Luciano Anselmo | Consiglio Nazionale delle Ricerche (CNR) (original) (raw)

Papers by Luciano Anselmo

cosp, 2010

A previous study (Pardini C., Anselmo L, Moe K., Moe M.M., Drag and energy accommodation coeffici... more A previous study (Pardini C., Anselmo L, Moe K., Moe M.M., Drag and energy accommodation coefficients during sunspot maximum, Adv. Space Res., 2009, doi:10.1016/j.asr.2009.08.034), including ten satellites with altitudes between 200 and 630 km, has yielded values for the energy accommodation coefficient as well as for the physical drag coefficient as a function of height during solar maximum conditions. The

International Institute of Space Law, 1994

A space mission is described which consists of a rigid spin-axis-stabilised spacecraft with two s... more A space mission is described which consists of a rigid spin-axis-stabilised spacecraft with two small, high-density masses free-falling inside. The gravitational attraction of the masses dominates all perturbations, providing a miniature "planet-satellite" system that can only be realised in space. Unlike any celestial two-body system, the masses can be weighed on Earth before launch. Thus, monitoring their motion by means

42nd COSPAR Scientific Assembly, Jul 1, 2018

40th COSPAR Scientific Assembly, 2014

Passive laser-ranged satellites, launched for geodynamics and geophysics purposes, not only have ... more Passive laser-ranged satellites, launched for geodynamics and geophysics purposes, not only have contributed to significant measurements in space geodesy that enabled, among several aspects, a deeper knowledge of the Earth's geopotential (both in its static and dynamic behavior), as well as of the geocenter motion and GM value up to the definition of the terrestrial reference frame, but they also provided an outstanding test bench to fundamental physics, as in the case of the first measurement of the Lense-Thirring precession on the combined nodes of the two LAGEOS satellites, or in the case of the total relativistic precession of the argument of pericenter of LAGEOS II. Indeed, the physical characteristics of such satellites -- such as their low area-to-mass ratio -- as well as those of their orbits, and the availability of high-quality tracking data provided by the International Laser Ranging Service (ILRS), allow for precise tests of gravitational theories. The aim of LARASE (LAser RAnged Satellites Experiment) is to go a step further in the tests of the gravitational interaction in the field of Earth, i.e. in the weak-field and-slow motion limit of general relativity, by the joint analysis of the orbits of the two LAGEOS satellites and that of the most recent LARES satellite. One of the key ingredients to reach such a goal is to provide high-quality updated models for the perturbing non-gravitational forces acting on the surface of such satellites. A large amount of Satellite Laser Ranging (SLR) data of LAGEOS and LAGEOS II has been analyzed using a set of dedicated models for satellite dynamics, and the related post-fit residuals have been analyzed. A parallel work is on-going in the case of LARES that, due to its much lower altitude, is subject to larger gravitational and non-gravitational effects; the latter are mitigated in part by its much lower area-to-mass ratio. Recent work on the data analysis of the orbit of such satellites will be presented together with the development of some new refined models to account for the impact of the subtle and complex non-gravitational perturbations. The general relativistic effects leave peculiar imprint on the satellite orbit, namely in the secular behavior of its three Euler angles. Recent results will be provided together with updated constraints on non-Newtonian gravitational dynamics. The measurement error budget will be discussed, emphasizing the role of the modeling of gravitational and, especially, non-gravitational forces on the overall precise orbit determination quality, as well as on future new measurements and constraints of the gravitational interaction. <P /

