Benjamin Malphrus - Academia.edu (original) (raw)
Papers by Benjamin Malphrus
American Astronomical Society Meeting Abstracts #224, Jun 1, 2014
Proceedings of the International Astronautical Congress, IAC, 2019
Journal of Remote Sensing & GIS, Aug 22, 2016
О р д е н а Л е н и н а ИНСТИТУТ ПРИКЛАДНОЙ МАТЕМАТИКИ имени М.В.Келдыша Р о с с и й с к о й а к ... more О р д е н а Л е н и н а ИНСТИТУТ ПРИКЛАДНОЙ МАТЕМАТИКИ имени М.В.Келдыша Р о с с и й с к о й а к а д е м и и н а у к M. Ovchinnikov, V. Penkov, B. Malphrus, K. Brown D. Roldugin Active magnetic attitude control algorithms for а CubeSat for astrophysics research Москва-2014 Овчинников М.Ю., Пеньков В.И., Малфрус Б.К., Браун К., Ролдугин Д.С. Алгоритмы магнитной ориентации кубсата для астрофизических исследований Рассматривается магнитная система ориентации для спутника CXBN-2. Аппарат представляет собой двойной кубсат (стандарта 2U), предназначенный для изучения рассеянного фонового рентгеновского излучения Вселенной. Система ориентации спутника состоит из трех магнитных катушек. В работе рассматриваются четыре потенциальных режима ориентации аппарата. На основе ряда критериев, в частности, максимизации объема получаемых научных данных, выбирается оптимальный алгоритм ориентации.
American Astronomical Society Meeting Abstracts, Dec 1, 2007
ABSTRACT The Space Science Center at Morehead State University has developed a medium aperture cm... more ABSTRACT The Space Science Center at Morehead State University has developed a medium aperture cm-wave radio telescope, the 21 M Space Tracking Antenna and Radio Telescope. Located in the radio-frequency quiet, mountainous region of eastern Kentucky, the telescope serves as an Earth Station for satellite mission support and provides telemetry, tracking, and control services with an emphasis on university cubesat missions. In addition, the telescope is engaged in research programs in radio astronomy and features receivers operating in the Ku-band (11.2 to 12.7 GHz, including a well-known methanol line) and the L-band (1.4 to 1.7 GHz, including lines of atomic hydrogen and molecular hydroxyl). At these bands, the telescope is capable of supporting a wide variety of niche astronomical research programs, including longitudinal studies (e.g., active galactic nuclei (AGN) monitoring), observations of transient phenomena (e.g., gamma-ray bursts and supernovae), and surveys (e.g., kinematic studies of Galactic HI). A description of the space tracking antenna system and radio telescope, its capabilities and research projects planned for or currently underway with the telescope (namely monitoring AGNs and surveying the Galactic supernova remnant population) will be presented and discussed. Funding for the 21m telescope has been provided by NASA, the SBA, the Kentucky Science and Engineering Foundation and Kentucky NSF EPSCoR.
American Astronomical Society Meeting Abstracts #208, Jun 1, 2006
Background Resection techniques for small polyps include cold snare polypectomy (CSP) and hot sna... more Background Resection techniques for small polyps include cold snare polypectomy (CSP) and hot snare polypectomy (HSP). This study compared CSP and HSP in 5-9 mm polyps in terms of complete resection and adverse events. Methods This was a multicenter, randomized trial conducted in seven Spanish centers between February and November 2019. Patients with ≥ 1 5-9 mm polyp were randomized to CSP or HSP, regardless of morphology or pit pattern. After polypectomy, two marginal biopsies were submitted to a pathologist who was blinded to polyp histology. Complete resection was defined as normal mucosa or burn artifacts in the biopsies. Abdominal pain was only assessed in patients without < 5 mm or > 9 mm polyps. Results 496 patients were randomized: 237 (394 polyps) to CSP and 259 (397 polyps) to HSP. Complete polypectomy rates were 92.5 % with CSP and 94.0 % with HSP (difference 1.5 %, 95 % confidence interval-1.9 % to 4.9 %). Intraprocedural bleeding occurred during three CSPs (0.8 %) and seven HSPs (1.8 %) (P = 0.34). One lesion per group (0.4 %) presented delayed hemorrhage. Post-colonoscopy abdominal pain presented similarly in both groups 1 hour after the procedure (CSP 18.8 % vs. HSP 18.4 %) but was higher in the HSP group after 5 hours (5.9 % vs. 16.5 %; P = 0.02). A higher proportion of patients were asymptomatic 24 hours after CSP than after HSP (97 % vs. 86.4 %; P = 0.01). Conclusions We observed no differences in complete resection and bleeding rates between CSP and HSP. CSP reduced the intensity and duration of post-colonoscopy abdominal pain.
