Aerospace Technologies Advancements Fig Part 11 pdf

Looking into Future - Systems Engineering of Microsatellites 333 of such systems. These new launchers, also known as converted-ICBMs, offer inexpensive and frequent launch opportunities to various space communities. It is being anticipated that in the next decade, there will be frequent and affordable launch opportunities provided by the Russian space-launch market. The following derivatives of the soviet ICBMs now serve as launch vehicles: 1. Rockot (Based on SS-19 ICBM; flight proven more than 140 times) 2. Shtil (a derivative from R-29-family of submarine-launched ballistic missiles) 3. Dnepr ( based on RS-20 ICBM; SS-18 Satan by NATO designation) 4. Start (based on RT-2PM Topol, NATO reporting name: RS-12M Topol ICBM) 5. Strela (based on UR-100 ICBM, NATO reporting name SS-11 Sego) 6. Tsyklon (based on R-36 ICBM, NATO reporting name SS-9 Scarp) 7. Volna (based on R-29R submarine-launched ballistic missiles) Current Status and Future Trends of Russian Space-Launch Market is being addressed by the same author in a separate paper [M.Malekan & H.Bonyan, 2010]. Table 4 summarizes launch cost per pound (kilogram) for different medium (5,001-12,000 lbs. to LEO) and intermediate (12,001-25,000 lbs. to LEO) launch vehicles, as of 1990-2000. Table 4. Launch cost per kilogram for different medium (5,001-12,000 lbs. to LEO) and intermediate (12,001-25,000 lbs. to LEO) launch vehicles, as of 1990-2000 Aerospace Technologies Advancements 334 Finally, Launch cost per kilogram for different heavy (more than 25,000 lbs. to LEO) launch vehicles is shown in table 5, as of 1990-2000. Table 5. Launch cost per kilogram for different heavy (more than 25,000 lbs. to LEO) launch vehicles, as of 1990-2000 The price-per-pound (kilogram) figures in the previous tables vary significantly from a launch vehicle to another. From the preceding tables, it is concluded that the non-western (Russian/Ukrainian, Chinese) vehicle offer lower prices than their western counterparts (American and European), primarily because of lower labour and infrastructure costs. The following table shows that these differences in average price-per-pound can be significant [Futron Corporation Manual, 2002]. Table 6. Average Price-per-pound for Western and Non-Western Launch Vehicles 11 , as of 1990-2000 11 The Zenit 3SL is considered a non-Western launch vehicle because of its Ukrainian and Russian heritage. Looking into Future - Systems Engineering of Microsatellites 335 7. Post-launch operations Post-launch (in-orbit) operation of microsatellites has been vastly ignored, both in practice and in the literature, until very recently. During the last decade, however, the significance of the issue has been highlighted by various communities and is evolving rapidly [R.Annes et al., 2002], [Hardhienata et al., 2005], [H.Bonyan 2010]. There, however, still remain certain shortcomings regarding in-orbit operations of microsatellites. In fact, most involved-parties are reluctant to officially declare inefficient in-orbit utilization of their microsatellites. Without referring to any specific project, it is being highlighted that according to the author's studies, there are several cases in which fully-operational microsatellites have been almost abandoned in orbit due to poor in-orbit operations strategy. These crafts could have provided invaluable services, with considerable financial benefit, if adequate short- /long- term in-orbit operations strategy had been carefully planned. It is being reminded that in the next decades, microsatellites will not only serve as hands-on experience to train university students and to be financially-valuable, much attention must be paid to the in-orbit operations of such vehicles. 