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NASA NTRS2020

Integration, Test, and On-Orbit Operation of a Ka-band Parabolic Deployable Antenna (KaPDA) for CubeSats

In the past decade, CubeSats have undergone a revolution, moving from universityresearch projects to enabling industry opportunities and government missions. Six yearsago, the Jet Propulsion Laboratory, California Institute of Technology (JPL/Caltech)initiated a research and technology development effort to advance CubeSat communicationcapabilities, with one of the key thrusts being the Ka-band parabolic deployable antenna(KaPDA). This antenna started with the ambitious goal of fitting a 42 dB, 0.5 meter, 35 GHzantenna in a 1.5U canister. At that time, there had been very limited development in the areaof high gain CubeSat antennas which are critical for both high data rate communicationsand remote sensing science. A Ka-band high gain antenna would provide a 10,000 timesincrease in data communication rates over an X-band patch antenna and a 100 timesincrease over state-of-the-art S-band parabolic antennas. This paper discusses the process ofbuilding, integrating, and operating the flight antenna, its final performance and lessonslearned. KaPDA was an enabling technology for RainCube mission, the first Earth ScienceCubeSat to have an active instrument. RainCube was launched in May of 2018, makingKaPDA the second deployable parabolic antenna to fly on a CubeSat and the first of its kindto operate at Ka-band enabling a number of opportunities for high rate, deep space antennacommunications and remote sensing science.

Thomson, Mark W.↗
NASA NTRS1970

Skylab Operations Handbook: Orbital Workshop (OWS), Airlock Module (AM), Multiple Docking Adapter (MDA): Systems Descriptions - Volume 1

The Skylab Program consists of three low-earth-orbit missions of the Orbital Assembly (OA) (figure 1.0-1), extending over.an a-month period. The OA consists of the CSM docked to the Saturn Workshop.(SWS). This handbook describes the systems for three of the four major components of the SWS (OWS, AM, and MDA), and also discusses significant interfaces with the Instrument Unit (IU), ATM, and CSM. The other major component of the SWS, the ATM, is treated separately in its own handbook. The OWS, AM, MDA, ATM Deployment Assembly (ATM-DA), Fixed Airlock Shroud (FAS), Payload Shroud (PS), and IU are addressed throughout this document as individual modules from a structural standpoint only. Although normally considered a part of the launch vehicle, the IU is treated in this document as part of the SWS because of its function in preparing the SWS for orbital operation. Section 1.0 describes vehicle and mission configurations of the Skylab program and provides general descriptions of the various systems. Section 2.0 provides detailed systems data covering system interfaces, functional description, subsystems and major components description, component operation, failure modes, performance and design data, operational limitations and restrictions, and instrumentation, and briefly outlines the experiments. Section 3.0 contains illustrations of all panels and identifies the controls and displays, panels, reference designators, nomenclature, functions, circuit breakers, and power sources. The Table of Contents lists in order of appearance all sections, subsections, major paragraphs, illustrations, and tables and provides their respective page locations. Appendix A defines the abbreviations and acronyms employed throughout this handbook, and Appendix B explains the symbols used. Appendix C is a locator index that references component controls contained in Section 3.0. Appendix D is an alphabetical index of paragraph headings, illustrations, and tables, according to the key word, with applicable page numbers. Additional items of significance to the user have been included in the index. The technical level to which this document is written assumes the reader to have general knowledge of engineering terms and principles.

West, W. D.↗
NASA NTRS1986

Scientific purposes of earth orbital tether operations

The earth orbiting tethered systems will allow long-term observations of the 90-130 km environment and spatial gradiometry at altitudes from 130-400 km. The advantages such tethered systems could provide to the physics of the atmosphere/magnetosphere boundary, and the spatial and temporal structure of the earth's gravity and magnetic fields are discussed. The physical characteristics of the polar and equatorial regions, and the ionosphere and upper atmosphere are described.

