The 2009 Mars Telecom Orbiter mission

A Mars relay network is being built using relay radios on nearly every Mars orbiter. Mars relay network performance has been limited because Mars orbiters are usually designed to support science missions from low, near-polar orbits; their relay functions are of secondary importance in spacecraft and mission design. The ASI/NASA G. Marconi Orbiter (GMO) will be the first Mars orbiter designed primarily for relay support; science experiments on GMO are secondary. Combining a high performance relay with a custom relay orbit, GMO can increase the data retumed from in-situ missions by an order of magnitude. GMO will increase connectivity to in-situ missions from a few minutes (typical of other orbit-ers) to hours at a time, offering much greater operational flexibility and resilience and enabling new relay services.

2007

MetNet Mars Mission is an in situ observational network and orbital platform mission to investigate the Martian environment and it has been proposed to European Space Agency in response to Call for proposals for the first planning cycle of Cosmic Vision 2015-2025 D/SCI/DJS/SV/val/21851. The MetNet Mars Mission is to be implemented in collaboration with ESA, FMI, LA, IKI and the payload providing science teams. The scope of the MetNet Mission is to deploy 16 MetNet Landers (MNLs) on the Martian surface by using inflatable descent system structures accompanied by an atmospheric sounder and data relay onboard the MetNet Orbiter (MNO), which is based on ESA Mars Express satellite platform. The MNLs are attached on the three sides of the satellite and most of the MNLs are deployed to Mars separately a few weeks prior to the arrival to Mars. The MetNet Orbiter will perform continuous atmospheric soundings thus complementing the accurate in situ observations at the Martian ground produced by the MetNet observation network, as well as the orbiter will serve as the primary data relay between the MetNet Landers and the Earth. The MNLs are equipped with a versatile science payload focused on the atmospheric science of Mars. Detailed characterisation of the Martian atmospheric circulation patterns, boundary layer phenomena, and climatological cycles, as well as interior investigations, require simultaneous in-situ meteorological, seismic and magnetic measurements from networks of stations on the Martian surface. MetNet Mars Mission will also provide a crucial support for the safety of large landing missions in general and manned Mars missions in particular. Accurate knowledge of atmospheric conditions and weather data is essential to guarantee safe landings of the forthcoming Mars mission elements.

2010

The Phoenix Lander, first of NASA's Mars Scout missions, arrived at the Red Planet on May 25, 2008. From the moment the lander separated from its interplanetary cruise stage shortly before entry, the spacecraft could no longer communicate directly with Earth, and was instead entirely dependent on UHF relay communications via an international network of orbiting Mars spacecraft, including NASA's 2001 Mars Odyssey (ODY) and Mars Reconnaissance Orbiter (MRO) spacecraft, as well as ESA's Mars Express (MEX) spacecraft. All three orbiters captured critical event telemetry and/or tracking data during Phoenix entry, descent and landing. During the Phoenix surface mission, ODY and MRO provided command and telemetry services, far surpassing the original data return requirements. The availability of MEX as a backup relay asset enhanced the robustness of the overall relay plan. In addition to telecommunications services, Doppler tracking observables acquired on the UHF link yielded a highly accurate position for the Phoenix landing site.

Acta Astronautica, 2001

The planned exploration of Mars will pose new and unique telecommunciations and navigation challenges. The full range of orbital, atmospheric, and surface exploration will drive requirements on data return, energyefficient communications, connectivity, and positioning. In this paper we will summarize the needs of the currently planned Mars exploration mission set, outline design trades and options for meeting these needs, and quantify the speofic telecommunications and navigation capabilities of an evolving infrastructure.

International …, 2001

Next-generation Mars communications networks will provide communications and navigation services to a wide variety of Mars science vehicles including: spacecraft that are arriving at Mars, spacecraft that are entering and descending in the Mars atmosphere, scientific orbiter spacecraft, spacecraft that return Mars samples to Earth, landers, rovers, aerobots, airplanes, and sensing pods. In the current architecture plans, the communication services will be provided using capabilities deployed on the science vehicles as well as dedicated communication satellites that will together make up the Mars network. This network will evolve as additional vehicles arrive, depart or end their useful missions. Cost savings and increased reliability will result from the ability to share communication services between missions.

Advances in Space Research, 2008

This paper analyses the possibility of exploiting a small spacecrafts constellation around Mars to ensure a complete and continuous coverage of the planet, for the purpose of supporting future human and robotic operations and taking advantage of optical transmission techniques. The study foresees such a communications mission to be implemented at least after 2020 and a high data-rate requirement is imposed for the return of huge scientific data from massive robotic exploration or to allow video transmissions from a possible human outpost.In addition, the set-up of a communication constellation around Mars would give the opportunity of exploiting this multi-platform infrastructure to perform network science, that would largely increase our knowledge of the planet.The paper covers all technical aspects of a feasibility study performed for the primary communications mission. Results are presented for the system trade-offs, including communication architecture, constellation configuration and transfer strategy, and the mission analysis optimization, performed through the application of a multi-objective genetic algorithm to two models of increasing difficulty for the low-thrust trajectory definition.The resulting communication architecture is quite complex and includes six 530 kg spacecrafts on two different orbital planes, plus one redundant unit per plane, that ensure complete coverage of the planet’s surface; communications between the satellites and Earth are achieved through optical links, that allow lower mass and power consumption with respect to traditional radio-frequency technology, while inter-satellite links and spacecrafts-to-Mars connections are ensured by radio transmissions. The resulting data-rates for Earth–Mars uplink and downlink, satellite-to-satellite and satellite-to-surface are respectively 13.7 Mbps, 10.2 Mbps, 4.8 Mbps and 4.3 Mbps, in worst-case.Two electric propulsion modules are foreseen, to be placed on a C3∼0 escape orbit with two Zenith Sea Launch rockets in March 2021 and carrying four satellites each. After the entrance in Mars sphere of influence, the single spacecrafts separate and spiral-down with Hall effect thrusters until they reach the final operational orbits in April 2025, at 17,030 km of altitude and 37 deg of inclination. The preliminary design includes 105 kg and 577 W of mass and power margin for each satellite, that can be allocated for scientific payloads.The main challenges of the proposed design are represented by the optical technology development and the connected strict pointing constraints satisfaction, as well as by the Martian constellation operations management.This mission study has therefore shown the possibility of deploying an effective communication infrastructure in Mars orbit employing a small amount of the resources needed for the human exploration programme, additionally providing the chance of performing important scientific research either from orbit or with a network of small rovers carried on-board and deployed on the surface.

