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AAWSAP DIRD, Cognitive Limits on Simultaneous Control of Multiple Unmanned Spacecraft, December 2010

U.S. Department of War · 2010-12-15 · 31 pages · text from the file's own layer

This Defense Intelligence Reference Document, DIA-08-1101-001, is dated 15 December 2010. The Defense Intelligence Agency's Defense Warning Office produced it under the Advanced Aerospace Weapons System Applications program. It asks how many unmanned spacecraft one pilot could control in a future deep-space fleet, drawing on air traffic control and multiple unmanned vehicle research. It concludes the limits are about 16 craft for simple tasks, 7 for moderately complex ones and 4 for complex heterogeneous craft. It adds that physiological measures can signal operator overload.

From the source: Release of 2026-09-18 Incident: 12/15/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD examines how many unmanned spacecraft a single human operator could realistically supervise or control at once, using research from air traffic control and multi-vehicle remote piloting as rough analogs. The report argues that the practical limit depends heavily on task complexity: about 16 craft for simple monitoring or destination assignment, about 7 for moderately complex piloting or mission tasks, and about 4 for complex heterogeneous operations. It places particular emphasis on the operator’s ability to maintain a coherent mental “big picture” of multiple vehicles at once, and it suggests that automation and external displays can help by offloading working-memory demands, though not eliminating them. The document also highlights physiological workload measures as a possible way to detect or predict operator overload in real time. Overall, it presents multi-spacecraft control as a human-factors and systems-integration problem in which progress depends on managing cognitive limits through interface design, automation, and workload monitoring.

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Lamoureaux researched in 1999 whether a proposed ATC augmentation system could
safely allow smaller distances between aircraft and thus increase traffic capacity
without building new airports or runways. Pairs of aircraft were characterized based on
their direction of travel and separation as shown in Table 1. During the task, operators
rated their instantaneous perceived workload on a five -point scale roughly
correspond ing to D, Al, A2, A3/B, and B/C.i Operators were prompted for their self
assessment once every two minutes. The experiment was able to generate self
assessment values between 1 and 4; no overload conditions were generated in this
study. Using a model based on task variance and complexity of current aircraft under
control, the researchers were able to predict perceived workload 74% of the time, but
more importantly, were able to predict a self-rating of 4 for 80% of the cases.
Predicting the boredom value of 1 was less successful, at about 60% . Besides the
numerical predictions, the authors conclude that complexity of the task drives perceived
workload . 26
Table 1. Variables used in Determining Complexity of the Traffic relationship between pairs of aircraft. Using
four variables with three thresholds gives different classes of complexity . For example, an aircraft pa ir could be 5
miles apart (3 to 7 threshold), traveling in the same lateral direction, flying with 2500 ft of vertical separation (>
2000ft), and both straight and level. There are 81 such combinations .
Variable
Threshold Low Mid High
Lateral separation 7 miles
Lateral direction Same direction Opposite direction Crossing
Vertical separation 2000 ft
Vertical direction Both straight and level One straight, one climbing
or descending
Both climbing or
descending
Physiological indicators of stress were measured at two low-traffic control centers
(Fayetteville, AR and Roswell, NM) and one higher traffic center (Oklahoma City). Heart
rates were measures along with hormone secretion levels in urine. The urine specimens
were pooled before analysis into two groups throughout a 5-day workweek: during the
8-hour workday, night time after work. Additionally, controllers completed the State
Trait Anxiety Index before and after each workday. Results showed that lower traffic
centers exhibited lower stress levels, and that the best biological indicator of stress was
epinephrine levels from urine rather than HR. The authors concluded that traffic load
and complexity were the main sources of stress in the ATC task rather than the nature
of the job itself. 27
A straightforward experiment to look at physiological responses using EEG and EOG to
lapses in attention during ATC tasks was performed by Peiris in 2005. The goal of the
study was to categorize expert analysis of EEG/EOG data to develop an automated
analysis program that could read the data online without human intervention to alert
operators to attention lapses and low levels of alertness. Professional ATC operators
were given 10 minute intervals of the psychomotor vigilance task (PVT). Recorded data
was evaluated by several human expert EEG and EOG analyzers. These experts were
not able to correctly identify alertness or attention lapses (EEG identified only 6 of 101
J In this study, t he A3/B rating described "Non -essential tasks suffering, could not work at this level for long, " while
8/C described getting behind and losing situational awareness.
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 31 pages are in the text index: search them above, or from the library's search.