1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 23339:2010Space systems Unmanned spacecraft Estimating the mass of remaining usable propellantBS ISO 23339:2010 BRITISH STANDARDNational forewordThis British Standard is t
2、he UK implementation of ISO 23339:2010. Although this standard contains requirements for estimating the amount of usable propellant on unmanned spacecraft in order to enable end-of-life disposal manoeuvres, some of the content of the standard may overlap, or be at variance with, the top-level space
3、debris mitigation standard BS ISO 24113 and the flow down of requirements to other debris mitigation standards. In the event that such a circumstance should arise, the UK committee recommends that BS ISO 23339 should not take precedence.The UK participation in its preparation was entrusted to Techni
4、cal Committee ACE/68/-/3, Space systems and operations - Operations and Ground Support.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for
5、its correct application. BSI 2011 ISBN 978 0 580 56729 2 ICS 49.140 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2011.Amendments issued since publicat
6、ionDate T e x t a f f e c t e dBS ISO 23339:2010Reference numberISO 23339:2010(E)ISO 2010INTERNATIONAL STANDARD ISO23339First edition2010-12-01Space systems Unmanned spacecraft Estimating the mass of remaining usable propellant Systmes spatiaux Vhicules spatiaux non habits Estimation de la masse der
7、gols rsiduels utilisable BS ISO 23339:2010ISO 23339:2010(E) 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
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11、permission in writing from either ISO at the address below 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
12、reservedBS ISO 23339:2010ISO 23339:2010(E) ISO 2010 All rights reserved iiiForeword 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 t
13、echnical committees. Each member body interested in a subject for which a technical 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 clos
14、ely with the International Electrotechnical Commission (IEC) on all matters 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. Draf
15、t International Standards adopted by the technical committees are circulated 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 docum
16、ent may be the subject of patent rights. ISO shall not be held responsible 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. BS ISO 23339:2010ISO 23339:2010(E) iv ISO
17、2010 All rights reservedIntroduction This International Standard acts as one of the supporting 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 Sta
18、ndard is, through requirements for the estimation of remaining propellant, to improve spacecraft disposal techniques and thereby mitigate orbital debris. BS ISO 23339:2010INTERNATIONAL STANDARD ISO 23339:2010(E) ISO 2010 All rights reserved 1Space systems Unmanned spacecraft Estimating the mass of r
19、emaining usable propellant 1 Scope This International Standard gives requirements for estimating the mass of 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 sp
20、acecraft with either mono- or bi-propellant propulsion systems using liquid or gaseous chemical propellants, 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 applicatio
21、n of this document. For dated references, only the edition cited applies. For undated references, the latest 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,
22、 the terms and definitions given in ISO 24113 and the following apply. 3.1 book-keeping method method for determining 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 protecte
23、d regions by either decreasing or increasing the altitude of the spacecraft 3.3 PVT method method for determining 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 propel
24、lant that remains in the propellant system and that is effective for attitude and orbit control manoeuvres BS ISO 23339:2010ISO 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 th
25、e atmosphere, that are non-functional 3.6 spacecraft system designed to perform specific tasks or functions in space NOTE A spacecraft that can no longer fulfil its intended mission is considered non-functional. Spacecraft in reserve or standby modes awaiting possible reactivation are considered fun
26、ctional. 4 Objectives 4.1 General Orbital debris could cause substantial damage to other spacecraft, space stations, shuttles, 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 create
27、s more debris in orbit. Disposing of spacecraft at EOL (end of life) reduces the risk of collision and increases safety. For the 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 d
28、esign parameter that determines the on-orbit lifetime. In order to reserve enough usable propellant to ensure the success of disposal manoeuvres, the propellant used over life shall be estimated with stated uncertainty and the remaining usable propellant shall be regularly monitored with quantified
29、uncertainty. 4.2 Objectives in estimating mass of remaining usable propellant The prime objectives in estimating the mass of remaining 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 f
30、or creating additional secondary debris caused by any primary debris impact. For debris mitigation, successful venting of residual 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
31、The estimation method (and allowances for estimation error) that best meets the objectives outlined in Clause 4 shall be selected 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
32、 A lists estimation methods suitable for applicable spacecraft. 5.2 Estimation of propellant mass The needed propellant amount 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
33、well. A careful consideration of the estimation error of remaining usable propellant at the design phase can optimize the design and reduce the propellant loading amount. BS ISO 23339:2010ISO 23339:2010(E) ISO 2010 All rights reserved 3During the on-orbit mission phase, the actual mass of remaining
34、usable propellant shall be monitored regularly over life to ensure that a positive margin of usable propellant remains to perform the disposal manoeuvre as planned. The margin shall include a mass equivalent to the assumed estimation error. The above stated requirements of this subclause shall be pe
35、rformed through the following process steps. a) Produce an initial propellant budget in the design phase, including all errors and margins to allow 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
36、 budget to define loaded propellant mass. d) Monitor and evaluate the propellant mass remaining throughout the mission at regular intervals. e) 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 th
37、ere will still be sufficient propellant remaining to perform the planned disposal manoeuvre 5.3 Uncertainty of estimation The measurement uncertainty estimation shall account for all significant error contributions. The error contributions shall be expressed as equivalent propellant amounts, typical
38、ly in kilograms. Examples of error contributing parameters are given in Annex A. When several methods are available after taking account of cost, mass, performance, etc., the optimal measurement or set of measurements should be used, considering that different kinds of measurements are best for each
39、 mission phase (early operation, partially consumed, nearly empty). Designers may choose between low-cost, coarse sensors and expensive, very precise sensors. Measurement uncertainty estimation shall reflect, as an additional propellant mass loading, its estimation error as well as the particular ch
40、aracteristics of the propulsion system, its performance and the planned propellant consumption. 5.4 Incorporating required function into spacecraft design After the estimation method or methods have been selected, the hardware and software required to estimate the mass of remaining propellant and to
41、 record, store and transmit the associated data shall be incorporated into the system design. The hardware and software design features required to estimate the mass of remaining propellant shall be assessed throughout the spacecrafts development. The functions of hardware and software required to e
42、stimate the mass of remaining propellant shall be verified at the test phase. If this cannot be verified in the ground test environment, alternatively it shall be verified by analysis to assure the functionality in space. The accounting of degradation of the overall measuring system over the mission
43、 life shall also be required. The mass of remaining propellant shall be re-estimated as necessary parameters are determined and their contributions to error become clear. The amount of propellant estimated as being necessary for the disposal manoeuvre (including the measurement uncertainty) shall be
44、 determined before launch and loaded on the spacecraft. The required propellant measurement uncertainty shall be specified and evidence shall be available to justify that the design will meet this requirement throughout the spacecrafts nominal life. EXAMPLE Pressure and temperature sensors for monit
45、oring the tank conditions are essential for the PVT method whereas thrust history data are crucial for the book-keeping method. 5.5 Documentation of data The data necessary for estimating the remaining usable propellant mass shall be documented throughout the manufacturing, testing and on-orbit miss
46、ion phases. The data shall include the estimation error relating to BS ISO 23339:2010ISO 23339:2010(E) 4 ISO 2010 All rights reservedeach parameter. The data acquired through the testing phase shall be described in the satellite handbook and shall be able to be referenced at the operation phase. A m
47、easurement of available propellant shall provide the following information: a) the time at which the measurement applies; b) the estimated amount of available propellant 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
48、 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 technique supported by documented evidence; d) a note of any significant issues relating to the use of the reported measurement. EXAMPLE The measu
49、rement 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 documented 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. BS ISO 23339:2010ISO 23339:2010(E) ISO 2010 All rights reserved 5Annex A (i