8. Reference R.Amini, Gerard Aalbers, Rob Hamann, Wim Jongkind (2006), New Generations of Spacecraft Data Handling systems Less Harness more Reliability, 57th International Astronautical Congress, Valencia, Spain Annes et al., (2002), Operation Delfi – A Space Mission Development Project, 17th AMSAT- UK Colloquium, Guildford, Surrey, England, UK H.Bonyan (2010). An in-depth Analysis of the Ambiguity of Economical-profitability of Microsatellite Missions, accepted for publication in IEEE Aerospace conference Big Sky, MT USA H.Bonyan (2010), Efficient In-orbit Operations of LEO Polar/Sun-synchronous Satellites; Southern Hemisphere Revisited?, accepted for publication in IEEE Aerospace conference Big Sky, MT USA H.Bonyan and A.R.Toloei (2009), Systems Engineering Analysis of Required Level of On-orbit Autonomous Operation of a LEO Student-microsatellite Mission, Recent Advances in Space Technology conference (RAST 2009), Istanbul, Turkey H.Bonyan and A.R.Toloei (2009), Systems Engineering Approach toward the Problem of Sunlight Collection of a Light-micro Satellite, Recent Advances in Space Technology conference (RAST 2009), Istanbul, Turkey H.Bonyan (2008), Investigation and Utilization oF the Low-earth Equatorial Orbits for Missions Concerning the African Continent, AIAA & IEEE joint conference, Big Sky, USA H.Bonyan (2007), System engineering approach toward the problem of battery depth-of- discharge of a LEO satellite, International Conference on Complex Systems (ICCS) Quincy MA USA Aerospace Technologies Advancements 336 H.Bonyan (2007), Systems Engineering Approach toward the Problem of Required Level of In-orbit Autonomous-operation of a LEO Microsatellite Mission, International Conference on Complex Systems (ICCS) Quincy MA USA T. Bretschneider, S.H. Tan, C.H. Goh, K. Arichandran, W.E. Koh, E. Gill (2003), X-SAT Mission Progress, 5th IAA Symposium on Small Satellites for Earth Observation IAA-B5-0504, Berlin, Germany Farmer, Mike and Randy Culver (1995), The Challenges of Low-Cost, Automated Satellite Operations, Proceedings of the 31st International Telemetering Conference, Las Vegas, Nevada, pp. 203-209 Futron Corporation Manual (2002), Space Transportation Costs: Trends in Price per Pound to Orbit 1990-2000 E. Gill et al. (2008), Atmospheric Aerosol Characterisation with the Dutch-Chinese FAST Formation Flying Mission, IAC-08-B1.I.1, In Proc. of the 59th IAC, Glasgow, Scotland G. Grillmayer et al, (2003), ILSE – First Laboratory Model of the Small Satellite Program at the University of Stuttgart 54th International Astronautical Congress, Bremen, Germany S. Hardhienata, A. Nuryanto, R. H. Triharjanto, U. Renner (2005), Technical Aspects and Attitude Control Strategy of LAPAN-TUBSAT Micro Satellite, 5th IAA Symposium on Small Satellites for Earth Observation, Berlin, Germany W.Hasbi, E.Nasser, A.Rahman (2007), Spacecraft Control Center of Lapan-Tubsat Micro Satellite, 3rd Asian Space Conference, NTU@one-north campus, Singapore Fei-Bin Hsiao ,Hui-Ping Liu , Chung-Cheng Chen (2000), The Development of a Low-Cost Amateur Microsatellite Ground Station for Space Engineering Education, Global J. of Engng. Educ., Vol.4, No.1 Printed in Australia http://www.freescale.com/webapp/sps/site/homepage.jsp?nodeId=0162468rH3 , last visited July 2009 http://www.ic.gc.ca/app/ccc/srch/nvgt.do?lang=eng&prtl=1&sbPrtl=&estblmntNo=1234 56114317&profile=cmpltPrfl&profileId=1421&app=sold , last visited July 2009 http://www.phytec.com/ , last visited July 2009 http://www.rockwellcollins.com/about/locations/deutschland/index.html , last visited July 2009 http://www.sstl.co.uk/ , last visited July 2009 http://www.sunspace.co.za/ , last visited July 2009 Kitts, Christopher A. and Michael A. Swartwout (1998), Experimental Initiatives in Space System Operations, In Proceedings of the Annual Satellite Command, Control and Network Management Conference, Reston, VA Presented by Kitts in the Systems and Mission Analysis Session. Also presented by Michael A. Swartwout at the 1998 INFORMS Conference, Monterey, CA, January, 1998, Spacecraft Automation Session Kitts, Christopher A (1996)., A Global Spacecraft Control Network for Spacecraft Autonomy Research, In Proceedings of SpaceOps '96: The Fourth International Symposium on Looking into Future - Systems Engineering of Microsatellites 337 Space Mission Operations and Ground Data Systems, Munich, Germany. Presented by Kitts in the Operations Automation Session Kitts, Christopher A., and Robert J. Twiggs (1994), the Satellite Quick Research Testbed (SQUIRT) Program, In Proceedings of the 8th Annual AIAA/USU Conference on Small Satellites, Logan, Utah Kitts, Christopher A., and Richard A. Lu (1994), The Stanford SQUIRT Micro Satellite Program, In Proceedings of the AMSAT-NA 12th Space Symposium and AMSAT Annual Meeting, Orlando, Florida, Presented