Honey, I shrunk the satellites: How CubeSats are taking space missions by storm

The US space agency Nasa is readying a micro-oven-sized robotic spacecraft, CAPSTONE, to send to the moon soon. Not long ago, MarCO- A and B, two briefcase-sized probes, trailed Nasa’s InSight spacecraft all the way to Mars.

The MarCO twins were the communication sentinels for the InSight mission. They relayed crucial information to earth about how the lander was holding up during its 8 minutes of excruciating descent to the red planet. In contrast, CAPSTONE will be the surrogate satellite that will check the feasibility of an orbiting station around the moon, ensuring the safety and viability of futuristic moon missions.

Do you know what the common factor between these two landmark deep space missions is? It’s the prowess of CubeSats.

The palm-sized marvels

Miniaturization is on a massive scale. If computers have shrunk to fit in our palms, why not satellites?

Standard satellites are large, heavy (typically a few tonnes) and cost several hundred million to build. They are carefully designed as there is hardly any room for errors and are usually low-risk ventures. Besides, heavy launchers are required to put them into orbits.

On the other hand, CubeSats are low-cost marvels belonging to the nanosatellite category. As their name implies, CubeSats are like cubes and have a compact design with a fixed skeletal structure. Each cube, called 1U (unit), is of standard size 4 X 4 X 4 inches (outer dimensions) and weighs around 1.33 kilos. The cubes can be stacked in multiples of 1U up to 12 U. For example, a 3U CubeSat will be 4 X 4 X 12 inches and weighs around 4 kilos. MarCO-A and B were 6U (13.5kilos) and CAPSTONE is 12U (25 kilos).

The primary cube satellite modules are often available as easy-to-assemble ‘commercial off-the-shelf (COTS)’ components, they are easy to assemble even by amateurs.. Hence CubeSats are economical (a few million) satellites that offer versatile options for conducting high-risk space experiments. Moreover, owing to their lightweight and modular design, CubeSats often hitch a ride into space on other launches. Sometimes, they travel as secondary payloads to the international space station and set into orbits from there.

It was just the beginning

Until the late 1990s, students or academic institutes relied on government-backed space agencies to carry out their space experiments. It was time-consuming as the regular space probes would take years to launch. Moreover, such experiments proved to be costly for the limited budget of students and institutions. Often, the students completed their course before they could know how their models were performing in space.

Recognising these drawbacks, two US professors, Robert Twiggs and Jordi Puig-Suari, designed a standard miniaturized box-like build for artificial satellites in 1999. These minisatellites were aimed as teaching tools for students. However, critics scoffed at the idea, labelling them as toys. Little did they know that the advent would revolutionise space ventures in no time.

After several hurdles, the first six CubeSats took to the skies in 2003 from Russia’s Plesetsk launch site. Reportedly, the project cost a mere $ 40,000 – a fraction of a regular launch cost of millions, and CubeSats haven’t looked back since.

CubeSats opened exciting opportunities for students and research institutes to conduct economic, time-bound and quick space experiments with autonomy in monitoring them. The easy-to-assemble modules can be launched in low earth orbit in a balloon or by mini rockets, or along with a regular mission depending on the payload specifications. Students of all ages -primary to graduate levels- can access and build CubeSats today.

Although the first CubeSats struggled to get launched into space, in no time, the scene changed. The world began to notice the hidden might of CubeSats, and that small was big for space ventures. As a result, government-backed and private agencies aggressively invest in CubeSat projects and development. Today, Nasa has several programmes, such as the CubeSat Initiative, to encourage minisatellite projects for R&D and space missions. For instance, CAPSTONE is built and operated entirely by private entities.

Spreading their wings

For the first decade after 2003, most CubeSats were from research institutions. However, as private space-faring companies began noticing the economic potential of CubeSats, their launches increased by 40 per cent after 2011. In the past decade, CubeSats grabbed the attention of leading space agencies, and the minisatellites are part of every space-faring nation’s agenda as forerunners and testing beds for more significant and critical space projects. Moreover, CubeSats offer a viable option to non-space faring developing countries to invest in affordable satellites.

Since their inception, more than 1,000 Cubes have been to space. In the past couple of years, CubeSats have played a crucial role in low earth orbits as earth observation satellites. They are on the path of dominating earth observation, remote sensing and data mining satellite systems. Several CubeSats have been launched in the past decade in Low Earth Orbits for earth observation, GPS, natural disaster forecasting and assessment, and other applications, besides dedicated space science experiments.

However, the MarCO twins demonstrated that CubeSats could travel to deep space independently and survive the harsh environs with aplomb. CAPSTONE will raise the bar.

The road ahead

Precision manoeuvring of these tiny packages in space remains the major challenge. As a result, active research is focusing on the satellite’s critical component, Micro thrusters. The thrusters expel a tiny jet of gas that generates a small controlled force to help precisely manoeuvre and maintain the robotized probes’ course for extended periods in space.

Thanks to breakthroughs in electronics and nanotechnology, CubeSats are transforming rapidly. Flexible and printable electronics are aiding the design of advanced power, communication, imaging and instrumentation modules.

Rapid advancement in microelectronics and miniaturization is further shrinking the size of CubeSats to PocketQubes, TubeSats, and PicoSats. AttoSats that weigh just a few grams are not far behind.