The National Aeronautics and Space Administration (NASA) is seeking to obtain information on innovative approaches for spacecraft hybrid attitude control that employ mixed-actuator combinations of two reaction wheels and reaction control thrusters. Specifically NASA is seeking innovative hybrid attitude control approaches for the distressed Kepler spacecraft which has suffered performance anomalies with two of its four-reaction wheel attitude control actuators. NASA is interested in identifying potential organizations that are capable of generating innovative spacecraft hybrid attitude control approaches. In particular the NESC is directly supporting the Kepler Project Office engineering and science staff with the identification of potential spacecraft hybrid attitude control approaches. The NESC is seeking information via this Request for Information (RFI) in an attempt to identify noteworthy hybrid control ideas, innovations and approaches that would allow NASA to continue its use of the Kepler observatorys remaining functional capabilities to accomplish potentially new and different scientific objectives. The NESC is primarily interested in identifying those hybrid control approaches that will enable the most compelling new science observations envisioned for a repurposed Kepler science mission. The NESC will review all submissions received in response to this RFI. NASA reserves the right to follow up with those responding organizations that present viable approaches for hybrid control. This is a Request for Information only and does not constitute a commitment, implied or otherwise, that NASA will take procurement action in this matter. THIS IS *NOT* A REQUEST FOR PROPOSAL, QUOTATION, OR INVITATION TO BID NOTICE. Further, NASA will not be responsible for any cost incurred in furnishing this information. This RFI is open to any organization that qualifies to see ITAR data such as U. S. industries, universities, non-profit organizations, NASA Centers, Federally Funded Research and Development Centers, and other U. S. government agencies. Kepler Mission and Spacecraft Background: The Kepler mission (NASA Discovery Mission #10) was specifically designed to perform a photometric survey of approximately 100,000 stars in a section of the Milky Way galaxy near the Cygnus constellation. The mission is to detect Earth-size planets in or near the habitable zone and determine how many of the billions of stars in our galaxy have such planets. It is NASA's first mission capable of finding Earth-size planets around other stars. General background information on the Kepler mission may be found at the following link: http://kepler.nasa.gov/ The Kepler spacecraft, which was designed and built by prime contractor Ball Aerospace and Technologies Corporation (BATC) of Boulder, Colorado, started with four (4) reaction wheel actuators to generate attitude control torques to slew, point and precisely stabilize the vehicle. A minimum of three reaction wheels is normally required to provide the zero-momentum three-axis stabilization of the spacecraft. Recently there have been a series of reaction wheel anomalies that have left the Kepler spacecraft with only two (2) nominally functioning reaction wheels. These reaction wheel anomalies have caused the Kepler mission managers to place the vehicle in a rest state thruster based attitude control mode and the collection of science data has been suspended. Kepler Hybrid Control Challenge Statement: NASA scientists are currently evaluating and investigating possible re-purposing mission for the Kepler observatory. A call for new Kepler science white papers has been issued by the Kepler Project and can be found at the following link as a reference for potential responders to this RFI: http://keplerscience.arc.nasa.gov/News.shtml#TwoWheelWhitePaper Although, the Kepler Mission has successfully completed its nominal mission requirements, the most desired outcome would be to return the spacecraft to the primary planet finding mode of operation which involves pointing the spacecraft at Cygnus with a 9 milli-arc sec pointing stability for long periods of time (i.e., >30 minutes per integration) and dwelling in the same mode for days or weeks, only changing orientation primarily to download the science data collected. Preliminary investigations appear to indicate that achieving this stringent level pointing stability is likely not feasible with a two-reaction wheel hybrid attitude control mode. However, it is worth noting that BATC has recently performed a preliminary analysis of a candidate two-reaction wheel hybrid attitude controller for the spacecraft that the Kepler science team is currently evaluating. The key to performing science with the Kepler observatory is maintaining the best pointing stability (ideally including control of the roll about the telescope boresight) for the longest time period possible. Arc-second level pointing stability while in a staring mode would be a very desirable target to achieve for a repurposed Kepler observatory. Possible other modes of science observation could include either a tracking mode, or a scanning mode, or a point and dwell type mode where the Kepler spacecraft is sequentially pointed to observe different parts of the sky. So ultimately the challenge here is to develop a two-reaction wheel (plus thrusters as needed) Kepler spacecraft hybrid attitude control mode that potentially can deliver at least one of these types of pointing and stabilization functions. Response Submission Guidelines and Response Deadline: Respondents are requested to provide information on spacecraft two-reaction wheel hybrid control attitude control/momentum management system concepts and innovative approaches that may have an application to the Kepler spacecraft. When responding, please include the following information: Organization information: Organization name and address, type of organization, point-of contact name, email address, and phone number, A statement that organizations response does not include any proprietary, organizational confidential, trade secret information. A short summary-level description of the two-reaction wheel hybrid attitude control approach that may apply to the Kepler spacecraft. Responders should conceptually describe their approach to the specific challenge of controlling the Kepler spacecraft with only two reaction wheels and some combination of reaction control thrusters. Responses should be submitted via email by August 30, 2013 at 5 PM Eastern Daylight Time to the LaRC Procurement Point of Contact at the email address listed below. The subject line of the submission should be "RFI for Kepler Hybrid Control Approaches". The files submitted should not be greater than 10MB in size. Please note that RFI responses must not exceed 5 pages in length. Use single-spaced, 12-point, Times New Roman font. The use of graphics to convey the hybrid control approaches is encouraged up to the page limit of 5 pages and the file size limit of 10MB. The following file naming convention should be used: Kepler_RFI_firstinitial_lastname_2013. Authorized file formats include: Adobe Acrobat versions 6 - 8 (.pdf) and Microsoft Word (.doc). It is emphasized that this RFI is for planning and information purposes only and is NOT to be construed as a commitment by the Government to enter into a contractual agreement. Likewise there should be no expectation that the Government will pay for information solicited. DISCLAIMER: All information NASA receives in response to this RFI will be open to ITAR qualified persons. NASA does not want responses that contain proprietary or company confidential information. The responses should not include any proprietary, organizational confidential, trade secrets. All questions about the RFI shall be directed by email to the LaRC Procurement Point of Contact listed below. The NESC Technical Point of Contact listed below is available to provide technical background and to answer questions as well. NASA LaRC Procurement Office Name: Ms. Octavia Hicks Title: LaRC Lead Contract Analyst Email:
[email protected] NESC Technical Point of Contact Name: Mr. Cornelius J. Dennehy Title: NASA Technical Fellow for Guidance, Navigation and Control (GN&C) Email:
[email protected]