Welcome to my site! I am a researcher and engineer in the Avionic Systems Division at NASA Johnson Space Center. My official title is Command and Data Handling System Architect. My focus is on improving the safety and performance of fault-tolerant computer systems and deterministic networks to enable crewed exploration of deep space. My work spans multiple areas, including distributed systems, real-time systems. networking, and security.
I earned a Ph.D. in Computer Science and Engineering (CSE) from the University of Michigan, where I was fortunate to be co-advised by Ron Dreslinski and Baris Kasikci. Before that, I completed an M.S. in CSE at the University of Michigan and a B.S. in Electrical Engineering at Purdue University.
- Had fun presenting at EMSOFT '23 and visiting colleagues in Germany! photo at Ishtar Gate (Sep. 2023)
- CrossTalk was accepted to appear at EMSOFT '23 (June 2023)
- I am grateful to have been awarded a NASA JSC Center Director’s Commendation Award (June 2023)
- It was great catching up with colleagues and friends at S&P '23! photo with Linh (May 2023)
- I successfully defended my Ph.D. thesis! group photo (Apr. 2023)
- CHEX-MIX was accepted to appear at EuroS&P '23. Congrats Deepika! (Mar. 2023)
- PCspooF was accepted to appear at S&P '23 (June 2022)
- RBS was accepted to appear at DASC '22. Congrats Robert! (Jan. 2022)
- Gatekeeper was accepted to appear at DASC '21. Congrats Brendan! (Jan. 2021)
- IGOR was accepted to appear at RTAS '21 (Jan. 2021)
- I am grateful to have been awarded a NASA Exceptional Technology Achievement Medal (Dec. 2020)
- I am grateful to have been awarded an NSF Graduate Research Fellowship (Apr. 2020)
CrossTalk: Making Low-Latency Fault Tolerance Cheap by Exploiting Redundant Networks
A. Loveless, L. T. X. Phan, L. Erickson, R. Dreslinski, and B. Kasikci
ACM SIGBED International Conference on Embedded Software (EMSOFT) 2023
PDF, Slides [acceptance rate: 23.3%]
Summary: Introduces a new way to reduce the worst-case latency of Byzantine fault-tolerant control systems by forwarding traffic between redundant network planes.
CHEX-MIX: Combining Homomorphic Encryption with Trusted Execution Environments for Oblivious Inference in the Cloud
D. Natarajan, A. Loveless, W. Dai, and R. Dreslinski
IEEE European Symposium on Security and Privacy (EuroS&P) 2023
PDF [acceptance rate: 35%]
Summary: Describes a new lightweight approach for privacy-ensuring machine learning in the cloud.
PCspooF: Compromising the Safety of Time-Triggered Ethernet
A. Loveless, L. T. X. Phan, R. Dreslinski, and B. Kasikci
IEEE Symposium on Security and Privacy (S&P) 2023
PDF, Slides, Talk [acceptance rate: 14.5%]
Summary: Describes a new attack that breaks the isolation guarantees of Time-Triggered Ethernet (TTE) by conducting EMI from a malicious device into a TTE switch over an Ethernet cable.
RBS: Profile-Guided Scheduling for Time-Triggered Applications
R. Esswein, B. Luksik, A. Loveless, and A. George
IEEE Digital Avionics Systems Conference (DASC) 2022
Summary: Describes a principled approach for reducing the bandwidth required to schedule time-triggered network traffic while still reaching a certain reliability target.
Gatekeeper: A Reliable Reconfiguration Protocol for Real-Time Ethernet Systems
B. Luksik, A. Loveless, and A. George
IEEE Digital Avionics Systems Conference (DASC) 2021
PDF [Best Student Paper]
Summary: Describes a novel approach for correctly reconfiguring Time-Triggered Ethernet networks in the presence of faulty devices.
IGOR: Accelerating Byzantine Fault Tolerance for Real-Time Systems with Eager Execution
A. Loveless, R. Dreslinski, B. Kasikci, and L. T. X. Phan
IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS) 2021
PDF, Slides, Teaser, Talk [acceptance rate: 27%]
Summary: Describes a new method for reducing the latency of real-time Byzantine fault-tolerant systems by speculatively executing on data from redundant sensors on different cores.
