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1.
We explore the likelihood that early remains of Earth, Mars, and Venus have been preserved on the Moon in high enough concentrations to motivate a search mission. During the Late Heavy Bombardment, the inner planets experienced frequent large impacts. Material ejected by these impacts near the escape velocity would have had the potential to land and be preserved on the surface of the Moon. Such ejecta could yield information on the geochemical and biological state of early Earth, Mars, and Venus. To determine whether the Moon has preserved enough ejecta to justify a search mission, we calculate the amount of terran material incident on the Moon over its history by considering the distribution of ejecta launched from the Earth by large impacts. In addition, we make analogous estimates for Mars and Venus. We find, for a well-mixed regolith, that the median surface abundance of terran material is roughly 7 ppm, corresponding to a mass of approximately 20,000 kg of terran material over a 10×10-square-km area. Over the same area, the amount of material transferred from Venus is 1-30 kg and material from Mars as much as 180 kg. Given that the amount of terran material is substantial, we estimate the fraction of this material surviving impact with intact geochemical and biological tracers.  相似文献   

2.
The European SMART-1 mission to the Moon, primarily a testbed for innovative technologies, was launched in September 2003 and will reach the Moon in 2005. On board are several scientific instruments, including the point-spectrometer SMART-1 Infrared Spectrometer (SIR). Taking into account the capabilities of the SMART-1 mission and the SIR instrument in particular, as well as the open questions in lunar science, a selection of targets for SIR observations has been compiled. SIR can address at least five topics: (1) Surface/regolith processes; (2) Lunar volcanism; (3) Lunar crust structure; (4) Search for spectral signatures of ices at the lunar poles; and (5) Ground truth and study of geometric effects on the spectral shape. For each topic we will discuss specific observation modes, necessary to achieve our scientific goals. The majority of SIR targets will be observed in the nadir-tracking mode. More than 100 targets, which require off-nadir pointing and off-nadir tracking, are planned. It is expected that results of SIR observations will significantly increase our understanding of the Moon. Since the exact arrival date and the orbital parameters of the SMART-1 spacecraft are not known yet, a more detailed planning of the scientific observations will follow in the near future.  相似文献   

3.
The demonstration of a compact imaging X-ray spectrometer (D-CIXS), which flew on ESA's SMART-1 mission to the Moon (Racca et al., 2001; Foing et al., 2006), was designed to test innovative new technologies for orbital X-ray fluorescence spectroscopy. D-CIXS conducted observations of the lunar surface from January 2005 until SMART-1 impacted the Moon in September 2006. Here, we present scientific observations made during two solar flare events and show the first detection of Titanium Kα from the lunar surface. We discuss the geological implications of these results. We also discuss how experience from D-CIXS has aided the design of a similar instrument (Chandrayaan-1 X-ray Spectrometer (C1XS)) that was launched on the 22nd October 2008 on India's Chandrayaan-1 mission to the Moon.  相似文献   

4.
A method for space mission trajectory design is presented in the form of a greedy global search algorithm. It uses invariant manifolds of unstable periodic orbits and its main advantage is that it performs a global search for the suitable legs of the invariant manifolds to be connected for a preliminary transfer design, as well as the appropriate points of the legs for maneuver application. The designed indirect algorithm bases the greedy choice on the optimality conditions that are assumed for the theoretical minimum transfer cost of a spacecraft when using invariant manifolds. The method is applied to a test case space mission design project in the Earth–Moon system and is found to compare favorably with previous techniques applied to the same project.  相似文献   

5.
The importance of an accurate model of the Moon gravity field has been assessed for future navigation missions orbiting and/or landing on the Moon, in order to use our natural satellite as an intermediate base for next solar system observations and exploration as well as for lunar resources mapping and exploitation. One of the main scientific goals of MAGIA mission, whose Phase A study has been recently funded by the Italian Space Agency (ASI), is the mapping of lunar gravitational anomalies, and in particular those on the hidden side of the Moon, with an accuracy of 1 mGal RMS at lunar surface in the global solution of the gravitational field up to degree and order 80. MAGIA gravimetric experiment is performed into two phases: the first one, along which the main satellite shall perform remote sensing of the Moon surface, foresees the use of Precise Orbit Determination (POD) data available from ground tracking of the main satellite for the determination of the long wavelength components of gravitational field. Improvement in the accuracy of POD results are expected by the use of ISA, the Italian accelerometer on board the main satellite. Additional gravitational data from recent missions, like Kaguya/Selene, could be used in order to enhance the accuracy of such results. In the second phase the medium/short wavelength components of gravitational field shall be obtained through a low-to-low (GRACE-like) Satellite-to-Satellite Tracking (SST) experiment. POD data shall be acquired during the whole mission duration, while the SST data shall be available after the remote sensing phase, when the sub-satellite shall be released from the main one and both satellites shall be left in a free-fall dynamics in the gravity field of the Moon. SST range-rate data between the two satellites shall be measured through an inter-satellite link with accuracy compliant with current state of art space qualified technology. SST processing and gravitational anomalies retrieval shall benefit from a second ISA accelerometer on the sub-satellite in order to decouple lunar gravitational signal from other accelerations. Experiment performance analysis shows that the stated scientific requirements can be achieved with a low mass and low cost sub-satellite, with a SST gravimetric mission of just few months.  相似文献   

