Toward Real-Time Earth Observation: Evaluating the Cost-Performance of Satellite Constellation Crosslinks and Propulsion
On June 10, 2026, the International Journal of Satellite Communications and Networking published a peer-reviewed original paper titled “Toward Real-Time Earth Observation With Satellite Constellation Crosslinks and Propulsion” (Chan et al., 2026). The paper appeared as an Early View article and was highlighted by co-author Dr. Olivier L. de Weck on LinkedIn, where he described it as “the first publication that I am aware of that has actually monetized the cost of speedup [sec/$] in Earth Observation constellation architectures” (de Weck, 2026). The research originated from the doctoral dissertation of lead author Manwei Chan, completed at the Massachusetts Institute of Technology (MIT) in February 2024 (Chan, 2024).
The Research Team
The paper was authored by four researchers affiliated with MIT’s Department of Aeronautics and Astronautics and the Technical University of Munich.
Manwei Chan (LinkedIn, ORCID, GitHub, personal website) is the corresponding author. Chan received a Ph.D. in Aerospace Engineering from MIT in 2024, completing the dissertation “Toward Real-time Earth Observation with Satellite Constellation Crosslinks and Propulsion” under the supervision of de Weck, Cahoy, and Golkar (Chan, 2024). He previously earned a Master of Science in Aeronautics and Astronautics from MIT in 2019, developing a guidance algorithm for satellite rendezvous and docking with uncontrolled tumbling objects. Chan was an NSF Fellow throughout his graduate studies. He has worked with NanoRacks, Orbit Fab, and a stealth-mode telecommunications satellite startup. At the time of the LinkedIn post, Chan was serving as the winter-over scientist for the BICEP telescope at the Amundsen-Scott South Pole Station in Antarctica, where the telescope probes the cosmic microwave background for evidence of inflationary cosmology (Chan, n.d.).
Kerri Cahoy (LinkedIn, ORCID, MIT profile, Wikipedia) holds the Sheila Evans Widnall (1960) Professorship in Aeronautics and Astronautics at MIT and serves as Head of the Space Sector and Director of the Space Telecommunications, Astronomy and Radiation Laboratory (STAR Lab) (MIT AeroAstro, n.d.). She received a B.S. in Electrical Engineering from Cornell University (2000), and both an M.S. (2002) and Ph.D. (2008) in Electrical Engineering from Stanford University, where her dissertation examined thermal tides at ionospheric altitudes on Mars. Cahoy joined the MIT faculty in 2011 and became a full Professor in July 2023. She is also co-founder of laser communications firm SpaceRake and co-director of the MIT Small Satellite Collaborative. Her research focuses on nanosatellite technology demonstrations, laser communications, atmospheric sensing, and exoplanet detection (Wikipedia, n.d.).
Oliver de Weck (LinkedIn, MIT profile, Wikipedia, Google Scholar) is the Apollo Program Professor of Astronautics and Engineering Systems at MIT and currently serves as Interim Department Head of the Department of Aeronautics and Astronautics (MIT AeroAstro, n.d.). Born in 1968 in Bern, Switzerland, de Weck earned a Dipl. Ing. in Industrial Engineering from ETH Zurich in 1993, an S.M. in Aeronautics and Astronautics from MIT in 1999, and a Ph.D. in Aerospace Systems from MIT in 2001. He has authored and co-authored more than 400 peer-reviewed publications. He is a Fellow of INCOSE and a Fellow of the AIAA, and serves as Editor-in-Chief of the Journal of Spacecraft and Rockets. From 2017 to 2018, de Weck took a leave of absence from MIT to serve as Senior Vice President for Technology Planning and Roadmapping at Airbus in Toulouse, France. His research spans Systems Engineering, Multidisciplinary Design Optimization, Space Logistics, and Remote Sensing (Wikipedia, n.d.). He leads the Engineering Systems Laboratory at MIT and holds a dual appointment with the Institute for Data, Systems, and Society (IDSS).
