Combining solar science and asteroid science with the space weather observation network (SWON)

The peculiarity of space weather for Earth orbiting satellites, air traffic and power grids on Earth and especially the financial and operational risks posed by damage due to space weather, underline the necessity of space weather observation. The importance of such observations is even more increasing due to the impending solar maximum. In recognition of this importance we propose a mission architecture for solar observation as an alternative to already published mission plans like Solar Probe (NASA) or Solar Orbiter (ESA). Based upon a Concurrent Evaluation session in the Concurrent Engineering Facility of the German Aerospace Center, we suggest using several spacecraft in an observation network. Instead of placing such spacecraft in a solar orbit, we propose landing on several asteroids, which are in opposition to Earth during the course of the mission and thus allow observation of the Sun's far side. Observation of the far side is especially advantageous as it improves the warning time with regard to solar events by about 2 weeks. Landing on Inner Earth Object (IEO) asteroids for observation of the Sun has several benefits over traditional mission architectures. Exploiting shadowing effects of the asteroids reduces thermal stress on the spacecraft, while it is possible to approach the Sun closer than with an orbiter. The closeness to the Sun improves observation quality and solar power generation, which is intended to be achieved with a solar dynamic system. Furthermore landers can execute experiments and measurements with regard to asteroid science, further increasing the scientific output of such a mission. Placing the spacecraft in a network would also benefit the communication contact times of the network and Earth. Concluding we present a first draft of a spacecraft layout, mission objectives and requirements as well as an initial mission analysis calculation.     

The Mars Sample Return Project.

The Mars Sample Return (MSR) Project is underway. A 2003 mission to be launched on a Delta III Class vehicle and a 2005 mission launched on an Ariane 5 will culminate in carefully selected Mars samples arriving on Earth in 2008. NASA is the lead agency and will provide the Mars landed elements, namely, landers, rovers, and Mars ascent vehicles (MAVs). The French Space Agency CNES is the largest international partner and will provide for the joint NASA/CNES 2005 Mission the Ariane 5 launch and the Earth Return Mars Orbiter that will capture the sample canisters from the Mars parking orbits the MAVs place them in. The sample canisters will be returned to Earth aboard the CNES Orbiter in the Earth Entry Vehicles provided by NASA. Other national space agencies are also expected to participate in substantial roles. Italy is planning to provide a drill that will operate from the Landers to provide subsurface samples. Other experiments in addition to the MSR payload will also be carried on the Landers. This paper will present the current status of the design of the MSR missions and flight articles.     

Success criteria and risk management for the new millennium program

The National Aeronautics and Space Administration (NASA) New Millennium Program (NMP) is a technology development and validation program that will flight-validate advanced, new technologies with space flight applications. NMP's purpose is twofold. First, it will develop technologies that will enable future spacecraft to be smaller, more capable and reliable, and to be launched more frequently. Second, it will validate the technologies in flight to reduce the risks to future science missions that fly these technologies for the first time. To measure the program's success, NMP has devised a set of criteria that stresses the relevance of technologies selected for flight validation to NASA's 21st-century science mission needs. Also, NMP has instituted a ‘risk management’ policy, where, through a combination of adequate resources and early risk assessment and risk mitigation plans for the technologies, the overall risk of the NMP flights can be rendered acceptable.     

Meditations on the new space vision: the Moon as a stepping stone to Mars

The Vision for Space Exploration invokes activities on the Moon in preparation for exploration of Mars and also directs International Space Station (ISS) research toward the same goal. Lunar missions will emphasize development of capability and concomitant reduction of risk for future exploration of Mars. Earlier papers identified three critical issues related to the so-called NASA Mars Design Reference Mission (MDRM) to be addressed in the lunar context: (a) safety, health, and performance of the human crew; (b) various modalities of mission operations ranging surface activities to logistics, planning, and navigation; and (c) reliability and maintainability of systems in the planetary environment. In simple terms, lunar expeditions build a résumé that demonstrates the ability to design, construct, and operate an enterprise such as the MDRM with an expectation of mission success. We can evolve from Apollo-like missions to ones that resemble the complexity and duration of the MDRM. Investment in lunar resource utilization technologies falls naturally into the Vision. NASA must construct an exit strategy from the Moon in the third decade. With a mandate for continuing exploration, it cannot assume responsibility for long-term operation of lunar assets. Therefore, NASA must enter into a partnership with some other entity--governmental, international, or commercial--that can responsibly carry on lunar development past the exploration phase.     