As small spacecraft venture out of Earth orbit, they will encounter challenges not experienced or... more As small spacecraft venture out of Earth orbit, they will encounter challenges not experienced or addressed by the numerous low Earth orbit (LEO) CubeSat and Smallsat missions staged to date. The LEO CubeSats typically use low-cost, proven CubeSat radios, antennas, and university ground stations with small apertures. As more ambitious yet cost-constrained space mission concepts to the Moon and beyond are being developed, CubeSats and smallsats have the potential to provide a more affordable platform for exploring deep space and performing the associated science. Some of the challenges that have, so far, slowed the proliferation of small interplanetary spacecraft are those of communications and navigation. In [23], we discussed the communications and tracking challenges facing interplanetary smallsats and CubeSats, and the next-generation ground network architecture being evolved to mitigate those challenges. In this paper we summarized the results in [23]. Based on our understanding on the mission set of interplanetary smallsats and ground network architecture, we discuss the preliminary thoughts on the operations concept that would transform the current DSN architecture to a federated network architecture that, in addition to traditional deep space missions, can also provide just-in-time communications and tracking services to a large number of interplanetary smallsats/CubeSats. We focus on the following topics: 1. DSN compatibility and interfaces. 2. Challenges on integrating heterogeneous non-DSN antennas into the DSN service management and service execution framework. 3. Cross-support with university antennas, with other space agencies, and with other research centers. 4. Network planning and scheduling concepts that maximize pass opportunities for smallsats and CubeSats.
Journal of Aeronautics and Aerospace Engineering, 2017
Interplanetary Network Progress Report, Aug 1, 2015
This article provides additional details and updates to the presented charts.
Elsevier eBooks, 2021
Abstract The launch and successful operation of the Mars Cube One (MarCO) CubeSats in May of 2018... more Abstract The launch and successful operation of the Mars Cube One (MarCO) CubeSats in May of 2018 ushered in a new era of solar system exploration. The 13 interplanetary CubeSats slated to fly on Artemis 1 in 2020 along with MarCO represent the beginning of a new paradigm of planetary exploration—one that utilizes the CubeSat form factor as both primary and supporting exploration platforms. Enabling technologies required by interplanetary CubeSats including relatively high Δv propulsion systems, capable high-frequency transponders, radiation-tolerant components, and extremely capable miniaturized science instruments are now becoming commercially available making these missions possible. Interplanetary CubeSats require different and more sophisticated spacecraft systems architectures and must utilize different and more sophisticated ground station systems than LEO missions. These differences are discussed in this chapter in detail, using specific examples from current and planned missions.
2022 IEEE Aerospace Conference (AERO), Mar 5, 2022
42nd COSPAR Scientific Assembly, Jul 1, 2018
AAS, May 1, 2007
ABSTRACT The Space Science Center at Morehead State University has developed a medium aperture cm... more ABSTRACT The Space Science Center at Morehead State University has developed a medium aperture cm-wave radio telescope, the 21 M Space Tracking Antenna and Radio Telescope. The telescope- located in the mountainous region of eastern Kentuck- is engaged in rigorous research programs in radio astronomy and will also serve as a ground station with the capability of tracking low earth orbiting satellites. Currently, the telescope features receivers sensitive to radiation in the Ku-band (11.2 to 12.7 GHz, including a well-known methanol line), S band (centered at 2.4GHz) and L- band (1.4 to 1.7 GHz, including lines of atomic hydrogen and hydroxyl). The instrument's performance characteristics support a wide variety of research. Sensitivity is in the 100 milliJansky range in L-band and in the 200 milliJansky range at Ku band. The spatial resolution achieved is 34.8 arcminutes at L-band and 1.8 arcminutes at Ku-band. Niche observational strategies for this telescope include: 1.) longitudinal studies (i.e. AGN monitoring), 2.) observations of transient phenomena (i.e. GRBs and supernovae), and 3.) surveys (i.e. kinematic studies of Galactic HI). A description of the antenna, its capabilities and research projects planned for or currently being conducted by the antenna (focusing on monitoring active galactic nuclei and surveying the Galactic supernova remnant population) will be presented and discussed. Funding for the 21m telescope has been provided by NASA, the SBA, the Kentucky Science and Engineering Foundation and Kentucky NSF EPSCoR.
