Mission and System Design of a 3U CubeSat passive GTO to LEO Orbit Transfer

Paper number

IAC-12,E2,1,x16316

Author

Mrs. Charlotte Bewick, OHB System AG, Germany

Year

2012

Abstract

This paper suggests a mission concept and system design for a 3U CubeSat technology demonstration. The spacecraft carries an inflatable, ejectable balloon that is used to engineer its area-to-mass-ratio. In this way, the effects of aerodynamic drag and solar radiation pressure on the orbit evolution can be exploited in order to passively transfer from a geostationary transfer orbit (GTO) to a low Earth orbit (LEO).
CubeSats have in the past decade become the leading platform for low cost space-borne experiments. This is due to their modularised structure and uncomplicated access to space. Because of their fixed dimensions they can be launched using a standardised deployment system and launcher interface, sharing a rocket with larger spacecraft. The main orbital region of interest for CubeSat operators is LEO. With the increasing interest in CubeSat missions, demand for piggy-back launches to LEO is exceeding the availability. In order to tap into the many GTO launches an appropriate strategy is needed to transfer CubeSats from the release orbit into a LEO orbit.
The strategy proposed exploits the effects of atmospheric drag and solar radiation pressure to passively decrease the apogee altitude and increase the perigee altitude respectively. This is achieved by deploying a light-weight balloon that increases the area-to-mass-ratio of the spacecraft. After the deployment and rigidisation the manoeuvre occurs completely passively, allowing to power down the spacecraft’s electronics for the transfer duration to avoid radiation damage from the Van Allen belts. Once the goal orbit is reached the spacecraft can be powered up again and the balloon is ejected to avoid rapid deorbiting. It is shown that the abandoned balloon is removed from orbit within weeks.
The paper focuses on the system design of the orbit transfer module which takes up a 1U unit of the 3U CubeSat. First the membrane is heated up by pointing a black surfaced lid towards the Sun. This is necessary to make the balloon, which has been impregnated with a cold-curing resin, pliable enough to deploy. Nitrogen gas generators are then used to inflate the balloon. Thermal analysis results show that the balloon rigidises quickly after deployment because of its reflective surface. The module also includes an ejector system consisting of a removable frame, tension wires and a pyrocutter to remove the balloon after manoeuvre completion. Moreover, the paper presents a summary of the orbital dynamics and the results of numerical analysis of the orbit transfer.

Abstract document

IAC-12,E2,1,x16316.brief.pdf

Manuscript document

IAC-12,E2,1,x16316.pdf (🔒 authorized access only).

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