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The application of small satellites is a new focus on deep space exploration. Small satellites are easy to launch as secondary payloads, and more suitable for international cooperation. However, small satellites have several major weaknesses for deep space missions, such as the lack of orbit transfer capability and large antenna. This paper presents an innovative concept of small satellite bus based on Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA). The proposed satellite bus is equipped with orbit control subsystem and a large parabolic antenna for the exploration of Jovian and Saturnian systems. In this paper, the mission requirements, the launch feasibilities and the design parameters of the proposed satellite bus are also discussed.

The susceptibility of spacecraft materials to HCl exposure was investigated in light of concerns to potential contamination during evolved expendable launch vehicle (EELV) overflight scenarios. Overflight refers to the circumstance where one spacecraft, resident on a launch pad, may be exposed to HCl generated from an earlier solid rocket launch at an adjacent pad. One aspect of the overflight risk assessments involves spacecraft materials susceptibility to HCl exposure. This study examined a wide range of spacecraft materials after being exposed to HCl vapor in a well-characterized facility. Sample thermal/optical and electrostatic dissipation properties, as well as surface chemical and morphological features, were characterized before and after the HCl exposure. All materials tested, except for indium tin oxide (ITO) coated Kapton film, showed no significant degradation after HCl exposure of up to 4800 ppb-hr. The ITO coated Kapton sample showed slight signs of degradation after being exposed to 500 ppb-hr HCl, as the surface resistance was increased by a factor of 5. However, the potential HCl dose inside the payload fairing (PLF) was estimated to be far below 500 ppb-hr in an EELV overflight event. These results, along with other relevant laboratory test data on the HCl removal efficiency of the filtration media used on the launch sites, provide the technical rationale that properly filtered air as the PLF purge should pose little risk in terms of HCl contamination under EELV overflight scenarios.

We present results of a study of a deployable version of the Advanced Technology Large-Aperture Space Telescope (ATLAST), designed to operate in a Sun-Earth L2 orbit. The primary mirror of the segmented 9.2-meter aperture has 36 hexagonal 1.315 m (flat to flat) glass mirrors. The architecture and folding of the telescope is similar to JWST, allowing it to fit into the 6.5 m fairing of a modest upgrade to the Delta-IV Heavy version of the Evolved Expendable Launch Vehicle (EELV). We discuss the overall observatory design, optical design, instruments, stray light, wavefront sensing and control, pointing and thermal control, and in-space servicing options.

The Air Force Research Laboratory, Space Vehicles Directorate (AFRL/RV) has developed the Demonstration and Science Experiments (DSX) mission to research technologies needed to significantly advance Department of Defense (DoD) capabilities to operate spacecraft in the harsh radiation environment of Medium-Earth Orbits (MEO). The ability to operate effectively in the MEO environment significantly increases the DoD's capability to field space systems that provide persistent global space surveillance and reconnaissance, high-speed satellite-based communication, lower-cost GPS navigation, and protection from space weather and environmental effects on a responsive satellite platform. The three DSX physics-based research/experiment areas are: 1. Wave Particle Interaction Experiment (WPIx): Researching the physics of Very-Low-Frequency (VLF) electromagnetic wave transmissions through the ionosphere and in the magnetosphere and characterizing the feasibility of natural and man-made VLF waves to reduce and precipitate space radiation; 2. Space Weather Experiment (SWx): Characterizing, mapping, and modeling the space radiation environment in MEO, an orbital regime attractive for future DoD, Civil, and Commercial missions; and 3. Space Environmental Effects (SFx): Researching and characterizing the MEO space weather effects on spacecraft electronics and materials. Collectively, thirteen individual payloads are combined together from these three research areas and integrated onto a single platform (DSX) which provides a low-cost opportunity for AFRL due to their common requirements. All three experiments require a 3-axis stabilized spacecraft bus (but no propulsion), a suite of radiation sensors, and extended duration in a low inclination, elliptical, MEO orbit. DSX will be launch-ready in summer 2010 for a likely launch comanifest with an operational DoD satellite on an Evolved Expendable Launch Vehicle (EELV).

