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KE-IIM (Kestrel Eye Block-II Microsatellite)

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Kestrel Eye, also referred to as Kestrel Eye-2M, is a small imaging technology demonstration spacecraft project of the U.S. Army Space and Missile Defense Command/U.S. Army Forces Strategic Command (SMDC/ARSTRAT) Technical Center (TC) in Huntsville, AL. The current KE program began as a KE Block I proof-of-concept or pathfinder. Derived from the KE Block I design, a KE Block II concept improvement was developed. In 2012, the Army, in conjunction with the OSD/JCTD (Office of the Secretary of Defense/Joint Capability Technology Demonstration) program, initiated the Kestrel Eye Block II as an electrooptical microsatellite-class imagery satellite to support the tactical warfighter. 1)

Two contractors were selected to build second-generation KE satellites, designated KE Block-IIA (Spaceflight Industries) and KE Block-IIM (Maryland Aerospace Incorporated). As a JCTD, the KE program is teamed with OSD, the Combatant Command (COCOM) sponsor - U.S. Pacific Command (USPACOM), and transition agent - the Army Program Executive Office (PEO) Missiles and Space.

KE-II scheduled to demonstrate its capability in Q3 of FY 17. The primary objective of the demonstration will be to task the satellite to take an image. An independent evaluator will assess the military value of the KE demonstration. KE will demonstrate the critical technologies required by an operational system. When the military utility and concept of operations (CONOPS) are verified through experimentation, an acquisition transition decision will be made.

The intent of KE-II is to demonstrate a tactical space-based imagery microsatellite. A KE-II satellite constellation would provide dramatically lower unit cost than typical space based assets. With this low unit cost, large numbers of satellites can be procured enabling the system to be dedicated to the tactical warfighters.

Key advantages of Kestrel Eye-II include:

• Smaller size and greater number: affordable, persistent presence, lower probability of detection, less vulnerable to anti-satellite weapons

• Graceful degradation: no single shot, launch failure or anomaly causes complete loss of service.



The KE Block-II microsatellite, developed by MAI (Maryland Aerospace Inc.) for operation by the U.S. Army Space and Missile Defense Command as a pathfinder for a constellation of low-cost satellites that can support ultra-quick tasking to deliver responsive imagery to the warfighter on the ground.

Kestrel Eye is being developed as a microsatellite-class (50 kg) imaging satellite that can be tasked directly by the tactical ground component warfighter and delivers user-ready imagery products directly to the warfighter via a data network that is also accessible by other warfighters without any relay via the U.S. main land and no data filtering. The primary objective is to demonstrate a tactical space-based imagery microsatellite that could be produced in series to provide a persistent capability to deployed forces.

The initial Kestrel Eye mission will demonstrate the satellite can be tasked to take a picture of a target ground area of interest and return that image to the warfighter during the same satellite pass with a tasking-to-product cycle of ten minutes or less. Up to 40 Kestrel Eye satellites are considered to be launched and concepts also exist for a responsive launch scheme to be able to set up passes over regions of interest as required. 2)

The Kestrel Eye program will extend the UAV (Unmanned Aerial Vehicle) paradigm and provide coverage over denied areas, invulnerable to surface-to-air missiles. The use of low-cost satellites enables a constellation of many satellites to be established to collect rapid revisit cycle imagery – covering relevant areas much more often than the current powerful & expensive space assets. Kestrel Eye's operational concept comprises the satellites in orbit and laptops & S-band transceivers on the ground to request, receive and display imagery collected by the satellite.

Plans for Kestrel Eye foresee a constellation with five orbital planes and eight satellites per plane with a unit cost of around $1.3 million and the use of small-satellite launch vehicles to be able to deliver the satellites to their correct positions within the constellation at the required schedule – not possible when taking a shared ride on a larger launch vehicle.


Figure 1: Illustration of the Kestrel Eye-2M spacecraft and its components (image credit: SMCD)

Operators on the ground would have a simple user interface displaying a map with the satellite's ground track and field of regard that allows users to select targets along the satellite's ground track and directly send the request to the satellite. A novel software on the satellite would then compute the planned imaging sequence, taking into account multiple requests made for a single pass, and actuate the satellite's pointing systems and imaging payload to capture 1.5 m resolution imagery of the targets. The operation of the satellite is fully autonomous and designed to maximize the number of targets imaged during a single pass.

