This papers gives an insight on different sub topics related to a micro-propulsion subsystem for a PocketQube. First, PocketQubes will be introduced and then Delfi-PQ will be presented, providing an overview of the mission for which this micro-propulsion system will be used. Step by step, the paper will explain the subsystem, its challenges, mechanical aspects, electronics aspects and future work. In the long term, these miniaturized micro-propulsion systems might play an important role for micro satellites for attitude control, low-altitude orbital maintenance, formation flying, orbital transfer and several other potential applications.@en

PocketQubes represent a new type of cube-shaped platforms with dimensions of 50x50 mm and mass of 250 g. Just like the CubeSats, these platforms are also split in units which are referred to as 1P. The Delft University of Technology has been working on Delfi-PQ, a 3P PocketQube with the dimensions of 50x50x178 mm. This miniaturized size brings its own challenges on every subsystem. In this paper, structural design, integration and kill switch mechanisms will be explained.@en

This paper presents the design of a multi-frequency deployable antenna system for femto-satellites as part of the Delfi-PQ project, a PocketQube with a size of 50x50x178 mm which is being developed by the Delft University of Technology. This new form factor brings its own challenges on every subsystem and it is seen as a stepping stone towards even more miniaturised satellites. In this paper we present the design trade-offs, the analysis and the and measurements on the antenna system. The system is designed to operate in 4 different bands to guarantee communications and payload operations. Due to the very limited available space on the external faces of the spacecraft, it was decided to deploy all the antennas and multiplex the different bands on the available antenna elements. VHF and UHF are used for satellite telemetry and commanding while a dual-frequency GPS receiver is intended as payload. The satellite design is presented, together with design drivers for such a system to justify the design choices. Three RF configurations are analysed and compared for omni-directional coverage and peak gain. RF measurements on one of the configurations is also presented to validate the simulations. The deployment system is also presented, giving details on the design and expected tests to complete the qualifications.@en

PocketQubes are a new form factor of highly miniaturized satellites with a body of one or more cubic units of 5 cm. The characteristics of PocketQubes in terms or legal and regulatory aspects, the technological readiness levels and financial considerations are assessed. In particular, an analysis of orbital decay characteristics has been carried out which together with existing space law suggest that PocketQubes should preferably be launched in very low Earth orbits below 500 km altitude. To make PocketQubes attractive platforms, not only the launch cost, but also the development, production and operations cost should be significantly lower than CubeSats . Due to technical constraints, such as form factor, power and attitude control, the domain of applications is, especially for single PocketQube mission constrained. Still, they can act as low cost training or technology demonstration platforms. When launched in high numbers, networks of PocketQubes can enable new applications for Earth observation and niche communication services. Applications considered feasible are in the field of (but not limited to) continuous surveillance using optical instruments, gravity field monitoring using precise orbit determination, in-situ measurements of the space environment and low data rate or bandwidth communication services.@en

Delft University of Technology has embarked on PocketQubes to showcase as the next class of miniaturized satellites. In the past decade, CubeSats have grown towards a successful business with mature capabilities. PocketQubes, however, are still in their infancy. The small size of the PocketQubes will trigger innovations in miniaturization and will force one to think differently about space technology. It is not sufficient to simply down-scale existing concepts used in CubeSats, there is a necessity to develop and qualify completely new components through which new applications can be enabled in the future. The new satellite platform, called Delfi-PQ, inspired by the success of previous Delfi satellite projects is seen as an opportunity for innovation and offers research challenges in the miniaturization field of systems and components. The focus of this paper is to highlight those innovations and challenges, and to communicate the progress that has been made with respect to building a core platform and standardized bus. The mission of Delfi-PQ is to demonstrate a reliable core bus and outer structure for a three unit PocketQube that shall be tested in flight as a first iteration of a series of PocketQubes to be developed by Delft University of Technology. The core bus shall fit in one unit - 1P (50x50x50mm), having as aim that after further miniaturization and optimization, the second unit shall contain an advanced subsystem (e.g. advanced Attitude Determination and Control System - ADCS) and the third unit shall consist of a scientific payload (e.g micro-propulsion, lensless camera). For Delfi-PQ, the focus was on the miniaturization process and on the structure of the PocketQube. The core platform of the first Delfi-PQ consists of the Electrical Power System (including two 3.7V batteries and solar panels with two cells/each X-Y face), On-board Computer, Communications System, ADCS (including two magnetorquers and three magnetometers), as well as: temperature sensors and two different sensors for assessing the rotational speed of the PocketQube.@en