NASA's Ares V cargo launch vehicle offers the potential to completely change the paradigm of future space science mission architectures. A major finding of the NASA Advanced Telescope and Observatory Capability Roadmap Study was that current launch vehicle mass and volume constraints severely limit future space science missions. And thus, that significant technology development is required to package increasingly larger collecting apertures into existing launch shrouds. The Ares V greatly relaxes these constraints. For example, while a Delta IV has the ability to launch approximate a 4.5 meter diameter payload with a mass of 13,000 kg to L2, the Ares V is projected to have the ability to launch an 8 to 12 meter diameter payload with a mass of 60,000 kg to L2 and 130,000 kg to Low Earth Orbit. This paper summarizes the Ares V payload launch capability and introduces how it might enable new classes of future space telescopes such as 6 to 8 meter class monolithic primary mirror observatories, 15 meter class segmented telescopes, 6 to 8 meter class x-ray telescopes or high-energy particle calorimeters.

Spitzer Space Telescope was launched on 25 August 2003 into an Earth-trailing solar orbit to acquire infrared observations from space. Development of the Mission Operations System (MOS) portion prior to launch was very different from planetary missions from the stand point that the MOS teams and Ground Data System had to be ready to support all aspects of the mission at launch (i.e., no cruise period for finalizing the implementation). For Spitzer, all mission-critical events post launch happen in hours or days rather than months or years, as is traditional with deep space missions. At the end of 2000 the Project was dealt a major blow when the Mission Operations System (MOS) had an unsuccessful Critical Design Review (CDR). The project made major changes at the beginning of 2001 in an effort to get the MOS (and Project) back on track. The result for the Spitzer Space Telescope was a successful launch of the observatory followed by an extremely successful In Orbit Checkout (IOC) and operations phase. This paper describes how the project was able to recover the MOS to a successful Delta (CDR) by mid 2001, and what changes in philosophies, experiences, and lessons learned followed. It describes how projects must invest early or else invest heavily later in the development phase to achieve a successful operations phase.

Sierra Lobo tested its patented Cryo-Tracker(R) probe and Mass Gauging System in a large scale Expendable Launch Vehicle (ELV) liquid oxygen tank simulation for NASA. Typical Liquid Oxygen (LOX) tank operations were simulated at Lockheed Martin's Engineering Propulsion Laboratory in Denver, Colorado. The Cryo-Tracker(R) probe is 33 feet long, the longest built to date. It was mounted in the tank at only two locations, separated by 26 feet. Each test simulated typical Lockheed Martin booster pre-launch tanking operations, including filling the tank with LOX at fill rates typically used at the launch pad, and maintaining the fill level for a period representative of a typical pad hold. The Cryo-Tracker(R) Mass Gauging System was the primary instrument used for monitoring the fill and controlling the topping operations. Each test also simulated a typical flight profile, expelling the LOX at representative pressures and expulsion flow rates. During expulsion, the Cryo-Tracker(R) System served to generate an Engine Cut-Off (ECO) signal. Test objectives were as follows: Cryo-Tracker(R) data will be validated by flight-like propellant instruments currently used in launch vehicles; the probe will survive the harsh environment (which will be documented by a digital video camera) with no loss of signal or structural integrity; the system will successfully measure liquid levels and temperatures under all conditions and calculate propellant mass in real-time; the system will successfully demonstrate its feasibility as a control sensor for LOX filling and topping operations, as well as for engine cut-off. All objectives were met and the test results are presented.

This paper gives a description of the mission design, launch, orbit, and navigation results for the Spitzer space telescope mission. The Spitzer telescope was launched by the Delta II Heavy launch vehicle into a heliocentric Earth trailing orbit. This orbit is flown for the first time and will be used by several future astronomical missions such as Kepler, SIM, and LISA. This paper describes the launch strategy for a winter versus a summer launch and how it affects communications. It also describes how the solar orbit affects the design and operations of the Observatory. It describes the actual launch timeline, launch vehicle flight performance, and the long term behavior of the as flown orbit. It also provides the orbit knowledge from in-flight navigation data.

