Articles and Whitepapers

• J. Ambrose, B. Yendler, and S. H. Collicott; "Modeling to Evaluate a Spacecraft Propellant Gauging System",
  Journal of Spacecraft and Rockets, vol. 37, Nov-Dec, 2000, pp. 833-835
  The paper describes modeling results for the on-orbit thermal response of spacecraft propellant used for orbit stationkeeping. It was a first attempt to develop a general approach for existing thermal gauging method. Download PDF
• B. Yendler, et all, "Anik E Spacecraft Life Extension",
  Space Operations 2004 Conference, May 17-21, 2004, Montreal, Canada
  Paper discusses a methodology of extension of Anik E1 and Anik E2 satellites mission life. It included multiple thermal gauging of tank loads and developed technique to balance tanks. Download PDF
• B. Yendler, T. A. Martin, S. H. Collicott; "Thermal Gauging and Rebalancing of Propellant in Multiple Tank Satellites",
  Journal of Spacecraft and Rockets, vol. 44, July-August 2007, pp. 878-883
  The paper discusses how an improved thermal propellant gauging system is applied to detect imbalances in a pair of satellites and to design and implement new technology: the thermal pumping procedures to correct the imbalances. Download PDF
• B.Yendler; "Active Propellant Management",
  2006 SpaceOps Conference, June 17–21, 2006, Rome, Italy, paper 2006- 5569
  The paper discusses an Active Propellant Management (APM) approach to control propellant migration between propellant tanks in order to reduce risk of an accidental depletion of a single tank in multi-tank propulsion system. Download PDF
• B.Yendler, "Review of Propellant Gauging Methods",
  44th AIAA Aerospace Sciences Meeting and Exhibit, January 9–12, 2006, Reno, Nevada, paper AIAA 2006-939
  Three of the most popular methods of propellant estimation, namely, bookkeeping, PVT (Pressure, Volume, Temperature) and the thermal propellant gauging methods are discussed in the current paper. Download PDF
• B.Yendler, "Unconventional Thermal Propellant Gauging System",
  45th AIAA Aerospace Sciences Meeting and Exhibit, January 8–11, 2007, Reno, Nevada, paper AIAA 2007-1363
  The paper discusses method of thermal propellant gauging when propellant tanks don't have installed heaters. It is shown that propellant gauging is possible even in this case. The biggest difference between conventional and unconventional thermal propellant gauging lies in role of tank environment in propellant gauging. Download PDF
• T. Narita, B.Yendler, "Thermal Propellant Gauging System for BSS 601",
  25th AIAA International Communications Satellite Systems Conference (organized by APSCC),
  September 18–20, 2007, Bangkok, Thailand, paper AIAA 2007-3149
  This paper describes how the Thermal Gauging method wos applied to an on-orbit Boeing 601 geosynchronous communications satellite. It is shown that propellant gauging is possible even when the propellant tanks do not have heaters. This paper examines an implementation of the Thermal PGS method on a Boeing 601 geosynchronous communications satellite which has been operated by JSAT Corporation of Japan. Download PDF
• B.Yendler, E. Jew, "Total Fuel Management at EOL",
  Space Operations 2008 Conference, May 12–16, 2008, Heidelberg, Germany, paper 2008-3376
  The paper discusses the strategy and planning for the extension of EOL operations for an LM3000 satellite that was de-orbited in 2007. The plan consisted of three phases. The first phase included monitoring of fuel level using a thermal gauging method of high accuracy which provides confidence that the satellite has a fuel load sufficient for de-orbiting. In the second phase, Active Propellant Management (APM) was employed to suppress daily fuel migration and to reduce the risk of accidental tank depletion. Due to the measures undertaken, the satellite life was extended for several years while being confident that the satellite still had enough fuel for de-orbiting. De-orbiting of the satellite constituted the third phase. Download PDF
• Apracio, B.Yendler,"Thermal Propellant Gauging at EOL, Telstar 11 Implementation",
  Space Operations 2008 Conference, May 12–16, 2008, Heidelberg, Germany, paper 2008-3375
  Implementation of a thermal method for propellant estimation for EuroStar 2000 satellite is discussed in this paper. The paper shows that the developed method does not require ground calibration of the thermal model and provides a high accuracy of propellant estimation at EOL. The method was used for estimation of propellant remaining on the Telstar 11 satellite.Download PDF
• B.Yendler, et all, "Thermal Propellant Gauging, SpaceBus 2000 (Turksat 1C) Implementation",
  AIAA SPACE 2008 Conference & Exposition, September 9–11, 2008, San Diego, California paper AIAA 2008-7697
  Development and implementation of thermal propellant gauging for Turksat 1C (SpaceBus 2000) satellite is discussed by this paper. The method consists of several steps, namely, building Tank and Satellite Thermal Models, calibration of the model using current flight data, running the integrated model for several propellant loads for each tank under identical boundary conditions, fitting flight data to simulation results and finding propellant load of the tank. Paper also compares different thermal methods of propellant estimation. Download PDF
• B. Yendler, et all, "Fuel Estimation for StarDust NExT mission",
  AIAA Space 2010 Conference and Exposition, Aug 30–Sep 2, 2010, Anaheim, CA, USA
  Implementation of a thermal estimation method for the Stardust spacecraft is discussed in this paper. Along with the propellant estimation, an uncertainty analysis was conducted. This paper compares fuel estimates made for Stardust by several techniques, including bookkeeping, PVT, and thermal PGS. These methods are described in detail, and their results and uncertainties for Stardust are compared. Download PDF
• B. Yendler, et all, "Implementation of Thermal Gauging Method for SpaceBus 3000A (ArabSat 2B) ", Space Operations 2012 Conference, June 11- 15, 2012, Stockholm, Sweden Paper discusses a development of Thermal Gauging Method (TGM) for ArabSat 2B (SpaceBus 300 A). It shows phases of development, results of estimation and accuracy analysis. It also discusses how TGM helped ArabSat to improve business. Download PDF
• B. Yendler, "Satellite Rescue - Luck or Skillful Application of Technology", AIAA SPACE 2012 Conference & Exposition; 11-13 September 2012, Pasadena, California, USA, paper AIAA 2012-5287 This paper shows that the need to rescue a satellite could arise from unfortunate circumstances, either poor quality control or lack of appropriate knowledge. It shows that a heavy reliance on the book-keeping method can lead to premature satellite loss or mission failure. Use of an accurate propellant estimation combined with the thermal pumping can save satellites. Download PDF