GHOSt (Global Hyperspectral Observation Satellite)
With the first satellites launched on 15 April 2023, Global Hyperspectral Observation Satellite (GHOSt) is a constellation of six technically identical hyperspectral imaging microsatellites by Orbital Sidekick Inc. (OSK). GHOSt aims to build on its predecessor Aurora to provide enhanced commercial data sets used in industrial, government, agriculture, environmental and defence sectors.
|15 Apr 2023
|End of life date
|15 Apr 2027
|Trace gases (excluding ozone)
|CH4 Mole Fraction, N2O (column/profile), CO2 Mole Fraction
|CEOS EO Handbook
|See GHOSt (Global Hyperspectral Observation Satellite) summary
Each GHOSt satellite features a proprietary hyperspectral imager manufactured by OSK. The sensor is developed to capture 512 spectral bands across the visible (VIS) to shortwave infrared (SWIR) region.
The enhanced monitoring provided by these imagers will enable GHOSt to produce the highest resolution commercial hyperspectral imagery launched to-date. Some key applications include capturing critical environmental and situational awareness information for defence, detecting minute real-time changes in physical infrastructure, monitoring energy infrastructure and regulatory compliance, detecting environmental erosion and degradation, and monitoring crop yield and agriculture.
With a revisit rate of up to daily for certain locations the hyperspectral sensors onboard the constellation will provide a spatial resolution of 8.3 m for multispectral band and 3 m for panchromatic bands.
GHOSt satellites are anticipated to operate at an average altitude of 525 km in a circular sun-synchronous orbit with an inclination of 97.5°.
Space and Hardware Components
Developed by Astro Digital, each of the GHOSt satellites have a mass of 91.4 kg and a planned total in-orbit lifetime of just over 5 years. The spacecraft are based on the flight-proven Corvus-XL smallsat platform and utilise Astro Digital’s heritage flight computer, attitude determination and control subsystem (AOCS), power and communications subsystems.
Payload data downlink is to be conducted via Ka-band, in addition to S-band for high speed data (HSD) transmissions.
GHOSt (Global Hyperspectral Observation Satellite)
Orbital Sidekick (OSK) Inc., a startup company of San Francisco, announced on 4 February 2021 that it has finalised plans to deploy its Global Hyperspectral Observation Satellite constellation known as GHOSt. The hyperspectral imaging (HSI) constellation consists of six 100 kg ESPA [EELV (Evolved Expendable Launch Vehicle) Secondary Payload Adapter] class microsatellites, designed and manufactured by Astro Digital, with Maverick Space Systems providing mission integration & management services for the launches on SpaceX’s Falcon 9. The custom hyperspectral imaging payload is provided by OSK. 1)
OSK provides innovative remote sensing solutions for a diverse set of industrial and governmental customers, including end users across the energy, surveying and extraction, agriculture, environmental monitoring, and defence sectors. Examples of the kinds of data sets OSK provides its customers include protein content and evapotranspiration levels for crops, corrosion identification and leak detection for monitoring pipelines, accurate mineral surveying, environmental monitoring for various applications, and real-time road/rail infrastructure conditions. The GHOSt constellation represents the next evolution of OSK’s sensing capabilities and will allow OSK to scale its commercial product with larger coverage, reduced revisit times, better spatial resolution, and more spectral capability.
GHOSt leverages OSK's previous experience collecting and analysing hyperspectral data with its ISS-HEIST (Hyperspectral Earth Imaging System Trial) mission on the International Space Station in 2019. The custom payload will produce the highest resolution commercial hyperspectral imagery launched to-date with a GSD (Ground Sample Distance) of approximately 8 metres. The payload will be integrated into Astro Digital's Corvus-XL satellite platform and will take advantage of its industry leading Ka-band data downlink capability.
"We're excited to partner with Astro Digital and Maverick Space for this initial constellation. Both companies bring a high degree of agility with proven execution to our mission, allowing OSK to focus on the payload and extracting information from our unique hyperspectral data," said Pete Friedhoff, Director of Space Systems for Orbital Sidekick.
