Satellite Missions Catalogue

WorldView Legion

Last updated:Sep 11, 2024

High resolution optical imagers

Land

Multi-purpose imagery (land)

WorldView Legion of commercial company Maxar Space Systems is a satellite constellation of electro-optical satellites that aims to address the growing demand for high resolution and frequency monitoring and mapping of the Earth’s surface. The first two satellites of the constellation were launched together in May 2024.

Quick facts

Overview

Mission type	EO
Agency	Maxar
Mission status	Commissioning
Launch date	May 2, 2024
Measurement domain	Land
Measurement category	Multi-purpose imagery (land)
Measurement detailed	Land surface imagery
Instruments	WorldView Legion Camera
Instrument type	High resolution optical imagers
CEOS EO Handbook	See WorldView Legion summary

Related Resources

Worldview-1 Worldview-2 Worldview-3 Worldview-4

Worldview Legion Satellites — WorldView Legion (Image credit: Maxar)

Summary

Mission Capabilities

WorldView Legion aims to provide high-resolution continuity to the previous generation WorldView fleet of WorldView-1, WorldView-2, WorldView-3, and GeoEye-1 with observations in support of frequent monitoring, mapping, and analytics. The mission plans to provide persistent monitoring of critical areas for defence and intelligence, maritime, and infrastructure. A high revisit capacity will enable frequent mapping of Earth’s surface at both local and global scales, which will be synergised with geospatial analytics to deliver actionable insights to customers.

Performance Specifications

Each satellite is equipped with a 30 cm resolution multispectral optical imager that can be pan-sharpened to 15 cm. Six sensors on orbit will cover five million square kilometres of Earth’s surface every day, sweeping in 9 km-wide swaths. Eight multispectral bands range from Coastal (400 - 500 nm) to Near Infrared (780 - 920 nm), with the addition of one panchromatic band imaging between 450 and 800 nm.

The six satellites will fly in mid-inclination low Earth orbits at 450 km in altitude. This orbit covers the most densely populated areas around the mid-latitudes of the Earth and enables up to 15 revisits per day. The orbit also provides a 15° Sun angle, and a ground sample distance (GSD) between 0.3-1.3 m at a latitude of 36° north.

Space and Hardware Components

Each WorldView Legion satellite has a mass of 750 kg and a ten year design life. Maxar developed their 500 series satellite platform with WorldView Legion in mind, with a focus on stability, agility, and accuracy and high mission versatility.

Overview

WorldView Legion is a high resolution electro-optical imaging satellite constellation owned and operated by the US-based commercial company Maxar Space Systems. Maxar began planning the constellation in 2017 to provide continuity to the company’s provision of high resolution satellite imagery. Maxar’s wider satellite constellation began with Ikonos launching in 1999, Quickbird in 2001, GeoEye-1 in 2008, and four WorldView satellites launched between 2007 and 2016. The development of WorldView Legion began in 2017 with a $600M commitment from Maxar (previously DigitalGlobe) to build six satellites. 1) 2) 3)

The next-generation WorldView Legion mission aims to provide high resolution, rapid revisit, and global optical imagery of the Earth for frequent monitoring, mapping, and analytics. The constellation is planned to consist of six high performance satellites. Maxar outlines four driving requirements to the constellation:

We had four driving requirements. First, we had to assure continuity, which meant continuing to offer the highest resolution and most accurate commercial satellite imagery in the industry with collection and delivery characteristics matched to customer needs, and to begin launches in 2021. Second—as we will describe later—the land surface area of the planet is not uniformly interesting to paying customers. As a result, we wanted to maximize our imaging capacity over the parts of the world that would generate the most revenue, and to provide synoptic (contiguous) coverage of sufficiently large areas. Third, not everything happens at 10:30 AM, so we wanted to have the ability to image from dawn to dusk throughout the day. Fourth—and most importantly—since we’re in business to be profitable, we had to do all of this for less than our previous constellation cost, i.e., we had to be even more capital efficient, as this creates the capacity to further invest in growing our business. 2)

Applications of WorldView Legion can range from defence and intelligence, maritime, and infrastructure from sunup to sundown. The constellation will offer persistent monitoring of critical areas through high frequency imagery acquisition. A high revisit capacity will also lend itself to delivering accurate, timely, and comprehensive mapping of the ground at both local and global scales.

Maxar plan to utilise WorldView Legion’s rapid revisit capacity, agility, and stereo abilities to create a living digital model of the Earth in 3D which will provide accurate, reliable, and up to date geospatial data around the globe.