Optimal and Error-Free Multi-Valued Byzantine Consensus Through Parallel Execution
A. Loveless, R. Dreslinski, and B. Kasikci
IACR Cryptology ePrint Archive
Summary: Describes the first Byzantine extension protocol that is simultaneously communication-optimal, error-free, and only requires processes to broadcast one bit with a binary Byzantine broadcast protocol.
(Developed concurrently with and independently of this paper)
Development and Testing of a Vehicle Management System for Autonomous Spacecraft Habitat Operations
G. Aaseng, J. Frank, M. Iatauro, C. Knight, R. Levinson, J. Ossenfort, M. Scott, A. Sweet, J. Csank, J. Soeder, D. Carrejo, A. Loveless, T. Ngo, and Z. Greenwood
AIAA SPACE Forum and Exposition 2018
Summary: Describes work done collaboratively between NASA centers to design a vehicle management system to autonomously control a future deep space habitat.
A Proposed Byzantine Fault-Tolerant Voting Architecture using Time-Triggered Ethernet
A. Loveless, C. Fidi, and S. Wernitznigg
SAE AeroTech Congress & Exhibition 2017
Summary: Describes how to construct a Byzantine fault-tolerant voting system based on Time-Triggered Ethernet that is suitable for safety-critical applications.
A Modular, Scalable Avionics Architecture for Future Exploration Missions
C. Fidi and A. Loveless
AIAA SPACE Forum and Exposition 2017
Summary: Gives a high-level overview of TTTech's Time-Triggered Ethernet products and describes how their features can be used as a part of future spaceflight architectures.
Approach for Sizing and Turndown Analysis of a Variable Geometry Spacecraft Radiator
L. Erickson and A. Loveless
NESC Thermal and Fluids Analysis Workshop 2017
Summary: Describes a novel approach for analyzing a variable-geometry spacecraft radiator.
On TTEthernet for Integrated Fault-Tolerant Spacecraft Networks
AIAA SPACE Forum and Exposition 2015
Publisher, PDF, Slides
Summary: Gives a general overview of how the Time-Triggered Ethernet protocol works and how it is being used in the NASA Advanced Exploration Systems Program.
On Augmented DVH Analysis
A. Loveless, A. Roy, I. Das, and O. Nohadani
AAPM Annual Meeting & Exhibition 2013
Summary: Describes a novel method for quantifying the difference between radiation treatment plans that appear visually similar.
Select Presentations  I give a lot of talks for work. Below are some publicly available talks that may be useful.
- Default Algorithm(s) for the Fault Tolerant Module (IEEE P802.1DP / SAE AS6675) (Sep. 2023)
- Impact of Switch Plane Redundancy on Network Availability (Feb. 2022)
- On Time-Triggered Ethernet in NASA’s Lunar Gateway (July 2020)
- TTEthernet Development and CFS Integration (Sept. 2017)
- Overview of TTE/CFS Integration (May 2017)
- Notional 1FT Voting Architecture with Time-Triggered Ethernet (Nov. 2016)
- Overview of TTE Applications and Development at NASA/JSC (Oct. 2016)
Press  November 2022 - PCspooF attack on TTE networks
University of Michigan Press Release
Ars Technica: "Researchers break security guarantees of TTE networking used in spacecraft"
The Hacker News: "PCspooF: New Vulnerability Affects Networking Tech Used by Spacecraft and Aircraft"
IEEE Spectrum: "New Ethernet Cyberattack Crunches Critical Systems"
Engadget: "NASA helped find a security hole in spacecraft networks"
TechRadar: "NASA uncovered a network security flaw that could affect spacecrafts"
The Hill: "Vulnerability identified in energy, space networks"
The Aerospace Corporation: "Introducing SPARTA using PCSpooF: Cyber Security for Space Missions"
NASA Spinoff Magazine: "Time-Triggered Ethernet Slims Down Critical Data Systems"