Project Icarus: A review of local interstellar medium properties of relevance for space missions to the nearest stars

Crawford, Ian

doi:10.1016/j.actaastro.2010.10.016

Cited by 20 publications

(12 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Schneider et al 2010), and it is certainly true that impacts with interstellar grains will be potentially damaging. This was considered in detail in the context of the Daedalus study by Martin (1978), and Crawford (2011) extended this discussion in the light of more recent knowledge of the local interstellar dust density. Martin (1978) adopted a beryllium shield for the Daedalus study owing to its low density and relatively high specific heat capacity, although further research could presumably identify better materials.…”

Section: Interstellar Dustmentioning

confidence: 81%

“…It is true that the upper boundary to the size distribution of interstellar dust particles in the solar neighbourhood is not well constrained (Landgraf et al 2000, Crawford 2011). If the local ISM contains a population of, as yet undiscovered, large grains (say tens to hundreds of μm in size, or even larger), then the individual kinetic energies of such particles would require special mitigation measures.…”

Section: Interstellar Dustmentioning

confidence: 99%

See 1 more Smart Citation

Direct Exoplanet Investigation Using Interstellar Space Probes

Crawford

2018

Handbook of Exoplanets

Self Cite

View full text Add to dashboard Cite

Experience in exploring our own solar system has shown that direct investigation of planetary bodies using space probes invariably yields scientific knowledge not otherwise obtainable. In the case of exoplanets, such direct investigation may be required to confirm inferences made by astronomical observations, especially with regard to planetary interiors, surface processes, geological evolution, and possible biology. This will necessitate transporting sophisticated scientific instruments across interstellar space, and some proposed methods for achieving this with flight-times measured in decades are reviewed. It is concluded that, with the possible exception of very lightweight (and thus scientifically limited) probes accelerated to velocities of ~0.1c with powerful Earth-based lasers, achieving such a capability may have to wait until the development of a space-based civilization capable of leveraging the material and energy resources of the solar system.

show abstract

Section: Interstellar Dustmentioning

confidence: 81%

Section: Interstellar Dustmentioning

confidence: 99%

Direct Exoplanet Investigation Using Interstellar Space Probes

Crawford

2018

Handbook of Exoplanets

Self Cite

View full text Add to dashboard Cite

show abstract

“…F Msail = 0.345π m p n o µ 0.5 IR 2 v 2 3 2 (1) where m p is the mass of the proton, n o the number density of interstellar ions, µ the free space permeability, I the current through the sail, R its radius and v its speed. Values for n o are proposed in [10] in the case of a space probe traveling to Alpha Centauri. In this work, a rather conservative value was implemented, with n o = 0.03 cm −3 corresponding to the expected values in the Local Bubble [10].…”

Section: Magnetic Sail (Msail)mentioning

confidence: 99%

“…Values for n o are proposed in [10] in the case of a space probe traveling to Alpha Centauri. In this work, a rather conservative value was implemented, with n o = 0.03 cm −3 corresponding to the expected values in the Local Bubble [10].…”

Section: Magnetic Sail (Msail)mentioning

confidence: 99%

“…In the Debye length definition, o is the electric permittivity of vacuum, k b the Boltzmann constant and T e the electron temperature of the interstellar plasma. T e was estimated according to [10], so for the present analysis the value T e = 8000 K was used. The wires were designed according to [11], with radius r w = 5 µm and density 1500 kg/m 3 It is evident from Equation 4, that the force increases proportionally to the number and length of the tethers as well as for a higher voltage.…”

Section: Electric Sail (Esail)mentioning

confidence: 99%

See 1 more Smart Citation

Combining magnetic and electric sails for interstellar deceleration

Perakis

Hein²

2016

Acta Astronautica

View full text Add to dashboard Cite

The main benefit of an interstellar mission is to carry out in-situ measurements within a target star system. To allow for extended in-situ measurements, the spacecraft needs to be decelerated. One of the currently most promising technologies for deceleration is the magnetic sail which uses the deflection of interstellar matter via a magnetic field to decelerate the spacecraft. However, while the magnetic sail is very efficient at high velocities, its performance decreases with lower speeds. This leads to deceleration durations of several decades depending on the spacecraft mass. Within the context of Project Dragonfly, initiated by the Initiative of Interstellar Studies (i4is), this paper proposes a novel concept for decelerating a spacecraft on an interstellar mission by combining a magnetic sail with an electric sail. Combining the sails compensates for each technologys shortcomings: A magnetic sail is more effective at higher velocities than the electric sail and vice versa. It is demonstrated that using both sails sequentially outperforms using only the magnetic or electric sail for various mission scenarios and velocity ranges, at a constant total spacecraft mass. For example, for decelerating from 5% c, to interplanetary velocities, a spacecraft with both sails needs about 29 years, whereas the electric sail alone would take 35 years and the magnetic sail about 40 years with a total spacecraft mass of 8250 kg. Furthermore, it is assessed how the combined deceleration system affects the optimal overall mission architecture for different spacecraft masses and cruising speeds. Future work would investigate how operating both systems in parallel instead of sequentially would affect its performance. Moreover, uncertainties in the density of interstellar matter and sail properties need to be explored.

show abstract

The Solar Wind in the Outer Heliosphere and Heliosheath

Richardson¹,

Burlaga²

2011

Cosmic Rays in the Heliosphere

View full text Add to dashboard Cite

The solar wind environment has a large influence on the transport of cosmic rays. This chapter discusses the observations of the solar wind plasma and magnetic field in the outer heliosphere and the heliosheath. In the supersonic solar wind, interaction regions with large magnetic fields form barriers to cosmic ray transport. This effect, the "CR-B" relationship, has been quantified and is shown to be valid everywhere inside the termination shock (TS). In the heliosheath, this relationship breaks down, perhaps because of a change in the nature of the turbulence. Turbulence is compressive in the heliosheath, whereas it was noncompressive in the solar wind. The plasma pressure in the outer heliosphere is dominated by the pickup ions which gain most of the flow energy at the TS. The heliosheath plasma and magnetic field are highly variable on scales as small as ten minutes. The plasma flow turns away from the nose roughly as predicted, but the radial speeds at Voyager 1 are much less than those at Voyager 2, which is not understood. Despite predictions to the contrary, magnetic reconnection is not an important process in the inner heliosheath with only one observed occurrence to date.

show abstract

Project Icarus: A review of local interstellar medium properties of relevance for space missions to the nearest stars

Cited by 20 publications

References 38 publications

Direct Exoplanet Investigation Using Interstellar Space Probes

Direct Exoplanet Investigation Using Interstellar Space Probes

Combining magnetic and electric sails for interstellar deceleration

The Solar Wind in the Outer Heliosphere and Heliosheath

Contact Info

Product

Resources

About