"Persistent, hyperspectral imaging is a critical new capability in remote sensing," said Chris Biddy, Co-founder and CEO of Astro Digital. "We are very pleased to be supporting Orbital Sidekick's mission with our proven satellite technology and capabilities."
Maverick Space Systems will provide mission integration hardware and services to launch GHOSt on SpaceX's Falcon 9 at the end of this year and continuing into 2022. "Taking advantage of frequent low-cost launch opportunities is critical to achieve Orbital Sidekick's constellation. We are excited to partner with them and further reduce their per-satellite launch costs by aggregating two GHOSt satellites per ESPA port," said Roland Coelho, CEO of Maverick Space.
GHOSt will capture more than 400 spectral bands in the visible to shortwave infrared range of 400 - 2500 nm to feed OSK's Spectral Intelligence Global Monitoring Application (SIGMA™) platform.
GHOSt will enable enhanced hyperspectral monitoring capabilities for commercial, scientific, and government applications. Upon deployment, the GHOSt constellation satellites will produce the highest resolution commercial hyperspectral imagery launched to-date. The market-leading sensing capabilities provided by OSK enable customers in the energy, extraction, infrastructure, agriculture, and forestry industries to make vital decisions with better information, thereby improving safety and potentially saving lives.
The following are just some of the key industry sectors that will benefit from capabilities unlocked by the GHOSt constellation:
- National Defence: GHOSt’s hyperspectral sensors can capture critical environmental and situational awareness information for use in national defence and crisis response efforts, including plume, camouflage, chemical weapon signatures, and target detection. In October 2020, the United States Department of the Air Force’s commercial investment group, in conjunction with the Space and Missile Systems Center, and the Air Force Research Laboratory, contracted with OSK to accelerate the deployment of these services.
- Infrastructure Monitoring: GHOSt’s hyperspectral imaging can detect minute changes in physical infrastructure and report such changes in real-time, allowing operators to monitor the integrity of their mission-critical infrastructure more closely and maintain infrastructure more cost effectively. GHOSt is particularly well suited for monitoring energy infrastructure, such as oil and gas pipelines, and for ensuring regulatory compliance, such as leak prevention and early leak detection.
- Environmental and Agricultural Monitoring: GHOSt will enable customers to collect and access vital data on environmental erosion and degradation, including the evapotranspiration levels for crops. These data sets provide OSK customers with early-warning detection of water, air, and land pollution, as well crop viability and yield. Taken together, the GHOSt constellation will provide valuable new services for customers in the United States and around the world.
The GHOSt mission will involve deploying a remote sensing constellation of small satellites with both radiofrequency and optical payloads. The satellite constellation will consist of six technically identical satellites launched into a sun-synchronous orbital inclination in Low Earth Orbit (LEO). Each satellite is planned to have a total in-orbit lifetime of 5.2 years.
The spacecraft bus is based on Astro Digital’s flight-proven Corvus-XL smallsat platform and utilises Astro Digital’s heritage flight computer, attitude determination and control system, power, and communications subsystems. The payload for each satellite consists of a proprietary hyperspectral imager manufactured by OSK. Each satellite has external dimensions of 57.8 cm x 57.8 cm x 111.4 cm and a total mass of 91.4 kg. Each satellite is equipped with state-of-the-art hardware and software solutions to ensure safe and efficient mission operations. Each GHOSt satellite will be capable of making orbital adjustments and performing collision avoidance manoeuvres by utilising differential drag, but will not carry propulsive systems.
The GHOSt system plans to operate in the radiofrequency bands outlined in Table 1 below. Satellite downlink transmissions can be turned on and off by ground telecommand. Although the GHOSt satellites are capable of transmitting throughout the entire orbit, they only transmit when visible to one of their Earth stations.