Comparative assessment of human–Mars-mission technologies and architectures

We compare a variety of mission scenarios to assess the strengths and weaknesses of options for Mars exploration. The mission design space is modeled along two dimensions: trajectory architectures and propulsion system technologies. We examine direct, semi-direct, stop-over, semi-cycler, and cycler architectures, and we include electric propulsion, nuclear thermal rockets, methane and oxygen production on Mars, Mars water excavation, aerocapture, and reusable propulsion systems in our technology assessment. The mission sensitivity to crew size, vehicle masses, and crew travel time is also examined. Many different combinations of technologies and architectures are applied to the same Mars mission to determine which combinations provide the greatest potential reduction in the injected mass to LEO. We approximate the technology readiness level of a mission to rank development risk, but omit development cost and time calculations in our assessment. It is found that Earth–Mars semi-cyclers and cyclers require the least injected mass to LEO of any architecture and that the discovery of accessible water on Mars has the most dramatic effect on the evolution of Mars exploration.     

Inflatable composite habitat structures for lunar and mars exploration

Recent advances in materials technology have improved the performance capabilities of inflatable, flexible composite structures, which have increased their potential for use in numerous space applications. Space suits, which are comprised of flexible composite components, are a good example of the successful use of inflatable composite structures in space. Space suits employ inflatables technology to provide a stand alone spacecraft for astronauts during extra-vehicular activity. A natural extension of this application of inflatables technology is in orbital or planetary habitat structures. NASA Johnson Space Center (JSC) is currently investigating flexible composite structures deployed via inflation for use as habitats, transfer vehicles and depots for continued exploration of the Moon and Mars.

Inflatable composite structures are being investigated because they offer significant benefits over conventional structures for aerospace applications. Inflatable structures are flexible and can be packaged in smaller and more complex shaped volumes, which result in the selection of smaller launch vehicles which dramatically reduce launch costs. Inflatable composite structures are typically manufactured from materials that have higher strength to weight ratios than conventional systems and are therefore lower in mass. Mass reductions are further realized because of the tailorability of inflatable composite structures, which allow the strength of the system to be concentrated where needed. Flexible composite structures also tend to be more damage tolerant due to their “forgiveness” as compared to rigid mechanical systems. In addition, inflatables have consistently proven to be lower in both development and manufacturing costs.

Several inflatable habitat development programs are discussed with their increasing maturation toward use on a flight mission. Selected development programs being discussed include several NASA Langley Research Center habitat programs that were conducted in the 1960s, the Lawrence Livermore National Laboratory inflatable space station study, the NASA JSC deployable inflatable Lunar habitat study, and the inflatable Mars TransHab study and test program currently ongoing at NASA JSC. Relevant technology developments made by ILC Dover are also presented.     

A concept for NASA's Mars 2016 astrobiology field laboratory

The Mars Program Plan includes an integrated and coordinated set of future candidate missions and investigations that meet fundamental science objectives of NASA and the Mars Exploration Program (MEP). At the time this paper was written, these possible future missions are planned in a manner consistent with a projected budget profile for the Mars Program in the next decade (2007-2016). As with all future missions, the funding profile depends on a number of factors that include the exact cost of each mission as well as potential changes to the overall NASA budget. In the current version of the Mars Program Plan, the Astrobiology Field Laboratory (AFL) exists as a candidate project to determine whether there were (or are) habitable zones and life, and how the development of these zones may be related to the overall evolution of the planet. The AFL concept is a surface exploration mission equipped with a major in situ laboratory capable of making significant advancements toward the Mars Program's life-related scientific goals and the overarching Vision for Space Exploration. We have developed several concepts for the AFL that fit within known budget and engineering constraints projected for the 2016 and 2018 Mars mission launch opportunities. The AFL mission architecture proposed here assumes maximum heritage from the 2009 Mars Science Laboratory (MSL). Candidate payload elements for this concept were identified from a set of recommendations put forth by the Astrobiology Field Laboratory Science Steering Group (AFL SSG) in 2004, for the express purpose of identifying overall rover mass and power requirements for such a mission. The conceptual payload includes a Precision Sample Handling and Processing System that would replace and augment the functionality and capabilities provided by the Sample Acquisition Sample Processing and Handling system that is currently part of the 2009 MSL platform.     

Phoenix--the first Mars Scout mission

NASA has initiated the first of a new series of missions to augment the current Mars Program. In addition to the systematic series of planned, directed missions currently comprising the Mars Program plan, NASA has started a series of Mars Scout missions that are low cost, price fixed, Principal [correction of Principle] Investigator-led projects. These missions are intended to provide an avenue for rapid response to discoveries made as a result of the primary Mars missions, as well as allow more risky technologies and approaches to be applied in the investigation of Mars. The first in this new series is the Phoenix mission which was selected as part of a highly competitive process. Phoenix will use the Mars 2001 Lander that was discontinued in 2000 and apply a new set of science objectives and mission objectives and will validate this soft lander architecture for future applications. This paper will provide an overview of both the Program and the Project.     

