle (CLV), has rounded up his interview with by addressing some of the outstanding questions relating to the vehicle that is hoped will return man to the moon at the end of the next decade.

The MSFC (Marshall Space Flight Center) manager also answered questions posed by readers in this final part of his interview.

**Interview Part 1**  **Interview Part 2**   

**Ares I Forum**

Related L2 Resources listed at the end of this article.

Interview: reader: What purpose at all the $500m test flight will provide, seen as it’s just a 4 seg booster with a dummy stage and nearly all the new areas of the U/S stage won’t be tested on this.

Davis: This is critical to informing our CDR in 2009 on integrated 1st stage performance and operability. The key objectives of the test are:
– Demonstrate ascent flight control system performance with dynamically similar 1st and 2nd stage CLV/CEV vehicle
– Demonstrate nominal 1st and 2nd stage separation and clearances
– Demonstrate 1st Stage motor parachute performance and separation/entry dynamics
– Characterize magnitude of integrated vehicle roll torque due to 1st Stage motor performance
– Demonstrate an operational flow of Ares I through KSC to launch
Finally, this test is not costing $500M – its on the order of $300M. reader: What consideration has there been for utilising two J-2X’s on the U/S to boost performance (Decatur trip, 6.5m
diameter option)? For that matter, is there any sort of evolutionary roadmap yet for increasing Ares-I’s performance envelope in the future? Strap-on boosters? Higher performance J-2X derivatives?

Davis: We can meet the performance requirements we have today with one J-2X. Two would significantly increase propellant load (making the vehicle longer), increase cost (MPS and engine) and reduce reliability with marginal performance gain. On your second question, given just about every vehicle ever flown has had updates, we plan to develop potential, downstream performance enhancement options. What is being done to provide for evolving the U/S into the EDS later For the Ares-V? What are the issues being concentrated on here?

Davis: We are continuing to refine the EDS design to develop the appropriate requirements for systems that may have commonality. We intend for the J-2X engine and its TVC to be common. We intend for the main propulsion systems (feedlines, valves, actuators, etc) to have significant commonality (especially those on the aft end of the stage). The welding and spray-on foam insulation practices for the tanks will have direct applicability to EDS. Finally, we are developing an open avionics and software architecture to be able to evolve to support later EDS missions. Manufacturing costs and considerations seem to focus highly in your answers. Can you please provide us with an overview to put it into perspective.

Davis: We are developing our manufacturing plans for the upperstage now. We are using lean-six sigma processes to develop the most efficient manufacturing flow possible for Ares I. In addition, we are planning to make maximum use of self-reacting friction stir welding to reduce expensive tooling and labor-intensive operations. Finally, we are planning on a paperless factory to reduce costs. Can you describe any of the Fixed and Variable Operational costs for the operational Ares-I?

Davis: We have detailed discrete event simulation models of the life cycle costs for the Ares I which we are using to drive out cost. From a variable cost perspective, Ares I has the potential to be a very affordable launch system. New MLP’s are being required for the Ares-I. What is the reasoning and justification for the additional costs involved?

Davis: We desire a ‘clean pad’ for operability and cost reasons – that requires new a new lightweight MLP with LUT incorporated – necessitating a change. More to come when KSC rolls out their plans for the pad. reader: As Program Manager, how will you be reducing the risks on not providing a solution that meets the requirements? Further, what is the process of mitigating such risks?

Davis: Combined answer with the question above: We have a detailed risk mitigation plan based on the Carnegie Mellon methodology, maintained on a database. We have identified our key risks with linkages up and down the system and have a set of mitigation plans. In addition, we are actively using a ‘risk based’ design process to inform key decisions. We use these risks and mitigations in order to appropriately allocate resources. If Ares-I were to have any critical ‘showstopper’ problems, is there a procedure or a specific defined point(s) where you would make the decision to change direction, or would that be a more fluid process?

Are there any backup plans in case Ares-I can’t perform? If so, is anything known about such plans?

