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CANYVAL-X (CubeSat Astronomy by NASA and Yonsei using Virtual Telescope Alignment eXperiment)

Overview   Spacecraft   Launch    Sensor Complement   References

CANYVAL-X is a collaborative nanosatellite technology constellation of NASA, Korea's Yonsei University and the KARI (Korea Aerospace Research Institute) with the goal of demonstrating the Vision Alignment System by maintaining flight formation of two separated CubeSats and ultimately prove a possibility of a virtual telescope system which is consistant of the optic satellite to focus a light from the sun and the detector satellite.

NASA engineers Neerav Shah and Phil Calhoun will realize a long-held ambition later this year when a Space-X launch vehicle deploys two tiny satellites that will fly in a precise formation to create, in effect, a single or "virtual" telescope benefitting a range of scientific disciplines. Through a NASA international agreement, Shah and his team have partnered with South Korea's Yonsei University and the KARI (Korea Aerospace Research Institute) to validate technologies that would allow a pair of miniature spacecraft to fly in tandem along an inertial line of sight toward the sun and then hold that configuration — a feat not yet performed in space. 1) 2)


Figure 1: This artist's rendition shows how CANYVAL-X's two CubeSats will align once they are in orbit (image credit: NASA)

"The key differentiator with our mission is that we are attempting to align two satellites along an inertial line of sight to a distant celestial target and hold them in alignment for a long enough time to make a science measurement," said Shah, an engineer at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Although others have flown two or more satellites in tandem, we are the first in the world to even try holding them in alignment to a distant source."

Currently, ESA (European Space Agency) is developing PROBA-3, a minisatellite science experiment that will fly a pair of satellites in a tight formation to form a solar coronagraph at a distance of 250-500 m to study the sun's faint corona, the outer atmosphere. Unlike CANYVAL-X, which is designed to test only the alignment technologies, PROBA-3 also will gather scientific measurements. According to ESA, however, the mission isn't expected to launch until the end of 2018.

The technology's obvious beneficiaries are scientists who study the sun's corona and more particularly coronal mass ejections that hurl enormous bubbles of superheated gas across the solar system. Traveling at 1.5 million km/h, they can disrupt low-Earth-orbiting satellites and terrestrial power grids when they strike Earth. The technology also could benefit scientists searching for planets beyond the solar system.

Both scientific disciplines rely on coronagraphs, which employ an occulter mask to block bright starlight to reveal faint objects hidden by the star's bright light and a camera or spectrograph to gather measurements. Today, spaceborne coronagraphs house both the occulter and a camera or spectrograph in the same telescope, positioning them relatively close to one another.



CANYVAL-X is a technology demonstration CubeSat mission with a primary objective of validating technologies that allow two spacecraft to fly in formation along an inertial line-of-sight (i.e., align two spacecraft to an inertial source). Demonstration of precision dual-spacecraft alignment achieving fine angular precision enables a variety of cutting-edge heliophysics and astrophysics missions. 3) 4)

Under the collaboration established by the international agreement, Yonsei and KARI are providing the two spacecraft, a 1U and a 2U CubeSat, integrating the Goddard-supplied sun sensor and GWU-Goddard µCAT system, and launching the spacecraft.

GWU (George Washington University) Micro-propulsion and Nanotechnology Lab

• Developed the µCAT (micro Cathode Arc Thruster) system analog electronics and control design, based on the system developed for the BRICSAT mission (launch 2015) of the U.S. Naval Academy.

• Delivered the µCAT thruster heads

Yonsei University

• Designed, built, and tested the 1U and 2U spacecraft and integrated the µCAT system.

• Spacecraft environmental testing at KARI.

• Developed ground system to conduct mission operations and alignment experiment.


• Delivered the Miniature Fine Sun Sensor – provides attitude measurement for the 2U CubeSat.

• Conducting an assessment of CANYVAL-X's GN&C in regards to formation acquisition and alignment.

• Traveled to Yonsei to collaborate with team.

Table 1: Allocation of functions and project status as of mid-2014 (Ref. 4)


Jerry (1U CubeSat)

Tom (2U CubeSat)

Mission life time

3-6 months


3 Laser Diodes

Visible Camera (NanoCam)

Payload performance

Half Intensity Beam
Angle = ±60º Minimum angle (15.5º) intensity > 96%

2048 x 1536 pixels, CMOS sensor
35mm lens/F1.9, 9.22º FOV


(Magnetorquer, sun sensor)

µCAT, Sun Sensor, Nano-Cam, reaction wheels, magnetorquer

Data rate

Up/downlink: 4.8 kbit/s (UHF)

Uplink: 4 kbit/s (UHF), Downlink 100 kbit/s (S-band)


1.0 kg

2.7 kg

Relative distance

> 10 m (collision avoidance)

Orbit control


20 cm (1 DOF µCAT x 4 + 3-axis reaction wheel)

Orbit determination

Each axis ± 10 cm (GPS)

Attitude control

5º (magnetorquer) 10 m x tan(5º) = 88 cm

1º (reaction wheel) 10 m x tan(1º) = 18 cm

Table 2: Mission an GN&C specification (Ref. 4)


Figure 2: Illustration of the 2U actively controlled CubeSat (Tom) and its elements (image credit: CANYVAL-X collaboration)


Figure 3: Illustration of the 1U passive target CubeSat (Jerry), image credit: CANYVAL-X collaboration


Launch: A launch of the CANYVAL-X CubeSats as secondary payloads is scheduled for 2016 aboard a SpaceX Falcon-9FT launch vehicle. The launch site is VAFB (Vandenberg Air Force Base), CA. — The primary payload on this mission is FormoSat-5 of NSPO ((National SPace Organization), Taiwan.

