CubeSats are a class of miniature satellites that have opened up space access and utilization to a wide range of new participants.

Standardized

The CubeSat standard specifies a modular cube-shaped satellite form factor measuring 10x10x10 cm per “unit” and with a maximum mass of 1-2 kg per unit. CubeSats can be configured as 1, 1.5, 2, 3, 6 or even 12 units stacked together, offering flexibility for different mission applications while retaining standardized interfaces for ease of integration.

Key Attributes and Benefits

The standardized CubeSat design offers several key advantages:

• Low Cost: By using commercial off-the-shelf components and a simple, non-redundant design, CubeSats can be developed for under $100k, much less than traditional satellites. This enables participation by universities, small companies, and countries with limited budgets.
• Rapid Development: CubeSats use standardized, modular components so they can be developed and launched in 1-2 years, much faster than larger satellites. Quick iterations enable testing of new technologies.
• Frequent Launch Access: CubeSats can piggyback on rocket launches as secondary payloads, providing regular, low-cost access to space. Deployers on the ISS also provide launch opportunities.
• Constellations/Swarms: The low cost enables deploying constellations of many CubeSats working together, allowing spatial/temporal measurements not possible with a single satellite.
• Education and Training: Hands-on development gives students and young engineers invaluable experience and skills in satellite design/testing/operation.

Applications and Missions

While initially used mostly for education, CubeSats are now being increasingly utilized for commercial and government applications:

• Technology Demonstrations: Testing components and systems in the space environment, de-risking their use in operational satellites
• Science Investigations: Conducting focused science experiments in fields like astronomy, space physics, Earth observation, and biology
• Commercial Services: Enabled by constellations of CubeSats, including communications, Internet of Things connectivity, Earth imaging, space situational awareness, and more
• Exploration Missions: As technology improves, interplanetary CubeSat missions are being developed for missions to the Moon, Mars, and beyond

To date over 2000 CubeSats have already been launched by organizations and companies around the world, across both low Earth orbit and deep space destinations. The number of CubeSat launches has been doubling every 2-3 years, showing the rapid adoption of this versatile, standardized satellite platform.

Structure and Subsystems

While payloads and capabilities grow more advanced, most CubeSats share a common architecture composed of several core subsystems:

Structure: The CubeSat structure houses and protects internal components. Made of aluminum or composite materials, it includes standard rail interfaces for deployment. External panels host solar cells, antennas, sensors, etc.

Command & Data Handling: The onboard computer runs software that controls satellite operation, processes payload data, and interfaces with communications and other subsystems.

Power: Solar panels and batteries provide power. Efficient triple-junction cells maximize power generation from the small satellite surface area.

Communications: UHF/VHF radios and antennas allow command uplink from ground stations and data downlink back, using amateur or custom frequencies.

Attitude Control: Miniaturized reaction wheels, magnetorquers, and thrusters orient the CubeSat and control its rotation and pointing direction.

Propulsion: Small thrusters provide propulsion for orbit changes, constellation phasing, drag compensation and attitude control. Many technologies including water plasma, ion, solid, and liquid propellant options have been demonstrated.

Challenges

While offering tremendous opportunities, CubeSats also come with some inherent challenges, which the community continues working to address:

Reliability: The short development cycles and off-the-shelf components can result in higher failure rates – currently around 50% for deep space missions. Improving reliability while retaining low cost and rapid development is an active area of work.

Debris: The growing number of CubeSats raises concerns about collisions and space debris. Designing CubeSats for reliable deorbit and end-of-life disposal will be increasingly important.

Tracking: The small size makes tracking and identifying individual CubeSats hard after deployment. Adding radio beacons and visual IDs aids space traffic management.

Regulations: As CubeSat applications commercialize, the lack of regulations tailored to these tiny satellites needs to be addressed regarding licensing, radio frequencies, debris mitigation standards, launch coordination etc. International coordination is essential.

The Future

CubeSats have already had a hugely disruptive and democratizing impact on the space industry, opening up space utilization to groups and countries that previously could not afford their own space programs. As technology matures, capabilities grow, and launch opportunities expand, CubeSats are poised to take on an increasingly pivotal role in our expanding use of space. The future looks bright for these tiny satellites!