Table 1: Transmission Specifications
Type of Link and Transmission Direction
25.5 – 27.0 GHz
EESS and TT&C Uplink
2025 – 2110 MHz
Inter-Satellite Service (Transmit)
1615 – 1617.5 MHz
Space Operations Service Downlink (TT&C)
400.15 – 401 MHz
L1 C/A, L1C, L2C, L2P, L5
A. Ka-Band Payload Downlink
OSK seeks to utilise the 25.5-27.0 GHz Ka-Band for payload downlink operations under the co-primary EESS (space-to-Earth) allocation. All data transmitted in the requested band will be limited to payload sensor data or metadata directly pertaining to the operation of the payload.
The high gain Ka-band antennas employed by the GHOSt satellites will use six band channels, allowing for six wideband emissions to share three frequency channels using polarisation diversity, thereby enabling the GHOSt satellites to utilise the spectrum at its highest efficiency.
B. S-Band Adaptive Coding and Modulation and TT&C Uplink
In addition OSK is looking to utilise the 2025-2110 MHz S-band for Telemetry, Tracking, and Command (TT&C), as well as modulation and coding of the high speed data (HSD) link for payload transmissions. Specifically, OSK plans to use the 2045.0-2050.0 MHz band for the HSD control uplink. This technique adjusts the satellite’s modulation and coding to optimise payload downlink conditions, ensure proper link performance and efficiency, and advise the spacecraft to retransmit any lost data frames. A second link, operating within the 2054.85-2055.15 MHz band, will provide the traditional TT&C uplink operations for the GHOSt satellites.
C. UHF TT&C Downlink
The GHOSt constellation will use the 400.15-401.0 MHz band for TT&C downlink telemetry operations consistent with the secondary allocation for the Space Operation service
D. L-Band Intersatellite Links
OSK plans to use a space-to-space L-band intersatellite link between its GHOSt satellites and the existing commercial Globalstar NGSO constellation. The GHOSt satellites will transmit to Globalstar satellites, pursuant to an agreement with Globalstar, but will not have the capability to receive communications from the Globalstar satellites.
GHOSt-1 and GHOSt-2, the first two satellites of Orbital Sidekick’s planned GHOSt constellation, were successfully launched on 15 April 2023 at 06:48 am UTC onboard the Transporter 7 rideshare mission on a SpaceX Falcon 9 rocket, from Vandenberg Space Force Base in California.
GHOSt-3 was launched on 12 June 2023 at 2:35 PDT (21:35 UTC) on SpaceX’s Transporter 8 rideshare mission, from Space Launch Complex 4E at Vandenberg Space Force Base (VSFB) in California. The Falcon 9 rocket carried72 payloads of varying sizes. 7)
GHOSt-1 has 498.6 km perigee, 514.7 km apogee, 97.4 ° inclination, a period of 94.6 minutes and a semi-major axis of 6877 km
GHOSt-2 has 497.1 km perigee, 514.5 km apogee, 97.4 ° inclination, a period of 94.6 minutes and a semi-major axis of 6876 km
Given that the first two satellites were launched together from the same launch vehicle, the initial phase angles are very small. Over time, the two satellites in the given plane will separate further within their respective orbital planes and eventually be separated by 180°.
GHOSt-3 has an altitude of 525 km and is in a sun-synchronous orbit. 8)
Table 2: Anticipated orbit specifications
Orbital Plane Number
Number of Satellites within the Orbital Plane
Argument of Perigee
Active Service Arc
-90° to 90°
Right Ascension of the Ascending Node
Initial Phase Angles
<10° between each satellite
Local Time of Descending Node
• Aug 23, 2023: Orbital Sidekick (OSK) unveiled the first set of insights from its GHOSt™ constellation. GHOSt 1, 2 and 3 launched aboard the Transporter 7 and 8 ride-share missions earlier this year and incorporate the most advanced hyperspectral commercial satellites in orbit with a ground sampling distance of eight meters.
These images demonstrate the power and possibilities of OSK’s intelligence, including the ability to monitor Earth with the highest hyperspectral resolution that exists. This level of hyperspectral monitoring provides unprecedented insights that will aid the global energy transition, starting with monitoring oil and gas pipeline infrastructure.