6.
In view of the scheduled satellite mission EXOSAT (European X-Ray Observatory Satellite) of ESA (European Space Agency) the lunar occultation technique to determine the position of point-like X-ray sources is investigated. An error analysis for the source coordinates resulting from this technique is presented and an occultation strategy is proposed to achieve optimum lunar occultations. The analysis takes into account the errors of the space coordinates of the satellite and the Moon, the unevenness of the lunar surface, the intensities of source and background, the apparent angular velocity of the Moon as seen from the satellite, the finite sizes of the preoccultation position error boxes of the X-ray sources and the inaccuracies in the satellite orbit correction manoeuvres necessary to achieve the occultations.  相似文献   

7.
Low Energy Transfer to the Moon   总被引：15，自引：0，他引：15  
In 1991, the Japanese Hiten mission used a low energy transfer with a ballistic capture at the Moon which required less Vthan a standard Hohmann transfer. In this paper, we apply the dynamical systems techniques developed in our earlier work to reproduce systematically a Hiten-like mission. We approximate the Sun–Earth–Moon-spacecraft 4-body system as two 3-body systems. Using the invariant manifold structures of the Lagrange points of the 3-body systems, we are able to construct low energy transfer trajectories from the Earth which execute ballistic capture at the Moon. The techniques used in the design and construction of this trajectory may be applied in many situations.  相似文献   

8.
Radar sounding of the surface and near-surface layer of the Moon by the RLK-L low-frequency radar complex from the orbiter module is planned for the Moon-Globe Russian mission. To forecast results of radar experiments, a simulation procedure of the reflection of the RLK-L radar signal by the Moon’s surface is designed. The 3D surface model, based on measurement results of the Lunar Orbiter Laser Altimeter (LOLA) of the Lunar Reconnaissance Orbiter mission was used in the calculations. The simulation results showed that the spectrum shape of the reflected signal depends on the relief type in the experimental area. Therefore, when the depth distribution of the permittivity of the geological media is determined, the topographic information should be taken into account.  相似文献   

9.
A statistical study has been carried out of the availability of favourable flight opportunities to near-Earth asteroids with orbits similar to the Earth's. Emphasis is given to rendezvous-type mission profiles employing two-burn impulsive transfers. Velocity-optimized Lambert trajectories for a sample of 27 actual objects were calculated and compiled in a database. The velocity and flight time statistics of the resulting 1200 different solutions covering a period of 11 years have been investigated and discussed. Comparison with typical flight profiles to the Moon and near planets has revealed flight opportunities to 5 objects within a decade from the present requiring less ΔV than favourable flight opportunities to Mars or Venus. One of the objects involved, 1999 AO10, can be rendezvoused with using a total velocity increment that is smaller than that required to establish a lunar orbiter. The use of slow flybys for the most scientifically appealing targets is illustrated through an example trajectory involving the C-class binary object 1996 FG3. The challenges and opportunities for doing science in proximity to such small objects are also discussed.  相似文献   

10.
This paper presents a definition study of a laser altimeter for the topographic exploration of Mercury. The reference scenario is the BepiColombo mission, a cornerstone mission of European Space Agency (ESA) planned for 2012. BepiColombo will offer the chance to make a remarkable new contribution to our knowledge of the Solar System, by venturing into the hot region near the Sun and exploring Mercury, the most enigmatic of the earth's sisters among the terrestrial planets. First images of Mercury surface were acquired by Mariner 10 in 1974 and 1975 offering a coverage and resolution comparable to Earth-based telescopic coverage of the Moon before spaceflight. BepiColombo mission can be very beneficial by using an optical rangefinder for Mercury exploration. In fact starting from the first missions in 1970s until today, laser altimeters have been demonstrating to be particularly appropriate as part of the scientific payload whenever the topography of earth, lunar and planetary surface is the scientific objective of a space mission.Our system design is compliant to Mercury Polar Orbiter (MPO) of the mission. System performance analysis is carried out simulating main hermean topographic features and the potential targets on the planet by means of analytical models and computer codes and several plot are presented to analyse the performance of the instrument.  相似文献   