Spacecraft

The WorldView Legion satellites are the first to use Maxar’s 500 Series of spacecraft buses, which are constructed at the company’s manufacturing facilities in Palo Alto and San Jose, California. The 500 series is branded as a versatile mid-sized satellite platform with high stability, agility, and pointing accuracy, suiting it to a range of missions and orbits. The platform is developed for WorldView Legion, equipping customers with the same capabilities that the Legion satellites present, for missions tailored to national security, and high precision Earth and space science. 9)
Each WorldView Legion satellite features a ten year design lifetime and a 750 kg mass. 2)

Figure 1: An illustration of the Maxar 500 Series satellite bus, which is based on WorldView Legion (Image credit: Maxar)

Launch

Table 1: Worldview Legion Constellation launches.
Spacecraft	Launch Date (UTC)	Description
WorldView-Legion 3, WorldView-Legion 4	August 15, 2024, at 13:00 UTC	Launched from the Cape Canaveral Space Force Station, Florida, onboard a SpaceX Falcon 9 rocket.
WorldView-Legion 1, WorldView-Legion 2	May 2, 2024, at 18:36 UT	Launched from the Vandenberg Space Force Base, onboard a SpaceX Falcon 9 rocket.

Orbit

The WorldView Legion satellites will operate from a low-Earth, mid-inclination orbit at 450 km altitude. Mid-inclination orbits are of interest as satellites here will orbit over the most densely populated portion of the planet, which is between ±50° latitude. However compared to a traditional Sun-synchronous orbit, the local time of imaging will vary such that a single satellite will not always face sunlit conditions. This drives the requirement for at least two satellites in orbit to avoid long ‘blackout’ periods, as well as a high signal-to-noise ratio to maintain image quality at low Sun elevation angles.

The WorldView Legion Constellation will provide up to 15 revisits per day above a 15° Sun angle between 0.3-1.3 m ground sample distance (GSD) at 36° latitude.

Mission Status

• August 15, 2024: WorldView-Legion 3 and 4, were successfully launched on SpaceX’s Falcon-9 rocket at 13:00 UTC, as part of the Maxar-2 mission. The launch took place from Cape Canaveral Space Force Station, Florida.
This is the second of three launches expected for this constellation and the first launch of where the Maxar satellites were deployed into mid-inclination orbit, making it easier to obtain coverage of various regions. 12)

• July 25, 2024: Maxar releases first light imagery from the first pair of WorldView Legion satellites, across Singapore, South Africa, Spain, Brazil, and California. This extraordinary high resolution imagery across various viewing angles demonstrates the capabilities of WorldView Legion. The imagery was collected on July 16 by one Legion satellite. 6)

Maxar’s CEO, Dan Smoot, states:

“In today’s increasingly complex world, our customers need access to faster, more timely geospatial insights to support their most critical missions—from precision mapping to site monitoring to space domain awareness. Soon, our WorldView Legion satellites will be collecting vast amounts of imagery, extending our collection capacity advantage for high-resolution imagery and enhancing the revisit rate of our industry-leading constellation. This added capacity will also strengthen our geospatial foundation, helping us build more sophisticated products that unlock the full potential of geospatial data and generate more actionable insights in 2D and 3D.”

Figure 2: Image of downtown Singapore acquired at a 32° off-nadir angle (Image credit: Maxar)

Figure 3: Image taken over Johannesburg, South Africa, of a rail yard adjacent to Johannesburg Park Station (Image credit: Maxar)

Figure 4: Puerta del Sol plaza in Madrid, Spain, imaged by WorldView Legion (Image credit: Maxar)

Figure 5: WorldView Legion captures surfers out at Leblon Beach in Rio de Janeiro, Brazil (Image credit: Maxar)

Figure 6: Highway 50 and Elvas Freeway interchange in Sacramento, United States, imaged by WorldView Legion (Image credit: Maxar)

• May 2, 2024: he first two WorldView Legion satellites were successfully launched at 11:36 PT from the Vandenberg Space Force Base onboard a SpaceX Falcon 9 rocket. The satellites begin the Legion Constellation that is planned to contain six satellites. 10)
After a successful separation, the Falcon 9 first stage returned to Landing Zone 4 at Vandenberg in SpaceX’s 303rd booster landing.

Maxar reports that the first pair of WorldView Legion satellites are performing well after a successful launch, and they begin commissioning with the deployment of solar panels and establishing communications. 7)

Figure 7: Side-by-side images of the first two WorldView Legion satellites’ deployment from the SpaceX Falcon 9 rocket (Image credit: Maxar)

• March 18, 2024: The first pair of WorldView Legion satellites arrive for launch preparations at the Vandenberg Space Force Base In the US. The WorldView Legion constellation will join Maxar’s wider fleet, totalling ten electro-optical satellites with the objective to image dynamic processes on Earth as frequently as every 20 minutes during daytime. 8)

Figure 8: The two WorldView Legion satellites are pictured in Maxar Space Systems’ manufacturing facility in California, US, prior to shipment to the launch site.

