Easily retrievable objects among the NEO population

Asteroids and comets are of strategic importance for science in an effort to understand the formation, evolution and composition of the Solar System. Near-Earth Objects (NEOs) are of particular interest because of their accessibility from Earth, but also because of their speculated wealth of material resources. The exploitation of these resources has long been discussed as a means to lower the cost of future space endeavours. In this paper, we consider the currently known NEO population and define a family of so-called Easily Retrievable Objects (EROs), objects that can be transported from accessible heliocentric orbits into the Earth’s neighbourhood at affordable costs. The asteroid retrieval transfers are sought from the continuum of low energy transfers enabled by the dynamics of invariant manifolds; specifically, the retrieval transfers target planar, vertical Lyapunov and halo orbit families associated with the collinear equilibrium points of the Sun-Earth Circular Restricted Three Body problem. The judicious use of these dynamical features provides the best opportunity to find extremely low energy Earth transfers for asteroid material. A catalogue of asteroid retrieval candidates is then presented. Despite the highly incomplete census of very small asteroids, the ERO catalogue can already be populated with 12 different objects retrievable with less than 500 m/s of Δv. Moreover, the approach proposed represents a robust search and ranking methodology for future retrieval candidates that can be automatically applied to the growing survey of NEOs

Narrowband Biphotons: Generation, Manipulation, and Applications

In this chapter, we review recent advances in generating narrowband biphotons with long coherence time using spontaneous parametric interaction in monolithic cavity with cluster effect as well as in cold atoms with electromagnetically induced transparency. Engineering and manipulating the temporal waveforms of these long biphotons provide efficient means for controlling light-matter quantum interaction at the single-photon level. We also review recent experiments using temporally long biphotons and single photons.Comment: to appear as a book chapter in a compilation "Engineering the Atom-Photon Interaction" published by Springer in 2015, edited by A. Predojevic and M. W. Mitchel

An all-solid-state laser source at 671 nm for cold atom experiments with lithium

We present an all solid-state narrow line-width laser source emitting $670\,\mathrm{mW}$ output power at $671\,\mathrm{nm}$ delivered in a diffraction-limited beam. The \linebreak source is based on a fre-quency-doubled diode-end-linebreak pumped ring laser operating on the ${^4F}_{3/2} \rightarrow {^4I}_{13/2}$ transition in Nd:YVO$_4$. By using periodically-poled po-tassium titanyl phosphate (ppKTP) in an external build-up cavity, doubling efficiencies of up to 86% are obtained. Tunability of the source over $100\,\rm GHz$ is accomplished. We demonstrate the suitability of this robust frequency-stabilized light source for laser cooling of lithium atoms. Finally a simplified design based on intra-cavity doubling is described and first results are presented

MIRS: an imaging spectrometer for the MMX mission

The MMX infrared spectrometer (MIRS) is an imaging spectrometer onboard MMX JAXA mission. MMX (Martian Moon eXploration) is scheduled to be launched in 2024 with sample return to Earth in 2029. MIRS is built at LESIA-Paris Observatory in collaboration with four other French laboratories, collaboration and financial support of CNES and close collaboration with JAXA and MELCO. The instrument is designed to fully accomplish MMX’s scientific and measurement objectives. MIRS will remotely provide near-infrared spectral maps of Phobos and Deimos containing compositional diagnostic spectral features that will be used to analyze the surface composition and to support the sampling site selection. MIRS will also study Mars atmosphere, in particular spatial and temporal changes such as clouds, dust and water vapor

Rosetta Comet Mission close proximity operations at comet 67P/Churyumov-Gerasimenko and landing Philae

The first ever dedicated comet Lander is Philae, an element of ESA´s Rosetta mission to comet 67/P Churyumov-Gerasimenko. Rosetta was launched in 2004. After about 7 years of interplanetary cruise (including three Earth and one Mars swing-by as well as two asteroid flybys) the spacecraft went into a deep space hibernation in June 2011. When approaching the target comet in early 2014, Rosetta is re-activated. The cometary nucleus will be characterized remotely to prepare Lander delivery, currently foreseen for November 2014. Comet escort by the spacecraft will continue until end 2015, beyond the peak comet activity at perihelion. In contrast to small body flyby missions (e.g., the Giotto mission to Halley's comet in 1986), Rosetta will actually orbit or "quasi-orbit" the comet nucleus, being inside it's Hill sphere. We discuss spacecraft navigation issues , comet characterization, the landing site selection process and Lander delivery