Sailing with E-Sail to the outer planets
- Paper number
IAC-11,C4,6,1,x9347
- Coauthor
Ms. Sini Merikallio, Finnish Meteorological Institute, FMI, Finland
- Coauthor
Dr. Pekka Janhunen, Finnish Meteorological Institute, FMI, Finland
- Coauthor
Dr. Petri Toivanen, Finnish Meteorological Institute, FMI, Finland
- Year
2011
- Abstract
The Electric Solar Wind Sail (E-sail) is a new propulsion method that uses long, thin and positively charged tethers to turn solar wind momentum flux into spacecraft thrust. The E-sail was invented in 2006 and is currently under development and funded e.g. by the European Union’s Seventh Framework Programme for Research and Technological Development, EU FP7. According to current estimates, the E-sail is 2-3 orders of magnitude more efficient than traditional propulsion methods (chemical rockets and ion engines) in terms of produced lifetime-integrated impulse per propulsion system mass. The force of an E-sail is inversely proportional to the distance from the sun (F α 1/r) while, in comparison, the force produced by a photonic solar sail is F α (1/r2) . Thus the E-sail has particular potential for outer solar system missions. Accurate knowledge of the atmospheric composition of the outer planets Jupiter, Saturn, Uranus and Neptune could be used to test different solar system formation theories. To do this, the scientist wants to look at trends in the composition of the accretion disk from which the planets formed, which implies that one should measure the atmospheres of all the outer planets. Thus far only Jupiter’s atmosphere has been probed (Galileo 1995). Now with E-sail technology, travel times to outer planets are significantly shorter than with traditional techniques and at the same time launch masses are reduced, which decreases the mission cost. As an example, with a standard 1 N E-sail we could fly 500 kg of payload to Uranus in 3 years, to Neptune in 4.6 years, to Saturn in a 1.7 years and to the Jupiter in a mere year. Whereas traditional missions need to carefully select their launch date within the so-called launch window, the E-sail probe could be launched at any time as there is no need to gather extra speed by suitable planetary fly-by’s. To gain the maximum science output for fixed cost, one could manufacture four identical atmospheric probes and send them towards all the giant planets. Designing spacecraft is expensive, but building identical reduces unit costs. The probes could be launched together or separately as opportunities arise. It does not matter into which Earth escape orbit the probe is launched since in the solar wind the propellantless E-sail takes care of the acceleration.
- Abstract document
- Manuscript document
(absent)