EGU General Assembly Conference Abstracts, Apr 1, 2017

Acta Astronautica, Sep 1, 2023

EGU General Assembly Conference Abstracts, Apr 1, 2018

Acta Astronautica, Nov 1, 2017

Journal of The Astronautical Sciences, Mar 1, 2000

Acta Astronautica, Sep 1, 2016

Abstract A new ranking index was developed and applied to a wide set of rocket body families, cha... more Abstract A new ranking index was developed and applied to a wide set of rocket body families, characterized by stage dry masses greater than 500 kg and by the presence of at least 5 stages abandoned in LEO. The upper stages selected accounted for more than 80% of the unclassified rocket bodies in LEO and nearly 95% of the associated dry mass. The detailed results obtained for 657 objects clearly identified the most critical altitude-inclination bands and stage models, to be targeted first if and when a debris remediation strategy including the active removal of intact abandoned objects were deemed necessary. Apart from the evaluation of the criticality regarding the long-term evolution of the debris environment, resulting in a priority listing for optimal active removal, the application of the new ranking index is not limited to debris remediation. In fact, if applied before launch to spacecraft and rocket bodies to be disposed in orbit, at the end of mission, it would provide an additional debris mitigation analysis tool for evaluating competing disposal options. Concerning the rocket bodies abandoned in LEO, 274 resulted to have a criticality equal or larger than the average intact object abandoned in an 800 km sun-synchronous orbit. Among them, 243 belonged to the Russian Federation and Ukraine, 25 to China, 5 to Europe and 1 to Japan. In addition to being concentrated in relatively few and narrow altitude-inclinations bands, the most numerous rocket body families often present a quite uniform distribution in right ascension of the ascending node, which is especially convenient for multiple target removal missions.

Acta Astronautica, May 1, 2016

cosp, 2010

International Institute of Space Law, 1994

42nd COSPAR Scientific Assembly, Jul 1, 2018

40th COSPAR Scientific Assembly, 2014

EGU General Assembly Conference Abstracts, Apr 1, 2017

Acta Astronautica, Sep 1, 2023

EGU General Assembly Conference Abstracts, Apr 1, 2018

Acta Astronautica, Nov 1, 2017

Journal of The Astronautical Sciences, Mar 1, 2000

Acta Astronautica, Sep 1, 2016

Acta Astronautica, May 1, 2016

Looking at the situation in low Earth orbit (LEO), i.e. below 2000 km, on September 9, 2017, ther... more Looking at the situation in low Earth orbit (LEO), i.e. below 2000 km, on September 9, 2017, there were 21 Italian satellites, one spent upper stage, crossing most of the region, and one debris related to the OptSat 3000 classified mission, probably a mission related object (MRO). They represented just 0.18% of the objects cataloged in LEO by the US Space Surveillance Network (SSN). Moreover, since the release, in 2002, of the first version of the Mitigation Guidelines compiled by the Inter-Agency Space Debris Coordination Committee (IADC), there had been a significant improvement in the level of compliance with debris mitigation requirements for the Italian satellites, included the so called “25-year” rule, i.e. the limitation of the post-mission disposal lifetime to less than 25 years. Several objects had been, however, launched before the introduction of the IADC Mitigation Guidelines, and also before the more than doubling of the debris population below 1000 km caused, in 2007, by the Fengyun 1C anti-satellite test and, in 2009, by the accidental collision between Iridium 33 and Cosmos 2251.
In this paper, the environmental criticality of the Italian satellites in LEO, from the orbital debris point of view, was evaluated addressing the following issues:
• Their residual lifetime;
• The probability of impact with other objects;
• The probability of catastrophic fragmentation;
• The number of expected fragments in case of catastrophic collisional breakups;
• The possible interference with the orbit of the International Space Station;
• An overall ranking, using a criticality index developed by the authors.
The results obtained not only represented an updated assessment for the Italian objects launched until the summer of 2017, but also a guide for planning and conducting future missions in LEO in a way as safe and sensible as possible.

An extensive calibration of semi-empirical atmospheric density models (JR-71, MSIS-86, MSISE-90, ... more An extensive calibration of semi-empirical atmospheric density models (JR-71, MSIS-86, MSISE-90, TD-88) was carried out, by analyzing the orbital decay of nine spherical satellites in the 200-1500 km altitude range. The orbital decay data used spanned a full solar activity cycle (1987-1999). The drag coefficients obtained by fitting the observed semimaior axis evolution with a high accuracy orbit propagator were compared with those estimated by theoretical analysis. MSIS-86 and MSISE-90, practically identical above 200 km, resulted to be the best models to compute air density below 400 km, in low solar activity conditions. However, JR-71 seemed more precise at greater altitudes and/or solar activity. TD-88 gave quite mixed results, but generally closer to JR-71. The intrinsic accuracy of JR-71, MSIS-86 and MSISE-90 was generally better than 20%, often better than 15% and, sometimes, close to 10%. But at altitudes greater than 400 km this picture resulted progressively degraded. A better drag coefficient theory and dedicated laboratory measurements will be needed to investigate in detail the deficiencies of the current models and improve the knowledge of the earth atmosphere with satellite drag analysis.

