SIS EAE-008, Revision A

MARS OBSERVER

Software Interface Specification

Maneuver Performance Data File

Jet Propulsion Laboratory

California Institute of Technology

Pasadena, California

Table of Contents

Author(s):  John E. Ekelund



                          SIS EAE-008, Revision A

                               MARS OBSERVER
                         MANEUVER PERFORMANCE FILE
                      Software Interface Specification

                               12 MARCH 1991



ABSTRACT:  The Maneuver Performance Data File is created by the Spacecraft
Team.  It is used by MOPS, within NAV.  The file contains current spacecraft
total mass properties, thruster geometry and performance.



                         Jet Propulsion Laboratory
                    California Institute of Technology
                        Pasadena, California 91109




               DISTRIBUTION LIST





                        DOCUMENT CHANGE LOG

     Change      Date       Affected Portions
     Letter

     Original    11/27/90   All

     Rev. A      3/12/91    Appendix A added.




                        List of TBD Items

        Page    Resolution Date         Item

1. GENERAL DESCRIPTION

1.1 PURPOSE OF INTERFACE

This Software Interface Specification (SIS) contains the description of the Maneuver Performance Data File.

1.2 SCOPE

The format and syntax specifications in this SIS apply to all phases of the mission.

1.3 APPLICABLE DOCUMENTS


 SFOC0038-01-09-01    1 May 90     SFOC-1-CDB-ANY-CATALOGUE2

 SFOC0099-01-00       13 Jun 90    Data Dictionary

 SFOC0038-00-08-01    26 Feb 88    SFOC-1-CDB-MGN-TIMESFILE

 SFOC0038-01-09-03    6 Feb 90     SFOC-2-SYS-ANY-TIMEFORMS

                      1 Jul 90     DPTRAJ-ODP User Reference Manual,
                                   SOM Vol. 1 and Vol. 2

                      1 Jul 90     DPTRAJ and ODP Interfaces and File
                                   Format Descriptions, SOM, Vol. 3

1.4 FUNCTIONAL DESCRIPTION

1.4.1 Data Source, Destination, and Transfer Method

The source of the data is SCT. The destination of the data is MOPS. Data transfer shall be via the Project Data Base (PDB) using the SFOC LAN.

1.4.2 Pertinent Relationships with Other Interfaces

During the design of a TCM, MOPS will use a MAPDF derived from that same data used by the SCT.

1.4.5 Labeling and Identification (Internal/External)

Separate files shall be provided for distinct S/C configurations. Each file shall have an identification record, described in section 4.2.1. Each file will be provided with a unique external identification.

1.4.4 Assumptions and Constraints

None.

2. ENVIRONMENT

2.1 HARDWARE CHACTERISTICS AND LIMITATIONS

N/A.

2.2 INTERFACE MEDIUM AND CHARACTERISTICS

The interface shall be a file written in ASCII format. The medium for the transmittal to the PDB shall be the SFOC LAN.

2.3 INPUT/OUTPUT PROTOCOLS

N/A

2.3.1 Device Addressing

N/A

2.3.2 Operating System Protocols

N/A

2.3.3 Deformatting

Users of the Maneuver Performance Data File will be required to have software to remove the SFDU data.

2.3.4 Calling Sequence

N/A

2.4 FAILURE PROTECTION, DETECTION, RECOVERY FEATURES

2.4.1 Backup Requirements

This file may be recreated by the SCT.

2.4.2 Security/Integrity Measures

This file has no inherent security because it is directly text editable using system routines.
Unit and system tests will debug the mechanisms for file writing by SCT and reading by MOPS.
As a stored file, the PDB security/integrity measures will be in effect.

2.5 END-OF-FILE (OR MEDIUM) CONVENTIONS

End-of-file shall be the standard end-of-file.

2.6 UTILITY PROGRAMS

A utility program will be required by the users of this file to remove the SFDU labels.

3. DATA FLOW CHARACTERISTICS

3.1 OPERATIONAL CHARACTERISTICS

3.1.1 Generation Method and Frequency

The file will be created by SCT using the PAS/G&C/UPDATE program. Additional files will be created to model the spacecraft as the mission progresses.

3.1.2 Time Span of Product

N/A

3.2 DATA VOLUME

This file will not exceed 2000 bytes.

3.3 FLOW RATE

TBD

4. DETAILED DATA OBJECT DEFINITION

4.1 STRUCTURE AND ORGANIZATION OVERVIEW

The Maneuver Performance Data File is an ASCII file which consists of the SFDU header, the Maneuver Performance Data File headers, and the Maneuver Performance Data File data. Each will be described in the following sections.