Sensor Complement

WorldView Legion Instrument

The requirement for a 30 cm spatial resolution is driven by an increasing number of high resolution customer use cases. This is achieved through an optical system with a sufficient resolution, signal, and minimal effects from optical and spacecraft disturbances. The sensor requirements presented in Table 1 are equivalent for both the sensor’s panchromatic band and the eight multispectral bands, which enables both pan-sharpening and further spectral analysis applications. The standard 30 cm resolution can be delivered as a pan sharpened bundle (RGBN) 15 cm product. 1) 2)

The WorldView Legion instrument was developed in collaboration with Raytheon. 11)

Table 2: WorldView Legion sensor parameters
Parameter	Value
Swath width at nadir (km)	9
GSD at nadir (m)	0.29 (Panchromatic), 0.48 (Multispectral)
Daily coverage (square km)	5,000,000
Geometric uncertainty	9 - 10% (at Nyquist frequency)
Root-mean-squared uncertainty (m)	< 1.5
Signal-to-Noise ratio	120

The WorldView Legion sensor houses one panchromatic band and eight multispectral bands, which are presented in Table 3 with their respective spectral coverage.

Table 3: WorldView Legion Sensor spectral bands
Spectral Band	Wavelength range (nm)
Panchromatic	450 - 800
Coastal	400 - 500
Blue	450 - 510
Green	510 - 580
Yellow	585 - 625
Red	630 - 690
Red Edge 1	695 - 715
Red Edge 2	730 - 750
Near IR	780 - 920

The mission’s applications related to precision mapping and targeting require not only a high resolution but a high positional accuracy, which is a measure of how precise pixels are measured against the ground. Maxar requires that their systems support a five metre 90% circular error (CE90) for each individual image, which can be post-processed to 1 metre with elevation data. 2) 4)

Ground Segment

WorldView Legion will leverage Maxar’s existing global network of satellite ground stations, which are being augmented to provide better coverage of mid-latitude regions. The company’s ground network is connected to a cloud environment which is fed to online platforms like SecureWatch and Global EGD, which can serve high priority imagery in as quick as ten minutes.
Due to some customers requiring satellite services outside of the internet, particularly those in defence, Maxar also allows customers to receive and task imagery directly from the satellite or from mobile ground stations. The satellites also support simultaneous uplink and downlink of data, which is illustrated in Figure 9. In order to point at successive targets while maintaining contact with the ground, the downlink antenna needs to be steerable from the main sensor.

Figure 9: Simultaneous tasking, imaging, and downlink principles illustrated (Image credit: Maxar)

A narrow beam with high data rate addresses the power inefficiency and ‘spectrum hog’ of a traditional omnidirectional broadcast. 2)

References

1) ”Introducing WorldView Legion,” Maxar, URL: https://www.maxar.com/worldview-legion

2) Walter S. Scott, Neal Anderson, Aaron Q. Rogers, ”Design Drivers for a Viable Commercial Remote Sensing Space Architecture,” Proceedings of the 34rd Annual AIAA/USU Virtual Conference on Small Satellites, August 1-6, 2020, Logan, UT, USA, paper: SSC20-I-05, URL: https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=4709&context=smallsat

3) ESA Earth Online. URL: https://earth.esa.int/eogateway/missions/worldview

4) Mary Pagnutti, “Measurement Sets and Sites Commonly Used for High Spatial Resolution Image Product Characterisation,” 2006 EO/IR Calibration and Characterization Workshop, NASA, March 2006, URL: https://ntrs.nasa.gov/api/citations/20060026069/downloads/20060026069.pdf

5) Satellite Imaging Corporation. URL: https://www.satimagingcorp.com/satellite-sensors/worldview-legion-satellite-constellation/

6) “Maxar Intelligence releases first images from its next-generation WorldView Legion satellites,” Maxar Press Releases, July 25, 2024, URL: https://www.maxar.com/press-releases/maxar-intelligence-releases-first-images-from-its-next-generation-worldview-legion-satellites

7) “First two WorldView Legion satellites performing well after launch,” Maxar Press Releases, URL: https://www.maxar.com/press-releases/first-two-worldview-legion-spacecraft-performing-well-after-launch

8) “First Two WorldView Legion Satellites Arrive at Launch Base,” Maxar Blog, March 2024, URL: https://blog.maxar.com/leading-the-industry/2024/first-two-worldview-legion-satellites-arrive-at-launch-base

9) “Maxar 500 Series: LEO Missions Enabled by WorldView Legion Technology,” Maxar, URL: https://maxar.com/maxar-space-systems/products/maxar-500-series

10) Sandra Erwin, “SpaceX launches Maxar’s first WorldView Legion imaging satellites,” SpaceNews, May 2024, URL: https://spacenews.com/spacex-launches-maxars-first-worldview-legion-imaging-satellites/

11) “WorldView Legion’s New Telescope Packs More Punch,” Maxar Blog, April 2024, URL: https://blog.maxar.com/earth-intelligence/2024/worldview-legions-new-telescope-packs-more-punch

12) Erwin Sandra, “SpaceX launches second pair of Maxar WorldView Legion imaging satellites”, August 15, 2024, URL: https://spacenews.com/spacex-launches-second-pair-of-maxar-worldview-legion-imaging-satellites/

FAQ

Who operates WorldView Legion?

How many satellites are in the WorldView Legion Constellation?

What applications does WorldView Legion have?