1、 Reference number ISO 23339:2010(E) ISO 2010INTERNATIONAL STANDARD ISO 23339 First edition 2010-12-01 Space systems Unmanned spacecraft Estimating the mass of remaining usable propellant Systmes spatiaux Vhicules spatiaux non habits Estimation de la masse dergols rsiduels utilisable ISO 23339:2010(E
2、) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file
3、, parties accept therein the responsibility of not infringing Adobes licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info rel
4、ative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPY
5、RIGHT PROTECTED DOCUMENT ISO 2010 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below
6、 or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2010 All rights reservedISO 23339:2010(E) ISO 2010 All rights reserved iii
7、Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a t
8、echnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters
9、 of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulate
10、d to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible
11、for identifying any or all such patent rights. ISO 23339 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 14, Space systems and operations. ISO 23339:2010(E) iv ISO 2010 All rights reservedIntroduction This International Standard acts as one of the supporti
12、ng technical standards for orbital debris mitigation. For spacecraft disposal manoeuvres to be performed as planned, the estimation of available propellant mass is essential. The aim of this International Standard is, through requirements for the estimation of remaining propellant, to improve spacec
13、raft disposal techniques and thereby mitigate orbital debris. INTERNATIONAL STANDARD ISO 23339:2010(E) ISO 2010 All rights reserved 1Space systems Unmanned spacecraft Estimating the mass of remaining usable propellant 1 Scope This International Standard gives requirements for estimating the mass of
14、the remaining usable propellant of an unmanned spacecraft in low Earth orbit (LEO) or geostationary Earth orbit (GEO), and for designing propellant measurement systems. It is applicable to spacecraft with either mono- or bi-propellant propulsion systems using liquid or gaseous chemical propellants,
15、and is limited to such systems because they are the most common for spacecraft in LEOs and GEOs. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest
16、edition of the referenced document (including any amendments) applies. ISO 24113, Space systems Space debris mitigation requirements 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 24113 and the following apply. 3.1 book-keeping method method for det
17、ermining fluid consumption by monitoring flow rates and the duration of propellant expenditure periods 3.2 disposal manoeuvre orbital manoeuvre that disposes of a spacecraft from the protected regions by either decreasing or increasing the altitude of the spacecraft 3.3 PVT method method for determi
18、ning the remaining mass of gas by deriving density in a known volume from pressure and temperature measurements NOTE PVT: pressure, volume, temperature. 3.4 remaining usable propellant propellant that remains in the propellant system and that is effective for attitude and orbit control manoeuvres IS
19、O 23339:2010(E) 2 ISO 2010 All rights reserved3.5 orbital debris space debris all man-made objects, including fragments and elements thereof, in Earth orbit or re-entering the atmosphere, that are non-functional 3.6 spacecraft system designed to perform specific tasks or functions in space NOTE A sp
20、acecraft that can no longer fulfil its intended mission is considered non-functional. Spacecraft in reserve or standby modes awaiting possible reactivation are considered functional. 4 Objectives 4.1 General Orbital debris could cause substantial damage to other spacecraft, space stations, shuttles,
21、 etc. Orbital debris include non-functioning payloads or used launch vehicle upper stages. The steady increase in orbital debris increases the risk of collision, which creates more debris in orbit. Disposing of spacecraft at EOL (end of life) reduces the risk of collision and increases safety. For t
22、he active disposal manoeuvre of a spacecraft at the end of mission, there usually has to be enough propellant for the manoeuvre. The amount of propellant is typically a key design parameter that determines the on-orbit lifetime. In order to reserve enough usable propellant to ensure the success of d
23、isposal manoeuvres, the propellant used over life shall be estimated with stated uncertainty and the remaining usable propellant shall be regularly monitored with quantified uncertainty. 4.2 Objectives in estimating mass of remaining usable propellant The prime objectives in estimating the mass of r
24、emaining usable propellant are a) to ensure the successful disposal of the spacecraft, and b) to drain the propellant system in order to remove a potential source of energy for creating additional secondary debris caused by any primary debris impact. For debris mitigation, successful venting of resi
25、dual propellant is often required at end of life and tends to be favoured by minimizing the amount of remaining propellant. 5 Requirements 5.1 Selection of estimation method The estimation method (and allowances for estimation error) that best meets the objectives outlined in Clause 4 shall be selec
26、ted at an early stage of the spacecraft design phase and mission development. The use of multiple estimation methods is recommended for redundancy and higher certainty. Annex A lists estimation methods suitable for applicable spacecraft. 5.2 Estimation of propellant mass The needed propellant amount
27、 and error shall be estimated at the design phase. Propellant mass and volume determine the spacecraft bus characteristics in size and mass, and influence the launch cost as well. A careful consideration of the estimation error of remaining usable propellant at the design phase can optimize the desi
28、gn and reduce the propellant loading amount. ISO 23339:2010(E) ISO 2010 All rights reserved 3During the on-orbit mission phase, the actual mass of remaining usable propellant shall be monitored regularly over life to ensure that a positive margin of usable propellant remains to perform the disposal
29、manoeuvre as planned. The margin shall include a mass equivalent to the assumed estimation error. The above stated requirements of this subclause shall be performed through the following process steps. a) Produce an initial propellant budget in the design phase, including all errors and margins to a
