Colorado Space Grant Consortium

The Citizen Explorer Design and Operations Planning System (CXDOPS) was developed by the Colorado Space Grant College as a comprehensive mission design, systems modeling and mission operations tool. This system provides visibility into how changes in mission architecture affect system performance throughout all phases of the project. Additionally it will provide manual and automated scheduling capabilities for satellite commanding over the course of mission operations.

This paper describes the DATA-CHASER Automated Planner/Scheduler (DCAPS) system for automatically generating low-level command sequences from high-level user goals. DCAPS uses Artificial Intelligence (AI)-based search techniques and an iterative repair framework in which the system selectively resolves conflicts with the resource and temporal constraints of the DATA-CHASER Shuttle payload activities.

The accuracy of atmospheric density measurements inferred from satellite drag is limited by errors in drag coefficient estimates. In this work, we use a unique opportunity in which the Drag and Atmospheric Neutral Density Explorer satellite and three Polar Orbiting Passive Atmospheric Calibration Spheres are deployed from a common launch vehicle. Each object flies through similar atmospheric conditions but has a different area-to-mass ratio. This allows aerodynamic analysis that is independent of atmospheric density via comparisons of measured and modeled ballistic coefficient ratios. A test particle method combined with a satellite energy accommodation model is used to model the aerodynamics of these objects. Fitted ballistic coefficients computed as a result of special-perturbations orbit analysis are then compared to the model results. The drag coefficient model and observations agree at the 1–2% level when coefficient ratios are compared. Comparisons of an additional shape with model predictions are made possible when one of the satellites shed its launch adapter. This work validates the aerodynamic model used here and can be applied in future research to improve models of atmospheric density and predictions of satellite drag. Beyond potential improvements to atmospheric models, the technique presented here is shown to identify objects based on their aerodynamic signature.

Summary form only given. The positive impact of passive microwave observations of tropospheric temperature, water vapor, and surface variables on short term weather forecasts has been clearly demonstrated in recent error growth studies. However, current-era spaceborne passive microwave sensors remain singularly expensive and risky components of global weather forecast systems, while at the same time offer only limited temporal sampling capabilities. A fleet of small, low-cost satellite microwave sensors has the potential to provide reduced system cost and risk while simultaneously improving the time sampling of rapidly evolving weather. In an effort to study the potential of such a fleet the University of Colorado is developing the first low-cost CubeSat-based passive microwave sounder for demonstration as an element of a larger fleet of sounders for weather forecasting. The PolarCube satellite is an 8-channel 118-GHz temperature sounder providing ~15 km spatial resolution from an orbital altitude of ~350 km. It is based on a spin-scanned concept using the CU ALL STAR 3U CubeSat bus with a two point calibration method using a warm load and cold space. The development of the radiometer payload and bus are led by student teams at CU using low cost components. A launch into a sun-synchronous orbit for evaluation of polar sounding and imaging capabilities is tentatively scheduled for late 2013. The 3U to 6U CubeSat envelope is well suited to passive microwave imaging at frequencies at approximately V-band and higher due to the available aperture size and anticipated orbital altitudes for CubeSats. The use of redundant satellites within a fleet launched either in groups or as single payloads will moreover provide enhanced temporal resolution previously attainable using only geostationary concepts. While data communications to such fleets will likely require relay satellites at higher altitudes it is envisioned that the available orbital lifetimes without propellant boost will require fleet replenishment at rates modest enough for reduced operational system costs as well as facilitate regular technology infusion into sensing, navigation, data, and control electronics. In this presentation the design characteristics of the PolarCube satellite will be discussed, along with the ramifications of the CubeSat envelope restrictions on the cost, sampling characteristics, scanning capabilities, communications requirements, and expected measurement precision of a CubeSat passive microwave fleet.

