Proceedings of the Human Factors and Ergonomics Society 59th Annual Meeting - 2015
6
Effects of Communication Lag in Long Duration Space Flight Missions:
Potential Mitigation Strategies
Joseph R. Keebler1, Aaron S. Dietz2, & Anthony Baker1
1
Embry-Riddle Aeronautical University
2
Johns Hopkins Armstrong Institute
As humanity aims to travel to Mars in the next two decades, it will be faced with numerous issues
related to the coupling of humans and technology. Specifically, the communication lag of up to
40 minutes between long duration space flight (LDSF) crews and mission control back on earth
will lead to unknown effects on teamwork and the multi-team system through the degraded
quality of communication. This paper will review research on virtual teamwork and unmanned
systems as it relates to communication, specifically with implications for extended
communication
delays
and
lag
that
may
occur
in
LDSF
missions.
Copyright 2015 Human Factors and Ergonomics Society. DOI 10.1177/1541931215591002
Introduction – the Importance of Communication
A major issue facing LDSF missions is the dearth of
optimization strategies targeting multiteam system (MTS)
performance. Specifically, the common operationalization of
LDSF teams has focused primarily on the flight crew, while
neglecting mission control and the interaction between the
flight crew and mission control (Noe, Dachner, Saxton, &
Keeton, 2011). Failure to consider MTS interactions may lead
to errors that are disastrous to LDSF missions. For instance,
poor communication and collaboration between the flight crew
and mission control can lead to lasting dysfunction for the
remainder of a mission (Tani, 2013). Breakdowns in MTS
processes and performance are not an option for LDSF: the
stakes are too high and the smallest error could lead to
catastrophic failures or loss of life.
The purpose of this paper is to address one of the major
challenges facing MTS performance for future LDSF mission:
the imminent and long communication lag between mission
control and the flight crew as the spacecraft travels farther and
farther from Earth. The human factors and ergonomic (HF/E)
implications are vast, including communication technologies,
training, team training, protocol development and validation,
and knowledge of communication breakdowns in the face of
slow response times. We intend to discuss parameters for
these communications and provide potential guidance for
mitigating the negative effects inherent to LDSF
communication lags.
In the following sections, we will discuss extended
communication lags and their effects on communication,
coordination, and other aspects of teamwork. A highly
efficient LDSF team will have to work around these lags by
having a greater level of autonomy, but until the current era,
mission control protocols have been developed around the fact
that human space crews have never been more than a few
minutes of communication time away. Noe et al., 2011
recognized this issue in their research report on flight crews,
specifically acknowledging the need for LDSF space crews to
be autonomous, or as NASA calls it, developing
‘expeditionary behavior’ (Tani, 2013, pg. 23). Noe et al.
acknowledges that the communication lag present in LDSF
can lead to potentially devastating issues that arise when there
is a lack of intervention from mission control:
“Long-duration crews will have to be self reliant…this
means that the crew needs to have support tools and know
how to apply these tools in the correct situations…A longduration crew must be capable of dealing with psychoses as
well because even normal, well-adjusted crew members can
experience psychoses after long periods of isolation. This is
especially important as ground support will be limited in the
psychological support that it can provide during a Mars
mission due to the time lag in communications.” (Noe et al.,
2011, pg. 23)
Current manned space missions have generally upheld
near-constant communication between the space crew and
mission control. Extant information on the effects of long
duration lags in communication is almost completely based on
proxy information from the current understanding of teams
and human systems integration. Therefore, in the following
sections, we will utilize research on virtual teamwork, team
training, handoff protocols, and communication modalities to
aid in understanding the effects of these lags.
The Problem – Communication Lag
Communication lag will place difficult constraints on the
link between the LDSF crew and the ground. Teams will take
longer to communicate solutions to problems, and the best
teams will be the most adaptable to the gaps between each mes
Proceedings of the Human Factors and Ergonomics Society 59th Annual Meeting - 2015
in the chain (Fischer & Mosier, 2014). The round-trip
radio communication time between Earth and Mars is
expected to take about 40 minutes (NASA) for the longest
distances of the journey. These significant delays in the
communication loop will severely affect the quality of the
communication events (Palinkas, Chou, Leventon, & Vessey,
2013). This reduction of communication quality within the
LDSF MTS will lead to a fundamental change in the decision
making processes compared to what currently exists. Further,
this issue will also require effective teamwork as the crew
becomes more autonomous during later stages of an approach
to Mars. This is a large change in pace from shuttle missions,
which had a full working schedule with crew activity
controlled by the ground. Lag constraints will drive a change
in the culture of mission control, from the current incarnation
that manages the ISS to something more flexible. In other
words, mission control needs to become mission facilitation.