The survivability analysis carried out to support the design of a new tether system, being studie... more The survivability analysis carried out to support the design of a new tether system, being studied in Italy for spacecraft and upper stages end-of-life de-orbiting, is presented. In particular, the problem represented by meteoroids and orbital debris impacts able to cut the tether was addressed, by considering several system configurations in order to find a solution able to meet the baseline mission requirements. In addition, the not negligible collision risk with large intact space objects, and between the tethers themselves, was analysed as well in its implications.

The paper presents a review of the management of the Mir deorbiting in Italy, with special emphas... more The paper presents a review of the management of the Mir deorbiting in Italy, with special emphasis on the role played by CNUCE, active in the field of reentry predictions for civil protection purposes since 1979.
After a short historical introduction, the criteria used for the definition of potentially risky space objects are presented and discussed, together with the lessons learned during previous reentry campaigns. The activity carried out for Mir is then described in detail, highlighting the end products needed for the civil protection emergency planning.
Mir was never declared a risk space object in Italy and only a limited alert status was activated, ready to switch to full emergency if needed. However, the event represented a useful training opportunity and a good example of international cooperation, paving the way for the future end-of-life disposal of large low earth spacecraft.

Tethers have been proposed for several space applications, like satellite de-orbiting or re-boost... more Tethers have been proposed for several space applications, like satellite de-orbiting or re-boost, electric energy generation, scientific research and so on. However, they may be vulnerable to orbital debris and meteoroid impacts.
The problem was assessed, to assist tether systems design, by detailed numerical computations of the average impact rate of artificial debris, taking into account the specific geometric properties of tethers as debris targets, when compared to typical satellites.
The results obtained confirm that, for single-strand tethers in low earth orbit, the probability to be severed by orbital debris and meteoroid impacts is quite significant, making necessary the adoption of innovative designs for long duration missions.

Following the catastrophic collisional breakups of three intact spacecraft (Fengyun 1C, Cosmos 22... more Following the catastrophic collisional breakups of three intact spacecraft (Fengyun 1C, Cosmos 2251 and Iridium 33) occurred in low Earth orbit, a detailed analysis was carried out, with a dedicated software tool (SDIRAT), in order to evaluate the additional impact flux of cataloged objects on the satellites of two operational constellations in high inclination orbits, Iridium and COSMO-SkyMed. As of 1 May 2011, the flux increase with respect to the debris background was 160%, on average, for the Iridium satellites, distributed on six equally spaced orbit planes at 781 km, and 47% at the altitude of the COSMO-SkyMed constellation, using a single orbit plane at 623 km.

This paper deals with the feasibility study of a mission for the active removal of a large massiv... more This paper deals with the feasibility study of a mission for the active removal of a large massive object, such as the second stage of the Zenit launcher or the Envisat spacecraft, abandoned in the most populated orbit region in low Earth orbit. Critical mission aspects and related technologies are investigated at a preliminary level. In particular, an innovative electro-adhesive system for target capture, mechanical systems for chaser-debris hard docking and a hybrid propulsion module for rendezvous and controlled de-orbiting and reentry are analyzed. A preliminary mass budget for the needed chaser platform and hybrid propulsion module is also performed, showing that the chaser spacecraft overall mass varies in the range 1500-1700 kg, with the propulsion module weighting about 900 kg.

In order to estimate the intrinsic accuracy of satellite reentry predictions, the residual lifeti... more In order to estimate the intrinsic accuracy of satellite reentry predictions, the residual lifetimes of 11 spacecraft and five rocket bodies, covering a broad range of inclinations and decaying from orbit in a period of high solar activity, were determined using three different atmospheric density models: JR-71, TD-88, and MSIS-86. For each object, the ballistic coefficient applicable to a specific phase of the flight was obtained by fitting an appropriate set of two-line orbital elements, while the reentry predictions were computed approximately one month, one week and one day before the final orbital decay. No clear correlation between the residual lifetime errors and satellite inclination or type (spacecraft or rocket body) emerged. JR-71 and MSIS-86 resulted in good agreement, with comparable reentry prediction errors (∼10%), semimajor axis residuals, and ballistic coefficient estimations. TD-88 exhibited a behaviour consistent with the other two models, but was typically characterised by larger reentry prediction errors (∼15–25%) and semimajor axis residuals. At low altitudes (<250 km), TD-88 systematically overestimated the average atmosphere density (by ∼25%) with respect to the other two models.

