Engineering topics

Wasiak, Francis

Publications and source records attributed to Wasiak, Francis.

5 records

NASA NTRS2015

Fundamentals for Team Based Rehearsals and the Differences Between Low Earth and Deep Space Missions

Presentation to be presented at the 2015 IEEE Aerospace Conference, Big Sky, Montana, March 7-14-2015.Rehearsals are mission level readiness tests that exercise personnel, operational process, and flight products, in a near flight like environment. The program is started 6-9 months prior to launch and is used to ensure the final as built system will meet mission goals (i.e. validation). On Deep Space missions you rehearse cruise activities post launch!Focus on critical activities to the mission, (i.e. propulsive maneuvers, instrument commissioning and any first time events or coordinating activities that involve major stakeholders).

Deep Space Missions↗

NASA NTRS2015

Essentials for Team Based Rehearsals and the Differences Between Earth Orbiting and Deep Space Missions

The mission readiness environment is where spacecraft and ground systems converge to form the entire as built flight system for the final phase of operationally-themed testing. For most space missions, this phase starts between nine to twelve months prior to the planned launch. In the mission readiness environment, the goal is to perform sufficient testing to exercise the flight teams and systems through all mission phases in order to demonstrate that all elements are ready to support. As part of the maturation process, a mission rehearsal program is introduced to focus on team processes within the final flight system, in a more realistic operational environment. The overall goal for a mission rehearsal program is to: 1) ensure all flight system elements are able to meet mission objectives as a cohesive team; 2) reduce the risk in space based operations due to deficiencies in people, processes, procedures, or systems; and 3) instill confidence in the teams that will execute these first time flight activities. A good rehearsal program ensures critical events are exercised, discovers team or flight system nuances whose impact were previously unknown, and provides a real-time environment in which to interact with the various teams and systems. For flight team members, the rehearsal program provides experience and training in the event of planned (or unplanned) flight contingencies. To preserve the essence for team based rehearsals, this paper will explore the important elements necessary for a successful rehearsal program, document differences driven by Earth Orbiting (Aqua, Aura, Suomi-National Polar-orbiting Partnership (NPP)) and Deep Space missions (New Horizons, Mars Atmosphere and Volatile EvolutioN (MAVEN)) and discuss common challenges to both mission types. In addition, large scale program considerations and enhancements or additional steps for developing a rehearsal program will also be considered. For NASA missions, the mission rehearsal phase is a key milestone for predicting and ensuring on-orbit success.

Gomez-Rosa, Carlos↗

NASA NTRS2012

The Building Blocks for JWST I and T (Integrations and Test) to Operations - From Simulator to Flight Units

The James Webb Space Telescope (JWST) Project has an extended integration and test (I&T) phase due to long procurement and development times of various components as well as recent launch delays. The JWST Ground Segment and Operations group has developed a roadmap of the various ground and flight elements and their use in the various JWST I&T test programs. The JWST Project s building block approach to the eventual operational systems, while not new, is complex and challenging; a large-scale mission like JWST involves international partners, many vendors across the United States, and competing needs for the same systems. One of the challenges is resource balancing so simulators and flight products for various elements congeal into integrated systems used for I&T and flight operations activities. This building block approach to an incremental buildup provides for early problem identification with simulators and exercises the flight operations systems, products, and interfaces during the JWST I&T test programs. The JWST Project has completed some early I&T with the simulators, engineering models and some components of the operational ground system. The JWST Project is testing the various flight units as they are delivered and will continue to do so for the entire flight and operational system. The JWST Project has already and will continue to reap the value of the building block approach on the road to launch and flight operations.

Fatig, Curtis↗

NASA NTRS2008

James Webb Space Telescope - Applying Lessons Learned to I&T

The James Webb Space Telescope (JWST) is part of a new generation of spacecraft acquiring large data volumes from remote regions in space. To support a mission such as the JWST, it is imperative that lessons learned from the development of previous missions such as the Hubble Space Telescope and the Earth Observing System mission set be applied throughout the development and operational lifecycles. One example of a key lesson that should be applied is that core components, such as the command and telemetry system and the project database, should be developed early, used throughout development and testing, and evolved into the operational system. The purpose of applying lessons learned is to reap benefits in programmatic or technical parameters such as risk reduction, end product quality, cost efficiency, and schedule optimization. In the cited example, the early development and use of the operational command and telemetry system as well as the establishment of the intended operational database will allow these components to be used by the developers of various spacecraft components such that development, testing, and operations will all use the same core components. This will reduce risk through the elimination of transitions between development and operational components and improve end product quality by extending the verification of those components through continual use. This paper will discuss key lessons learned that have been or are being applied to the JWST Ground Segment integration and test program.

Johns, Alan↗

NASA NTRS2008

James Webb Space Telescope - L2 Communications for Science Data Processing

JWST is the first NASA mission at the second Lagrange point (L2) to identify the need for data rates higher than 10 megabits per second (Mbps). JWST will produce approximately 235 Gigabits of science data every day that will be downlinked to the Deep Space Network (DSN). To get the data rates desired required moving away from X-band frequencies to Ka-band frequencies. To accomplish this transition, the DSN is upgrading its infrastructure. This new range of frequencies are becoming the new standard for high data rate science missions at L2. With the new frequency range, the issues of alternatives antenna deployment, off nominal scenarios, NASA implementation of the Ka-band 26 GHz, and navigation requirements will be discussed in this paper. JWST is also using Consultative Committee for Space Data Systems (CCSDS) standard process for reliable file transfer using CCSDS File Delivery Protocol (CFDP). For JWST the use of the CFDP protocol provides level zero processing at the DSN site. This paper will address NASA implementations of Ground Stations in support of Ka-band 26 GHz and lesson learned from implementing a file base (CFDP) protocol operational system.

Johns, Alan↗