by Robert J. Twiggs at the 1994 AMSAT-NA Space Symposium, Orlando, Florida Larson Wiley J., James R.Wertz (1992) Space Mission Analysis and Design, pp. 393 & 397 Maessen D.C. et al. (2009), Mission Design of the Dutch-Chinese FAST Micro-Satellite Mission, 7th IAA Symposium on Small Satellites for Earth Observation, Berlin, Germany Maessen D.C. et al. (2008), Preliminary Design of the Dutch-Chinese FAST Micro-Satellite Mission, In Proc. of the 4S Symposium, Rhodes, Greece M.Malekan & H.Bonyan (2010), On the Current Status and Future Trends of Russian Space- Launch Market, accepted for publication in IEEE Aerospace conference Big Sky, MT USA U.Renner, Matthias Buhl (2008), High Precision Interactive Earth Observation with LAPAN- TUBSAT, Proceedings of the 4S Symposium Small Satellites, Systems and Services, Rhodos, Greece A.Sabirin, M.Othman (2007), Razaksat- High resolution imaging satellite for near equatorial orbit (Neqo) COSPAR/IAF Symposium, "Use of the equatorial orbit for space science and applications: Challenges and opportunities", Vienna, Austria A.Sierra, Juan J. Quiroga, Roberto Fernández and Gustavo E. Monte (2004), An Intelligent Maintenance System for Earth-based Failure Analysis and Self-repairing of Microsatellites, Acta Astronautica Volume 55, Issue 1, Pages 61-67 Swartwout, Michael A., and Christopher A. Kitts (1997), Automated Health Operations for the SAPPHIRE Spacecraft, In Proceedings of ITC/USA '96: The 33rd Annual International Telemetering Conference, Las Vegas, NV. Presented by Swartwout in the Space Systems Session Swartwout, Michael A., and Christopher A. Kitts (1996), A Beacon Monitoring System for Automated Fault Management Operations, In Proceedings of the Tenth Annual AIAA/USU Small Satellite Conference, Logon, UT. Presented by Swartwout in the University Student Session. Honourable Mention Winner in Student Paper Competition Third United Nations Conference on the Exploration and Peaceful Uses of Outer Space, UNISPACE III, 1998 Triharjanto, H.R., et al, (2004), LAPAN-TUBSAT: Micro-satellite platform for surveillance and remote sensing, 4S symposium, Paris, France E. Vicente-Vivas, Fabián García-Nocetti and Francisco Mendieta-Jiménez (2005), Automatic maintenance payload on board of a Mexican LEO microsatellite, Acta Astronautica Journal, Elsevier Science, Volume 58, Issue 3, Pages 149-167 Aerospace Technologies Advancements 338 A. M. Woodroffe and P. Madle (2004), Application and experience of CAN as a low cost OBDH bus system, MAPLD 2004, Washington D.C. USA Part V 17 An Aircraft Separation Algorithm with Feedback and Perturbation White, Allan L. NASA Langley Research Center USA 1. Introduction An open question in air traffic management is whether or not algorithms can be realistically shown to meet Federal Aviation Administration (FAA) safety requirements. This current work shows such a demonstration is possible for a separation algorithm with perturbations from feedback control and atmospheric turbulence in a local setting. This project can accept a three to four magnitude increase in complexity and still remain viable, but clearly this is not enough of a margin to include every detail in a global analysis. Future work is needed in sensitivity analysis to determine what must be included in the simulation. Section two contains a probability and statistical analysis of a recent FAA requirement, and it is this analysis that most distinguishes this paper from other efforts. Section three presents the assumptions about the aircraft and flight space. Section four shows that the minimum- distance point determines the relative angle of approaching aircraft, and section five gives a pictorial description of the separation maneuver. Section six gives the precise description of the maneuver and a proof that it maintains separation if no perturbations are present. The aircraft proceed along their flight paths by means of feedback control, and section seven presents the control equations. The algorithm is simple and generic and needs more development. In its current state, it is intended to represent either control-with-pilot-in-the- loop or future-automatic-control. Once feedback control is introduced, it is possible to include perturbations in a realistic manner, and section eight describes its stochastic nature while section nine offers more commentary. The approach to perturbation in this paper is to examine distributions of increasing severity. If the algorithm can survive these distributions, then it can survive the real world perturbations. The severity of the examined perturbations can be seen in figure 10 in section nine. This paper does not include a test of any decision algorithm since such a test should include the uncertainty due to instrumentation error where the position and heading of the aircraft are not precisely known. 