David Greeson Email & Phone Number

Washington, Dc, Us

Currently, I am assigned to the Space Nuclear Propulsion (SNP) project, responsible for development of the Model Based Systems Engineering (MBSE) models and methods. Previously, I was in the Mission & Fault Management group for the Human Landing System (HLS) and Space Launch System (SLS), working on Functional Fault Analysis, Abort Effectiveness Analysis, Safing False Positive Analysis, and Detailed Verification Objectives. An SLS or HLS Abort is when the crew has to maneuver the vehicle during flight to avoid an explosion or other malfunction, so it is a safety-critical event. The Aborts area is a very complex, interdisciplinary task involving engineers from the areas of avionics and software design, structural failures, safety & mission assurance, and from across program elements. During this assignment I helped define the abort conditions, identify abort triggers, and analyze how effective they will be in a given launch vehicle failure scenario.Previously I was the Change Package Engineer responsible for the SLS Core Stage to Core Stage Engine Interface Control Document (ICD). In this position, I learned the technical details of the RS-25 Core Stage Engine (Space Shuttle Main Engine) and how it operates to propel the SLS. In addition to the Core Stage engine, I worked in the same role on the Exploration Upper Stage to Exploration Upper Stage Engine ICD, which will use a smaller engine than the RS-25. Prior to the ICD assignment I was the lead for the SLS Functional Analysis. The effort was concerned with analyzing the functional behavior, interfaces, and requirements of the launch vehicle, spacecraft, and ground systems that NASA is designing to take future astronauts Beyond Earth Orbit (BEO). I was working with Systems Modeling Language (SysML) in the Enterprise Architect tool, which is a relatively new approach at NASA.

Cambridge, Ma, Us

At Draper Lab, I worked on the functional analysis of the Crew Launch Vehicle, which later became the Ares I. I also performed a States & Modes analysis of the vehicle avionics & software early in the project.

New York, Ny, Us

At L-3, I was the systems engineering lead for the Cockpit Avionics Upgrade Independent Verification & Validation project. My primary focus was on software safety issues. I also worked on a number of proposals to win new business for the company. During the time I was with this company, which started out as Intermetrics, Inc., the name and logo changed from AverStar to Titan to several different flavors of L-3, with a merger of Titan and LinCom in there somewhere.

Norfolk, Va, Us

At Futron, I performed a schedule risk analysis of a future ISS mission, and then became the Project Risk Manager of the Consolidated Space Operations Contract, responsible for implementing a risk management plan and process.

Irvine, California, Us

While I was with SM&A, I worked on two major proposals. One was at Motorola in Scottsdale, AZ for an "Internet in the Sky" project to create a broadband satellite network. The other proposal was at GEC-Marconi in Rancho Bernado, CA for a Joint Mission Planning System to be used by the Air Force and Navy for aircraft mission planning. Both projects were eventually canceled.

At Lear Astronics, I worked on avionics technology trade studies for the Joint Strike Fighter, and Bell-Boeing 602 Civil Tiltrotor aircraft. I also performed a functional analysis of the JSF avionics using a simulation analysis tool called Foresight by a company called Nu-Thena. It was one of the better systems engineering tools I've used, but sadly the company went out of business and the tool disappeared from the marketplace.

While I was with Dynacs, I worked in the International Space Station program office at JSC, in the Vehicle Effectiveness & Trades group. I used a decision analysis tool called DPL to build large decision trees for complex trade studies that balanced cost, schedule, performance, and risk..

At McDonnell Douglas, I worked on a variety of projects and programs, including the Space Shuttle flight software Level 8 certification, Space Station Freedom test and verification, and the Space Exploration Initiative. The highlight of my time there was a year long cost and operations analysis of a future Lunar Transfer Vehicle.

During my time at Martin Marietta, I worked on a FORTRAN simulation model of the Titan IV Centaur upper stage vehicle. I also went skiing in the Rockies a lot!

Reston, Va, Us

Living and working in the South Bay was great. At SAIC, I worked on the Space Defense Command and Control System, building simulation models of Soviet space weapons and U.S. space surveillance networks. The simulations were called SCENE, for a scenario-based, deterministic astrodynamics model; and SPASIM, for a probabilistic simulation of the space operations on the U.S. side. I learned a lot and it was very interesting work.

Armonk, New York, Ny, Us

I co-oped at IBM FSD three semesters, working on Space Shuttle flight software and analysis tools, early Space Station concept studies, and various computer programming tasks. During my three tours at IBM, I learned to program in FORTRAN, HAL/S, PL/1, APL, Assembler, JCL, and CLIST.

Randolph Afb, Tx, Us

My first ever engineering job, as a GS-4, making $500 a month gross pay. I worked on structural repair and replacement of the C-5A Galaxy and C-130 Hercules aircraft. The majority of the work was done inside an enormous hangar at Kelly AFB that could hold 12 football fields.

Professional Certificate Program, 8.5 Continuing Education Units (Ceus), Architecture And Systems Engineering: Models And Methods To Manage Complex Systems

Bachelor Of Science, Aerospace Engineering

Education record

H.S. Diploma