Abstract An energy spectrum of electrons from 180 to 550 keV precipitating into the dayside polar ionosphere was observed under a geomagnetically quiet condition (AE ≤ 100 nT, Kp = 1‐). The observation was carried out at 73–184 km altitudes by the HEP instrument onboard the RockSat‐XN sounding rocket that has been launched from Andøya, Norway. The observed energy spectrum of precipitating electrons follows a power law of −4.9 ± 0.4 and the electron flux does not vary much over the observation period (∼274.4 s). A nearby ground‐based VLF receiver observation at Lovozero, Russia shows the presence of whistler‐mode wave activities during the rocket observation. A few minutes before the RockSat‐XN observation, POES18/MEPED observed precipitating electrons, which also suggest whistler‐mode chorus wave activities at the location close to the rocket trajectory. A test‐particle simulation for wave‐particle interactions was carried out using the data of the Arase satellite as the initial condition which was located on the duskside. The result of the simulation shows that whistler‐mode waves can resonate with sub‐relativistic electrons at high latitudes. These results suggest that the precipitation observed by RockSat‐XN is likely to be caused by the wave‐particle interactions between whistler‐mode waves and sub‐relativistic electrons.

Abstract The Automated Meteorology—Ice—Geophysics Observation System 3 (AMIGOS-3) is a multi-sensor on-ice ocean mooring and weather, camera and precision GPS measurement station, controlled by a Python script. The station is designed to be deployed on floating ice in the polar regions and operate unattended for up to several years. Ocean mooring sensors (SeaBird MicroCAT and Nortek Aquadopp) record conductivity, temperature and depth (reported at 10 min intervals), and current velocity (hourly intervals). A Silixa XT fiber-optic distributed temperature sensing system provides a temperature profile time-series through the ice and ocean column with a cadence of 6 d −1 to 1 week −1 depending on available station power. A subset of the station data is telemetered by Iridium modem. Two-way communication, using both single-burst data and file transfer protocols, facilitates station data collection changes and power management. Power is supplied by solar panels and a sealed lead-acid battery system. Two AMIGOS-3 systems were installed on the Thwaites Eastern Ice Shelf in January 2020, providing data well into 2022. We discuss the components of the system and present several of the data sets, summarizing observed climate, ice and ocean conditions.

DATA-CHASER consists of two synergetic projects, DATA and CHASER, which flew together as a hitchhiker payload aboard the Space Shuttle Discovery in August of 1997. CHASER (Colorado Hitchhiker And Student Experiment of solar Radiation) is a solar science experiment used to test the primary DATA payload. A technology experiment, DATA (Distribution and Automation Technology Advancement) seeks to advance human support technology. Specifically, the DATA technologies support cooperative operations originating from different geographic sites as well as between humans and machines.

Public reporting burden for this collection of infonnatlon Is estimated to average 1 Hour per response, Including the time Ibr reviewing instructions, searching existing data sources, gathering and mainlaining the data needed, and completing and reviewing this collection of infonhation.

The Colorado Space Grant Consortium (CSGC) has identified the need for a mission operations concept that supports both reusability and the integration of advanced technologies. The current application of this concept, CSGC's Citizen Explorer-I (CX-I) satellite project, supports the "faster, better, cheaper" ideology embraced by today's technological community. The key features of this system are robustness, distributed automation and sophisticated assessment capabilities. This paper will discuss the mission operations system's origin, its application to the CX-I project and its intended support of future space missions.

Pluto is the last known planet in our Solar System awaiting spacecraft reconnaissance. In its eccentric orbit taking it 50 AU from the Sun, Pluto presently has a thin atmosphere containing methane, which is projected to "collapse" back to the icy planet's surface in about three decades, following Pluto's 1989 perihelion pass at 30 AU. Based on ground and Earth-orbit-based observing capabilities limited by Pluto's small size and extreme distance, present top-priority scientific questions for the first mission concern Pluto and Charon's surface geology, morphology and composition, and Pluto's neutral atmosphere composition. Budgetary realities preclude a large, many-instrument flyby spacecraft, while distance and launch energy requirements preclude any but the smallest orbiter using presently available launch vehicles and propulsion techniques. A NASA sponsored Pluto Mission Development activity began this year at the Jet Propulsion Laboratory. The Pluto Fast Flyby (PFF) tentative mission baseline utilizes two 125-160 kg spacecraft launched in 1998-99 aboard Titan IV(SRMU)/Centaurs or Protons on 7-10 year direct trajectories to Pluto. Instruments are likely to include a CCO imaging camera combined with an infrared spectrometer, plus an ultraviolet spectrometer. An ultra-stable oscillator is to be added to the telecommunications subsystem for radio occultation measurements. Solid state memory stores data during the brief encounter. to be played back over several months. Cost is the primary design driver with major tradeoffs between spacecraft development, launch services, radioisotope thermoelectric generator procurement and launch approval, and mission operations. Significant benefits are apparent from incorporating "small satellite" technologies from Earth orbiters, with a primary challenge to upgrade component lifetimes consistent with mission duration. The Pluto Team is presently identifying hardware, software and experience from the small satellite community and elsewhere which will be helpful in implementing the Pluto Fast Flyby mission within stringent cost, lifetime and performance constraints. The desired technology flight qualification date is 1994.