Landing on small bodies: From the Rosetta Lander to MASCOT and beyond

Recent planning for science and exploration missions has emphasized the high interest in the close investigation of small bodies in the Solar System. In particular in-situ observations of asteroids and comets play an important role in this field and will contribute substantially to our understanding of the formation and history of the Solar System.The first dedicated comet Lander is Philae, an element of ESA's Rosetta mission to comet 67/P Churyumov–Gerasimenko. Rosetta was launched in 2004. After more than 7 years of cruise (including three Earth and one Mars swing-by as well as two asteroid flybys) the spacecraft has gone into a deep space hibernation in June 2011. When approaching the target comet in early 2014, Rosetta will be re-activated. The cometary nucleus will be characterized remotely to prepare for Lander delivery, currently foreseen for November 2014.The Rosetta Lander was developed and manufactured, similar to a scientific instrument, by a consortium consisting of international partners. Project management is located at DLR in Cologne/Germany, with co-project managers at CNES (France) and ASI (Italy). The scientific lead is at the Max Planck Institute for Solar System Science (Lindau, Germany) and the Institut d'Astrophysique Spatiale (Paris).Mainly scientific institutes provided the subsystems, instruments and the complete, qualified lander system. Operations are performed in two dedicated centers, the Lander Control Center (LCC) at DLR-MUSC and the Science Operations and Navigation Center (SONC) at CNES. This concept was adopted to reduce overall cost of the project and is foreseen also to be applied for development and operations of future small bodies landers.A mission profiting from experience gained during Philae development and operations is MASCOT, a surface package for the Japanese Hayabusa 2 mission. MASCOT is a small (∼10 kg) mobile device, delivered to the surface of asteroid 1999JU3. There it will operate for about 16 h. During this time a camera, a magnetometer, a thermal monitor and an IR analytical instrument will provide ground truth and thus will even be able to support the selection of possible sampling sites for the main spacecraft.MASCOT is a flexible design that can be adapted to a wide range of missions and possible target bodies. Also the payload is flexible to some extent (with an overall mass in the 3 kg range). For example, the surface package is part of the optional strawman payload for MarcoPolo-R, a European asteroid sample return mission, proposed for ESA Cosmic Vision M-class.     

Technology readiness and risk assessments: A new approach

Systems that depend upon the application of new technologies inevitably face three major challenges during development: performance, schedule and budget. Technology research and development (R&D) programs are typically advocated based on argument that these investments will substantially reduce the uncertainty in all three of these dimensions of project management. However, if early R&D is implemented poorly, then the new system developments that plan to employ the resulting advanced technologies will suffer from cost overruns, schedule delays and the steady erosion of initial performance objectives. It is often critical for senior management to be able to determine which of these two paths is more likely—and to respond accordingly. The challenge for system and technology managers is to be able to make clear, well-documented assessments of technology readiness and risks, and to do so at key points in the life cycle of the program.Several approaches have been used to evaluate technology maturity and risk in order to better anticipate later system development risks. The “technology readiness levels” (TRLs), developed by NASA, are one discipline-independent, programmatic figure of merit (FOM) that allows more effective assessment of, and communication regarding the maturity of new technologies. Another broadly used management tool is of the “risk matrix”, which depends upon a graphical representation of uncertainty and consequences. However, for the most part these various methodologies have had no explicit interrelationship.This paper will examine past uses of current methods to improve R&D outcomes and will highlight some of the limitations that can arise. In this context, a new concept for the integration of the TRL methodology, and the concept of the “risk matrix” will be described. The paper will conclude with observations concerning prospective future directions for the important new concept of integrated “technology readiness and risk assessments”.     

Lunette: A network of lunar landers for in-situ geophysical science

Over the last 3 years, a team at JPL has worked to design a new concept for a small, low cost lander applicable to a variety of in-situ lunar exploration activities. This concept, named Lunette, originated as a design which would exploit potential excess capacity of EELV launches by being compatible with the EELV Secondary Payload Adapter (ESPA). The original Lunette mission concept would have allowed up to six low cost landers to be delivered to a targeted region of the moon, with landings separated by a few km, allowing establishment of a regional network with a single, shared launch. The original concept faced limits in the extent of regional distribution of landing sites since all six landers were dependent on a single solid rocket braking motor. In the last year the Lunette team has focused on a modification of the original ESPA-based concept to a design that would allow launch of multiple individual landers (each with its own braking stage) on a single launch vehicle, where each lander would be capable of independent targeting and landing. With such an implementation, the entire lunar surface could be accessed for establishment of network nodes that could enable high priority geophysical measurements on a scale not seen since Apollo. The present paper discusses the current state of the design of the Lunette geophysical network lander, as well as describing mission design, science operations, and an innovative design solution allowing the lander to take critical data continuously, even over the lunar night, without the need for radioisotope power systems.     

