Making Early-Stage Design Decisions for New Aerospace Technology in the Absence of Spaceflight-Heritage Data

In development of new hardware and technology for spaceflight, heritage data is helpful in evaluating the success of a component or proposed solution – even more so in the challenging environment of space. However, as we push the bounds of space exploration, developing new technology to accomplish goals like sending humans to Mars and exploring new places, spaceflight-heritage data becomes more limited. So, then the question becomes, how do engineers make early-stage design decisions with this challenge in mind? The following technical paper will discuss some methods for making early-stage design decisions in the absence of spaceflight-heritage data, as applied to the Modular Assembled Radiators for Nuclear Electric Propulsion (NEP) VehicLes (MARVL) project. MARVL is developing a radiator system for a NEP Mars transit vehicle. First, some foundational items that occur during the Pre-Design stage will be presented, such as clear definition of the problem to be solved, and regular communication with stakeholders to understand their expectations and priorities. The focus then shifts to Overall System Design, where the paper looks at methods for making early-stage design decisions based on the space environment that the spacecraft will experience during the mission, highlighting Micrometeoroids and Orbital Debris (MMOD). The section on MMOD explores example orbital debris environment data and how to utilize this data for preliminary design sizing and component placement, in addition to some potential ways to optimize the mass of MMOD shielding. The section also briefly mentions both mission operation and assessing spacecraft protection against MMOD impact. The focus will then shift to the Component Design stage, where a case study from the MARVL project will be examined, demonstrating how the identification and evaluation of qualitative factors helped make design decisions for a deployment mechanism in the early stages of a project that is developing new technology. There is also a mention of comparing advantages and disadvantages, which can help narrow down component options further, if needed. While not an all-encompassing guide, this paper focuses on some practices that were helpful for the MARVL project, and can be adapted to specific engineering applications.