Initiated in 2012, the Kestrel Eye program planned a Block I pathfinder mission which was replaced with two types of improved Block II satellites – Block IIM contracted to MAI (Maryland Aerospace Inc.) and Block IIA contracted to Spaceflight Industries, Inc. in 2013 to have a resilient constellation immune to systematic failures intrinsic to a single satellite platform.

The Kestrel Eye-2M satellites are based on MAI's MAGICBus platform – a low-cost microsatellite bus with built-in communications encryption, propulsive orbit maintenance capability for constellation control, accurate attitude control and fast pointing combined in a compact satellite platform that enables launch as secondary payload on large launchers or dedicated rides on small satellite launchers. In its electro-optical imaging configuration, the satellite platform is purpose-built to be able to deliver imagery in near-real time, featuring a 25 cm aperture telescope.

The MAGICBus can provide total mass budgets between 50 and 102 kg with sizes between 38 x 38 x 97 cm and 46 x 46 x 107 cm. The satellite uses Star Trackers as primary attitude sensors with coarse sun sensors, magnetometers and an inertial platform in an assisting role while three reaction wheels and magnetic torquers provide attitude actuation. The platform achieves a pointing knowledge of 0.01º and a pointing accuracy of ±0.15º, capable of supporting slew rates of 3º/s and off-nadir imaging at up to 30º.

Communications are software-encrypted and sent to the ground via >10 W S-band Earth Coverage Antennas. When used for Kestrel Eye & deployment from ISS, the MAGICBus uses its cold gas propulsion system option that allows for a ΔV budget of 16 m/s, allowing for limited orbit maintenance in the low-altitude regime as well as stationkeeping within a potential future constellation of satellites.


Figure 2: Artist's rendition of the KE-IIM microsatellite in orbit (image credit: SMDC)


Launch: The Kestrel Eye-IIM was launched as a secondary payload on August 14, 2017 (16:31.37 UTC) from Launch Complex 39A (LC-39A) at NASA's Kennedy Space Center, Florida. The primary mission was the SpaceX CRS-12 Dragon logistics flight on a Falcon-9 v1.2 vehicle to the ISS. 3) 4) 5)

SpaceX's twelfth contracted cargo resupply mission with NASA to the International Space Station deliver ed more than 2,910 kg of science and research, crew supplies and vehicle hardware to the orbital laboratory and its crew. This included 1,652 kg of pressurized cargo with packaging bound for the ISS, and 1,258 kg of unpressurized cargo composed of the CREAM (Cosmic-Ray Energetics and Mass) instrument, to be mounted externally to the ISS (mounting on a facility outside the station's Japanese Kibo module). The CREAM payload, also referred to as ISS-CREAM) will spend at least three years sampling particles sent speeding through the universe by cataclysmic supernova explosions, and perhaps other exotic phenomena like dark matter. 6)

Orbit: Near circular orbit, altitude of ~400 km, inclination = 51.6º.

The secondary payloads were:

Four small satellites inside the Dragon capsule will be transferred inside the space station for deployment later this year.

• Kestrel Eye-2M is a pathfinder microsatellite (~50 kg) for a potential constellation of Earth-imaging spacecraft for the U.S. military. From the ISS orbit, Kestrel Eye-2M's optical camera will be able to spot objects on Earth's surface about the size of a car. The objective Kestrel Eye imaging data is to downlink directly to provide rapid situational awareness to Army brigade combat teams in theater without the need for continental United States relays.

After launch, the KE-2M satellite will spend a period of time on the ISS awaiting JEM (Japanese Experiment Module) airlock scheduling before deployment. During the first two months on-orbit, the satellite checkout operations will be conducted, culminating in a technical demonstration.

Operational Requirements and Protocols: The NanoRacks-KE- IIM mission requirements include crew resources for on-orbit assembly and pre-deployment logistics. Deployment is to occur as soon as possible after ISS reboost to maximize orbital lifetime. Video and photogrammetry services are required to characterize NanoRacks Kaber deployment kinematics and provide payload developer mission assurance feedback and ephemeris data at the time of deployment. ISS crew assembly procedures have been prepared to guide the crew through proper and safe assembly of the NanoRacks-KE- IIM. JEM airlock and MSS SPDM operations are governed by the standard operations in place for those resources. Following deployment by the NanoRacks Kaber deployer, the NanoRacks-KE- IIM begins nominal mission operations limited by its orbital lifetime expected to be approximately six months. 7)

• ASTERIA (Arcsecond Space Telescope Enabling Research in Astrophysics), a 6U CubeSat (12 kg) of MIT and NASA/JPL. The objective is to test miniature telescope components that could be used in future small satellites to observe stars and search for exoplanets.

