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Is the satellite industry entering a “low-cost” era?

Nanosatellites: more than an educational tool?

Antoine Tavant, Technical Director of the Space Centre at École polytechnique (IP Paris)
On April 27th, 2021 |
4 mins reading time
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Nanosatellites: more than an educational tool?
Antoine Tavant
Antoine Tavant
Technical Director of the Space Centre at École polytechnique (IP Paris)
Key takeaways
  • A nanosatellite can weigh up to 6,000 times less than a “standard” telecommunications satellite. This raises the question: what can you do in space with such a light object?
  • The interest in nanosatellites lies largely in their ability to be sent in constellations; one of the reasons why the number of launches has increased more than tenfold since 2013.
  • Their plug-and-play nature is also one of their major assets, as is their low cost.
  • All of this makes nanosatellites an excellent teaching tool for university projects such as the one at the École Polytechnique Space Centre.

Space, hith­er­to an area restrict­ed to a few gov­ern­men­tal agen­cies, is now acces­si­ble to a wide range of peo­ple. As such, satel­lites have ben­e­fit­ed from the minia­tur­i­sa­tion of elec­tron­ics to shrink to the size of “nanosatel­lites”. Even if this cat­e­go­ry is not clear­ly defined, it gen­er­al­ly des­ig­nates small-sized satel­lites: between 1 and 25 kg, while “min­isatel­lites” weigh between 100 and 500 kg and a stan­dard telecom­mu­ni­ca­tions satel­lite weighs near­ly 6,000 kg.

Their small size, low cost and the rise of an ecosys­tem of sup­pli­ers have grant­ed stu­dents, sci­en­tists, or pri­vate com­pa­nies, an eas­i­er access to space. From 1998 to 2012, only 136 nanosatel­lites were launched. In the past sev­en years, this fig­ure has been mul­ti­plied by 10 and has reached a total of 1338 nanosatel­lites. They have a bright future ahead of them: an esti­mat­ed 630 nanosatel­lites are to be launched on aver­age each year in the near future1.

The ori­gins of nanosatellites

Intro­duced as a design exer­cise at the Stan­ford Uni­ver­si­ty in 1999, the Cube­Sat for­mat is one of the pre­cur­sors of nanosatel­lites. It is the first stan­dard space plat­form which made it pos­si­ble to reuse sys­tems between dif­fer­ent mis­sions. It allowed many com­pa­nies to offer ele­ments based on the plug-and-play mod­el to rapid­ly devel­op new mis­sions. In view of the pro­lif­er­a­tion of these satel­lites, rideshare launch ser­vices (to allow com­pa­nies to share launch­ers) became wide­spread and many launch projects emerged. More than 140 micro-launch­ers are now in devel­op­ment to meet the increas­ing demand and eight of them are already oper­a­tional2.

Sci­en­tists and engi­neers very quick­ly used these new low-cost plat­forms to devel­op mis­sions of tech­nol­o­gy demon­stra­tion, like the GomX series (ESA and Gom­Space), as well as sci­en­tif­ic mis­sions like AMI­Cal Sat, UVSQSat and Eye­sat to only men­tion French Cube­Sats launched in the past two years.

Their small size does not pre­clude com­mer­cial mis­sions. This has not gone unno­ticed by French com­pa­nies which have sent into orbit satel­lites such as ANGELS to locate bea­cons (Heme­ria, 2019), or the BRO satel­lites for elec­tro­mag­net­ic intel­li­gence (Unseen­Labs, 2019 and 2020).

Ion­Sat satel­lite Satel­lite Ion­Sat © Space Cen­tre at École polytechnique

A pow­er­ful edu­ca­tion­al tool

Their reduced cost usu­al­ly makes nanosatel­lites a first-class edu­ca­tion­al tool. They answer a real need in high­er edu­ca­tion by mak­ing it pos­si­ble for stu­dents to acquire con­crete expe­ri­ence through stu­dent projects. Indeed, up until now, an engi­neer left his or her school with a won­der­ful the­o­ret­i­cal back­ground, but with no prac­ti­cal expe­ri­ence. This prob­lem is even more impor­tant in the space sec­tor because engi­neers, once they get a posi­tion, can spend years design­ing a space sys­tem with­out ever real­ly see­ing it.

Par­tic­i­pat­ing in a space project dur­ing stud­ies thus rep­re­sents a rich expe­ri­ence for stu­dents. All the more so since they work on var­i­ous fields cov­er­ing mechan­i­cal design and embarked data pro­cess­ing, as well as ther­mal analy­sis and flight mechan­ics, not to men­tion project man­age­ment and team­work. The expe­ri­ence is all the more reward­ing because a nanosatel­lite remains a com­plete­ly non-repairable autonomous sys­tem oper­at­ing in a dif­fi­cult, even hos­tile, envi­ron­ment: there is no sec­ond chance.

