Lightband Interface Control Document
PSC DOCUMENT 2,000,421 Rev D
Revised January 17, 2002
PSC, Copying and use limited to University Nanosatellite Program, AFRL and NASA
By:
Walter Holemans
Planetary Systems Corporation
2303 Kansas Avenue
Silver Spring, MD 20910
(301) 495-0737 Tel
(301) 495-0738 Fax
TABLE OF CONTENTS
1.Approving Authorities......
2.Revision Process......
3.Revision History......
4.Purpose......
5.Scope......
6.Lightband Fabrication Schedule......
7.Designation Of Serial Numbers......
8.Mechanical Specification......
8.1Common To All Lightbands......
8.2Stiffness Estimates (All Lightbands)......
8.3Variable By Serial Number Of Lightband......
9.Electrical Specification......
9.1Common To All Lightbands......
9.2Variable By Serial Number Of Lightband......
10.Testing Requirements
10.1Structural Test Requirements......
10.2Electrical Test Requirements......
10.3Test Sequence......
10.4Testing Of The Lightband At Higher Levels Of Spacecraft Integration......
11.Deliverable Items......
11.1Hardware......
11.2Documentation......
11.3Certification To Operate The Lightband......
11.4Shipping......
12.Appendixes......
12.1Lightband Footprint, bolt pattern, stay-out zone and side view......
12.2Additional protrusion into Lightband stay out zone......
12.3Random Vibration Environments......
12.4Electrical Schematic: De-tensioner......
1.Approving Authorities
The following individuals are the sole approving authorities for this ICD. Once signed by all parties, fabrication may begin and design revision is handled by a formal revision process described in a later section.
Organization / Name / Signature / Date / Email addressVirginia Polytechnic Institute / Chris Hall /
University of Washington
Utah State University / Rees Fullmer /
Arizona State University
University of Colorado at Boulder
New Mexico State University
Stanford and Santa Clara Universities / Chris Kitts /
Planetary Systems Corporation / Walter Holemans /
2.Revision Process
In the event it becomes necessary to modify any part of this ICD following its sign-off, the following procedure shall be used:
1.The required changes will be submitted to all affected organizations
2.Following authorization by affected parties, this document will be revised and re-issued to all approving authorities
3.Revision History
REVISION / ISSUED / CHANGE DESCRIPTION- / 12 October 1999 / Initial document
A / 14 January 2000 / Interface bolt pattern slightly more curved
Four additional connector locations added
Flatness requirement levied on users
Updated weight statement
B / 14 February 2000 / Micro switches removed
Added random vibration levels
Added fracture control plan
Added pressurization requirements
Changed delivery schedule
Added electrical schematic
Increased detail on initiator voltage
ION-F now has three separation connectors
3 Corner Sat now has four separation connectors
Added safety factors for mechanical test
Stiffness requirements removed*
Added Stanford University inter-satellite separation system as Lightband
Changed orientation of separation connector
Added strength and creep testing for retaining line
C / 7 April 2000 / Separation Connector pin current maximum decreased from 5 amps to 4.0 amps
Added additional protrusion into stay out zone
Added stiffness estimates
Added identification of fracture critical components
Added figure showing thermal vacuum temperature profile
Increased thermal environment extremes
Changes voltage requirement of separation initiator from 14 to 12 V on 18-005
Added 2 separation connectors to 18-005
Eliminated separation connectors on 18-006, -007, -008, -009
Added names of individuals on Emerald program to several tables
D / 17 January 2002 / Editorial corrections throughout document.
Updated names of people and organizations throughout the document: Sections 1, 7, 11.3, and 11.4.
Removed Table 10.1.8 and re-numbered.
Updated information in the tables of Sections 8.1, 8.3, 9.2.1, 10.1.5, 10.1.8, and 10.3.
Added recommended initiation sequence to Section 9.2.1.
Updated retaining line test requirements to reflect safety, fracture control, and structural test requirements.
Updated Lightband information throughout the document to reflect the incorporation of the current limiter.
Updated Section 10.1.7: heading changed to “Fracture Control” and contents states only that Lightband complies with NASA-STD-5003.
Provided test result summaries in Sections 11.1 and 11.2.
Add Section 11.2.9, summarizing electrical conductivity testing.
*However stiffness will be measured.
4.Purpose
This document has several purposes:
1.Tells users of the Lightband what will be delivered and when
2.Describes the required shape, required structural and required electrical performance of the Lightband
3.Tells the manufacturer (PSC) what to deliver and when
4.Documents testing of the Lightband
This document is the one and only document used to specify the Lightband for University Nanosatellite program.
5.Scope
This document covers the Lightband separation system to be used by satellites of the University Nanosatellite program.
