No abstract

REGULUS is an Iodine-based electric propulsion system. It has been designed and manufactured at the Italian company Technology for Propulsion and Innovation SpA (T4i). REGULUS integrates the Magnetically Enhanced Plasma Thruster (MEPT) and its subsystems, namely electronics, fluidic, and thermo-structural in a volume of 1.5 U. The mass envelope is 2.5 kg, including propellant. REGULUS targets CubeSat platforms larger than 6 U and CubeSat carriers. A thrust T = 0.60 mN and a specific impulse Isp = 600 s are achieved with an input power of P = 50 W; the nominal total impulse is Itot = 3000 Ns. REGULUS has been integrated on-board of the UniSat-7 satellite and its In-orbit Demonstration (IoD) is currently ongoing. The principal topics addressed in this work are: (i) design of REGULUS, (ii) comparison of the propulsive performance obtained operating the MEPT with different propellants, namely Xenon and Iodine, (iii) qualification and acceptance tests, (iv) plume analysis, (v) the IoD.

The non-intrusive density measurement of the thin plasma produced by a mini-helicon space thruster (HPH.com project) is a challenge, due to the broad density range (between 10(16) m(-3) and 10(19) m(-3)) and the small size of the plasma source (2 cm of diameter). A microwave interferometer has been developed for this purpose. Due to the small size of plasma, the probing beam wavelength must be small (λ = 4 mm), thus a very high sensitivity interferometer is required in order to observe the lower density values. A low noise digital phase detector with a phase noise of 0.02° has been used, corresponding to a density of 0.5 × 10(16) m(-3).

No abstract

The design of a measurement system for the analysis of electric and magnetic field strength in the frequency range from few Hz up to 100 kHz is discussed. The purpose is to show how the design can be optimized in order to improve measurement performances and to simplify hardware complexity. To this aim, a system architecture is presented and the design of some system critical blocks is discussed. The proposed system can be also efficiently used for the analysis of power currents. Some meaningful results obtained by experimental tests on a suitable prototype are reported and compared with commercial systems specifications. A real-life example showing the usefulness of the proposed system for in-the-field investigations is finally described and commente

No abstract

This paper describes the SPONGE experiment (Sounding rocket Propellant OrieNtation microGravity Experiment) developed at CISAS in collaboration with Thales Alenia SpaceItaly. The aim of this experiment is to provide the data for the validation of the CFD code created to study and design propellant management devices.SpongeCompressibleFoam is a code based on the OpenFOAM Platform, written at CISAS to simulate propellant management devices. The latter are passive static metal structures used in rocket tanks to control propellant behavior; they work using surface tension to ensure gas-free liquid delivery to the tank outlet. SPONGE flew on board the REXUS 9 ESA/SSC/DLR sounding rocket in February 2011, it is based on two counter rotating plates: (i) the experimental plate, on which the control equipment and a polycarbonate tank containing the sponge test-sample are placed and (ii) the balancing plate, rotating in the opposite direction with respect to the experimental plate and ensuring no momentum transfer to the rocket.The system rotates at four different angular velocities, allowing the study of the sponge and its retention capability under different centrifugal forces. The design and results are presented.

In this communication we report on a combined experimental-numerical activity that was conducted to assess the antenna-plasma interaction within a Helicon plasma source for space thrusters. The experiment is based on a versatile, re-configurable set-up which allows testing multiple thruster configurations under different operating conditions, featuring a high-efficiency RF antenna. The numerical results were obtained by means of various simulation tools for both RF circuit and antenna-plasma interface analysis; these tools were validated against experimental data. The results helped to improve our understanding of antenna-plasma coupling and the assessment/prediction of the RF system performance. Nomenclature RF= Radio Frequency HPT = Helicon Plasma Thruster RPA = Retarding Potential Analyzer IEDF = Ion Energy Distribution Function DAQ = Data AcQuisiton Pp = Active power coupled to the plasma Zp = Plasma impedance Rp = Plasma resistance Xp = Plasma reactance ηa = Antenna efficiency _______________________________________________________________________________________