A review of the problem of the long-term uncontrolled growth of man-made objects in earth orbit i... more A review of the problem of the long-term uncontrolled growth of man-made objects in earth orbit is presented. After a discussion of the main underlying concepts, the relative effectiveness of the adoption of some mitigation measures over 100 – 200 years is analysed, including the minimisation of mission related objects release, the on-orbit explosion avoidance and the de-orbiting of spacecraft and upper stages in low earth orbit. It is shown that only the implementation of the full set of mitigation measures discussed would be able to guarantee the long-term approximate stabilisation of the population of large objects, maintaining at acceptable levels the growth of millimetre and centimetre sized debris.

Following the admission of the Italian Space Agency (ASI) in the Inter-Agency Space Debris Coordi... more Following the admission of the Italian Space Agency (ASI) in the Inter-Agency Space Debris Coordination Committee (IADC), the CNUCE Institute was involved, as the National Technical Contact Point, in the three test re-entry campaigns carried out between 1998 and 2000. The purpose of these campaigns was to test the timely distribution of data and information during high-risk re-entries by means of the IADC international communication network. During the second campaign, a further analysis was also performed at CNUCE to assess the confidence level of our computed re-entry predictions. Different semi-empirical atmospheric density models were used at the same time to predict the satellite's orbital decay as a function of solar activity conditions and altitude. In particular, the performances of two widely used thermospheric models were investigated and the resulting re-entry forecasts compared. The aim of this paper is to present the results obtained and the lessons learned during these international exercises.

EDOARD (Electrodynamic De-Orbiting And Re-entry Device) exploits the basic concepts of electrodyn... more EDOARD (Electrodynamic De-Orbiting And Re-entry Device) exploits the basic concepts of electrodynamic drag on conductive tethers to de-boost LEO spacecraft efficiently and reliably. The system is jointly developed by Alenia Spazio and by University " La Sapienza " in view of potential commercial exploitation. An innovative engineering approach has tackled four critical issues: 1) the deployment mechanism, which ensures a purely passive extension of the tether under extremely small gravity gradients; 2) the tether structure and configuration, which guarantees a very high survivability to impacts from artificial and natural debris; 3) the inflatable passive electron collector, which increases the efficiency of the system while reducing the tether length to 4-5 km and 4) the electrodynamic control of the tether librations, which limits the effects of inherent dynamical system instability, while preserving high de-orbiting efficiencies. The configuration ensures de-orbiting times per unit mass of about 0.09 day/kg from a circular, 1500 km altitude, 55 degree inclination.

The uncommon nature of the GOCE reentry campaign, sharing an uncontrolled orbital decay with a fi... more The uncommon nature of the GOCE reentry campaign, sharing an uncontrolled orbital decay with a finely controlled attitude along the atmospheric drag direction, made the reentry predictions for this satellite an interesting case study, especially because nobody was able to say a priori if and when the attitude control would have failed, leading to an unrestrained tumbling and a sudden variation of the orbital decay rate. As in previous cases, ISTI/CNR was in charge of reentry predictions for the Italian civil protection authorities, monitoring also the satellite decay in the frame of an international reentry campaign promoted by the Inter-Agency Space Debris Coordination Committee (IADC). Due to the peculiar nature of the GOCE reentry, the definition of reliable uncertainty windows was not easy, especially considering the critical use of this information for civil protection evaluations. However, after an initial period of test and analysis, reasonable and conservative criteria were elaborated and applied, with good and consistent results through the end of the reentry campaign. In the last three days of flight, reentries were simulated over Italy to obtain quite accurate ground tracks, debris swaths and air space crossing time windows associated with the critical passes over the national territory still included in the global uncertainty windows.