International Workshop on Instrumentation for Planetary Missions, Oct 1, 2012
Journal of Aeronautics and Aerospace Engineering, May 22, 2017
Following the successful SMDC (Space and Missile Defense Command) TechSat F-cubed (Form, Fit, Fun... more Following the successful SMDC (Space and Missile Defense Command) TechSat F-cubed (Form, Fit, Function) demonstration in 2012, DM CubeSat technology development continued its path to space. In March 2013, Yosemite Space, formerly known as Advanced Materials Applications, LLC, and Honeywell Aerospace were awarded a CASIS (the Center for the Advancement of Science in Space) grant to perform both ground-based and space-based radiation testing of Gumstix™ COM (Compute-On-Module) modules. Ground-based proton testing of a variety of Gumstix modules has been completed. The space-based radiation testing and performance validation will be conducted as an ISS (International Space Station) National Laboratory flight experiment. Originally scheduled for launch in late 2014, the launch of the Gumstix flight experiment has been delayed to early 2015. In September 2014, Honeywell and Morehead State University (MSU) were awarded a CASIS grant to fly a DM (Dependable Multiprocessor) CubeSat payload processor as a 2015 ISS National Laboratory flight experiment. This ISS flight experiment will culminate with the TRL7 validation of DM CubeSat technology. Following a brief overview of DM and DM CubeSat technology, the paper discusses the two ISS flight experiments and other DM CubeSat-related developments.
The Wallops 18-Meter diameter UHF-Band and the Morehead State 21-Meter diameter current S-band an... more The Wallops 18-Meter diameter UHF-Band and the Morehead State 21-Meter diameter current S-band and future X-Band and UHF-Band CubeSat Groundstations answer a growing need for high data rate from CubeSats over government licensed frequencies. Ten years ago, when CubeSats began, they were nothing more than simple science experiments, typically consisting of a camera and a low data rate radio. The success and wide community support for the National Science Foundation (NSF) CubeSat Program combined with the increasing number of NASA proposals that utilize CubeSats, and other large government organizations that have started funding CubeSats, demonstrates the maturation of the CubeSat platform. The natural gain provided by the large diameter UHF-, X-and S-Band Groundstations enables high data rates (e.g. 3.0 Mbit, 300 times the typical 9.6 Kbit for CubeSats over UHF). Government funded CubeSats using amateur radio frequencies may violate the intent of the amateur radio service and it is a violation of National Telecommunications Information Administration (NTIA) rules for a government funded ground station to use amateur radio frequencies to communicate with CubeSats. The NSF has led the charge in finding a suitable government frequency band for CubeSats. Although amateur frequency licensing has historically been easy and fast to obtain, it limits downlink data rate capability due to narrow spectrum bandwidth allocation. In addition to limited bandwidth allocation, using unencrypted and published downlink telemetry data, easily accessible by any receiver, has not satisfied the needs of universities, industry and government agencies. After completing a decade mainly operating at the amateur radio frequency and using inexpensive but unreliable amateur commercial off-the-shelf (COTS) space and ground hardware, the CubeSat community is looking for different Cu-beSat and ground system communication solutions to support their current and future needs.
The planetary science journal, Mar 18, 2021
As the solar wind flows by the Moon, an antisunward-directed low-density wake forms as the plasma... more As the solar wind flows by the Moon, an antisunward-directed low-density wake forms as the plasma expands to fill in the trailing void in the plasma flow. Analytical modeling and modern plasma simulations suggest that plasma quasi-neutrality could possibly be broken close to the terminator obstruction as solar wind electrons expand into the wake ahead of the ions, leading to the formation of a standing (time-stationary) double layer. The objective of the Terminator Double Layer Explorer is to extend the fundamental understanding of the plasma expansion into the trailing near-vacuum wake region by (1) identifying any plasma expansion density anomalies at low altitudes near the terminator wake initiation region, (2) assessing the highly variable solar wind’s effect on the low-altitude wake region, and (3) determining if plasma neutrality is maintained or lost during passages through the low-altitude expansion region. The mission concept uses a propulsion-driven CubeSat with ion spectrometer and plasma wave system in elliptical orbit about the Moon with periselene near the terminator. Over the course of the mission, the periselene decreases, placing the CubeSat ever closer to the terminator wake initiation location and the possible nonneutral region.