The Citizen Explorer mission is being developed to educate students of all ages about space, science, and technology. This mission is the first in a series of Earth-orbiting satellites designed by and for students to take measurements of the Earth's environment. Citizen Explorer is a small satellite that will be launched in June 1999 to measure atmospheric ozone and downlink these observations directly into classrooms through a UHF transponder. Citizen Explorer provides hands-on experiences in science and technology for pre-college students and real-world experience for student engineers and scientists.

Use of small and very small spacecraft is rapidly becoming more common. Methods to intentionally deorbit these spacecraft at the end of useful satellite life are required. A family of mass efficient Roll-Out De- Orbiting devices (RODEOTM) was developed by Composite Technology Development, Inc. (CTD). RODEOTM consists of lightweight film attached to a simple, ultra-lightweight, roll-out composite boom structure. This system is rolled to stow within a lightweight launch canister, allowing easy integration to the small satellite bus. The device is released at the end of useful lifetime and the RODEOTM composite boom unrolls the drag sail in a matter of seconds. This dramatically increases the deployed surface area, resulting in the higher aerodynamic drag that significantly reduces the time until reentry. A RODEOTM flight demonstration was recently conducted as part of the Colorado Space Grant Consortium's (COSGC) RocketSat-8 program, a program to provide students hands-on experience in developing experiments for space flight. The experiment was ultimately a success and RODEO (trademark) is now ready for future CubeSat missions.

Future Earth and Space Science missions will address increasingly broad and complex scientific issues. To accomplish this task, we will need to acquire and coordinate data sets from a number of different instrumetns, to make coordinated observations of a given phenomenon, and to coordinate the operation of the many individual instruments making these observations. These instruments will need to be used together as a single ‘‘Virtual Mission.’’ This coordinated approach is complicated in that these scientific instruments will generally be on different platforms, in different orbits, from different control centers, at different institutions, and report to different user groups.Before this Virtual Mission approach can be implemented, techniques need to be developed to enable separate instruments to work together harmoniously, to execute observing sequences in a synchronized manner, and to be managed by the Virtual Mission authority during times of these coordinated activities. Enabling technologies include object‐oriented designed approaches, extended operations management concepts and distributed computing techniques.Once these technologies are developed and the Virtual Mission concept is available, we believe the concept will provide NASA’s Science Program with a new, ‘‘go‐as‐you‐pay,’’ flexible, and resilient way of accomplishing its science observing program. The concept will foster the use of smaller and lower cost satellites. It will enable the fleet of scientific satellites to evolve in directions that best meet prevailing science needs. It will empower scientists by enabling them to mix and match various combinations of in‐space, ground, and suborbital instruments − combinations which can be called up quickly in response to new events or discoveries. And, it will enable small groups such as universities, Space Grant colleges, and small businesses to participate significantly in the program by developing small components of this evolving scientific fleet.

The Educational Ozone Researcher (EOR) is a small scientific spacecraft designed by students of the Colorado Space Grant College (CSGC) at the University of Colorado at Boulder. EOR was a finalist in the Universities Space Research Association (USRA) Student Explorer Demonstration Initiative (STEDI) program and received Phase I funding in the amount of $160K during late 1994 and early 1995. This paper provides a description of the scientific objectives and the design of the EOR mission.

housed at the University of Colorado Boulder, working with students on campus as well as across the state on