Advanced flight computing technologies for validation by NASA's new millennium program

The New Millennium Program (NMP) consists of a series of Deep-Space and Earth Orbiting missions that are technology-driven, in contrast to the more traditional science-driven space exploration missions of the past. These flights are designed to validate technologies that will enable a new era of low-cost highly miniaturized and highly capable spacebome applications in the new millennium. In addition to the series of flight projects managed by separate flight teams, the NMP technology initiatives are managed by the following six focused technology programs: Microelectronics Systems, Autonomy, Telecommunications, Instrument Technologies and Architectures, In-Situ Instruments and Micro-electromechanical Systems, and Modular and Multifunctional Systems. Each technology program is managed as an Integrated Product Development Team (IPDT) of government, academic, and industry partners. In this paper, we will describe elements of the technology roadmap proposed by the NMP Microelectronics IPDT. Moreover, we will relate the proposed technology roadmap to existing NASA technology development programs, such as the Advanced Flight Computing (AFC) program, and the Remote Exploration and Experimentation (REE) program, which constitute part of the on-going NASA technology development pipeline. We will also describe the Microelectronics Systems technologies that have been accepted as part of the first New Millennium Deep-Space One spacecraft, which is an asteroid fly-by mission scheduled for launched in July 1998.     

归因于空间环境的航天器故障与异常

天然空间环境对航天器设计、研制和运行的影响是NASA马歇尔空间飞行中心系统分析和集成实验室电磁与航空宇宙环境部组织编写的一系列NASA RP报告的主题.其中,NASA RP-1390详细概述了天然空间环境7个主要环境因素,包括它们的简单定义、相关的型号计划事项以及对各种航天器分系统的影响.该报告提供100多个从1974...     

A gateway for human exploration of space? The weak stability boundary

NASA's plans for future human exploration of the Solar System describe only missions to Mars. Before such missions can be initiated, much study remains to be done in technology development, mission operations and human performance. While, for example, technology validation and operational experience could be gained in the context of lunar exploration missions, a NASA lunar program is seen as a competitor to a Mars mission rather than a step towards it. The recently characterized weak stability boundary in the Earth–Moon gravitational field may provide an operational approach to all types of planetary exploration, and infrastructure developed for a gateway to the Solar System may be a programmatic solution for exploration that avoids the fractious bickering between Mars and Moon advocates. This viewpoint proposes utilizing the concept of Greater Earth to educate policy makers, opinion makers and the public about these subtle attributes of our space neighborhood.     

Human exploration of near earth asteroids: Mission analysis for chemical and electric propulsion

This paper presents a mission analysis comparison of human missions to asteroids using two distinct architectures. The objective is to determine if either architecture can reduce launch mass with respect to the other, while not sacrificing other performance metrics such as mission duration. One architecture relies on chemical propulsion, the traditional workhorse of space exploration. The second combines chemical and electric propulsion into a hybrid architecture that attempts to utilize the strengths of each, namely the short flight times of chemical propulsion and the propellant efficiency of electric propulsion. The architectures are thoroughly detailed, and accessibility of the known asteroid population is determined for both. The most accessible asteroids are discussed in detail. Aspects such as mission abort scenarios and vehicle reusability are also discussed. Ultimately, it is determined that launch mass can be greatly reduced with the hybrid architecture, without a notable increase in mission duration. This demonstrates that significant performance improvements can be introduced to the next step of human space exploration with realistic electric propulsion system capabilities. This leads to immediate cost savings for human exploration and simultaneously opens a path of technology development that leads to technologies enabling access to even further destinations in the future.     

