Date of Award

Fall 2018

Access Restriction

Thesis

Degree Name

Master of Science

Department

Systems Engineering

School or College

Seaver College of Science and Engineering

First Advisor

Claire Leon

Abstract

Access to space is becoming less expensive, which is allowing smaller companies with big ideas, such as on-orbit servicing and repair, to enter into the space industry. On-orbit servicing and repair provides capabilities, such as towing, refueling, inspections, and physical repair, to add additional life to on-orbit satellites by resolving life-limiting issues. On-orbit servicing and repair is technically possible, but there is still one major issue that continues to stifle the on-orbit servicing and repair market -- “satellites are not built with servicing in mind” (Parker, 2015).

The on-orbit servicing and repair industry is stagnate due to a challenging conundrum. Potential satellite customers are unwilling to pay for on-orbit servicing or repair until the capability is successfully demonstrated on-orbit. Unfortunately, it is difficult for the industry to prove the capability without customers willing to take a little risk. This “chicken and egg” scenario leaves several satellite manufacturers unwilling to change their satellite architectures and designs to accommodate on-orbit servicing and repair. This paper attempts to show the “how” and the “why” the space industry should change their architectures and designs to enable on-orbit servicing and repair.

There are many satellite bus components/consumables, including software, that could fail and shorten a satellite’s life. However, the bus components/consumables that fail the most, batteries, solar arrays, propellant, reaction wheels, and power distribution components, are best suited for on-orbit servicing and repair. These five bus components/consumables, in addition to the satellite as a whole, will require several design changes specific to each bus component, which will drive new or updated requirements for each. Additionally, to increase the effectiveness and efficiency of on-orbit servicing and repair, satellite architectures will require changes, such as an on-orbit depot, on-orbit warehouse, and on-orbit gas tank.

The consequence of changing satellite design will affect satellite ground testing. The on-orbit servicing and repair processes, such as rendezvous, docking, and EMI/EMC will require testing between the on-orbit servicer and its customer satellite. The on-orbit servicing and repair capability provides the satellite manufacturer the ability to reduce qualification testing, run-time testing, and burn-in testing. This capability increases the probability that redundancy for these five bus components/consumables is no longer required, which reduces the hardware cost and testing schedule for each satellite. On-orbit servicing and repair creates seven new risks -- do no harm, debris and contamination, on-orbit servicer reliability, politics, cyber security, liability, and unintended consequences -- that must be mitigated.

Two simple business cases demonstrate the possible value of this new capability. The business case for Low Earth Orbit (LEO) does not provide a return on investment, because on-orbit servicing and repair in LEO is too difficult and too expensive to justify an investment. On the other hand, the business case for Geosynchronous Orbit (GEO), in two distinct scenarios, does provide a return on investment. Those two scenarios are a beginning of life anomaly, and an extension of life.

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