Air Force Research Laboratory’s space experiment XSS-10 was flown on the Air Force Global Positioning Satellite (GPS) mission IIR-8 launched on January 29, 2003. The mission objectives of XSS-10 were to demonstrate autonomous navigation, proximity operations, and inspection of a Resident Space Object (RSO). XSS-10 was a 28-kilogram micro-satellite was launched as a secondary mission on a Delta II expendable launch vehicle carrying a GPS satellite. XSS-10 was equipped with a visible camera, a star sensor, and mini SGLS system, all specially built for this program. In addition, a visible camera was attached to the second stage to observe the release of the micro-satellite and observe its maneuvers. Following the release of the GPS satellite, the Delta II initiated three depletion burns to reorient into an 800 KM circular orbit. The XSS-II was ejected from the Delta II second stage approximately 18 hours after launch. Operating autonomously on a preplanned course, XSS-10 performed its mission of navigating around the Delta II second stage at preplanned positions; the micro-satellite took images of the second stage and send them back to earth in real time. During these demonstrations the XSS-10 mission operations team accomplished responsive checkout of the micro-satellite and all of its subsystems, autonomous navigation on a preplanned course and a variety of algorithms and mission operations that pave the way for more ambitious missions in the future. This paper will discuss the results of the mission and post mission analysis of the XSS-10 space flight.

Payloads delivered to orbit by expendable launch vehicles experience high levels of vibration. This vibration can cause component failures, or more frequently, lead to extra weight that would otherwise be useful for added functions on orbit. Vibration isolation systems have been flown to protect various components as well as entire spacecraft, dramatically reducing launch loads and saving costs in redesign and tests. Future spacecraft and components may benefit from further load reduction through the use of higher performance active isolation systems. These active systems are capable of introducing compliance in selected axes, while maintaining required rigidity in others. They can also produce excellent isolation without large amplification. Passive and active vibration isolation systems were developed for the Vibro Acoustic Launch Protection Experiment (VALPE) and flew aboard sounding rockets. The paper describes the design and development of the isolation systems, actuation and isolation architectures and control strategies. Integration of two flight experiments is summarized. Ground test results are presented for passive and active systems. Results of the experiments are provided, and recommendations for active vibration isolation are offered.

The cost of performing any mission on orbit is a strong function of the cost of getting the mass into orbit and the mass of a spacecraft is driven by the launch loads that the components must be deigned to survive. Additionally, these design loads vary between launch vehicles so if circumstances arise that require a change in launch vehicle significant time and money can be spent in modifying and testing to meet different requirements. Technologies that reduce both the vibration and acoustic environments during launch have the potential to both reduce the design load levels, and eventually equalize them between boosters. To this end the Air Force Research Laboratory, Space Vehicles Directorate in cooperation with the Space Test Program, Boeing SVS, CSA Engineering, and Delta Velocity have been investigating methods to decrease the acoustic and vibration loads induced on payloads by the launch environment and demonstrating them on a sounding rocket launch. The Vibro-Acoustic Launch Protection Experiment (VALPE) mission included an acoustically designed Chamber-Core skin, two passive/active vibration isolation experiments, a passive/active acoustic damping experiment, and an energy recovery experiment integrated onto a Terrier-Improved Orion sounding rocket and launched from NASA Wallops Island. A description of the overall mission, experiments, and general results from the flight test are discussed.

Small satellite programs offer opportunities for conducting technical demonstrations, engineering development and scientific missions. To accomplish these missions, launch systems are needed whose costs and capacity are commensurate with the use of small, low-cost satellites. Lower launch costs would open the door to more technology demonstrations and scientific missions that will drive the need for more launch vehicle. There are several new ventures that could increase the opportunity for small payloads to achieve economical access to space. These new ventures include low cost launch vehicles, standard adapters, orbit transfer vehicles, and space maneuver vehicles. The National Reconnaissance Office's (NRO) Broad Agency Announcement (BAA) includes competitive selection for proposals to study the need for a small payload broker, to define the broker's services, and innovative ideas to simplify the process of integrating payloads, spacecraft buses, and launch vehicles. The NRO and Goddard Spaceflight Center (GSFC) combined resources to develop the Access to Space (ATS) web site that contains both a mission database and launch vehicle information. It provides both the information and the tools necessary to assist mission planners in selecting and planning their ride to space. Users can search the site for available rides and also post information about their payloads. Launch providers can submit information about planned missions and launch vehicle configuration.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Despite growing international interest in small satellites, high dedicated expendable launch vehicle costs and the lack of secondary launch opportunities continue to hinder the full exploitation of small satellite technology. In the United States, the Department of Defense (DoD), NASA, other government agencies, commercial companies, and many universities use small satellites to perform space experiments, demonstrate new technology, and test operational prototype hardware. In addition, the DoD continues to study the role of small satellites in fulfilling operational mission requirements. However, the US lacks sufficient small satellite launch capacity. Furthermore, US government agencies are restricted to the use of US launch vehicles, which eliminates many affordable launch opportunities. In an effort to increase the number of space experiments that can be flown with a small, fixed budget, the DoD Space Test Program (STP) has teamed with the Air Force Research Laboratory Space Vehicles Directorate (AFRL/VS) to develop a low-cost solution for the small satellite launch program. Our solution, which can be implemented on both Boeing and Lockheed-Martin Evolved Expendable Launch Vehicle-Medium (EELV-M) boosters, is called the EELV Secondary Payload Adaptor (ESPA). ESPA will increase the number of launch opportunities for 180kg-class (or smaller) satellites at prices highly competitive with other secondary launch services worldwide.