6.Lightband Fabrication Schedule
Following sign-off of this document by all approving authorities and an issuance of a purchase order (PO) with PSC for the Lightbands at T= 0, the schedule is as follows:
Event / Completion at T+ [months]1 / Release production drawings and parts list of all Lightbands for production / 0.5
2 / Assemble Engineering units* and Qualification Lightbands / 2.5
3 / Ship Engineering units to Universities / 3.0
4 / Complete Testing of Qualification Unit / 4.5
5 / Fabricate Flight units / 6.5
6 / Certify users to operated the Lightband / 7.5
7 / Ship all deliverable items to users / 8.0
*Engineering unit is an untested Lightband used to support satellite and stack related testing while qualification and flight Lightbands are fabricated and tested. The engineering units may be returned to PSC for acceptance testing.
7.Designation Of Serial Numbers
To discriminated between variants of the Lightband and provide trace ability of the manufacture and test, serial numbers are assigned to each flight Lightband.
The entire Lightband is designated as “18-XXX”
The “upper” half of the separation system is shown in the appendix and is designated as “18-XXX Upper”
The “lower” half of the separation system is shown in the appendix and is designated as “18-XXX Lower”
Users may invert the relative position of the upper and lower half
Users should consider how they will hold their satellite and/or stacks to shipping containers
Notes:
The above figure is not meant to imply actual placements of stacks on a particular shuttle flight. It is a convenient way to show all the separation systems associated with the University Nanosatellite Program.
Separation systems at the base of each stack is nominally not a Lightband, but may be come so in the future
Place holders exist throughout this document as a provision for all present non-users of the Lightband to specify their needs in the case where the Lightband would be used.
8.Mechanical Specification
8.1Common To All Lightbands
Parameter / Unit / Nominal RequirementQuasistatic Acceleration Environment / g / 11 in each of three orthogonal axes, simultaneously through the center of mass supported by the Lightband
Safety Factor applied to flight hardware during strength testing (applied to quasistatic acceleration environment) / - / 1.25
Safety Factor applied to qualification unit during strength testing (applied to quasistatic acceleration environment) / - / 1.25
Safety Factor on ultimate strength / - / 1.40
Safety Factor on analysis in lieu of test (applied to quasistatic acceleration environment) / - / 2.0
Minimum margin of safety (MS) for test and analytical prediction / - / >0.0
Margin of safety equation / - /
Acceptance and Qualification Random vibration environments / - / See 12.2
Concentricity of mated halves / m / 0.00025
Fastener between Lightband and Adjoining Vehicle / - / #10-32 Socket head cap screw
Fastener between Lightband and Adjoining Vehicle quantity / - / 24 at each bolted interface of Lightband Assembly
Bolt pattern / - / as shown 12.1
Height while separated and while joined / - / as shown in 12.1
Flight limit thermal extremes / °C / -30 to +50
Shock generation by Lightband / - / <1000 g at 10,000 Hz
Out gassing compliance / - / TML <1.0 %, CVCM < 0.1 % per ASTM E 595-84
Required Flatness (prior to mating) of surface mating to Lightband / inches per inch / 0.0005
Maximum fastener size between Lightband and mated vehicle / - / #10
Fastener Source / - / GSFC S-313-100, Fastener Integrity Requirements
Time to separate once an initiator has been switched on (see 9.2.1) / second / 60
Number of separation tests on qualification unit / - / >100
Number of separation tests on each flight unit / - / >20
Variation on time to separate (3 sigma, sample size >30) / second / 30
Fracture control / - / Conformance to NASA-STD-5003
Pressurization rate Lightband shall be capable of / psi/sec / ±0.30
Materials usage for primary load path and fracture critical components / - / Table I MSFC-SPEC-522B (High resistance to Stress Corrosion Cracking)
Notes
Flatness specification is levied on the mated vehicles. Failure to comply may result in serious degradation of separation system performance.
Users may employ smaller fasteners but may have to make special provisions for assuring proper preload
Users are responsible for designing the bolted joint between the Lightband and mated vehicles
Users may employ socket head cap, pan head or hex head hardware. Additionally users may employ stud/nut arrangement
Washers should be used below fasteners. Small pattern is recommended
Variation on time to separate is likely to considerably smaller.
8.2Stiffness Estimates (All Lightbands)
The table below contains original stiffness estimates. Section 11.2.3 contains results of strength and stiffness testing.
