Formation flying within a constellation of nano-satellites: The QB50 mission

Abstract

QB50 is a mission establishing an international network of 50 nano-satellites for multi-point, in-situ measurements in the lower thermosphere and re-entry research. As part of the QB50 mission, the Delft University of Technology intends to contribute two nano-satellites both being equipped with a highly miniaturized propulsion system in addition to the science payload. This allows to demonstrate formation flying between these two nano-satellites which will enhance the mission both with respect to technology demonstration and science return. The opportunities and challenges of formation flying by a subset of satellites within a constellation of freely floating spacecraft are systematically identified and analyzed.

Atmospheric Drag, Occultation ‘N’ Ionospheric Scintillation (ADONIS) mission proposal

“…The mission's orbit improves on the coverage provided by the past GOCE (Drinkwater et al 2003) and the planned QB50 (Gill et al 2013) missions, which can also measure drag. Because of its main mission objective of measuring the Earth's gravitational potential from a very low orbit, GOCE constantly compensated the drag of the atmosphere to ensure accurate measurements of gravity.…”

“…Neutral compounds are important for drag measurement since their density dominates the ionised particle density, and the change in total composition is important for ionospheric monitoring. The instrumental design is intended to draw on the experience gained in the QB50 project (Gill et al 2013), in which a similar instrument will be used in a large constellation of CubeSats. The range and sensitivity of the measurements are adjusted to our mission requirements.…”

“…In the near future, the QB50 mission, which will use a constellation of 50 CubeSats, plans to investigate the drag in the lower thermosphere over a period of 3 months (Gill et al 2013). Although QB50 will perform drag measurements, due to the short mission duration these measurements are not comprehensive nor do they monitor the variations over a full solar cycle.…”

Analysis of Nonisothermal Rarefied Gas Flow in Diverging Microchannels for Low-Pressure Microresistojets

“…Another numerical parameter that has been validated is the particles-per-cell value. Besides the actual-to simulated-particle ratio S of 10 4 , two other values were tested: 10 3 and 10 5 , see Table 3. The exit pressure also does not show significant changes and the exit velocity presents a difference of 1.3% in the worst case.…”

“…Nano-satellites are typically used in Low-Earth Orbit (LEO), where some specific missions might require a capable propulsion system to enable, for instance, formation flying, orbit change and/or station keeping of constellations. These propulsion systems need to be extremely miniaturized and highly integrated; they shall usually provide thrust levels in the order of some µN up to a few mN, with a limited power consumption [3,4]. In addition, there is currently a societal urge to use "green" space systems, that shall be free of components or materials publicly recognized as toxic or potentially hazardous for the environment.…”