2. Representative FAA requirement 2.1 Probability The stated FAA goals are changing, but this paper addresses a recently expressed goal which was stated in terms of a moving average: no more than three incidents (of all types) over the last three years. Since there are about ten million flights per year, this translates into Aerospace Technologies Advancements 340 one or fewer incidents per 10 million (10 7 ) flights. The examination compares this moving average to a goal stated in terms of one year. There are two comments. First, future FAA goals or their interpretation may be different from the ones examined below, but the examination below outlines an approach to analyzing any stated goal. Second, as they stand, these goals are not probability statements, and they require interpretation. In the absence of information and for simplicity, the typical assumption is that all flights are equivalent and independent, and the typical interpretation of the goal is that the expected number of incidents for 10 million flights be equal to one. Using the expectation does not require any more information from the FAA, but it does have a disadvantage as will be seen below. The disadvantage of this interpretation appears when we consider the probability of more than one incident during 10 million flights. It’s reasonable to want the probability of more than one incident to be low, but it will be shown that using the expectation-interpretation does not guarantee this. On the other hand, the low-probability approach raises the question of how low the FAA wishes the probability to be. With the assumption that the flights are equivalent and independent, the distribution is binomial with the probability of an incident equal to 10 -7 per flight. The binomial distribution with parameter p gives the probability of zero or one incidents during 10 million flights as Q = (1-p) 10000000 + 10000000 p (1-p) 9999999 = 0.7358 if p=1e-7. (1) The probability of two or more incidents for p = 1e-7 is 1-Q = 0.2642. Hence, if the probability of an incident is equal to 10 -7 per flight, then the probability of more than one incident during 10 million flights is greater than 1/4. If the goal is a less than one in a hundred chance of more than one incident per ten million flights, then a little numerical work gives that for p = 1.5e-8, Q = 0.9898 and 1-Q = 0.0102. The moving average reduces the likelihood of not achieving the goal provided the probability of an incident during a flight is smaller than required. Suppose the probability of an incident is equal to 10 -7 per flight. Then Prob{more than one incident in a year | p=1e-7} = 0.26. Prob{more than three incidents in three years | p=1e-7} = 0.35. Whereas Prob{more than one incident in a year | p=1e-8} = 0.0047. Prob{more than three incidents in three years | p=1e-8} = 0.0003. The crossover point appears to be p=7e-8. Prob{more than one incident in a year | p=7e-8} = 0.16. Prob{more than three incidents in three years | p=7e-8} = 0.16. Returning to the interpretation of the FAA goal as a probability statement, one possibility is that the FAA would desire there is only 1 in N chance the goal not be met. A reasonable choice for N is some number between 10 and 100. Looking at the extremes, the computations below give values for p = probability of an incident during a flight if the requirement is a 1 in N chance the goal not be met. [...]