4.2 DATA FORMAT AND DEFINITION

4.2.1 SFDU Data Description

The SFDU information and structure, for the Maneuver Performance Data File, (DDID = 0251) in diagramatic representation is as follows: 
CCSD3ZS00001AAAAAAAA
    NJPL3KS0L015BBBBBBBB
        <CR><LF>
        MISSION_NAME=MARS_OBSERVER;<CR><LF>
        SPACECRAFT_NAME=MARS_OBSERVER1;<CR><LF>
        DATA_SET_ID=MANEUVER_PERF;<CR><LF>
        FILE_NAME=perf.ssf;<CR><LF>
        PRODUCER_ID=MO_SCT;<CR><LF>
        APPLICABLE_START_TIME=1990-06-06T00:00:00;<CR><LF>
        APPLICABLE_STOP_TIME=1990-07-02T00:00:00;<CR><LF>
        PRODUCT_CREATION_TIME=1990-06-06T15:00:00;<CR><LF>
    CCSD3RE00000BBBBBBBB
    NJPL3IS00251CCCCCCCC
In the actual Maneuver Performance File, the following SFDU data is located at the end of the file, following the non-SFDU data which is described in Section 4.2.2. 
    CCSD3RE00000CCCCCCCC
CCSD3RE00000AAAAAAAA

4.2.2 Non-SFDU Data Description

The non-SFDU portion of this file is described as follows:
System of Units
All parameters specified in this file are expressed in MKS units, specifically: 
	Length				     meters

	Force				     Newtons

	Mass    			     kilograms

	Moments and products of inertia      kilogram-meter^2

	Time  				     Seconds

Header Record

A header record will be provided containing the following information: 
LINE    COLUMN    FORMAT    DESCRIPTION
-------------------------------------------------------------
 1         1      CHAR*12   `S/C'
 1        13      CHAR*36   S/C ID number (`TBD' for MGN),
                            Text identifying spacecrat
 2         1      CHAR*12   `PREP'
 2        13      CHAR*26   Name and extension of the analyst
                            who generated this file
 3         1      CHAR*12   `CREATION'
 3        13      CHAR*8    Creation date of this file
 3        25      CHAR*8    Creation time of this file
 4         1      CHAR*12   `VALID'
 4        13      CHAR*8    Beginning valid date of this file
 4        25      CHAR*8    Ending valid date of this file
Since the format of the header is fixed, there is no need for an "end-of-header" indicator.

Data Record

The following items are passed to the user via Fortran-style namelist $MAPDF: 

ITEM       TYPE        UNITS       DESCRIPTION
------------------------------------------------------------
MSC        R           kg       Spacecraft total mass
                           2
IISC       R(3,3)      kg-m     Spacecraft products and
                                moments of inertia w.r.t.
                                the spacecraft coordinates
                                translated to spacecraft
                                c.m.

CMSC       R(3)        meters   Spacecraft center of mass
                                w.r.t. Spacecraft body
                                coordinates.

FVEC       R(3,25)      ---     Effective thrust direction
                                unit vectors w.r.t.
                                Spacecraft body coordinates.

FMAG       R(25)       Newton   Effective thrust magnitude.

RF         RF(3,25)    meters   Thruster location w.r.t.
                                Spacecraft body coordinates.
FLORAT     R(25)       kg/sec   Propellant effective flow rate.
NOTE: Products of Inertia
Products and moments of inertia are defined in accordance with the following convention:
	I_xy = + (xy)dm,        I_yz = + (yz)dm,       I_zx = + (zx)dm

	I_xx = + (y^2 + z^2)dm, I_yy = + (x^2 + z^2)dm, I_zz = + (y^2 + x^2)dm
The moment of inertia matrix is then given by:

		|  I_xx   -I_xy	  -I_xz |
		|			|
	I  =    | -I_xy	   I_yy   -I_yz |
		|			|
		| -I_xz   -I_yz	   I_zz |