The following two sections elaborate on the communication
issues inherent to LDSF that will cause this change.
Effects of Lag on Closed-Loop Communication
The first and most obvious effect of the LDSF-driven
communication lag is that closed-loop communication, one of
the best methods for communication (Salas, Rosen, Burke, &
Goodwin, 2008), will become very challenging, especially
during off-nominal events. It will be task dependent,
especially reliant on the time pressure for decision making
available to the crew. It is almost certain that closed-loop
communication will become more challenging as tasks
become critical and unexpected. As an example, at the longest
distances, closing the loop in a communication event (i.e.,
sending, receiving, sending receipt) would take upwards of 60
minutes. In the case of off-nominal events, this is unfeasible
and unacceptable. Due to the lack of closed loop
communication in some circumstances, it becomes paramount
to aid the space crew in communicating as effectively as
possible when they need to, but also enabling autonomy to the
greatest degree possible. This may require the passing of
information that is not normally passed in current-day space
missions to ensure that mission control is as current as
possible on all system states. One strategy that can aid this
process is the use of semi-structured protocols during
communication events, which we will speak to in more detail
below.
Effects of Lag on Congruent Coordination
Coordination has been defined as the “process of
orchestrating the sequence and timing of interdependent
actions” (Marks, Mathieu, & Zaccaro, 2001, pg. 367). The
LDSF lag will be just as detrimental to the MTS’s
coordination as it will be to its communication. Due to the
autonomy of the space crew and the inability to update the
plan at an efficient rate, circumstances may readily arise
where the space crew solves some problem, e.g. problem X,
which was initially communicated to mission control. During
lag-time, the space crew solves X, but uncovers additional
problems Y and Z. During this time, mission control has also
7
solved X, and begins communicating this to the space crew at
the same time the space crew is communicating that they
solved that problem and have uncovered two additional
problems. This incongruence in the state of the problem-model
and MTS coordination could have devastating effects in offnominal events (Sebok, Wickens, Clegg, & Sargent, 2014).
Overcoming Lag – Solutions and Strategies
To address the issues in communication logistics
presented by LDSF, strategies from other areas of research can
be adapted to aid in the development of effective and efficient
communication guidelines for the MTS. Research into virtual
teams has shown that they have some useful parallels to the
format of expected LDSF teams. Understanding and utilizing
research into the effectiveness of different communication
modalities will also be critical in developing best practices.
Perhaps most importantly, team training and handoff protocols
will need to be evaluated and optimized to ensure that the
MTS can endure the crippling communication delays inherent
to LDSF. The following sections will expand on each of these
areas.
Virtual Teams as a Proxy for LDSF Teams
Virtual teams are ubiquitous in today’s working
environments. For example, 41% of human resource
professionals use virtual teamwork (Cohen & Alphonso,
2013). Although the area is relatively new, it has been shown
that the major failures in virtual teamwork are due to poor
communication, coordination, leadership, and trust among
dispersed team members (Society for Human Resource
Management [SHRM], 2011). These are unsurprisingly
similar issues as those that have been hypothesized to arise
during communication lags in LDSF missions by Noe et al.
and others. Arguably, LDSF teams are a form of virtual team,
with the further negative parameter of an ever lengthening
communication lag. In fact, time differences have been noted
as one of the major challenges to virtual team success (SHRM,
2011).
Virtual teams can give insight into the effects of
communication lags. Specifically, Wilson (2013) argues that
“frequent and regular communication breakdowns leave open
the possibility for conflict and misunderstanding” (pg. 275).
Further, she notes that frequency and responsiveness are
contributing factors that are important to reducing conflict –
two aspects of communication that will arguably vanish
altogether as distance increases between the space crew and
Earth. Others have discussed major challenges faced by virtual
teams, which include lack of engagement, absence of
preparation and training, and lack of scheduling flexibility –
all potential issues with LDSF crews and mission control.