Annals of The New York Academy of Sciences, 2005

Abstract: The author developed the MarsSat concept during the 1990s. For this task, he designed a class of orbits to solve the problem of communicating with crews on Mars when the planet is in solar conjunction as seen from Earth, a planetary configuration that occurs near the midpoint of a conjunction class mission to Mars. This type of orbit minimizes the distance between Mars and the communications satellite; thus, minimizing the size, weight, and power requirements, while providing a simultaneous line-of-sight to both Earth and Mars. The MarsSat orbits are solar orbits that have the same period as Mars, but are inclined a few degrees out of the plane of the Mars orbit and also differ in eccentricity from the orbit of Mars. These differences cause a spacecraft in this orbit to rise North of Mars, then fall behind Mars, then drop South of Mars, and then pull ahead of Mars, by some desired distance in each case—typically about 20 million kilometers—in order to maintain an angular separation of a couple of degrees as seen from a point in the orbit of Earth on the opposite side of the Sun. A satellite in this type of orbit would relay communications between Earth and Mars during the period of up to several weeks, when direct communication is blocked by the Sun. These orbits are far superior for this purpose when compared to stationing a satellite at one of the Sun-Mars equilateral Lagrangian points, L4 or L5, for two reasons. First, L4 and L5 are 228 million kilometers from Mars, about 10 times the distance of a spacecraft in one of the MarsSat orbits, and by virtue of the inverse-square law, all other things being equal, the signal strength received at L4 or L5 would be one percent of the signal strength received by a spacecraft in one of the MarsSat orbits. Thus, a relay satellite stationed at L4 or L5 would have to be that much more powerful to receive data at the same rate, with concomitant increases in spacecraft size and weight. Second, a number of Martian Trojan asteroids have been discovered at the Sun-Mars L4 and L5 points, and there are probably countless smaller objects that have collected in these regions that pose a significant threat to any spacecraft located there.

Deep Space Communications, 2016

Geoscientific Instrumentation, Methods and Data Systems Discussions, 2016

Bandwidth utilization in the Mars exploration environment has been projected to increase past 1 Gbps duplex within the next decade. At present, all communication is routed through the Deep Space Network and is subject to the variable orbital geometry of Earth, Mars and the Sun. Data Communication speeds, between Earth and Mars, are neither satisfactory nor can they be utilized on a 24x7 basis, due in part to the lack of a space based telecommunication backbone. A holistic assessment of the merits of multi-hop communication in deep space was undertaken during 2009-2010, and a potentially robust new solution, employing a novel Linear-Circular Commutating Chain (LC3) architecture, developed for persistent, broadband connectivity between Earth and Mars. New classes of spacecraft suitable for use as Multi-purpose Interplanetary Relay (MIR) satellites in heliocentric orbit are outlined. Preliminary communication link budget and orbital analysis of a two-constellation MIR satellite network is presented, consisting of a linear chain of satellites ( group, 36 nodes) following Mars, and a circular chain of satellites located inside of Earth's orbit ( group, 292 nodes). Potential orbital tracks are presented for network (365 nodes,

Digest of the LEOS Summer Topical Meetings, 2005.

This paper provides an overview of the Mars Laser Communications Demonstration Project, a joint project between NASA's Goddard Space Flight Center (GSFC),

2009

Sahara. Nineteen experiments were conducted by a field crew in Morocco under simulated Mars surface exploration conditions, supervised by a Mission Support Center in Innsbruck, Austria. A Remote Science Support team analyzed field data in near-real time, providing planning input for the management of a complex system of field assets: two advanced spacesuit simulators, four robotic vehicles, an emergency shelter and a stationary sensor platform in a realistic workflow were coordinated by a Flight Control Team. A dedicated Flight Planning group, external control centers for rover tele-operations and a biomedical monitoring team supported the field operations. A ten minutes satellite communication delay and other limitations pertinent to human planetary surface activities were introduced. The fields of research for the experiments were geology, human factors, astrobiology, robotics, telescience, exploration and operations research. This paper provides an overview of the geological context and environmental conditions of the test site and the mission archtitecture, in particular the communication infrastructure emulating the signal travel time between Earth and Mars. We report on the operational workflows and the experiments conducted, including a deployable shelter prototype for multiple-day extravehicular activities and contingency situations.

2005 IEEE Aerospace Conference, 2005

The Mission Management Office at the Jet Propulsion Laboratory was tasked with coordinating the relay of data between multiple spacecraft at Mars in support of the Mars Exploration Rover missions in early 2004. The confluence of three orbiters (Mars Global Surveyor, Mars Odyssey, and Mars Express), two rovers (Spirit and Opportunity), and one lander (Beagle 2) has provided a challenging operational scenario that required careful coordination between missions to provide the necessary support and to avoid potential interference during simultaneous relay sessions. As these coordination efforts progressed, several important lessons were learned that should be applied to future Mars relay activities. TABLE OF CONTENTS 1.0 INTRODUCTION.