By 2024, OSK will add three more satellites to its GHOSt constellation and increase monitoring capabilities significantly.
Figure 1 below shows methane plumes detected by OSK’s GHOSt constellation. Yellow indicates the highest concentration of methane and purple indicates the lowest.
OSK has invested heavily into building tools that can extract information out of HSI datasets to provide customers with actionable insights. These tools enable OSK to spectrally identify specific risks to energy infrastructure, including vehicles that may be acting suspiciously on a pipeline Right-of-Way (RoW), along with any new construction, and entities looking to dig that could damage a pipeline.
Last year, OSK monitored 12,000 miles of pipeline via aerial scans using GHOSt’s hyperspectral sensors. During this time, OSK flagged 100 suspected methane leaks, 200 suspected liquid hydrocarbon leaks and more than 300 intrusive events related to construction. With the initial datasets, OSK can analyze the chemical composition of each pixel and have started building their proprietary spectral library, which will assist them to understand the dynamic nature of our planet on a chemical level. 10)
• June 12, 2023: Orbital Sidekick (OSK), announced the successful launch of GHOSt 3, the third satellite in its planned GHOSt (Global Hyperspectral Observation Satellite) constellation aboard the Transporter 8 rideshare mission.
This launch marks the halfway point for deployment of the company’s planned six-satellite constellation. OSK is on track to deploy two more satellites this year aboard the Transporter 9 rideshare mission and by early next year, GHOSt will consist of six equivalent, fully operational microsatellites, each featuring a proprietary hyperspectral imager unique to OSK. 9)
• April 15, 2023: Orbital Sidekick, the global leader in space-based hyperspectral intelligence, have announced the successful launch of GHOSt 1 and 2, the first satellites in its planned GHOSt(™) (Global Hyperspectral Observation Satellite) constellation, aboard the Transporter 7 rideshare mission on a SpaceX Falcon 9 rocket.
- Four more satellites are planned for deployment this year, aboard the Transporter 8 and Transporter 9 rideshare missions, to complete the company’s initial constellation. By year-end, GHOSt will consist of six equivalent hyperspectral imaging microsatellites, each featuring a proprietary hyperspectral imager unique to OSK. 6)
• October 3, 2022: Orbital Sidekick announced today that as part of the Joint Agency Commercial Imaging Evaluation (JACIE) partnership, it has signed a technical assistance agreement with the U.S. Geological Survey’s (USGS) Earth Resources Observation and Science (EROS) Center. This agreement will allow remote sensing subject matter experts across multiple government agencies to evaluate OSK satellite imagery and its capacity for scientific analysis.
Reliable product quality is critical for supporting the wide range of challenging remote sensing applications across government, NGOs, industry, and academia. This agreement enables JACIE partners across USGS, NASA, NGA, NOAA, USDA, and NRO to characterise and evaluate OSK’s satellite imagery to ensure the entire remote sensing community is supported by reliable hyperspectral data products for years to come. By working with USGS, OSK can also expand their market reach in the ESG sector, enabling more objective and consistent monitoring services.
• June 23, 2022: OSK announced today it has been selected by Dallas-based Energy Transfer to monitor its assets in the Permian Basin through satellite technology. Energy Transfer is one of the largest energy infrastructure companies in North America with more than 120,000 miles of pipeline and related assets crossing 41 states. OSK is the first company to commercially deploy hyperspectral sensors in space. 2)
Energy Transfer selected OSK to monitor its Permian Basin assets as part of its Partnership-wide pipeline integrity programs designed to ensure the continued safety of its pipelines. The use of OSK’s satellite technology allows Energy Transfer to go above and beyond the minimum regulatory requirements in monitoring the integrity of its pipelines, something Energy Transfer has done for decades. OSK’s satellite technology enables earlier detection and prevention of leaks along pipeline rights of way, using hyperspectral data analysis to drive broad improvements in community safety, environmental performance, and overall operating efficiency.