Aeroshell design techniques for aerocapture entry vehicles

A major goal of NASA's In-Space Propulsion Program is to shorten trip times for scientific planetary missions. To meet this challenge arrival speeds will increase, requiring significant braking for orbit insertion, and thus increased deceleration propellant mass that may exceed launch lift capabilities. A technology called aerocapture has been developed to expand the mission potential of exploratory probes destined for planets with suitable atmospheres. Aerocapture inserts a probe into planetary orbit via a single pass through the atmosphere using the probe's aeroshell drag to reduce velocity. The benefit of an aerocapture maneuver is a large reduction in propellant mass that may result in smaller, less costly missions and reduced mission cruise times. The methodology used to design rigid aerocapture aeroshells will be presented with an emphasis on a new systems tool under development. Current methods for fast, efficient evaluations of structural systems for exploratory vehicles to planets and moons within our solar system have been under development within NASA having limited success. Many systems tools that have been attempted applied structural mass estimation techniques based on historical data and curve fitting techniques that are difficult and cumbersome to apply to new vehicle concepts and missions. The resulting vehicle aeroshell mass may be incorrectly estimated or have high margins included to account for uncertainty. This new tool will reduce the guesswork previously found in conceptual aeroshell mass estimations.     

The new millennium program: Fast-track procurements

The National Aeronautics and Space Administration's (NASA's) New Millennium Program (NMP) has embarked on a technology flight-validation demonstration program to enable the kinds of missions that NASA envisions for the 21st century. Embedded in this program is the concept of rapid mission development supported by a fast-track procurement process. This process begins with the decision to initiate a procurement very early in the program along with the formation of a technical acquisition team. A close working relationship among the team members is essential to avoiding delays and developing a clear acquisition plan. The request for proposal (RFP) that is subsequently issued seeks a company with proven capabilities, so that the time allotted for responses from proposers and the length of proposals they submit can be shortened. The fast-track procurement process has been demonstrated during selection of NMP's industrial partners and has been proven to work.     

Cost effectiveness of Spacelab experiments

Spacelab permits investigation in new seicntific disciplines like material processing, life sciences, chemistry, etc. The large mass and volume capabilities of Spacelab offer better possibilities for some areas of traditional space sciences like infrared astronomy, multi-spectral solar observations and large instruments for astronomical observations.Since free-flyers will require normally a new spacecraft development for each mission, the reusability of space qualified components and experiments will be a significant cost reduction factor over a long period. In the early phase of Spacelab utilisation, however, the scaling factor introduced by Spacelab utilisation, however, the scaling factor introduced by Spacelab results in higher payload development costs than originally appreciated.The costs of Spacelab utilisation are computed and compared with those of conventional free-flying satellites. The mission implementation costs and experiment development costs are shown for both cases. The Spacelab mission implementation costs are subdivided into NASA charges for the Standard Shuttle Mission, NASA charges to fly and operate Spacelab, the European costs of Spacelab payload integration and experiment development costs. In order to evaluate and compare mission implementation costs, the simple parameters are adopted of the cost per kg of experiments and the data collection-transmission capability of Shuttle/Spacelab and ESRO/ESA satellites. The mission implementation costs turn out to be very favourable for Spacelab. The experiment development costs, which are not included in the mission implementation costs, are compared for several free flyers with the corresponding development costs for several experiments of the first Spacelab payload. The comparison shows that the cost per kg of Spacelab experiment development is about five times less than of satellite experiments.     

A Canadian system for satellite based advanced personal communications at the Ka-band

A Canadian Government program is currently under way to define, in detail, services and applications, user requirements, end-to-end system architecture and subsystem equipment design requirements for a demonstration on-board-processing (OBP) communications satellite system. The program has reached an advanced stage of definition. The prime directive of the overall mission is to provide demonstration and development of technology and services.

This paper begins by describing the development of our understanding of the true scope of advanced personal communications services and applications; the user expectations and hence terminal characteristics are also reviewed in the context of the competitive environment of other service offerings both existing and planned. In addition, the results of considerations on spacecraft complexity and hence feasibility, caused by the impact of each service option and the requirements for internetworking, are reviewed.     

A complexity-based risk assessment of low-cost planetary missions: when is a mission too fast and too cheap?

Under constrained budgets and rigid schedules, NASA and industry have greatly increased their utilization of small satellites to conduct low-cost planetary investigations. Recent failed small planetary science spacecraft such as Mars Polar Lander (MPL) and Mars Climate Orbiter (MCO), and impaired missions such as Mars Global Surveyor (MGS) have fueled the ongoing debate on whether NASA's “Faster, Better, Cheaper” (FBC) approach is working. Several noteworthy failures of earth-orbiting missions have occurred as well including Lewis and the Wide-field Infrared Experiment (WIRE). While recent studies have observed that FBC has resulted in lower costs and shorter development times, these benefits may have been achieved at the expense of lowering probability of success. One question remaining to be answered is when is a mission “too fast and too cheap” that it is prone to failure? This paper assesses NASA FBC missions in terms of a complexity index measured against development time and spacecraft cost. A comparison of relative failure rates of recent planetary and earth-orbiting missions are presented, and conclusions regarding dependence on system complexity are drawn.