30、llow safe disposal. b) Refine the budget throughout the design/build process as better mass and delta-V budgets become available. c) Use the final propellant budget to define loaded propellant mass. d) Monitor and evaluate the propellant mass remaining throughout the mission at regular intervals. e)
31、 Compare the usage rate with the mission plan. If propellant is being consumed at a greater rate than planned, the mission plan shall be changed to ensure there will still be sufficient propellant remaining to perform the planned disposal manoeuvre 5.3 Uncertainty of estimation The measurement uncer
32、tainty estimation shall account for all significant error contributions. The error contributions shall be expressed as equivalent propellant amounts, typically in kilograms. Examples of error contributing parameters are given in Annex A. When several methods are available after taking account of cos
33、t, mass, performance, etc., the optimal measurement or set of measurements should be used, considering that different kinds of measurements are best for each mission phase (early operation, partially consumed, nearly empty). Designers may choose between low-cost, coarse sensors and expensive, very p
34、recise sensors. Measurement uncertainty estimation shall reflect, as an additional propellant mass loading, its estimation error as well as the particular characteristics of the propulsion system, its performance and the planned propellant consumption. 5.4 Incorporating required function into spacec
35、raft design After the estimation method or methods have been selected, the hardware and software required to estimate the mass of remaining propellant and to record, store and transmit the associated data shall be incorporated into the system design. The hardware and software design features require
36、d to estimate the mass of remaining propellant shall be assessed throughout the spacecrafts development. The functions of hardware and software required to estimate the mass of remaining propellant shall be verified at the test phase. If this cannot be verified in the ground test environment, altern
37、atively it shall be verified by analysis to assure the functionality in space. The accounting of degradation of the overall measuring system over the mission life shall also be required. The mass of remaining propellant shall be re-estimated as necessary parameters are determined and their contribut
38、ions to error become clear. The amount of propellant estimated as being necessary for the disposal manoeuvre (including the measurement uncertainty) shall be determined before launch and loaded on the spacecraft. The required propellant measurement uncertainty shall be specified and evidence shall b
39、e available to justify that the design will meet this requirement throughout the spacecrafts nominal life. EXAMPLE Pressure and temperature sensors for monitoring the tank conditions are essential for the PVT method whereas thrust history data are crucial for the book-keeping method. 5.5 Documentati
40、on of data The data necessary for estimating the remaining usable propellant mass shall be documented throughout the manufacturing, testing and on-orbit mission phases. The data shall include the estimation error relating to ISO 23339:2010(E) 4 ISO 2010 All rights reservedeach parameter. The data ac
41、quired through the testing phase shall be described in the satellite handbook and shall be able to be referenced at the operation phase. A measurement of available propellant shall provide the following information: a) the time at which the measurement applies; b) the estimated amount of available p
42、ropellant in units chosen by the user; c) the uncertainty on this estimate to a confidence level chosen by the user and in the same units as the measurement (e.g. 95 % confidence that the actual amount of propellant is within x kg of the reported measurement), which shall be evaluated using a techni
43、que supported by documented evidence; d) a note of any significant issues relating to the use of the reported measurement. EXAMPLE The measurement is based on the book-keeping method and was made just after a standard orbit maintenance burn. NOTE See Annex A for examples of key parameters to be docu
44、mented for each estimation method. The measurement uncertainty of, for example, a pressure sensor shall be documented at the design phase, at the component test level and, finally, at the system test level, in order to evaluate its contribution to the estimated remaining usable propellant value. ISO
45、 23339:2010(E) ISO 2010 All rights reserved 5Annex A (informative) Examples of estimation methods Table A.1 gives examples of estimation methods typically used in propulsion systems using liquid or gaseous chemical propellants. Table A.1 Examples of estimation methods (reproduced with permission fro
46、m Reference 2, ESA) NOTE “Thermal knocking” is also called “thermal gauging”. ISO 23339:2010(E) 6 ISO 2010 All rights reservedTable A.2 shows examples of key parameters to be documented, for the two methods generally used on LEO and GEO satellites. Table A.2 Examples of key parameters Method Key par
47、ameters Book-keeping method Propellant mass flow rate, m Each thrusters on-time, t Thrust Specific impulse Bipropellant mixture ratio Propellant consumption ( = m t) Thrust estimation error Specific impulse estimation error Mixing ratio estimation error Propellant loading error PVT method Pressurant
48、 gas amount in tank Pressurant gas pressure Pressurant gas volume Pressurant gas temperature Tank volume Pressurant gas pressure measurement error Pressurant gas temperature measurement error Propellant density Oxidizer density Bipropellant mixture ratio Propellant loading error ISO 23339:2010(E) IS
49、O 2010 All rights reserved 7Bibliography 1 ISO 26872, Space systems Disposal of satellites operating at geosynchronous altitude 2 HUFFENBACH et. al., Comparative Assessment of Gauging Systems and Description of a Liquid Level Gauging Concept for a Spin Stabilised Spacecraft, Proceedings of the Second European Propulsion Conference, 2729 May 1997, ESA SP-398, Aug 1997 1)3 YENDLER, B., Review of Propellant Gauging Methods, 44 thAIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, USA, 912 January 2006 4