Upon deployment of OSK’s GHOSt constellation, beginning late 2022 / early 2023, OSK will offer frequent monitoring of pipeline assets to the global oil and gas industry through its SIGMA Platform. OSK’s technology will help the industry meet its compliance & regulatory obligations as well as help transition towards more sustainable operations.
• February 24, 2022: Capacity is the biggest constraint for Orbital Sidekick, the hyperspectral imaging startup that is acquiring data from Aurora, its first satellite launched in June 2021. - Sidekick’s Aurora hyperspectral imaging satellite is a precursor to their upcoming GHOSt constellation. The Aurora satellite was launched on the SpaceX Transporter-2 rideshare mission on June 30, 2021 at 19:31 UTC from SLC-40 at Cape Canaveral Space Force Station. 3)
“There’s huge demand for dual-use satellite technology,” Daniel Katz, Orbital Sidekick CEO and co-founder told SpaceNews. “We are working to ramp up production and get hyperspectral data into the hands of customers.”
San Francisco-based Orbital Sidekick is pleased with the performance of the Aurora sensor, which achieved its goal of outperforming NASA Hyperion hyperspectral sensor, Katz said. Hyperion is on the space agency’s Earth Observation-1 satellite launched in 2000.
Orbital Sidekick plans to launch its six-satellite Global Hyperspectral Observation Satellite constellation, known as GHOSt, later this year. While Aurora, like Hyperion, gathers hyperspectral imagery with a resolution of approximately 30 metres per pixel, the GHOSt constellation will “get down to 8 metre ground sample distance, which blows everything else out of the water,” Katz said.
With capacity largely booked for the six GHOSt satellites, Orbital Sidekick is drafting plans to expand production, while hiring to nearly double its 33-person staff by the end of the year.
In-Q-Tel, the U.S. intelligence community’s nonprofit investment arm, recently made a strategic investment in Orbital Sidekick, which already is backed by the AFVentures’s Strategic Financing program. In return, Orbital Sidekick has agreed to share data with In-Q-Tel government partners.
Intelligence agencies increasingly are embracing a hybrid approach to Earth observation, gathering data from government sources and an array of commercial Earth-observation satellites.
• October 15, 2020: Orbital Sidekick (OSK) announced today that it has been awarded a $16 million multi-year contract by the Department of the Air Force‘s commercial investment group (AFVentures), in conjunction with the Space and Missile Systems Center (SMC) and the Air Force Research Laboratory (AFRL), as part of its Strategic Financing (STRATFI) program. This award, which is matched by private investment funds, will allow OSK to accelerate the deployment of six advanced hyperspectral imaging (HSI) satellites with edge processing capabilities as well as integrate its Spectral Intelligence Global Monitoring Application (SIGMA™) platform with the USAF Advanced Battle Management System (ABMS). 4)
SIGMA™ is a dual-use global persistent monitoring services platform that provides access to OSK’s data archive, analytics engine (including its proprietary hyperspectral neural network), and intelligent satellite tasking system for both defence and commercial applications.
OSK’s satellites leverage advanced hyperspectral capabilities, capturing more than 400 spectral bands in the visible to shortwave infrared range (VIS-SWIR, 400 – 2500 nm) at <10 m GSD. The first of these microclass satellites are targeted for a December 2021 launch. The constellation will achieve a better-than-daily target revisit rate.
“High spectral fidelity is essential for solving some of the most challenging remote sensing problems our customers face today,” Dr. Katie Corcoran, Director of Operations & Government Programs, said. “This new capability will allow OSK to offer best-in-class data products to our defence and industry end-users, enabling analytical insights not currently achievable with existing space-based imaging systems, on a global scale.”
“Orbital Sidekick is emerging as a leader in the commercial sector for providing objective, persistent monitoring services for critical energy infrastructure. As we broaden our market reach into the defence sector, we’re honoured to receive this ‘big bet’ by the innovative team at AFVentures,” Daniel Katz, CEO & Co-Founder of OSK, said. “The opportunity to work with SMC and AFRL will further enable the rapid scaling of our capabilities.”