American Astronomical Society Meeting Abstracts #224, Jun 1, 2014
Proceedings of the International Astronautical Congress, IAC, 2019
Journal of Remote Sensing & GIS, Aug 22, 2016
О р д е н а Л е н и н а ИНСТИТУТ ПРИКЛАДНОЙ МАТЕМАТИКИ имени М.В.Келдыша Р о с с и й с к о й а к ... more О р д е н а Л е н и н а ИНСТИТУТ ПРИКЛАДНОЙ МАТЕМАТИКИ имени М.В.Келдыша Р о с с и й с к о й а к а д е м и и н а у к M. Ovchinnikov, V. Penkov, B. Malphrus, K. Brown D. Roldugin Active magnetic attitude control algorithms for а CubeSat for astrophysics research Москва-2014 Овчинников М.Ю., Пеньков В.И., Малфрус Б.К., Браун К., Ролдугин Д.С. Алгоритмы магнитной ориентации кубсата для астрофизических исследований Рассматривается магнитная система ориентации для спутника CXBN-2. Аппарат представляет собой двойной кубсат (стандарта 2U), предназначенный для изучения рассеянного фонового рентгеновского излучения Вселенной. Система ориентации спутника состоит из трех магнитных катушек. В работе рассматриваются четыре потенциальных режима ориентации аппарата. На основе ряда критериев, в частности, максимизации объема получаемых научных данных, выбирается оптимальный алгоритм ориентации.
American Astronomical Society Meeting Abstracts, Dec 1, 2007
ABSTRACT The Space Science Center at Morehead State University has developed a medium aperture cm... more ABSTRACT The Space Science Center at Morehead State University has developed a medium aperture cm-wave radio telescope, the 21 M Space Tracking Antenna and Radio Telescope. Located in the radio-frequency quiet, mountainous region of eastern Kentucky, the telescope serves as an Earth Station for satellite mission support and provides telemetry, tracking, and control services with an emphasis on university cubesat missions. In addition, the telescope is engaged in research programs in radio astronomy and features receivers operating in the Ku-band (11.2 to 12.7 GHz, including a well-known methanol line) and the L-band (1.4 to 1.7 GHz, including lines of atomic hydrogen and molecular hydroxyl). At these bands, the telescope is capable of supporting a wide variety of niche astronomical research programs, including longitudinal studies (e.g., active galactic nuclei (AGN) monitoring), observations of transient phenomena (e.g., gamma-ray bursts and supernovae), and surveys (e.g., kinematic studies of Galactic HI). A description of the space tracking antenna system and radio telescope, its capabilities and research projects planned for or currently underway with the telescope (namely monitoring AGNs and surveying the Galactic supernova remnant population) will be presented and discussed. Funding for the 21m telescope has been provided by NASA, the SBA, the Kentucky Science and Engineering Foundation and Kentucky NSF EPSCoR.
American Astronomical Society Meeting Abstracts #208, Jun 1, 2006
Background Resection techniques for small polyps include cold snare polypectomy (CSP) and hot sna... more Background Resection techniques for small polyps include cold snare polypectomy (CSP) and hot snare polypectomy (HSP). This study compared CSP and HSP in 5-9 mm polyps in terms of complete resection and adverse events. Methods This was a multicenter, randomized trial conducted in seven Spanish centers between February and November 2019. Patients with ≥ 1 5-9 mm polyp were randomized to CSP or HSP, regardless of morphology or pit pattern. After polypectomy, two marginal biopsies were submitted to a pathologist who was blinded to polyp histology. Complete resection was defined as normal mucosa or burn artifacts in the biopsies. Abdominal pain was only assessed in patients without < 5 mm or > 9 mm polyps. Results 496 patients were randomized: 237 (394 polyps) to CSP and 259 (397 polyps) to HSP. Complete polypectomy rates were 92.5 % with CSP and 94.0 % with HSP (difference 1.5 %, 95 % confidence interval-1.9 % to 4.9 %). Intraprocedural bleeding occurred during three CSPs (0.8 %) and seven HSPs (1.8 %) (P = 0.34). One lesion per group (0.4 %) presented delayed hemorrhage. Post-colonoscopy abdominal pain presented similarly in both groups 1 hour after the procedure (CSP 18.8 % vs. HSP 18.4 %) but was higher in the HSP group after 5 hours (5.9 % vs. 16.5 %; P = 0.02). A higher proportion of patients were asymptomatic 24 hours after CSP than after HSP (97 % vs. 86.4 %; P = 0.01). Conclusions We observed no differences in complete resection and bleeding rates between CSP and HSP. CSP reduced the intensity and duration of post-colonoscopy abdominal pain.
