“You can get there from here”: Advanced low cost propulsion concepts for small satellites beyond LEO

• Published in: Acta astronautica 2005-07, Vol.57 (2), p.288-301
• Main Authors: Baker, Adam M., da Silva Curiel, Alex, Schaffner, Jake, Sweeting, Martin
• Format: Article
• Language: English
• Subjects: Butanes; Low cost; Manoeuvring; Missions; Propulsion; Satellite constellations; Small satellites; Xenon
• ISSN: 0094-5765; 1879-2030
• DOI: 10.1016/j.actaastro.2005.03.046

Small satellites have historically been forced to use low cost propulsion, or to do without in order to maintain low cost. Since 1999 an increasing number of SSTL's customers have demanded the capability to precisely position and subsequently manoeuvre their satellites, driven largely by the current attraction of small satellite constellations such as Disaster Monitoring (DMC), which require propulsion for launcher injection error correction, drag compensation, constellation phasing and proximity manoeuvring and rendezvous. SSTL has successfully flight qualified a simple, low cost propulsion system based on a low power (15–100 W) resistojet employing green propellants such as butane and xenon, and demonstrated key constellation manoeuvres. The system is capable of up to 60 m/s deltaV and will be described here. The SSTL low power resistojet is however limited by a low Isp ( ∼ 50 s for Xenon in the present design, and ∼ 100 s with nitrogen and butane) and a slow reaction time ( 10 min warm-up required). An increasing desire to apply small satellite technology to high deltaV missions while retaining the low cost aspect demands new solutions. ‘Industry standard’ solutions based on cryogenic propulsion, or toxic, carcinogenic storable propellants such as hydrazine/nitrogen oxides combination are not favourable for small satellite missions developed within SSTL's low cost engineering environment. This paper describes a number of strawman missions with high deltaV and/or precision manoeuvring requirements and some low cost propulsion solutions which have been explored at the Surrey Space Centre to meet future needs: (1) Deployment of a complex constellation of nano- or pico-satellites from a secondary launch to a new orbit. The S3TV concept has been developed to allow deployment up to 12 payloads from an ‘off-the-shelf’ thrust tube, using a restartable nitrous oxide hybrid engine, operating in a dual mode with resistojets for attitude control. (2) Orbit transfer of an enhanced microsatellite from a typical 700 km sun-synchronous orbit to a lower or higher orbit using a low cost 40 N thrust concentrated hydrogen peroxide/kerosene bipropellant engine. A spin stabilized ‘tug’ concept capable of providing between 130 and 300 m/s of deltaV to the payload is described. (3) Transfer of an enhanced microsatellite from LEO to lunar orbit using a novel, storable propellant solar thermal propulsion system under development at the Surrey Space Centre. The solar thermal prop