“Orbital Sidekick leans heavily into the implementation of a Hybrid Space Architecture for tactical ISR support with its innovative hyperspectral technology and analytics platform,” Charlene Jacka, AFRL HAD Program Lead, said. “The AFRL Hybrid Architecture Demonstrations (HAD) program vision is further enabled by participating with the innovative team at Orbital Sidekick.”
GHOSt will capture more than 400 spectral bands in the visible to shortwave infrared range of 400 – 2500 nm to feed OSK’s Spectral Intelligence Global Monitoring Application (SIGMA TM) platform.
The Mission Operations Center for GHOSt will be located at OSK’s headquarters in San Francisco, California and at Astro Digital’s facility in Santa Clara, California. Consistent with OSK’s National Oceanic and Atmospheric Administration (NOAA) licence, the GHOSt constellation will be monitored at all times via automated and human systems, facilitating rapid response to any technical or regulatory concerns. OSK will conduct its mission operations through a network of ground stations that will initially consist of facilities in (i) Santa Clara, California; (ii) Tromso, Norway, (iii) Svalbard, Norway, and (iv) Troll, Antarctica. OSK may expand its ground station network over the course of the operational lifetime of the GHOSt constellation to include additional commercial stations either within or outside the United States and will seek to modify its authorization as conditions arise. OSK has initiated coordination efforts with Federal operators in its requested bands and will operate in accordance with the terms of any agreements.
1) ”Orbital Sidekick Announces Upcoming Launch of its Newest Global Hyperspectral Earth Observation Constellation: GHOSt,” PR Newswire, 4 February 2021, URL: https://www.prnewswire.com/news-releases/orbital-sidekick-announces-upcoming-launch-of-its-newest-global-hyperspectral-earth-observation-constellation-ghost-301222258.html
2) ”Orbital Sidekick to Monitor Pipeline Assets for Energy Transfer Using Satellite Technology,” OSK, 23 June 2022, URL: https://www.orbitalsidekick.com/news-blog/orbital-sidekick-to-monitor-pipeline-assets-for-energy-transfer-using-satellite-technology
3) Debra Werner, ”Orbital Sidekick notes growing demand for hyperspectral data,” SpaceNews, 24 February 2022, URL: https://spacenews.com/orbital-sidekick-aurora-in-q-tel/
4) ”Orbital Sidekick Awarded $16M U.S. Air Force STRATFI Contract,” Orbital Sidekick, 15 October 2020, URL: https://orbitalsidekick.com/news-blog/
5) “Orbital Sidekick secures UGSG Technical Assistance Agreement”, News Desk, 3 October 2022, URL: https://www.geospatialworld.net/news/orbital-sidekick-secures-usgs-technical-assistance-agreement/
6) GeoSpatial World, "Orbital Sidekick Successfully Launches First Satellites in GHOSt Constellation", April 18, 2023, URL: https://www.geospatialworld.net/news/orbital-sidekick-successfully-launches-first-satellites-in-ghost-constellation-2/
7) Lentz Danny, "SpaceX Transporter-8 launches 72 payloads marking 200th booster landing", NSF (Nasa Space Flight), June 12, 2023 https://www.nasaspaceflight.com/2023/06/spacex-transporter-8/
8) Gunter’s Space Page, “GHOSt 1, 2, 3, 4, 5, 6”, URL: https://space.skyrocket.de/doc_sdat/ghost-1.htm
9) Geospatial World, “Orbital Sidekick Successfully Launches Third GHOSt Satellite”, June 14, 2023, URL: https://www.geospatialworld.net/news/orbital-sidekick-third-ghost-satellite/
10) Orbital Sidekick (OSK), “OSK Debuts Initial Hyperspectral Insights from GHOSt Constellation”, Aug 23, 2023, URL: https://www.orbitalsidekick.com/news-blog/osk-debuts-initial-hyperspectral-insights-from-ghost?utm_source=substack&utm_medium=email
The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (firstname.lastname@example.org).