Alessandro Golkar (LinkedIn, ORCID, TUM profile) is Full Professor and Chair of Spacecraft Systems at the Technical University of Munich (TUM), where he joined on September 1, 2022, founding the Chair of Pico-, Nanosatellites, and Satellite Constellations. He holds a Ph.D. in Aeronautics and Astronautics from MIT. Prior to TUM, Golkar spent ten years as one of the founding faculty members of Skoltech (Skolkovo Institute of Science and Technology) in Moscow. From 2017 to 2019, he served as Vice President in the Technology Roadmapping and Planning department of Airbus CTO in Toulouse, France — a role he held concurrently with de Weck. His research focuses on advanced space mission concepts, distributed satellite systems, and systems engineering for pico- and nanosatellites (TUM, n.d.). Golkar is a Karman Fellow (2021), Senior Member of IEEE, and the 2017 Overall Winner of the Copernicus Masters competition.
Publication Venue
The paper was published in the International Journal of Satellite Communications and Networking, a peer-reviewed journal published by John Wiley & Sons and edited by Professor Barry G. Evans. The journal carries a CiteScore of 4.4, a Journal Impact Factor of 1.8, and an acceptance rate of approximately 8%. It covers the theory, practice, and operation of satellite systems and networks (Wiley Online Library, n.d.). The paper’s DOI is 10.1002/sat.70060.
Research Problem and Motivation
The proliferation of small-satellite constellations for remote sensing has created the technical potential for high-resolution EO data to reach end users faster than was previously possible with traditional, large-aperture satellite architectures. However, achieving near real-time data delivery requires advanced satellite capabilities — specifically, intersatellite links (ISL) and propulsive maneuverability — that add cost and complexity to constellation designs. Prior to this study, no published research had explicitly quantified the monetary cost of reducing data latency in EO constellation architectures, i.e., how many seconds of latency reduction can be purchased per million dollars of investment (Chan et al., 2026).
Performance Metrics
The study evaluated constellation performance using three distinct metrics:
| Metric | Definition |
|---|---|
| Age of Information (AoI) | The time elapsed since the most recent piece of useful data was generated at its source and delivered to the end user; a measure of data freshness (Arafa, n.d.) |
| System Response Time | The total duration from a data collection request to delivery of the requested data |
| Total Pass Time | The cumulative time over a given period during which a satellite or constellation has line-of-sight access to specified ground targets |
The Age of Information metric is particularly relevant in time-critical applications such as disaster monitoring, military ISR, and environmental surveillance, where the timeliness of data directly affects decision-making quality.
Simulation Framework and Methodology
The research produced four primary technical contributions (Chan, 2024):
The first contribution is an open-source constellation simulation framework capable of propagating satellites and executing propulsive maneuvers. This framework was verified against the industry-standard Systems Tool Kit (STK) software. The second contribution is a planning and scheduling algorithm for propulsive maneuvers, target observation times, and optimal data routing paths. The third contribution is a set of high-performance constellation designs optimized with respect to constellation cost and the three performance metrics. The fourth contribution is a set of cost-estimating relationships (CERs) that model the trade-off between cost and system performance.
The cost model was developed from two sources: the Small Satellite Cost Model (SSCM), a parametric tool maintained by The Aerospace Corporation for estimating development and production costs of satellites under 1,000 kilograms (The Aerospace Corporation, n.d.), and a custom launch cost model developed in the dissertation. The SSCM, now in its SSCM19 version (released December 2019), is based on a database of actual, as-flown technical and cost data from spacecraft bus manufacturers.
The simulation ran 21 different constellation designs, 3 satellite models, and 432 distinct ground targets. Scenarios were executed across all four seasons to eliminate geometric biases, resulting in 108,864 individual scenario simulations (Chan, 2024).
Walker Constellation Notation
The study employed the standard Walker constellation notation, expressed as i°:T/P/F, where i is the orbital inclination in degrees, T is the total number of satellites, P is the number of equally spaced orbital planes, and F is the phasing parameter describing the relative spacing between satellites in adjacent planes (Wikipedia, n.d.).