Appendix A. SAMPLE WRAPPED FILE

A sample wrapped Maneuver Performance File is provided in order to show the expected format of the data. The user should not code specifically to the real numbers as printed.
CCSD3ZS00001AAAAAAAANJPL3KS0L015BBBBBBBB
MISSION_NAME=MARS_OBSERVER;
SPACECRAFT_NAME=MARS_OBSERVER1;
DATA_SET_ID=MANEUVER_PERF;
FILE_NAME=perf.ssf;
PRODUCER_ID=MO_SCT;
APPLICABLE_START_TIME=1990-06-06T00:00:00;
APPLICABLE_STOP_TIME=1990-07-02T00:00:00;
PRODUCT_CREATION_TIME=1990-06-06T15:00:00;
CCSD3RE00000BBBBBBBBNJPL3IS00251CCCCCCCC
S/C         MO
PREP        T Bell, X7-6204/6395
CREATION    06-06-90    15:00:00
VALID       06-06-90    07-02-90
     MSC=  2415.000
    IISC= 1.6500000e+03,-3.0000000e+00, 2.6000000e+01
	 -3.0000000e+00, 2.2000000e+03,-3.0000000e+00
	  2.6000000e+01,-3.0000000e+00, 1.4380000e+03
    CMSC= 0.0000000e+00, 0.0000000e+00, 3.5400000e-01
    FVEC= 0.0000000e+00, 0.0000000e+00, 1.0000000e+00
          0.0000000e+00, 0.0000000e+00, 1.0000000e+00
          0.0000000e+00, 0.0000000e+00, 1.0000000e+00
          0.0000000e+00, 0.0000000e+00, 1.0000000e+00
          0.0000000e+00, 0.0000000e+00, 1.0000000e+00
          0.0000000e+00, 0.0000000e+00, 1.0000000e+00
          0.0000000e+00, 0.0000000e+00, 1.0000000e+00
          0.0000000e+00, 0.0000000e+00, 1.0000000e+00
         -9.0600000e-01, 3.4900000e-01, 2.3800000e-01
         -9.0600000e-01,-3.4900000e-01, 2.3800000e-01
         -9.0600000e-01,-3.4900000e-01,-2.3800000e-01
         -9.0600000e-01, 3.4900000e-01,-2.3800000e-01
          9.0600000e-01,-3.4900000e-01, 2.3800000e-01
          9.0600000e-01,-3.4900000e-01,-2.3800000e-01
          9.0600000e-01, 3.4900000e-01,-2.3800000e-01
          9.0600000e-01, 3.4900000e-01, 2.3800000e-01
         -5.7400000e-01, 0.0000000e+00,-8.1900000e-01
          5.7400000e-01, 0.0000000e+00, 8.1900000e-01
         -5.7400000e-01, 0.0000000e+00, 8.1900000e-01
          5.7400000e-01, 0.0000000e+00,-8.1900000e-01
    FMAG= 4.6964034e+02, 4.9000000e+02, 4.6964034e+02, 4.9000000e+02
	  2.2000000e+01, 2.2000000e+01, 2.2000000e+01, 2.2000000e+01
	  4.4500000e+00, 4.4500000e+00, 4.4500000e+00, 4.4500000e+00
	  4.4500000e+00, 4.4500000e+00, 4.4500000e+00, 4.4500000e+00
	  9.0000000e-01, 9.0000000e-01, 9.0000000e-01, 9.0000000e-01
      RF=-9.4000000e-01, 4.0600000e-01, 1.2400000e-02
         -9.4000000e-01,-4.0600000e-01, 1.2400000e-02
          9.4000000e-01,-4.0600000e-01, 1.2400000e-02
          9.4000000e-01, 4.0600000e-01, 1.2400000e-02
         -1.1176000e+00,-7.0490000e-01, 3.1800000e-02
          1.1176000e+00,-7.0490000e-01, 3.1800000e-02
          1.1176000e+00, 7.0490000e-01, 3.1800000e-02
         -1.1176000e+00, 7.0490000e-01, 3.1800000e-02
          1.1880000e+00, 6.6700000e-01, 1.4670000e+00
          1.1880000e+00,-6.0980000e-01, 1.4670000e+00
          1.1880000e+00,-6.0980000e-01, 5.9700000e-01
          1.1880000e+00, 6.6700000e-01, 5.9700000e-01
         -1.1880000e+00,-6.0980000e-01, 1.4670000e+00
         -1.1880000e+00,-6.0980000e-01, 5.9700000e-01
         -1.1880000e+00, 6.6700000e-01, 5.9700000e-01
         -1.1880000e+00, 6.6700000e-01, 1.4670000e+00
          1.1100000e+00,-7.2390000e-01, 6.7400000e-01
         -1.1100000e+00,-7.2390000e-01, 1.3630000e+00
          1.1100000e+00,-7.2390000e-01, 1.3630000e+00
         -1.1100000e+00,-7.2390000e-01, 6.7400000e-01
  FLORAT= 1.5712107e-01, 1.6280000e-01, 1.5712107e-01, 1.6280000e-01
          7.8240000e-03, 7.8240000e-03, 7.8240000e-03, 7.8240000e-03
	  2.0500000e-03, 2.0500000e-03, 2.0500000e-03, 2.0500000e-03
          2.0500000e-03, 2.0500000e-03, 2.0500000e-03, 2.0500000e-03
          4.1500000e-04, 4.1500000e-04, 4.1500000e-04, 4.1500000e-04
CCSD3RE00000BBBBBBBBNJPL3IS00251CCCCCCCC

Revision date: 15 April 1996

For information about this on-line document, contact Vic Legerton
For information about the file described by this document, contact John Ekelund