As small spacecraft venture out of Earth orbit, they will encounter challenges not experienced or... more As small spacecraft venture out of Earth orbit, they will encounter challenges not experienced or addressed by the numerous low Earth orbit (LEO) CubeSat and Smallsat missions staged to date. The LEO CubeSats typically use low-cost, proven CubeSat radios, antennas, and university ground stations with small apertures. As more ambitious yet cost-constrained space mission concepts to the Moon and beyond are being developed, CubeSats and smallsats have the potential to provide a more affordable platform for exploring deep space and performing the associated science. Some of the challenges that have, so far, slowed the proliferation of small interplanetary spacecraft are those of communications and navigation. In [23], we discussed the communications and tracking challenges facing interplanetary smallsats and CubeSats, and the next-generation ground network architecture being evolved to mitigate those challenges. In this paper we summarized the results in [23]. Based on our understanding on the mission set of interplanetary smallsats and ground network architecture, we discuss the preliminary thoughts on the operations concept that would transform the current DSN architecture to a federated network architecture that, in addition to traditional deep space missions, can also provide just-in-time communications and tracking services to a large number of interplanetary smallsats/CubeSats. We focus on the following topics: 1. DSN compatibility and interfaces. 2. Challenges on integrating heterogeneous non-DSN antennas into the DSN service management and service execution framework. 3. Cross-support with university antennas, with other space agencies, and with other research centers. 4. Network planning and scheduling concepts that maximize pass opportunities for smallsats and CubeSats.
Journal of Aeronautics and Aerospace Engineering, 2017
Interplanetary Network Progress Report, Aug 1, 2015
This article provides additional details and updates to the presented charts.
Elsevier eBooks, 2021
Abstract The launch and successful operation of the Mars Cube One (MarCO) CubeSats in May of 2018... more Abstract The launch and successful operation of the Mars Cube One (MarCO) CubeSats in May of 2018 ushered in a new era of solar system exploration. The 13 interplanetary CubeSats slated to fly on Artemis 1 in 2020 along with MarCO represent the beginning of a new paradigm of planetary exploration—one that utilizes the CubeSat form factor as both primary and supporting exploration platforms. Enabling technologies required by interplanetary CubeSats including relatively high Δv propulsion systems, capable high-frequency transponders, radiation-tolerant components, and extremely capable miniaturized science instruments are now becoming commercially available making these missions possible. Interplanetary CubeSats require different and more sophisticated spacecraft systems architectures and must utilize different and more sophisticated ground station systems than LEO missions. These differences are discussed in this chapter in detail, using specific examples from current and planned missions.
2022 IEEE Aerospace Conference (AERO), Mar 5, 2022
42nd COSPAR Scientific Assembly, Jul 1, 2018
AAS, May 1, 2007
ABSTRACT The Space Science Center at Morehead State University has developed a medium aperture cm... more ABSTRACT The Space Science Center at Morehead State University has developed a medium aperture cm-wave radio telescope, the 21 M Space Tracking Antenna and Radio Telescope. The telescope- located in the mountainous region of eastern Kentuck- is engaged in rigorous research programs in radio astronomy and will also serve as a ground station with the capability of tracking low earth orbiting satellites. Currently, the telescope features receivers sensitive to radiation in the Ku-band (11.2 to 12.7 GHz, including a well-known methanol line), S band (centered at 2.4GHz) and L- band (1.4 to 1.7 GHz, including lines of atomic hydrogen and hydroxyl). The instrument's performance characteristics support a wide variety of research. Sensitivity is in the 100 milliJansky range in L-band and in the 200 milliJansky range at Ku band. The spatial resolution achieved is 34.8 arcminutes at L-band and 1.8 arcminutes at Ku-band. Niche observational strategies for this telescope include: 1.) longitudinal studies (i.e. AGN monitoring), 2.) observations of transient phenomena (i.e. GRBs and supernovae), and 3.) surveys (i.e. kinematic studies of Galactic HI). A description of the antenna, its capabilities and research projects planned for or currently being conducted by the antenna (focusing on monitoring active galactic nuclei and surveying the Galactic supernova remnant population) will be presented and discussed. Funding for the 21m telescope has been provided by NASA, the SBA, the Kentucky Science and Engineering Foundation and Kentucky NSF EPSCoR.