Webster, W. J., Jr.↗
NASA NTRS2010

A Comparison Between Orion Automated and Space Shuttle Rendezvous Techniques

The Orion spacecraft will replace the space shuttle and will be the first human spacecraft since the Apollo program to leave low earth orbit. This vehicle will serve as the cornerstone of a complete space transportation system with a myriad of mission requirements necessitating rendezvous to multiple vehicles in earth orbit, around the moon and eventually beyond . These goals will require a complex and robust vehicle that is, significantly different from both the space shuttle and the command module of the Apollo program. Historically, orbit operations have been accomplished with heavy reliance on ground support and manual crew reconfiguration and monitoring. One major difference with Orion is that automation will be incorporated as a key element of the man-vehicle system. The automated system will consist of software devoted to transitioning between events based on a master timeline. This effectively adds a layer of high level sequencing that moves control of the vehicle from one phase to the next. This type of automated control is not entirely new to spacecraft since the shuttle uses a version of this during ascent and entry operations. During shuttle orbit operations however many of the software modes and hardware switches must be manually configured through the use of printed procedures and instructions voiced from the ground. The goal of the automation scheme on Orion is to extend high level automation to all flight phases. The move towards automation represents a large shift from current space shuttle operations, and so these new systems will be adopted gradually via various safeguards. These include features such as authority-to-proceed, manual down modes, and functional inhibits. This paper describes the contrast between the manual and ground approach of the space shuttle and the proposed automation of the Orion vehicle. I will introduce typical orbit operations that are common to all rendezvous missions and go on to describe the current Orion automation architecture and contrast it with shuttle rendezvous techniques and circumstances. The shuttle rendezvous profile is timed to take approximately 3 days from orbit insertion to docking at the International Space Station (ISS). This process can be divided into 3 phases: far-field, mid-field and proximity operations. The far-field stage is characterized as the most quiescent phase. The spacecraft is usually too far to navigate using relative sensors and uses the Inertial Measurement Units (IMU s) to numerically solve for its position. The maneuvers are infrequent, roughly twice per day, and are larger than other burns in the profile. The shuttle uses this opportunity to take extensive ground based radar updates and keep high fidelity orbit states on the ground. This state is then periodically uplinked to the shuttle computers. The targeting solutions for burn maneuvers are also computed on the ground and uplinked. During the burn the crew is responsible for setting the shuttle attitude and configuring the propulsion system for ignition. Again this entire process is manually driven by both crew and ground activity. The only automatic processes that occur are associated with the real-time execution of the burn. The Orion automated functionality will seek to relieve the workload of both the crew and ground during this phase

Ruiz, Jose O,↗
NASA NTRS1979

Orbit transfer operations for the Space Shuttle era

Orbit transfer operations are reviewed relative to the objectives, operational factors, and crew model concepts of future mission requirements. The review is based on studies presently underway and on projected needs and goals of the Space Shuttle era. Numerous tradeoff studies and further analyses are needed before the best form of the manned geostationary vehicle becomes fixed. However, the Shuttle can provide the necessary low-orbit logistics service for dispatching manned geostationary missions on as frequent a schedule as will be needed to serve the advanced geostationary satellites of the near future.

Davis, H. P.↗
NASA NTRS1992

TOPEX/Poseidon orbit acquisition maneuver design

The current baseline injection orbit for the jointly sponsored NASA/CNES TOPEX/Poseidon mission is near-circular, approximately 30 km below the desired operational orbit altitude and at the operational orbit inclination. A baseline maneuver sequence to retarget from this injection orbit to the desired operational orbit has been designed based upon the expected worst-case 3-sigma injection and maneuver execution errors. The sequence requires seven maneuvers, including an initial calibration burn, and achieves the operational orbit with the desired ground track pattern in 30 days. A delay sensitivity analysis has been conducted to estimate the allowable operational delay for each maneuver without increasing the total orbit acquisition period. The baseline sequence provides back-ups for a one-revolution delay for each maneuver and one-day delay for most maneuvers. It is also shown that a higher injection orbit allows the maneuver sequence to achieve the operational orbit in 26 days under a worst-case scenario.

Bhat, Ramachandra S.↗
NASA NTRS1971

Lunar mission safety and rescue: Escape/rescue analysis and plan

The results are presented of the technical analysis of escape/rescue/survival situations, crew survival techniques, alternate escape/rescue approaches and vehicles, and the advantages and disadvantages of each for advanced lunar exploration. Candidate escape/rescue guidelines are proposed and elements of a rescue plan developed. The areas of discussions include the following: lunar arrival/departure operations, lunar orbiter operations, lunar surface operations, lunar surface base escape/rescue analysis, lander tug location operations, portable airlock, emergency pressure suit, and the effects of no orbiting lunar station, no lunar surface base, and no foreign lunar orbit/surface operations on the escape/rescue plan.

