Search NASA⌕ Search

SEARCH · Search NASA

Results for “orbital operations”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Natural and Induced Environment around the International Space Station (ISS) as Observed during On-Orbit Operations of the Robotic External Leak Locator (RELL)

Final Document is attached. The Robotic External Leak Locator (RELL) was deployed to the International Space Station (ISS) with the goal of detecting and locating on-orbit leaks around the ISS. Three activities to investigate and corroborate the background natural and induced environment of ISS were performed with RELL as part of the on-orbit validation and demonstration conducted in November – December 2016. The first demonstration activity pointed RELL directly in the ram and wake directions for one orbit each. The ram facing measurements showed high partial pressure for mass-to-charge ratio 16, corresponding to atomic oxygen (AO), as well as the presence of mass-to-charge ratio 17. RELL™s view in the wake-facing direction included more ISS structure and several Environmental Control and Life Support System (ECLSS) on-orbit vents were detected, including the Carbon Dioxide Removal Assembly (CDRA), Russian segment ECLSS, and Sabatier vents. The second demonstration activity pointed RELL at three faces of the P1 Truss segment. Effluents from ECLSS and European Space Agency (ESA) Columbus module on-orbit vents were detected by RELL. The partial pressures of mass-to-charge ratios 17 and 18 remained consistent with the first on-orbit activity of characterizing the natural environment. The third demonstration activity involved RELL scanning an Active Thermal Control System (ATCS) radiator. Three locations along the radiator were scanned and the angular position of RELL with respect to the radiator was varied. Mass-to-charge ratios 16 and 17 both had upward shifts in partial pressure when pointing toward the Radiator Beam Valve Modules (RBVMs), likely corresponding to a known, small ammonia leak.

International Space Station↗
NASA NTRSDate not supplied

A Common Habitat Deep Space Exploration Vehicle for Transit and Orbital Operations

When outfitted as a habitat, the SLS Core Stage Liquid Oxygen Tank is a pressure vessel that can be used to support human exploration in deep space. An exploration spacecraft can be constructed with this habitat, known as the Common Habitat, as its central element. More than just a transit vehicle, this spacecraft is a Deep Space Exploration Vehicle – a microgravity science laboratory capable of conducting research with onboard human crews throughout the inner solar system. Supplied with propellant by LEO depots, preliminary trajectory and v estimates indicate that the spacecraft can perform fly-by or orbital missions with trajectories close enough to the sun to intersect the orbit of Mercury or far enough away to fly by the main belt asteroid Vesta. Its primary mission, however, is to support human expeditions to Mars. Many, though not all, of the pressurized and unpressurized elements that compose the Deep Space Exploration Vehicle can also be used in surface base camps on the Moon and Mars. In additional to traditional space science disciplines, the spacecraft offers unique potential for small asteroid retrieval and for artificial gravity research. Three launches are used to deploy the spacecraft, but thirty-nine launches are used to deliver propellant to orbit to fully fuel the spacecraft for deep space missions. Key operations in a Mars crewed mission are described to illustrate how the vehicle is used and forward work is listed to mature the spacecraft concept.

Robert L. Howard Jr.↗
DOE OSTI2025

Initial in-orbit operation of the soft X-ray spectrometer Resolve onboard the X-ray imaging and spectroscopy mission satellite

The X-Ray Imaging and Spectroscopy Mission satellite was launched on September 6, 2023 (UT). Its Resolve instrument is a high-resolution X-ray spectrometer enabled by a microcalorimeter array thermally anchored to a 50-mK heat sink. Many sensitive, critical sub-systems comprise Resolve, including a multistage cryogenic cooling system, thin-film aperture filters, low-noise electronics, on-board signal processing, and several sources of X-rays for calibration. We summarize the initial on-orbit power-on and checkout of Resolve that commenced immediately after launch. Soon after launch, the cryocoolers were activated, and their operation was successfully established. On October 9, 2023, the first cycle of the adiabatic demagnetization refrigerator was carried out, bringing the sensors to their steady-state operational temperatures. Following this, the energy resolution at 5.9 keV was successfully measured. The energy scale of the system is highly sensitive to the thermal environment surrounding both the sensors and their analog electronics. Gain correction was performed using reference X-ray lines from onboard calibration sources. To optimize cooler frequency settings, noise spectra were collected across a range of frequencies, and the most suitable frequency pair was selected based on the in-orbit environment. During the final phase of the checkout, an attempt was made to open the gate valve, which is designed to protect the Dewar’s interior from external pressure during ground operations and launch. Unfortunately, this attempt was unsuccessful. As a result, the checkout process was temporarily paused, and a stable operational strategy was subsequently developed to enable Resolve to function effectively with the gate valve remaining closed.