Virtual team research is not a perfect parallel for LDSF
team research, however. In the context of business (the most
common environment in which these teams are used), virtual
teams are typically assembled for a specific purpose from
team members that are previously unfamiliar—these members
may only stay together until a certain goal is met, and their
trust in each other tends to be based in their abilities to
Proceedings of the Human Factors and Ergonomics Society 59th Annual Meeting - 2015
complete required tasks (Greenberg, Greenberg, & Antonucci,
2007). In contrast, the relationship between the space crew and
ground control is truly critical, as ground control is the only
lifeline that the space crew has to Earth. Team members trust
each other with their lives. Training between space crews is
far more intensive, and by mission start, or launch time, there
is at least some level of rapport between crew members. We
can learn much from virtual team research, but to inform and
develop a foundation of effective LDSF communication
practices, we must draw more information from other areas of
research.
Concerning communication, one of the major
recommendations for the challenges imposed by
communication in virtual teams is the use of a protocol
(Cohen & Alphonso, 2013). Due to evidence that crew errors
are related to factors including poorly designed protocols
(Morphew, 2001) we will explore this further as a potential
way to remedy the effects of communication lag. Below we
will discuss technologies that can potentially enhance
communication. Following we will discuss research conducted
on handoff protocols for space teams, and implications of
these findings for LDSF.
Communication Modalities and the LDSF Team
Research on virtual teams has shown that individuals
often assume that the quality of communication is contingent
on the modality of communication (Wilson, 2013). Some
argue that this is incorrect; instead showing that
communication via text can lead to the same level of
psychological closeness as high end face-to-face technology
(Walther & Bazarova, 2008). Given this, we believe that
LDSF teams are a special case of virtual team, and will indeed
need to rely on richer communication technology – especially
in the case of off-nominal events where detailed information
about system states in the space craft may be needed for
mission control to aid in problem solution generation. Below
we will discuss research that has attempted to understand the
effects of different communication technologies on teamwork,
specifically pulling from literature on unmanned system
command and control teams.
Video Feeds and Teleguidance
Video feeds will be absolutely crucial in LDSF. Although
their usefulness is disputed in virtual teamwork, it seems that
LDSF is a unique type of virtual team that will benefit from
the provision of video feeds (Wilson, 2013). Situational
awareness and communication patterns are grounded in the
position and dynamics of objects, other people, and activities
in the environment (Ford, 1999; Tang, 1991). By allowing
LDSF operators to share their visual field with ground control,
communication can be made clearer and situational awareness
of all parties can be maximized (Gergle, Kraut, & Fussell,
2013). These factors are especially important when
engineering teams need to observe specific phenomena
occurring within the spacecraft that cannot be easily described
verbally and are not directly communicated from the systems
themselves.
8
Fussell, Setlock, and Kraut (2003) demonstrated the
utility of video feeds for teleguidance of isolated operators: if
a video feed of the operator’s work scene is available, an
expert is able to guide the operator through a task more
quickly than if it’s an audio-only channel. Further, the quality
of information that can be provided to the operator is richer: in
critical medical situations where teams are ill- or un-trained
for the task at hand, teleguidance from trained medical staff
very often leads to improved patient outcomes (Otto, 2010;
Påhlsson et al., 2013).
There are obstacles to applying teleguidance techniques to
LDSF, the greatest of which stems from potentially crippling
round-trip communication delays. Effective use of
teleguidance techniques will have to account for these delays.
Melton & Sargasyan (2003) discussed principles for managing
and interpreting video data acquired by ultrasound equipment
aboard the ISS, noting that real-time video downlink and
bidirectional voice capabilities would best aid diagnosis speed
and accuracy. However, the authors also noted that computerbased ultrasound training tools should be available on board
for predictable scenarios where ultrasound is indicated, such
as blunt abdominal and chest trauma. This knowledge-ondemand principle can be adapted to other domains where
communication with ground control is not absolutely
necessary; it would allow crew with minimal training in
certain domains to carry out important repair and maintenance
procedures in situations where video communication with
ground control would previously have been necessary.
Application of this technique would help to mitigate the
significant obstacles to rapid communication imposed by
LDSF.
Audio Recorded as Text
Audio recordings have been shown to be an effective
modality of communication in unmanned vehicle operations.
Specifically, research has demonstrated that audio
communication leads to almost double the number of taskrelated statements compared to text alone (Fincannon,
Keebler, Jentsch, Phillips & Evans, 2011). Given this, there
are issues that arise when communications are not indexed.
Therefore, it becomes pertinent to also record audio into text.
This can be done using modern software. Specifically,
converting audio conversations into time-stamped text files
can aid both crews and mission control in finding specific
parts of a conversation quickly. Due to the dynamic state of
space flight, there will be instances where a previous
communication
becomes
nullified
by
incoming
communications due to the high amount of lag present in the
system. Having a record of audio recordings in text will aid
with teamwork through updating mental models and providing
reference points for previous communication, while not
relying heavily on the working memory of individual team
members.