... to instrumentation error 346 Aerospace Technologies Advancements As an example, consider two aircraft whose initial minimum distance point is in the first sector which is displayed in figure 4 Fig 4 Flight paths when the minimum-distance point lies in the first sector The burden of maneuver falls on the aircraft moving along the x-axis This is illustrated in figure 5 Fig 5 The separation maneuver... loss-of-separation as illustrated in figure 1 Fig 1 Two aircraft on nearly coincident course The solution is either trivial: have one aircraft perform a circle for delay, or it is global: have one aircraft change altitude or arrange traffic to avoid such circumstances Hence, the examination of nearly-coincident flight paths is postponed to a later study 344 Aerospace Technologies Advancements 4 The minimum... segment goes from (-4,0) to (-2,-2) along the path 348 Aerospace Technologies Advancements Fig 8 The separation maneuver when the minimum-distance point lies in the fourth sector x 1 (t) = a − 4 cosα + t cosα y 1 (t) = b − 4 sinα + t sinα 2 t 2 2 y 2 (t) = 0 − t 2 for 0 ≤ t ≤ 2 2 The second segment goes from (-2,-2) to (+2,-2) along the path x 2 (t) = −4 + (11) x 1 (t) = a − (4 − 2 2 ) cosα + t cosα y 1 (t)... such lack of information is to use the uniform distribution, the second problem is obtaining a distribution and demonstrating it is uniform Suppose the sector is part of a circle of radius 1 Consider an arbitrary subsector as in figure 11 Fig 11 Subsector inside a sector Suppose the subsector lies between angles β1 and β2 and radii r1 and r 2 The area of the subsector divided by the area of the one-eighth... indicate whether inter-symbol and inter-carrier interference will be experienced by the channels 2 IEEE 802.11a model 2.1 Overview of the IEEE 802 .11 standards The IEEE 802 .11 standards deployed today are a result of technological advancements, both in hardware and software The first IEEE 802 .11 standard was deployed in 1997 with a maximum throughput of 2Mbps (Crow, B.P et al, 1997) This has gone a... (11) is ⎡ 2 ⎤ s 2 = ⎢a − 4 cosα + t cosα + 4 − t⎥ 2 ⎥ ⎢ ⎣ ⎦ ⎡ 2 ⎤ t⎥ + ⎢ b − 4 sinα + t sinα + 2 ⎥ ⎢ ⎣ ⎦ 2 2 (19) for 0 ≤ t ≤ 2 2 2 t is greater than or equal to Now, ( -4 + t ) cosα is greater than or equal to zero, and 4 − 2 2 Hence, the distance is greater than or equal to 2 The distance while traversing the second segment in terms of the parametric equations (12) is 350 Aerospace Technologies Advancements. .. 4 are given in figures 6, 7, and 8 Because of the symmetrical nature of the separation maneuvers, it is sufficient to examine the case where the minimum-distance point lies in the first sector and the maneuver is given in figure 5 An Aircraft Separation Algorithm with Feedback and Perturbation 347 Fig 6 The separation maneuver when the minimum-distance point lies in the second sector Fig 7 The separation... aircraft This model must be capable of estimating the power level that can be received at any point inside the enclosed structure, thus creating a 362 Aerospace Technologies Advancements propagation map Therefore, any changes in aircraft model and/or its configuration can be easily accommodated and the propagation map recomputed This map can then be used to determine the parameters associated with the... one way to accomplish this is to have P(A i | C i ) ≤ p for all i since this gives 342 Aerospace Technologies Advancements P(A 1 | C 1 ) P(C 1 ) + P(A 2 | C 2 ) P(C 2 ) + …+ P(A K | C K ) P(C K ) ≤ p P(C 1 ) + p P(C 2 ) + …+ p P(C K ) ≤ p [ P(C 1 ) + …+ P(C K ) ] ≤ p (4) The generalization of the above eliminates the partition requirement That is, different C i can have a non-empty intersection, allowing... (k+1) For the third equation, write ( ) ( s(k) + τ v(k) = s d (k) + τ v d (k) + s(k) - s d (k) + τ v(k) − v d (k) ( ) ( = s d (k + 1) + s(k) - s d (k) + τ v(k) − v d (k) This gives ) ) (27) 352 Aerospace Technologies Advancements a ( k + 1 ) = α a(k) + β ⎡ v(k)-v d (k)⎤ + δ ⎡s(k)-s d (k)⎤ ⎣ ⎦ ⎣ ⎦ v(k + 1) - v d (k + 1) = ατ a(k) + (1 + β τ ) ⎡ v(k)-v d (k)⎤ + δ τ ⎡s(k)-s d (k)⎤ ⎣ ⎦ ⎣ ⎦ ⎛ τ2 ⎞⎡ s(k + 1) . error. Aerospace Technologies Advancements 346 As an example, consider two aircraft whose initial minimum distance point is in the first sector which is displayed in figure 4. Fig. . 149-167 Aerospace Technologies Advancements 338 A. M. Woodroffe and P. Madle (2004), Application and experience of CAN as a low cost OBDH bus system, MAPLD 2004, Washington D.C. USA Part V. segments. The first segment goes from (-4,0) to (-2,-2) along the path Aerospace Technologies Advancements 348 Fig. 8. The separation maneuver when the minimum-distance point lies in the