11.
The SMART-1 mission has recently arrived at the Moon. Its payload includes D-CIXS, a compact X-ray spectrometer. SMART-1 is a technology evaluation mission, and D-CIXS is the first of a new generation of planetary X-ray spectrometers. Novel technologies enable new capabilities for measuring the fluorescent yield of a planetary surface or atmosphere which is illuminated by solar X-rays. During the extended SMART-1 cruise phase, observations of the Earth showed strong argon emission, providing a good source for calibration and demonstrating the potential of the technique. At the Moon, our initial observations over Mare Crisium show a first unambiguous remote sensing of calcium in the lunar regolith. Data obtained are broadly consistent with current understanding of mare and highland composition. Ground truth is provided by the returned Luna 20 and 24 sample sets.  相似文献   

12.
NASA and ESA have outlined visions for solar system exploration that will include a series of lunar robotic precursor missions to prepare for, and support a human return to the Moon, and future human exploration of Mars and other destinations, including possibly asteroids. One of the guiding principles for exploration is to pursue compelling scientific questions about the origin and evolution of life. The search for life on objects such as Mars will require careful operations, and that all systems be sufficiently cleaned and sterilized prior to launch to ensure that the scientific integrity of extraterrestrial samples is not jeopardized by terrestrial organic contamination. Under the Committee on Space Research’s (COSPAR’s) current planetary protection policy for the Moon, no sterilization procedures are required for outbound lunar spacecraft, nor is there a different planetary protection category for human missions, although preliminary COSPAR policy guidelines for human missions to Mars have been developed. Future in situ investigations of a variety of locations on the Moon by highly sensitive instruments designed to search for biologically derived organic compounds would help assess the contamination of the Moon by lunar spacecraft. These studies could also provide valuable “ground truth” data for Mars sample return missions and help define planetary protection requirements for future Mars bound spacecraft carrying life detection experiments. In addition, studies of the impact of terrestrial contamination of the lunar surface by the Apollo astronauts could provide valuable data to help refine future Mars surface exploration plans for a human mission to Mars.  相似文献   

13.
《Planetary and Space Science》2007,55(11):1518-1529
Low-energy neutral atom (LENA) observations bring us important information on particle environments around celestial objects such as Mercury and the Moon. In this paper, we report on new development of an LENA instrument for planetary explorations. The instrument is light weight (2 kg), and capable of mass and energy discrimination with a large sensitivity. The performance of the instrument is investigated by numerical simulations. By using our new computer code, we calculated 3D particle trajectories including ionization, neutralization, surface scattering, and secondary electron creation. This enables us to obtain detailed performance characterization of LENA measurements. We also made trajectory tracing of photons entering the instrument to acquire photon rejection capability. This LENA instrument has been selected for both the Indian lunar exploration mission Chandrayaan-1 and European–Japanese Mercury exploration mission BepiColombo.  相似文献   

14.
The UK-built Chandrayaan-1 X-ray Spectrometer (C1XS) is flying as an ESA instrument on India's Chandrayaan-1 mission to the Moon. The Chandrayaan-1 mission launched on the 22nd October 2008 and entered a 100 km polar lunar orbit on the 12th November 2008. C1XS builds on experience gained with the earlier D-CIXS instrument on SMART-1, but will be a technically much more capable instrument. Here we describe the instrument design.  相似文献   

15.
We describe a project for the measurement of elemental composition of the primary cosmic radiation to be performed by a space observatory orbiting around the Moon. The absence of atmosphere and the low intrinsic magnetic field of the Moon give access to the very low energy component of the cosmic radiation, allowing the search for rare events.The quest for antinuclei, the determination of the lunar lepton albedo and the abundance measurement of galactic radioactive clocks (Be10, C14, Al26) are the major tasks of the ANTARES apparatus (ANTimatter Assessment RESearch).We report details of the instrument design, the expected performance for single detectors, their capability to accomplish the proposed measurements and the characteristics of the space mission.  相似文献   