Davis: Combined answer with the question above: We believe we have completed enough analysis over the past year (combined with previous work) with our partners to validate the concept. As we find issues, we will apply sound engineering practices to solve. It’s important to stick with a plan and execute. NSF obtained a document from KSC showing an alternative design for a Crew Launch Vehicle – known as ‘Stumpy’. Can you tell us where that design fits in the grand scheme of things and why was it proposed? Also what realistic consideration has it gotten? 

Davis: This concept was never analyzed or assessed by Constellation – on the surface, it would increase CLV costs (larger core stage vs. smaller CLV upperstage), require 2 variants of the J-2X – a shorter nozzle boost version and a later upperstage version, would still require a significant development for a 3 segment booster, would reduce safety/reliability (more propulsion systems) and would increase CaLV costs since we would have to still develop a 5 segment booster (2 booster variants vs. 1) and a 33ft core. In addition, it has no apparent operational savings or benefits since it requires more elements and integration. Bottom line, it’s a system which costs more (near and long term), is less safe/reliable and is not easily evolvable to lunar needs. reader: How do you expect the Stick to get off the pad successfully with such as slow reacting First Stage TVC coping with wind-shear?

Davis: We have completed detailed 6 DOF analysis flying through winds which show that we have 2x the TVC rate capability required and 2x the maximum gimbal required with the current shuttle TVC system – significant margin. reader: Have they committed to any one type of thrust structure?

Davis: No – this is still in trade – looking a separate vs. integral with LOX tank. reader: Can he (Davis) provide details about any of the US instrumentation and guidance they want to use (not only what kind of hardware, but how sophisticated they want the software to be in terms of accuracy and updates per second)?

Davis: All this is subject to design and in -work. Right now, we are focused on developing and validating our requirements. reader: Since the idea is to automate the monitoring and control during the launch process and boost phases as much as possible (less people, more computers), how is that part of the design planning progressing?

Davis: We are working closely with our KSC and JSC partners to automate processes to the maximum extent practical to reduce CLVcosts. and various readers: EELV’s and derivative’s as alternatives. What are your thoughts?

Davis: The ESAS study was an apples-to-apples assessment on an even playing field. A wide variety of EELV’s (Atlas V, Delta IV, Atlas Phase 3 and X, etc) and Shuttle Derived Vehicles were assessed and Shuttle Derived was the clear winner from a cost, schedule, risk and safety/reliability perspective. The ESAS results were validated by group of external reviewers and the DoD and White House concurred. We have a decision and are executing to that plan.

Final Words from Danny Davis:

We believe we have a sound plan and we need to execute – forward momentum is important at this stage of the development. Thanks again for all your help and support. It’s important! would like to thank Mr Davis for his generosity of time – especially during this busy time for Constellation – in answering the questions posed by this site and its readers.

L2 Resources: Ares I-1 Test Flight Plan (full outline) Presentation. ARES I Reference Trajectory. Boeing’s STS to Ares – Lessons Learned Presentation. Latest Ares I and Ares V baseline Configuration image and data. CLV DAC-1C (Changes to CLV Upper Stage).

Ares I-1: Four Seg+Dummy ‘Tuna Can’ stage. Ascent Developmental Flight Test Presentation. CLV Pad 39B Handover Info and Latest. New images of CLV on top of new MLP and LUT. Lockheed Martin CEV/Orion Updates. Constellation news updates. ATK figures on the 5-Seg Booster weight for CLV. 90 Minute Video of Constellation all hands meeting. CLV TIM Meeting Information. CLV/CaLV Infrastructure, Timelines and Information.

CEV-CLV Design Analysis Cycle Review (DAC-2) Presentation. Constellation SRR updates. CLV Stick – Troubleshooting/Alternatives/Updates. New CEV Images (include abort mode). Flight Design and Dynamics Division CEV update. CLV Mono-propellant RCS system. CEV pressurisation system review. CLV/CEV Configuration Images. The 2×3 Seg SRB Crew Launch Vehicle Option Presentation…plus more.

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