• Dellingr, a NASA demonstration mission on a 6U CubeSat.

• OSIRIS (Orbital Satellite for Investigating the Response of the Ionosphere to Stimulation and Space Weather) is a 3U Cubesat of PSU (Penn State University), University Park, PA, USA. Working in coordination with the Arecibo Observatory, a giant radar antenna in Puerto Rico, OSIRIS-3U will fly into a region of the ionosphere heated to simulate the conditions caused by solar storms.



Mission status:

• Aug. 16, 2017: Two days after departing from a launch pad on Florida's Space Coast, the SpaceX Dragon cargo capsule arrived at the International Space Station on August 16 with more than 2,910 kg of experiments and supplies after concluding an automated laser-guided approach. 8)

- Astronaut Jack Fischer aboard the space station used the lab's Canadian-built robotic arm (Canadarm2) to snare the robotic cargo craft at 10:52 GMT on Aug. 16 as they sailed about 400 km over the Pacific Ocean north of New Zealand.

- Around two hours later, ground controllers finished the installation of Dragon on the station's Harmony module, commanding 16 bolts to close and create a firm seal between the two vehicles.

- The station crew opened hatches between the Harmony module and Dragon's pressurized compartment later, a day earlier than planned.

- Flying under contract to NASA, the SpaceX supply ship ferried mostly research hardware, but also carried computer equipment, clothing, fresh food, ice cream and other treats for the crew.

- The cargo mission marked SpaceX's 11th successful operational supply delivery in 12 tries. - NASA inked a $1.6 billion contract with SpaceX in 2008 for 12 logistics flights to the station. This mission wraps up work under the original resupply contract, but NASA extended the agreement for eight additional cargo launches through 2019. SpaceX also has a separate, follow-on contract with NASA for at least flights of upgraded Dragon cargo capsules to the station from 2019 through 2024.

- The station's six-person crew will unload the payloads inside, overseeing a multitude of biological experiments before the ship's departure and return to Earth next month.


Figure 3: This illustration of the ISS shows the locations of current visiting vehicles, including the newly-arrived Dragon-12 (image credit: NASA)



The KE-IIM primary payload is a medium resolution electro-optical imaging system, an element of which is a COTS (Commercial Off-The-Shelf) telescope.The Kestrel Eye Block- 2M imager captures imagery in spotlight mode with a resolution of 1.5 m, covering a ground area of 3 km x 5 km from a 400 km orbit. Strip-imaging of larger areas is also possible. Onboard storage is provided for up to 600 images.


1) Billy E. Johnson, Jon T. Dodson, Timothy A. Farmer, Wheeler K. Hardy, Barry W. Heflin, Melanie G. Klinner, John R. London III, Katherine E. Mott, Mason E. Nixon, Mark E. Ray, Travis S. Taylor, Barbara M. Urena, David J. Weeks, Martin F. Lindsey, "U.S. Army Small Space Update," Proceedings of the 30th Annual AIAA/USU SmallSat Conference, Logan UT, USA, August 6-11, 2016, paper: SSC16-III-06, URL:

2) "Kestrel Eye 2M Satellite," Spaceflight 101, 2017, URL:

3) "SpaceX CRS-12 Cargo Mission Launch," NASA, August 14, 2017, URL:

4) "CRS-12 Dragon Resupply Mission," SpaceX, URL:

5) Lori Keesey, "NASA Set to Launch Dellingr; CubeSat Purposely Designed to Improve Reliability of Small Satellites," NASA, August 2, 2017, URL:

6) SpaceX CRS-12 Mission Overview," URL:

7) "NanoRacks-SMDC-Kestrel Eye IIM (NanoRacks-KE IIM)," NASA, Aug. 16, 2017, URL:

8) Stephen Clark, "Station crew captures Dragon supply ship, gets early start on unpacking," Spaceflight Now, August 16, 2017, URL:

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 (

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