ESPA, the Secondary Payload Adapter for Evolved Expendable Launch Vehicles, addresses two of the major problems currently facing the launch industry: the vibration environment of launch vehicles, and the high cost of putting satellites into orbit. (1) During the 1990s, billions of dollars have been lost due to satellite malfunctions, resulting in total or partial mission failure, which can be directly attributed to vibration loads experienced by payloads during launch. Flight data from several recent launches have shown that whole- spacecraft launch isolation is an excellent solution to this problem. (2) Despite growing worldwide interest in small satellites, launch costs continue to hinder the full exploitation of small satellite technology. Many small satellite users are faced with shrinking budgets, limiting the scope of what can be considered an 'affordable' launch opportunity.

This paper is the culmination of the research effort which was reported on last year while still in-progress. As previously reported, statistical methods for expressing the impact risk posed to space systems in general [and the International Space Station (ISS) in particular] by other resident space objects have been examined. One of the findings of this investigation is that there are legitimate physical modeling reasons for the common statistical expression of the collision risk. A combination of statistical methods and physical modeling is also used to express the impact risk posed by reentering space systems to objects of interest (e.g., people and property) on Earth. One of the largest uncertainties in the expressing of this risk is the estimation of survivable material which survives reentry to impact Earth's surface. This point was demonstrated in dramatic fashion in January 1997 by the impact of an intact expendable launch vehicle (ELV) upper stage near a private residence in the continental United States. Since approximately half of the missions supporting ISS will utilize ELVs, it is appropriate to examine the methods used to estimate the amount and physical characteristics of ELV debris surviving reentry to impact Earth's surface. This report details reentry survivability estimation methodology, including the specific methodology used by ITT Systems' (formerly Kaman Sciences) 'SURVIVE' model. The major change to the model in the last twelve months has been the increase in the fidelity with which upper- atmospheric aerodynamics has been modeled. This has resulted in an adjustment in the factor relating the amount of kinetic energy loss to the amount of heating entering and reentering body, and also validated and removed the necessity for certain empirically-based adjustments made to the theoretical heating expressions. Comparisons between empirical results (observations of objects which have been recovered on Earth after surviving reentry) and SURVIVE estimates are presented for selected generic upper stage or spacecraft components, a Soyuz launch vehicle second stage, and for a Delta II launch vehicle second stage and its significant components. Significant similarity is demonstrated between the type and dispersion pattern of the recovered debris from the January 1997 Delta II 2nd stage event and the simulation of that reentry and breakup.

