ESA has designed its first stand-alone CubeSat mission for deep space – aimed at targeting a little- known class of asteroid: small in size and rapidly spinning.
Studied in the Concurrent Design Facility, ESA’s highly networked facility for designing novel missions, the ‘Miniaturised – Asteroid Remote Geophysical Observer’, or M–Argo, is a nano-spacecraft based on the CubeSat design employing standardised 10 cm cubic units within which electronic boards can be stacked and subsystems attached.
M–ARGO would be a 12-unit CubeSat – with bodily dimensions of 22 x 22 x 34 cm – that would hitch a ride on the launch of a larger space mission whose trajectory takes it close to beyond Earth orbit – such as large astronomy missions to a Sun–Earth Lagrange point.
The CubeSat would then use its own high-efficiency electric propulsion system to take it into deep space and rendezvous with an asteroid target.
“CubeSats were originally developed for educational purposes, but they have become a cheap and fast method of demonstrating space technologies,” comments Roger Walker, overseeing ESA’s Technology CubeSats.
“But these CubeSat studies assumed the availability of a nearby ‘mothership’ to be relied on for transportation and then communication home. M–Argo by contrast would be completely stand-alone in nature.
“Our CDF study shows the concept is promising and would have a high potential of cutting the entry-level cost of deep-space exploration by about a factor of ten.”
The study confirmed a total of four separate asteroids the CubeSat could reach under its own power – and potentially up to 30 in total – as Roger explains: “They are all less than 50 m in diameter – half the length of a football field – and all rapidly spinning, modelled accordingly to have no remaining surface dust but instead to be monolithic in nature.
“So this would be a quite new type of planetary body to visit, thereby offering the potential for new scientific discoveries.”
M–ARGO would spend around six months surveying its target, using two miniaturised instruments: a multispectral imager and a laser altimeter.
Data would be returned using a specially designed transponder and high-gain antenna array, communicating with existing 15-35 m ESA-operated ‘Estrack’ ground stations, with the potential to be backed up by Italy’s larger 64-m diameter Sardinia Radio Telescope for a greater data return.
M–Argo could be ready launch in mid-2021 at the earliest, assuming that some key technology development starts soon. Most of its key technologies are already available, and the study pinpointed other R&D needed to make it possible – including a CubeSat-sized solar array drive mechanism, electric propulsion and X-band communications, plus radiation hardness of components – to be performed within ESA technology programmes.
The study also considered an alternative mission concept for M–ARGO, as a space weather observatory placed at the Sun–Earth L5 Lagrange Point, hosting a radiation monitor and boom-based magnetometer instrument.
The next step will be to start the key technology developments and find a suitable flight opportunity. Then afterwards the main mission and system definition phase could commence.
While the M-Argo concept is studied, ESA will be marking 30 June, Asteroid Day, and spreading the word on the tiny bodies that Earth shares space with, as both a scientific resource and a potential danger. For more information on Asteroid Day click here.