Design of Hypersonic Lifting Body Vehicle (Lead Chief Engineer’s Report) · Chapter XI

AClosing Remarks

This report summarizes the activities and results of the lead chief engineer for the first half of the semester dedicated to the MAE 4351 Senior Capstone Project. The project assignment was to develop the multi-disciplinary methodology to reverse engineer the Douglas Model-176 and an associated SpaceX launch system. The team was split into two functional sub-teams between the upper-stage Model-176 and its launch system.

After an introductory section, literature review was conducted for all the disciplines, particularly in the author-specific roles regarding management, the business case, synthesis, and costing. This was brought together from a wide variety of sources: aerospace conceptual design literature, the professor’s recommended text, teammates’ input, and reports found online.

In accordance with the presentation format, the business case for the combined vehicle was developed starting with market research. This market research provided a basis to run an operation supporting space tourism and low-Earth orbit access at a high flight frequency at a rate of once an hour, sustained by a 48-hour turn-around time for a civilian fleet size of fifty. This flight frequency allows for the amortization of infrastructure and development costs to allow for an affordable ticket price of 73k USD per seat. This civilian market will support a military capability which will not be as frequent.

The three missions are designed around the operations, where the civilian version is simply designed to carry passengers to a 200km orbit. The military variant will be equipped to enter a 600km orbit and stay there for up to a week. Both of these variants are carried by the Falcon Block 5 launch vehicle. The reconnaissance vehicle was designed to conduct its mission at a 400km orbit and perform a synergetic maneuver to increase its inclination-change capability. Various trades were examined to determine the best mission profile for meeting geopolitical goals and achieving a realizable fuel requirement by the use of aerodynamic performance.

The methodology was inspired by disciplinary literature review and underwent several iterations. Starting with a flow diagram, the author attempted to illustrate how the vehicle may be reverse engineered per flight phase. After revision and iteration with the synthesis team and constructive critique from Dr. Chudoba, the multi-disciplinary analysis underwent several drastic changes. The flow chart was thrown out in favor of the Nassi-Schneiderman format, which was designed as a two-tiered MDA to improve robustness at the higher level. Lower levels would iterate or could change with respect to each sub-team’s implementation into actual MATLAB code.

The history of program development was added around week 4 to document the activities of the lead chief engineer that do not necessarily produce tangible results directly. This also doubled as a more in-depth look at the weekly issues and lessons learned, which may prove valuable in the future.

BFuture Work

Future work entails exploring additional launch systems to reduce flight costs. The currently existing launch vehicles are oversized for the most frequent variant: the civilian point-to-point. However, the development of a specialized launch system may not be the right move to minimize program costs.

The author recommends the exploration of an additional civilian variant redesigned to carry cargo. High-value goods which are time-critical may have a significant market to further sustain a large flight rate by slightly modifying the existing civilian variant. The two variants will have the same trajectory capability, but one will not need the rigorous certification associated with transporting human passengers.

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