CubeSats

12th October 2020 | Tech stuff

Introduction

CubeSats are miniature satellites that have been used exclusively in low Earth orbit for 15 years. They are now being used for interplanetary missions as well. The CubeSat design was initially proposed in the late 1990s by two professors: Jordi Puig-Suari of California Polytechnic State University and Bob Twiggs of Stanford University. They became popular tools for students seeking to learn all aspects of spacecraft design and development.

Today, they are opening up space research to public and private entities.

They have been commonly used in low Earth orbit for applications like remote sensing or communications. In mid-2018, two CubeSats were deployed on a mission flying to Mars. Other CubeSats are now being considered for the moon and Jupiter.

CubeSats are able to demonstrate spacecraft technologies intended for small satellites, or where feasibility questions would not justify the cost of a larger satellite. Scientific experiments with unproven underlying theory may also find themselves aboard CubeSats. This is because their low cost can justify higher risks. Biological research payloads have been flown on several missions.

What are CubeSats used for?

CubeSats are a class of research spacecraft called nanosatellites and are built to standard dimensions. The basic design of a CubeSat is a 10-centimeter (4-inch) cube with a mass of less than 1.33 kilograms (2.93 lbs.). But variations on the theme are possible. CubeSats can also be designed to encompass two, three or six 10-centimeter units for more complicated missions.

CubeSats reduce launch costs in two fundamental ways. They don’t weigh that much, which means a rocket doesn’t need a lot of fuel to get them into orbit. In most cases, they also share a rocket with a larger satellite. This makes it possible to get to space on the back of a heavier payload.

Who has CubeSats and how many are there?

The searchable Nano-satellite database lists almost 2,000 CubeSats that have been launched since 1998. By providing educational opportunities for students, teachers, and faculties, NASA, for example, assists the USA in attracting and retaining students in STEM [Science, Technology, Engineering and Maths] disciplines.

You can see a comprehensive list of world-wide organizations who have developed CubeSats here: CUBESAT LIST

The types of organizations range from student bodies, research centers and universities, through to large aerospace/space corporations and defense bodies. The missions are many and varied: communications, earthquake and bushfire detection, small microgravity experiments, ionospheric research—to name but a few.

Expanding the horizon

CubeSats are gradually venturing away from the Earth’s atmosphere.

NASA has now formally ended the Mars Cube One mission. MarCO consisted of two tiny cubesats that hitchhiked along with the InSight lander and reached the Red Planet in November 2018. These twin MarCO satellites were the first cubesats to leave Earth orbit. They successfully completed their mission of reporting on InSight’s perilous landing to scientists on Earth.

“WALL-E and EVE performed just as we expected them to,” MarCO chief engineer Andy Klesh, of NASA’s Jet Propulsion Laboratory in California, said at the time [their nicknames taken from the 2008 film “WALL-E]. “They were an excellent test of how cubesats can serve as ‘tag-alongs’ on future missions, giving engineers up-to-the-minute feedback during a landing.”

As another example – the Arcsecond Space Telescope Enabling Research in Astrophysics satellite (ASTERIA) stopped transmitting in December 2019. The satellite, which launched in 2017, was designed to determine whether small cubesats could manage the sort of technically precise measurements required by scientists looking for distant planets.

Conclusion

It seems that these miniature space vessels are with us for good, although too many in Earth orbit may cause tracking and collision problems. Their use further afield has already proved fruitful and they are a wonderful educational tool for students of all kinds.

More and more start-ups, companies and governments will have their own satellites. In fact, it is anticipated that there will be between 500 and 800 launches going into 2023. Some of the advances we will see for small satellites (greater data processing and transmission capacity, artificial intelligence, propulsion systems, etc.) are trending towards the use of somewhat larger CubeSats. The 6U and 12U platforms [numbered by module counts] are gaining prominence in the sector in order to respond to these new needs.

It is also proposed to remotely build a modular satellite in space, where different CubeSats can function as building blocks of a larger structure.

To reduce space junk, de-orbiting systems, which allow the CubeSat to be guided towards the Earth’s atmosphere once it has completed its mission, will certainly be necessary.

References:

https://info.alen.space/predictions-about-the-future-of-small-satellites-and-new-space

https://www.nasa.gov/content/goddard/the-future-of-cubesats