X-ray micro-calorimeter↗
NASA NTRS1978

Concepts and requirements for shuttle/payload orbital operations of the space transportation system

The results of studies and software development activities are summarized. Technical reports and memoranda are presented in a graphical history of contract activities and the expenditure of engineering manhours. Major topics and activities are: (1) flight phase standardization; (2) flight profile standardization; (3) maneuver targeting for solid rocket motors; (4) relative motion and RCS (Reaction Control System) jet flowfield plotting programs; (5) on-orbit aerodynamic models; (6) terminal approach strategy for payload retrieval/docking; (7) proximity navigation; and (8) desk-top flight simulator for proximity operations. A list of recommendations is also presented.

Wilson, S. W.↗
NASA NTRS2016

Sixteen Years of Terra MODIS On-Orbit Operation, Calibration, and Performance

Terra MODIS has successfully operated for more than 16 years since its launch in December 1999. From its observations, many science data products have been generated in support of a broad range of research activities and remote sensing applications. Terra MODIS has operated in a number of configurations and experienced a few anomalies, including spacecraft and instrument related events. MODIS collects data in 36 spectral bands that are calibrated regularly by a set of on-board calibrators for their radiometric, spectral, and spatial performance. Periodic lunar observations and long-term radiometric trending over well-characterized ground targets are also used to support sensor on-orbit calibration. Dedicated efforts made by the MODIS Characterization Support Team (MCST) and continuing support from the MODIS Science Team have contributed to the mission success, enabling well-calibrated data products to be continuously generated and routinely delivered to users worldwide. This paper presents an overview of Terra MODIS mission operations, calibration activities, and instrument performance of the past 16 years. It illustrates and describes the results of key sensor performance parameters derived from on-orbit calibration and characterization, such as signal-to-noise ratio (SNR), noise equivalent temperature difference (NEdT), solar diffuser (SD) degradation, changes in sensor responses, center wavelengths, and band-to-band registration (BBR). Also discussed in this paper are the calibration approaches and strategies developed and implemented in support of MODIS Level 1B data production and re-processing, major challenging issues, and lessons learned. (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Xiong, X.↗
NASA NTRS2019

TSIS Experiences with ISS Jitter from Inception to On-Orbit Operation

The TSIS instrument has been measuring solar irradiance on a continual basis since January 2018 as an external payload on the ISS. In 2014 when TSIS was directed to fly on the ISS, the jitter environment was highly uncertain, so TSIS designed a robust gimbaled pointing system that showed excellent disturbance attenuation throughout the design, test, and on-orbit phases of the program. This paper discusses how TSIS accounted for this uncertain jitter environment through-out the life of the program.TSIS was able to measure the ISS jitter during commissioning and determined that it was a relatively benign environment less than 4 arcseconds 1σ at low frequencies (<0.5 Hz). More importantly, the measured pointing performance of TSIS was consistently found to be 4 arcseconds 1σ, which easily satisfied the jitter requirement of 60 arcseconds 1σ.

solar irradiance instrument↗
NASA NTRS2005

Early On-Orbit Operation of the Loop Heat Pipe System on the Swift BAT Instrument

The Burst Alert Telescope (BAT) is one of three instruments on the Swift satellite. Two Loop Heat Pipes (LHP's), one at either side of the BAT's Detector Array Plate (DAP), transfer heat to a common radiator for rejection to space. This viewgraph presentation provides information on LHP design for the BAT, and the performance of the LHPs in orbit.