16.
Space astronomy in the last 40 years has largely been done from spacecraft in low Earth orbit (LEO) for which the technology is proven and delivery mechanisms are readily available. However, new opportunities are arising with the surge in commercial aerospace missions. We describe here one such possibility: deploying a small instrument on the Moon. This can be accomplished by flying onboard the Indian entry to the Google Lunar X PRIZE competition, Team Indus mission, which is expected to deliver a nearly 30 kgs of payloads to the Moon, with a rover as its primary payload. We propose to mount a wide-field far-UV (130–180 nm) imaging telescope as a payload on the Team Indus lander. Our baseline operation is a fixed zenith pointing but with the option of a mechanism to allow observations of different attitudes. Pointing towards intermediate ecliptic latitude (50° or above) ensures that the Sun is at least 40° off the line of sight at all times. In this position, the telescope can cover higher galactic latitudes as well as parts of Galactic plane. The scientific objectives of such a prospective are delineated and discussed.  相似文献   

17.
Vaduvescu  O.  Aznar Macias  A.  Wilson  T. G.  Zegmott  T.  Pérez Toledo  F. M.  Predatu  M.  Gherase  R.  Pinter  V.  Pozo Nunez  F.  Ulaczyk  K.  Soszyński  I.  Mróz  P.  Wrona  M.  Iwanek  P.  Szymanski  M.  Udalski  A.  Char  F.  Salas Olave  H.  Aravena-Rojas  G.  Vergara  A. C.  Saez  C.  Unda-Sanzana  E.  Alcalde  B.  de Burgos  A.  Nespral  D.  Galera-Rosillo  R.  Amos  N. J.  Hibbert  J.  López-Comazzi  A.  Oey  J.  Serra-Ricart  M.  Licandro  J.  Popescu  M. 《Earth, Moon, and Planets》2022,126(2):1-26
Earth, Moon, and Planets - The Perseverance rover (Mars 2020) mission, the first step in NASA’s Mars Sample Return (MSR) program, will select samples for caching based on their potential to...  相似文献   

18.
The Mission MAGIA (Missione Altimetrica Geofisica GeochImica lunAre) was proposed in the framework of the ??Bando per Piccole Missioni?? of ASI (Italian Space Agency) in 2007. The mission was selected for a phase A study by ASI on February 7th 2008. The tight budget allocation, combined with quite ambitious scientific objectives, set challenging requirements for the satellite design. The paper gives a fast overview of the payloads complement and of the mission-constrained design drivers, including cost minimization, risk reduction, and AIT flexibility. The spacecraft architecture is then outlined, along with an overview of the key subsystems and trade-offs. Some details are given of a Moon gravitometric experiment based on a mother?Cdaughter satellite configuration with the daughter being a subsatellite released from the MAGIA satellite and intended to circle the Moon at a very low altitude. Budgets are appended at the end of the paper showing the key study results.  相似文献   

19.
The D-CIXS X-ray spectrometer on ESA's SMART-1 mission will provide the first global coverage of the lunar surface in X-rays, providing absolute measurements of elemental abundances. The instrument will be able to detect elemental Fe, Mg, Al and Si under normal solar conditions and several other elements during solar flare events. These data will allow for advances in several areas of lunar science, including an improved estimate of the bulk composition of the Moon, detailed observations of the lateral and vertical nature of the crust, chemical observations of the maria, investigations into the lunar regolith, and mapping of potential lunar resources. In combination with information to be obtained by the other instruments on SMART-1 and the data already provided by the Clementine and Lunar Prospector missions, this information will allow for a more detailed look at some of the fundamental questions that remain regarding the origin and evolution of the Moon.  相似文献   

20.
Recent geochemical and geophysical data suggest that the initial temperature of the Moon was strongly peaked toward the lunar surface. To explain such an initial temperature distribution, a simple model of accretion process of the Moon is presented. The model assumes that the Moon was formed from the accumulation of the solid particles or gases in the isolated, closed cloud. Two equations are derived to calculate the accretion rate and surface temperature of the accreting Moon. Numerical calculations are made for a wide range of the parameters particle concentration and particle velocity in the cloud. A limited set of the parameters gives the initial temperature profiles as required by geochemical and geophysical data. These models of the proto-moon cloud indicate that the lunar outershell, about 400 km thick, was partially or completely molten just after the accretion of the Moon and that the Moon should have been formed in a period shorter than 1000 yr. If the Moon formed at a position nearer to the Earth than its present one, the Moon might have been formed in a period of less than one year.On leave from Geophysical Institute, University of Tokyo.Contribution No. 2104, Division of Geological and Planetary Sciences, California Institute of Technology.  相似文献   

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