International Workshop on Instrumentation for Planetary Missions, Oct 1, 2012
Journal of Aeronautics and Aerospace Engineering, May 22, 2017
Following the successful SMDC (Space and Missile Defense Command) TechSat F-cubed (Form, Fit, Fun... more Following the successful SMDC (Space and Missile Defense Command) TechSat F-cubed (Form, Fit, Function) demonstration in 2012, DM CubeSat technology development continued its path to space. In March 2013, Yosemite Space, formerly known as Advanced Materials Applications, LLC, and Honeywell Aerospace were awarded a CASIS (the Center for the Advancement of Science in Space) grant to perform both ground-based and space-based radiation testing of Gumstix™ COM (Compute-On-Module) modules. Ground-based proton testing of a variety of Gumstix modules has been completed. The space-based radiation testing and performance validation will be conducted as an ISS (International Space Station) National Laboratory flight experiment. Originally scheduled for launch in late 2014, the launch of the Gumstix flight experiment has been delayed to early 2015. In September 2014, Honeywell and Morehead State University (MSU) were awarded a CASIS grant to fly a DM (Dependable Multiprocessor) CubeSat payload processor as a 2015 ISS National Laboratory flight experiment. This ISS flight experiment will culminate with the TRL7 validation of DM CubeSat technology. Following a brief overview of DM and DM CubeSat technology, the paper discusses the two ISS flight experiments and other DM CubeSat-related developments.
The Wallops 18-Meter diameter UHF-Band and the Morehead State 21-Meter diameter current S-band an... more The Wallops 18-Meter diameter UHF-Band and the Morehead State 21-Meter diameter current S-band and future X-Band and UHF-Band CubeSat Groundstations answer a growing need for high data rate from CubeSats over government licensed frequencies. Ten years ago, when CubeSats began, they were nothing more than simple science experiments, typically consisting of a camera and a low data rate radio. The success and wide community support for the National Science Foundation (NSF) CubeSat Program combined with the increasing number of NASA proposals that utilize CubeSats, and other large government organizations that have started funding CubeSats, demonstrates the maturation of the CubeSat platform. The natural gain provided by the large diameter UHF-, X-and S-Band Groundstations enables high data rates (e.g. 3.0 Mbit, 300 times the typical 9.6 Kbit for CubeSats over UHF). Government funded CubeSats using amateur radio frequencies may violate the intent of the amateur radio service and it is a violation of National Telecommunications Information Administration (NTIA) rules for a government funded ground station to use amateur radio frequencies to communicate with CubeSats. The NSF has led the charge in finding a suitable government frequency band for CubeSats. Although amateur frequency licensing has historically been easy and fast to obtain, it limits downlink data rate capability due to narrow spectrum bandwidth allocation. In addition to limited bandwidth allocation, using unencrypted and published downlink telemetry data, easily accessible by any receiver, has not satisfied the needs of universities, industry and government agencies. After completing a decade mainly operating at the amateur radio frequency and using inexpensive but unreliable amateur commercial off-the-shelf (COTS) space and ground hardware, the CubeSat community is looking for different Cu-beSat and ground system communication solutions to support their current and future needs.
The planetary science journal, Mar 18, 2021
As the solar wind flows by the Moon, an antisunward-directed low-density wake forms as the plasma... more As the solar wind flows by the Moon, an antisunward-directed low-density wake forms as the plasma expands to fill in the trailing void in the plasma flow. Analytical modeling and modern plasma simulations suggest that plasma quasi-neutrality could possibly be broken close to the terminator obstruction as solar wind electrons expand into the wake ahead of the ions, leading to the formation of a standing (time-stationary) double layer. The objective of the Terminator Double Layer Explorer is to extend the fundamental understanding of the plasma expansion into the trailing near-vacuum wake region by (1) identifying any plasma expansion density anomalies at low altitudes near the terminator wake initiation region, (2) assessing the highly variable solar wind’s effect on the low-altitude wake region, and (3) determining if plasma neutrality is maintained or lost during passages through the low-altitude expansion region. The mission concept uses a propulsion-driven CubeSat with ion spectrometer and plasma wave system in elliptical orbit about the Moon with periselene near the terminator. Over the course of the mission, the periselene decreases, placing the CubeSat ever closer to the terminator wake initiation location and the possible nonneutral region.