Ottenstein, Laura↗
NASA NTRS1985

Failure analysis and performance evaluation of NASA inertial reference unit (DRIRU 2) after 50 months of orbital operation

The first production DRIRU 2 (NASA standard high performance inertial reference unit) system was launched as a subsystem of the Modular Attitude Control System for the Solar Maximum Mission (SMM) spacecraft in February 1980. This hardware was retrieved during the repair of the SMM during Shuttle Flight 41-C in April 1984 and returned to Teledyne Systems Company (manufacturer) for investigation and performance measurements as directed by Goddard Space Flight Center. A failure of one of the three gyro channels occurred approximately 6.5 months after launch. The built in redundancy functioned properly, the DRIRU 2 continued to provide the required attitude control function without performance degradation. Subsequent failure of other attitude control subsystems made the SMM a candidate for the first demonstration of the shuttle in-orbit repair capabilty. The in-orbit DRIRU 2 II failure scenario and the results of the analyses/tests conducted after retrieval are discussed. Comparison of this data with similar data prior to launch demonstates the excellent stability of performance parameters achieveable with DRIRU 2.

Green, K. N.↗
DOE OSTI2025

In-orbit operation of Resolve Filter Wheel and modulated X-ray source

The Resolve soft X-ray spectrometer is a high spectral resolution microcalorimeter spectrometer for the X-ray Imaging and Spectroscopy Mission. In the beam of Resolve, there is a filter wheel containing X-ray filters. In the beam, there is also an active calibration source, the modulated X-ray source (MXS), which can provide pulsed X-rays to facilitate gain calibration. The filter wheel consists of six filter positions. Two open positions, one 55 Fe source to aid in spectrometer characterization during the commissioning phase, and three transmission filters: a neutral density filter, an optical blocking filter, and a beryllium filter. The X-ray intensity, pulse period, and pulse separation of an MXS are highly configurable. Furthermore, the switch-on time is synchronized with the spacecraft’s internal clock to give accurate start and end times of the pulses. One of the issues raised during ground testing was the susceptibility of an MXS at high voltage to ambient light. Although measures were taken to mitigate the light leak, the efficacy of those measures must be verified in orbit. Along with an overview of issues raised during ground testing, we will discuss the calibration source and the filter performance in-flight and compare with the transmission curves present in the Resolve calibration database.

X-ray Imaging and Spectroscopy Mission/Resolve↗
NASA NTRS1971

Orbital operations studies

Nautical units being developed for coordinating the space-time positions of things throughout the earth's atmosphere and the earth-centered region of space are considered. Three aspects of the problem are briefly summarized.

Bellamy, J. C.↗
NASA NTRS1975

IUS/TUG orbital operations and mission support study. Volume 4: Project planning data

Planning data are presented for the development phases of interim upper stage (IUS) and tug systems. Major project planning requirements, major event schedules, milestones, system development and operations process networks, and relevant support research and technology requirements are included. Topics discussed include: IUS flight software; tug flight software; IUS/tug ground control center facilities, personnel, data systems, software, and equipment; IUS mission events; tug mission events; tug/spacecraft rendezvous and docking; tug/orbiter operations interface, and IUS/orbiter operations interface.

Source record↗
NASA NTRS1976

Utilization of solid-propellant upper stages in STS payload orbital operations

The main purpose of this report is to discuss techniques of trajectory design, maneuver execution, and stage loading that are compatible with the use of SRM's (solid rocket motors) which, once ignited, must burn to propellant depletion. It is anticipated that some shuttle payloads will use non-IUS (interim upper stage) solid propellant kick stages; therefore this subject is also pertinent to shuttle flights other than those involving the use of the IUS. The SRM utilization techniques can be divided into two major categories: (1) those in which the stage performance is adjusted to match the velocity increment magnitude requirements of a preselected trajectory, and (2) those in which the trajectory is designed to match the velocity increment magnitude capability of the stage(s).

Wilson, S. W.↗
NASA NTRS1984

The Shuttle Remote Manipulator System and its use in orbital operations

It is pointed out that the Shuttle Remote Manipulator System (RMS) is a key element in the Space Transportation System's ability to deploy, retrieve, and handle payloads in space. In addition, the RMS has the capability of performing other critical tasks such as inspection, construction, and satellite servicing. The present investigation is concerned with various end of arm tool concepts which could augment the RMS's capability enabling it to perform functions such as pushing/holding (applying pressure), prying, clamping (nonimpulse release) and shearing. Attention is also given to a tool for satellite servicing, a method for augmenting the operator's 'feel' for the job by force/moment sensing, and a possible four phase program for implementation of the tool system. A description is given of the key elements of RMS flight testing carried out to date.

Sachdev, S. S.↗