Source record↗
NASA NTRS2004

Mars Telecom Orbiter mission operations concepts

The Mars Telecom Orbiter (MTO) relay capability enables next decadal missions at Mars, collecting gigabits of data a day to be relayed back at speeds exceeding 4 Mbps and it facilitates small missions whose limited resources do not permit them to have a direct link to Earth.

Mars Telecom Orbiter↗
NASA NTRS1992

Ulysses mission operations

The Ulysses mission is described in terms of in-Shuttle operations, initial in-orbit operations, routine operations, operational organization, and data gathering and production. The configuration of the Ulysses payload is illustrated, and the flight to orbit is described including a three-hour on-orbit checkout. The first contact was reported at the Deep Space Network station followed by an adjustment of the spacecraft solar-aspect angle and the acquisition of ranging and Doppler data. In-orbit operations include the earth acquisition maneuver, a trajectory correction maneuver, and a payload switch. Continuous data gathering is discussed with reference to the Jupiter encounter and the first and second oppositions and conjunctions. The data-gathering components comprise ground stations, a data-processing computer, and a data-records system. Data production is performed in an off-line mode that does not interfere with the real-time operations.

Beech, P.↗
NASA NTRS2003

Launch Condition Deviations of Reusable Launch Vehicle Simulations in Exo-Atmospheric Zoom Climbs

The Defense Advanced Research Projects Agency has proposed a two-stage system to deliver a small payload to orbit. The proposal calls for an airplane to perform an exo-atmospheric zoom climb maneuver, from which a second-stage rocket is launched carrying the payload into orbit. The NASA Dryden Flight Research Center has conducted an in-house generic simulation study to determine how accurately a human-piloted airplane can deliver a second-stage rocket to a desired exo-atmospheric launch condition. A high-performance, fighter-type, fixed-base, real-time, pilot-in-the-loop airplane simulation has been modified to perform exo-atmospheric zoom climb maneuvers. Four research pilots tracked a reference trajectory in the presence of winds, initial offsets, and degraded engine thrust to a second-stage launch condition. These launch conditions have been compared to the reference launch condition to characterize the expected deviation. At each launch condition, a speed change was applied to the second-stage rocket to insert the payload onto a transfer orbit to the desired operational orbit. The most sensitive of the test cases was the degraded thrust case, yielding second-stage launch energies that were too low to achieve the radius of the desired operational orbit. The handling qualities of the airplane, as a first-stage vehicle, have also been investigated.

Urschel, Peter H.↗
NASA NTRS1985

Reactor power system deployment and startup

This paper addresses issues that should receive further examination in the near-term as concept selection for development of a U.S. space reactor power system is approached. The issues include: the economics, practicality and system reliability associated with transfer of nuclear spacecraft from low earth shuttle orbits to operational orbits, via chemical propulsion versus nuclear electric propulsion; possible astronaut supervised reactor and nuclear electric propulsion startup in low altitude Shuttle orbit; potential deployment methods for nuclear powered spacecraft from Shuttle; the general public safety of low altitude startup and nuclear safe and disposal orbits; the question of preferred reactor power level; and the question of frozen versus molten alkali metal coolant during launch and deployment. These issues must be considered now because they impact the SP-100 concept selection, power level selection, weight and size limits, use of deployable radiators, reliability requirements, and economics, as well as the degree of need for and the urgency of developing space reactor power systems.

Wetch, J. R.↗
NASA NTRS1999

Effects on Training Using Illumination in Virtual Environments

Camera based tasks are commonly performed during orbital operations, and orbital lighting conditions, such as high contrast shadowing and glare, are a factor in performance. Computer based training using virtual environments is a common tool used to make and keep CTW members proficient. If computer based training included some of these harsh lighting conditions, would the crew increase their proficiency? The project goal was to determine whether computer based training increases proficiency if one trains for a camera based task using computer generated virtual environments with enhanced lighting conditions such as shadows and glare rather than color shaded computer images normally used in simulators. Previous experiments were conducted using a two degree of freedom docking system. Test subjects had to align a boresight camera using a hand controller with one axis of rotation and one axis of rotation. Two sets of subjects were trained on two computer simulations using computer generated virtual environments, one with lighting, and one without. Results revealed that when subjects were constrained by time and accuracy, those who trained with simulated lighting conditions performed significantly better than those who did not. To reinforce these results for speed and accuracy, the task complexity was increased.

Maida, James C.↗
NASA NTRS1965

Relay system operations

In-orbit operational aspects of Relay I satellite and requirements for satellite command and for real time telemetry data reduction

DATA REDUCTION↗