It is for these rea­sons that the École Poly­tech­nique chose to men­tor Cube­Sat stu­dent projects as ear­ly as 2011. The X‑CubeSat mis­sion (mem­ber of the QB-50 mis­sion launched in April 2017, and which end­ed in Feb­ru­ary 2019) involved more than 80 stu­dents from 7 dif­fer­ent year groups. Fol­low­ing that oper­a­tional and aca­d­e­m­ic suc­cess, a sec­ond project, named Ion­Sat3, was ini­ti­at­ed by the Space Cen­tre of the École Poly­tech­nique in 2017, in col­lab­o­ra­tion with the ThrustMe start-up. The main mis­sion of Ion­Sat is keep­ing the nanosatel­lite in very low orbit thanks to an elec­tric thruster. More than 50 stu­dents have already con­tributed to the pre­lim­i­nary design of this 6‑unit Cube­Sat (a vol­ume of 30x20x10 cm). But these projects are also of inter­est for major stake­hold­ers. Thus, Ion­Sat is led in part­ner­ship with Thales Ale­nia Space, which is, in addi­tion to Ari­ane­Group, a spon­sor of the edu­ca­tion pro­gram “Space: sci­ence and space-relat­ed chal­lenges” of École polytechnique.

The new par­a­digm of constellations

The lim­it­ed per­for­mance of these nanosatel­lites is off­set by their use as satel­lite con­stel­la­tions (mean­ing in net­works or swarms) in order to offer ser­vices which typ­i­cal mis­sions can­not achieve. The Amer­i­can com­pa­ny Plan­et thus launched more than 100 3‑unit Cube­Sats (30x10x10 cm) between 2013 and 2020 to observe all the Earth’s sur­face at least once a day. In 2020, 90 con­stel­la­tion projects were thus record­ed4.

How­ev­er, all the weak­ness­es of nanosatel­lites can­not be solved by launch­ing them in great num­bers. For exam­ple, there is a ques­tion of bal­ance between the part of the satel­lite ded­i­cat­ed to the mis­sion and the oth­er func­tion­al­i­ties, for instance to main­tain orbit. For obser­va­tion, res­o­lu­tion is pro­por­tion­al to sen­sor size, nanosatel­lites are thus lim­it­ed in this respect. The for­mat pos­es fur­ther lim­i­ta­tions, espe­cial­ly with regard to com­mu­ni­ca­tions: these are lim­it­ed by the low agili­ty and elec­tri­cal capac­i­ty of the platform.

To face these chal­lenges, some com­pa­nies, like the Kineis com­pa­ny from Toulouse, pro­duce slight­ly big­ger satel­lites, but which are still small enough to belong to the “nanosatel­lite” cat­e­go­ry. Oth­ers, with a big­ger mar­ket, have cho­sen to increase the per­for­mance of their satel­lites by tak­ing advan­tage of the ben­e­fits of con­stel­la­tion with­out lim­it­ing their size to the nanosatel­lite for­mat. That is why more ambi­tious mega-con­stel­la­tion projects, such as OneWeb and Star­link, focus on “Small­Sats” (150 kg and 230 kg, respec­tive­ly). With a big num­ber of low-cost but pow­er­ful satel­lites, they have the best of both worlds.

A strong latent potential

Yet nanosatel­lites will not stay lim­it­ed to low-cost or edu­ca­tion­al projects only. Indeed, the expe­ri­ence feed­back from pio­neer mis­sions has shown their val­ue in the con­text of sci­en­tif­ic mis­sions5. In addi­tion to observ­ing Earth, as pre­vi­ous­ly men­tioned, these Cube­Sats can be used in solar weath­er research thanks to mass spec­trom­e­ters (SENSE in 2013) or X‑ray detec­tors (MinXSS in 2016); in astro­physics with the minia­ture tele­scope ASTERIA (2017) or the HaloSat mis­sion (2018); in space explo­ration, as was the case for the Mar­CO Cube­Sats (Mars Cube One) which accom­pa­nied the Insight Probe to Mars in 2018, and the Lunar Flash­light which will accom­pa­ny the Artemis I mis­sion on the Moon in 2021. The appli­ca­tions of nanosatel­lites are thus lim­it­ed only by our imagination!

1https://​www​.nanosats​.eu/
2Joseph N. Pel­ton, Scott Madry – Hand­book of Small Satel­lites-Springer Inter­na­tion­al Publishing_Springer (2020)
3https://​cen​tres​pa​tial​-poly​tech​nique​.fr/​i​o​nsat/
4G. Curzi et al. Large Con­stel­la­tions of Small Satel­lites: A Sur­vey of Near Future Chal­lenges and Mis­sions. Aero­space. 2020; 7(9):133. https://​doi​.org/​1​0​.​3​3​9​0​/​a​e​r​o​s​p​a​c​e​7​0​90133
5A. Poghosyan, A. Golkar, Cube­Sat evo­lu­tion: Ana­lyz­ing Cube­Sat capa­bil­i­ties for con­duct­ing sci­ence mis­sions, Progress in Aero­space Sci­ences, 2017, https://​doi​.org/​1​0​.​1​0​1​6​/​j​.​p​a​e​r​o​s​c​i​.​2​0​1​6​.​1​1.002

Contributors

Antoine Tavant

Antoine Tavant

Technical Director of the Space Centre at École polytechnique (IP Paris)

Antoine Tavant coordinates the activities of the Centre Spatial de l'École polytechnique (CSEP), which proposes and conducts space-related student projects at the École polytechnique. These projects include two nanosatellite projects and three experimental rocket projects in 2021. These projects aim to have students work on concrete and innovative projects, in line with the current space sector. Antoine is an alumnus of both École polytechnique and ISAE SUPAERO, having started his research at the University of California at Berkley, before doing a thesis on electric propulsion for satellites with Safran at the Plasma Physics Laboratory.