This paper updates the status of the Ranger Telerobotic Shuttle Experiment (TSX). Originally planned as the Ranger Telerobotic Flight Experiment (TFX), a free-flying spacecraft servicing telerobot to be launched on an expendable launch vehicle, the Ranger mission has been recast as a Space Shuttle-based flight experiment to demonstrate key telerobotic technologies associated with servicing the International Space Station (ISS) and other orbital assets. Several modifications have been made to the flight system configuration and the operational concept, but the primary payload package -- namely the four manipulator arms and their supportive structure -- have remained relatively unchanged. This paper addresses these technical and operational modifications, and lays out the plans for the future of the flight experiment.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Spartan Lite is a proposed series of very low-cost spacecraft missions which offer potential flight opportunities for pointed solar experiments. Early versions will be launched as Space Shuttle attached payloads with the capability of being released for free flight. They would not be recovered, allowing useful lifetimes of six months to one year. An expendable launch vehicle option will be added later. The spacecraft is 3-axis stabilized with a cylindrical instrument cavity 100 cm long and 36 cm in diameter. If approved, the program would provide multiple launch opportunities during the upcoming solar maximum. A conceptual instrument design for a solar pointed mission on Spartan Lite is shown and discussed. The Extreme-Ultraviolet Normal Incidence Spectrograph will observe the solar spectrum between 290 and 466 A with high spatial and spectral resolutions. The large bandpass is due to the compact design, fitting two optical systems into the instrument cavity, each observing a different, but overlapping, wavelength range.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The Mid-Infrared Spectrometer (MIRS) is one of four instruments that will fly aboard the orbiting Infrared Telescope in Space (IRTS). This telescope is a joint NASA/Japanese Space Agency (ISAS) project that is scheduled for a Spring, 1995, launch aboard a Japanese expendable launch vehicle and subsequent retrieval by the space shuttle. The telescope itself is liquid helium-cooled with a 15 cm aperture and will survey approximately 10% of the sky before its cryogen runs out and it begins to warm up. The MIRS was developed jointly by NASA, the University of Tokyo, and ISAS and operates over a wavelength range of 4.5 to 11.7 microns with a resolution of 0.23 and 0.36 microns. The MIRS has a conventional entrance aperture, so that spectral studies can be made of extended as well as point-sources. A cold shutter and an internal calibrator allow accurate absolute flux determinations. Calibration and sensitivity tests in the laboratory have shown that the instrument sensitivity will be limited by the fluctuations due to the zodiacal dust emission over the wavelength range of the spectrometer. The large A-omega of the spectrometer, the cryogenic optics, and the survey nature of the telescope will allow very sensitive studies of the spectral characteristics of diffuse extended emission. These observations will help in determining the composition of the galactic dust responsible for the warm component of the infrared cirrus. In secondary observing programs, the MIRS will also take spectra of the zodiacal dust emission as well as measure the infrared spectra of an estimated 9,800 point-source objects.

A lidar wind measurement system is described which can be used as an alternative to the current Jimsphere/Rawinsonde method. The decrease in wind measurement time provides significant benefits to launch vehicle operations. The faster acquisition time associated with the lidar system provides better estimates of wind persistency and gust prediction.

The confluence of microelectronics developments, Space Shuttle and expendable launch vehicle maturation and emergence of miniature satellite technology (MST) is providing a new resource for astronomy research. A small, low cost satellite can provide significant on orbit data collection and transmission capability on a budget and time scale accessible to a diverse community of researchers. but like any other complex research tool careful application of MST is critical to obtaining good results. Small satellite capabilities in electric power, pointing, overall size and weight, orbit adjustment, downlink data rate and other parameters are limited compared with today's large scale systems (though in many cases they are comparable to or exceed large systems of a decade or two ago). However, the convenience and low cost of typical MST ground facilities provide enhanced resource accessibility compared to conventional approaches. Proliferation of ground stations and their operation at the research institution or observation site by research team members are features easily integrated within the MST approach. To introduce the potential of MST, missions are treated which most easily adapt to the small satellite environment. Design to operational requirements and close integration of payload and bus are fundamental to the MST approach. A summary of typical MST design capabilities and tradeoffs illustrates the current state of the art of MST application in astronomy. Construction of the small satellite is moot without attention to launch opportunities and costs. Here too properly conceived implementation of MST is important in securing the earliest, lowest cost, most dependable launch opportunity. the launch vehicle flexibility inherent to small satellites can be maximized by engineering compatibility to the largest number of potential launch vehicles. The capabilities, costs and availability of several launch options are assayed. With the current relative scarcity of launch opportunities MST payloads are increasingly appealing compared with conventional, larger systems which demand a larger share of the available orbit insertion resource.

Features of the Space Station coorbiting and polar orbiting platforms (COP and POP, respectively) are described that will allow them to be configured optimally to meet mission requirements and to be assembled, serviced, and modified on-orbit. Both of these platforms were designed to permit servicing at the Shuttle using the remote manipulator system with teleoperated end effectors; EVA was planned as a backup and for unplanned payload failure modes. Station-based servicing is discussed as well as expendable launch vehicle-based servicing concepts.