Radioisotope sails for deep space propulsion and power

JBIS - Journal of the British Interplanetary Society

Volumn 49, Issue 4, 1996, Pages 147-149

  Forward, Robert L ^a  

^a Forward Unlimited   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

DEEP SPACE MISSIONS; ELECTRICAL POWER; HIGH ENERGY DENSITIES; INTERSTELLAR PROBES; POWER LEVELS; SOLAR-POWERED SYSTEM; TARGET STAR; THRUST LEVELS;

INTERPLANETARY FLIGHT; PROBES; RADIOISOTOPES; ROBOTICS; SOLAR ENERGY; SOLAR SAILS; SPACECRAFT;

PROPULSION;

EID: 0012639634     PISSN: 0007084X     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (5)

1. Arthur Berman, Physical Principles of Astronautics, Wiley, New York, 1961, p.252. [The text refers to prior studies of radioisotope alpha emission propulsion in the 1940s.]
2. Robert L. Forward, "Zero Thrust Velocity Vector Control for Interstellar Probes: Lorentz Force Navigation and Circling", AIAA Journal, Vol.2, No.5, pp.885-889 (May 1954).
3. M. Rosa-Clot and C. Burao, "Alpha Emission Thruster for Deep Space Missions", AIAA preprint 94-2790, 30th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Indianapolis, Indiana, USA (27-29 June 1994). [Profs Rosa-Clot and Bruno wish to take this opportunity to make the following corrections in their paper: The "mean life" t should be the I/e decay time, not the half-life. The "mean path" should be the alpha particle range in the given material. Except for Table III, for 210Po read 208Po throughout. The density of Po is 9.4 g/cc. In equations 5 through 9, for mα read M, the mass of radioisotope material. These corrections lead to different (and in most cases improved) numerical results, while the general conclusions of the paper remain the same.]
4. A.A. Bolonkin, "Simple Space Nuclear Reactive Motors and Electric Generators Running on Radioactive Substances", IAF Preprint 92-0573. [The brief three-page paper is devoid of equations, references, or technical details. The figures look like patent drawings, which could explain the lack of detail.There also seem to be some technical errors. (A) In some designs, conductive nets biased +5 MV with respect to the radioisotope metal film are used to repel the forward-going alpha particles. Realistically, it is probably not feasible to maintain a 5 megavolt potential over the short distances between the conductive net and the radioisotope metal layer without experiencing breakdown or serious current leakage due to the conductivity of the ion plasma existing in space. (B) The plastic film dimensions mentioned, of 20-30 μm (mkm in the paper), are not adequate to stop the 5 MeV alpha particles from 210Po. It is possible the author may be assuming a high-density plastic (1.5 g/cc), or in optimising thrust to mass, may be allowing the alpha particles to escape after taking away only part of their forward momentum.]
5. Dwight E. Gray, American Institute of Physics Handbook, 3rd Edition (McGraw-Hill, New York, 1972). [See Table 8b-l, pp.8-8 to 8-91 for list of radioisotopes and Fig. 8I-2, p.8-295 for alpha particle ranges.]