Key Findings
Propulsion Reconfiguration
A single satellite executing the reconfiguration algorithm produced up to a 125% increase in pass time over seven days compared to an identical satellite without propulsive capabilities. For an access cone with a nadir half-angle of 20°, the reconfiguration algorithm produced a 67% increase in pass time (Chan, 2024).
Pareto Optimal Analysis
The Pareto optimal analysis of constellation designs with both ISL and propulsion capabilities revealed the following distributions:
| Optimization Objective | Percentage of Designs with Both ISL and Propulsion |
|---|---|
| Age of Information | 29% |
| System Response Time | 7% |
| Total Pass Time | 33% |
Optimal Architectures
Two specific architectures were identified as Pareto optimal across all three metrics simultaneously (Chan et al., 2026):
| Architecture | Cost (FY24) | Configuration | Capabilities |
|---|---|---|---|
| Low-cost baseline | $127 million | 60°:12/1/0 Walker | No ISL, no propulsion |
| High-capability | $2.2 billion | 60°:72/24/0 Walker | ISL and propulsion |
Cost-Estimating Relationships
For constellations with costs between $150 million and $1 billion (FY24), the study established the following cost-estimating relationships (Chan et al., 2026):
| Metric | Performance Gain per $1 Million Invested |
|---|---|
| Age of Information | Reduced by 32 seconds |
| System Response Time | Reduced by 35 seconds |
| Total Pass Time (over 3 days) | Increased by 2 seconds |
References
Chan, M., Cahoy, K., de Weck, O., & Golkar, A. (2026). Toward real-time Earth observation with satellite constellation crosslinks and propulsion. International Journal of Satellite Communications and Networking. https://doi.org/10.1002/sat.70060
Chan, M. (2024). Toward real-time Earth observation with satellite constellation crosslinks and propulsion [Doctoral dissertation, Massachusetts Institute of Technology]. MIT DSpace. https://dspace.mit.edu/handle/1721.1/154033
Chan, M. (n.d.). Manwei Chan — Personal website. Retrieved June 30, 2026, from https://manweichan.com/
de Weck, O. (2026, June 10). Toward Real-Time Earth Observation With Satellite Constellation Crosslinks and Propulsion [LinkedIn post]. LinkedIn. https://www.linkedin.com/posts/olivierdeweck_toward-real-time-earth-observation-with-satellite-share-7477366479911350272-OTXm/
Massachusetts Institute of Technology. (n.d.). Kerri Cahoy — MIT AeroAstro. Retrieved June 30, 2026, from https://aeroastro.mit.edu/people/kerri-cahoy/
Massachusetts Institute of Technology. (n.d.). Olivier L. de Weck — MIT AeroAstro. Retrieved June 30, 2026, from https://aeroastro.mit.edu/people/olivier-de-weck/
Technical University of Munich. (n.d.). Prof. Dr. Alessandro Golkar. Retrieved June 30, 2026, from https://www.professoren.tum.de/en/golkar-alessandro
The Aerospace Corporation. (n.d.). Small Satellite Cost Model (SSCM). Retrieved June 30, 2026, from https://aerospace.org/sscm
Wiley Online Library. (n.d.). International Journal of Satellite Communications and Networking. Retrieved June 30, 2026, from https://onlinelibrary.wiley.com/journal/15420981
Wikipedia. (n.d.). Kerri Cahoy. Retrieved June 30, 2026, from https://en.wikipedia.org/wiki/Kerri_Cahoy
Wikipedia. (n.d.). Olivier de Weck. Retrieved June 30, 2026, from https://en.wikipedia.org/wiki/Olivier_de_Weck
Wikipedia. (n.d.). Satellite constellation. Retrieved June 30, 2026, from https://en.wikipedia.org/wiki/Satellite_constellation
Arafa, A. (n.d.). Age-of-Information (AoI). Retrieved June 30, 2026, from https://webpages.charlotte.edu/aarafa/age-of-information.html
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