Orbit of primary payload: Sun-synchronous near-circular orbit of FormoSat-5, altitude = 720 km, inclination = 98.28º, period = 99.19 minutes, LTDN (Local Time on Descending Node) at ~ 10 hours.

Secondary payloads: 5)

The secondary payloads will by carried on a Spaceflight Services SHERPA tug. SHERPA can accommodate a variety of small satellites from CubeSats up to ESPA [EELV (Evolved Expendable Launch Vehicle) Secondary Payload Adapter] class and beyond.

• eXCITe (eXperiment for Cellular Integration Technologies) of DARPA built by NovaWurks of Los Alamitos, CA; eXCITe is also known as PTB-1 (Payload Test Bed-1)

• BlackSky Pathfinder-1 and BlackSky Pathfinder-2, microsatellites (~50 kg each) of BlackSky Global, Seattle WA.

• Arkyd-6, a 6U CubeSat technology demonstration mission of Planetary Resources, Redmond, WA, USA.

• EcAMSat (E. coli Anti Microbial Satellite), a 6U CubeSat of NASA/ARC.

• CNUSail-1 (Chungnam National University Sail), a 3U CubeSat (4 kg) solar sail experiment, developed at the CNU (Chungnam National University), Korea.

• ISARA (Integrated Solar Array and Reflectarray Antenna), a NASA/JPL 3U CubeSat (~ 5 kg) and solar array with an integrated deployable reflect antenna and a Ka-band downlink (100 Mbit/s).

• KAUSAT-5 (Korea Aviation University Satellite), a 3U CubeSat (4 kg), developed at the SSRL (Space System Research Laboratory) at the Korea Aviation University, Korea.

• SIGMA (Scientific cubesat with Instruments for Global Magnetic field and rAdiation), or KHUSAT 3 (Kyung Hee University Satellite), a 3U CubeSat developed at the KHU (Kyung Hee University), Korea.

• CANYVAL-X 1,2 (CubeSat Astronomy by NASA and Yonsei using Vision ALignment eXperiment), a mission consisting of a 1U and a 2U CubeSat developed at Yonsei University, Korea in collaboration with NASA.

• STEP Cube Lab, a 1U CubeSat developed at Chosun University, Gwangju, Korea.

• OCSD (Optical Communications and Sensor Demonstration) of The Aerospace Corporation, El Segundo, CA, USA. OCSD-B and -C are two 1.5U CubeSats.

• Fox-1C, a 1U CubeSat of AMSAT.

• Nayif-1, a 1U CubeSat developed by the Mohammed Bin Rashid Space Center of Dubai, formerly EISAT (Emirates Institution for Advanced Science and Technology) in partnership with AUS (American University of Sharjah).

• skCUBE, a 1U CubeSat, the first Slovak satellite developed by the University of Zilina (UNIZA) in cooperation with the University of Technology (STU) in Bratislava and with SOSA (Slovak Organization for Space Activities).

Orbit of secondary payloads: Sun-synchronous elliptical orbit, 450 km x 720 km, inclination = 98º.



Sensor complement:

The 2U CubeSat will carry two Goddard-provided technologies that make up the mission's all-important GN&C (Guidance, Navigation and Control) system: a miniature sun sensor and the micro cathode arc thruster (µCAT) system. Developed at the Wallops Flight Facility in Virginia's Eastern Shore, the sun sensor calculates a direction to the sun. The George Washington University (GWU)-designed the µCAT (micro-Cathode Arc Thruster) system, which is about the size of a coffee mug, fires its thrusters to move the spacecraft so that it maintains its alignment with the 1U CubeSat separated by about 10 m.

µCAT: Recent advancements in miniaturization, with volumes less than 6 cm x 9 cm x 9 cm, for four independent channels, increased performance of 2 µNs per impulse-bit can be reported, as well as the ongoing work towards expanding the operating range from 1 Hz to 50 Hz with new controller functionality: power management, power distribution, event signaling, command and data handling. Computer models have been developed to generate physical and volumetric requirement arrays and cluster arrangements of µCAT elements to create a whole subsystem for a given delta-V and thrust levels, and EMI studies are in progress. 6)


Figure 4: NASA delivered hardware. Left: µCAT delivered in Sept. 2015; Right: FSS (Fine Sun Sensor) delivered in June 2015 (image credit: NASA)


1) "NASA Engineer Awaits Launch of CubeSat Mission Demonstrating Virtual-Telescope Tech," NASA, Feb. 18, 2016, URL:

2) "CANYVAL-X: CubeSat Astronomy by NASA and Yonsei using Virtual Telescope Alignment eXperiment," NASA, Oct. 13, 2015, URL:

3) "NASA Fact Sheet," URL:

4) Neerav Shah, Joe Davila, Phil Chamberlin, Phil Calhoun, "Next-Generation Formation Flying Solar Coronagraph," Proceedings of iCubeSat 2014, 3rd Interplanetary CubeSat Workshop, Pasadena, CA, USA, May 27-28, 2014, URL:

5) United States Commercial ELV Launch Manifest," June 17, 2015, URL:

6) Samudra E. Haque, Christopher K Dinelli, "Preliminary sizing of a Micro-Cathode Arc Thruster subsystem for operations in cis-lunar space," 2014, 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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