The Need for Team Training in LDSF
Successful missions rely on excellent teamwork (Salas,
DiazGranados, Klein, Burke, Stagl, Goodwin, & Halpin,
Proceedings of the Human Factors and Ergonomics Society 59th Annual Meeting - 2015
2008). The beneficial effects of exceptional teamwork are
often characterized by crew and flight controllers having
positive interactions, trust, stronger communication, and high
levels of space flight resource management (Noe, et al. 2011).
Although many influencing conditions (i.e., context,
composition, and culture) in which the team is functioning
must be considered in the initial selection of the team, the core
processes and states (i.e., cooperation, coordination, cognition,
conflict, coaching, and communication) of the team system
needs training (Salas, Shuffler, Thayer, Bedwell, & Lazzara,
2014). On long-duration missions, the crew will be out of
touch with ground control. The crew will have to know tasks
and time constraints, and will be given more tactical control
(i.e., what tasks have to be completed at a certain time vs. at
the discretion of the crew?).
strategies were identified that dictated the effectiveness of the
procedure:
1.
2.
3.
4.
5.
Handoffs as a Solution to Communication Lags During
Mission Critical Decisions
Defining Handoffs for LDSF
6.
Usually handoffs are described within a medical context
as the transition of patient care between two providers or units
(Solet, Norvell, Rutan, Frankel, 2005). In the context of
LDSF, a handoff may instead be defined as a key
communication event where information is sent between the
flight crew and mission control at pre-designated points in
time, before or after critical mission waypoints, or in the case
of an emergency or off-nominal event.
Effective and Efficient Handoffs: Requirements for handoff
training and flexible-standardization
Research in space shuttle mission control has identified
potential costs of failing to be told, forgetting, or
misunderstanding information communicated during a shift
change handoff. Patterson, Roth, Woods, Chow, & Gomes
(2004) specifically defined seven instances where failed
handoffs can be disastrous:
9
Outgoing person writes a one-paragraph summary of the
shift to prep for verbal handoff
The incoming person assessed the current status of the
monitored system before or during the update
The incoming person scanned historical data immediately
before or following the handoff to strengthen information
learned during handoff
The incoming person was expected to review
automatically captured changes to sensor-derived data
(‘automated logs’) before the update in situations where
there were known problems or instability
In space shuttle mission control, two personnel
designated ‘on call’, one for the first 12 hours in a day,
one for the second 12 hours in a day, were required to
receive daily, 15 minute updates so that they would be
better prepared to accept responsibility quickly if needed
(strategy 13).
The outgoing person providing the handoff was the
individual who held the position in the previous shift. He
or she was thus highly knowledgeable of the activities
that occurred during that shift, increasing the chance that
the information transmitted was correct and complete
(Patterson et. al, 2004).
Given these well thought out procedures, future research
will need to examine the effectiveness of these methods when
a communication lag is introduced. Although we believe this
is the starting point for the development of protocols and
standardization, work will need to focus on how to maintain
flexibility in the face of off-nominal events, how to aid the
space flight crew in conducting these procedures using
automated systems, and how to best develop software that
allows for individuals to conduct these tasks efficiently, and
finally, how to best train the crew in preparation for missions
using this systematic approach.
Conclusion
1.
2.
3.
4.
5.
6.
7.
Having an incorrect or incomplete model of the
system’s state
Being unaware of significant data or events
Being unprepared to deal with impacts from previous
events
Failing to anticipate future events
Lacking knowledge that is necessary to perform tasks
Dropping or reworking activities that are in progress
or that the team has agreed to do
Creating an unwarranted shift in goals, decisions,
priorities, or plans
Each of these potential failures seems to couple to wellknown human factors constructs. Specifically, these seven
concepts seem to be manifestations of the following: mode
awareness/ loss of situation awareness (1, 2, & 4), dynamic
fault management (3 & 6), lack of cross-training (5) and
mission prioritization (7). According to Patterson et al’s
(2004) work on handoffs in space shuttle missions, six
This is a relatively little explored area that is in need of
empirical research. It appears that a mixture of applying what
we know about virtual teams, team training, communication
modalities, and handoffs may help mitigate some of the issues
brought about by communication lag in LDSF. As a result,
empirical work will need to investigate the efficacy of these
ideas as we move closer to a manned mission to Mars.
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