AXIS / UNIT / VALUEAxial (Maximum) / N/m / 2.39 E9
Axial (Minimum) / N/m / 9.56 E7
Lateral (Maximum) / N.m/radian / 9.02 E7
Lateral (Minimum) / N.m/radian / 3.61 E6
8.3Variable By Serial Number Of Lightband
Lightband Serial Number / Mass [kg] / Separation spring assemblies / Energy in each separation spring [N*m] / Fastener between Lightband and Adjoining Vehicle Designation18-001 Upper / 0.624 / - / - / #10 (0.190 in dia)
18-001 Lower / 0.961 / 4 / 0.73 / #10 (0.190 in dia)
18-002 Upper / 0.626 / - / - / #10 (0.190 in dia)
18-002 Lower / 0.959 / 4 / 0.73 / #10 (0.190 in dia)
18-003 Upper / 0.624 / - / - / #10 (0.190 in dia)
18-003 Lower / 0.955 / 4 / 0.73 / #10 (0.190 in dia)
18-004 Upper / 0.626 / - / - / #10 (0.190 in dia)
18-004 Lower / 0.957 / 4 / 0.73 / #10 (0.190 in dia)
18-005 Upper / 0.630 / - / - / #10 (0.190 in dia)
18-005 Lower / 0.962 / 4 / 0.73 / #10 (0.190 in dia)
18-006 Upper / 0.626 / - / - / #10 (0.190 in dia)
18-006 Lower / 0.959 / 4 / 0.73 / #10 (0.190 in dia)
Notes
PSC will not supply fasteners to attach Lightband to adjoining vehicles.
The mass of the fasteners to attach the Lightband to adjoining structures and the mass of the wiring harness is not included in the above mass statement.
The mass of one (1) separation spring assembly is 0.011 kg; four are included in above
The mass of one separation connector mated pair is 0.023 kg (excluding wiring harness) and is included in table above.
The mass of one half of a separation connector mated pair is 0.0115 kg (excluding wiring harness).
Additional (as many as 12) separation spring assemblies may be used, in even numbers
9.Electrical Specification
9.1Common To All Lightbands
Parameter / Unit / Nominal RequirementSeparation connector / - / PSC Assembly 4000200
Pins in Separation Connector / - / 15
Wire gage for separation connector and de-tensioner / AWG / 22
Wiring Specification for separation connectors (all separation connectors will come with wiring harness already attached) and de-tensioner / - / M22759/33-22-9
Length of wiring harness from each separation connector half / in / 36.0
Maximum Current in each pin / A / 4.0
Steady State Current in each pin
(this value is driven by maximum allowables in bundles of 22AWG wire) / A / 2.5
Break-down voltage from pin to pin / V / 500
EMI shielding of connector housing / - / Yes
Keying of connector / - / All supplied keys unique and not interchangeable when in stack
Electrical conductivity of joined separation system / / <0.01
Notes
The back shells of the separation connectors have a provision for shield termination.
9.2Variable By Serial Number Of Lightband
9.2.1Initiator Voltage And Current
Lightband Serial Number / Separation Initiator Voltage [V] / Separation Initiator Current [A]18-001 / 11.5 to 16.0 / 2.03
18-002 / 11.5 to 16.0 / 2.03
18-003 / 11.5 to 16.0 / 2.03
18-004 / 11.5 to 16.0 / 2.03
18-005 / 11.5 to 16.0 / 2.03
18-006 / 11.5 to 16.0 / 2.03
Notes:
Each initiator is a resistor with very low self-inductance or capacitance. Power is regulated through an in-line current limiter.
See Electrical Schematic in Section 12.4.
Each of two initiators requires this voltage, though both initiators need not be on simultaneously
The separation initiator may be left on indefinitely without degradation of Lightband performance
Voltage is set at the factory. Voltages below limits will result in extended times to separate. Voltages above limits create risk of initiator failure (by overheating) to separate. Section 10.1.4 summarizes dependence of time to separate upon voltage.
9.2.2Separation Connectors
Lightband Serial Number / Flight Separation Connector Assemblies / Location of Separation connectors (degrees ccw from +x axis, about z axis in Section AA) as shown in 12.1 / Ground Support Separation Connector quantity18-001 / 3 / 16.7,136.7, 256.7 / One for each flight connector
18-002 / 3 / 16.7,136.7, 256.7 / One for each flight connector
18-003 / 4 / 16.7, 76.7, 196.7, 256.7 / One for each flight connector
18-004 / 4 / 16.7, 76.7, 196.7, 256.7 / One for each flight connector
18-005 / 4 / 16.7, 76.7, 196.7, 256.7 / One for each flight connector
Notes
The location of separation connectors is an important consideration when trying to minimize wiring harness mass.
Quantities of one or five separation connectors are discouraged, as doing so will increase tip-off.
A total of six separation connectors are possible.
10.Testing Requirements
PSC will design and conduct all these tests. All personnel associated with University Nanosat are invited to review test plans and observe testing. Except as noted, the test items will be a fully assembled Lightband, tensioned to flight levels of preload.
10.1Structural Test Requirements
Structural tests will be conducted by PSC on all flight hardware to verify conformance with structural specifications listed in Section 8.1. Qualification testing will be completed on a separate, not-for-flight qualification unit. Ultimate strength will not be intentionally determined. (Lightband will not be intentionally broken)
10.1.1Mass Properties
Measure:
1.Each assembled unit’s mass
2.The mass of the separated halves of each unit
3.Center of mass in X, Y and Z axes
10.1.2Strength And Stiffness Testing
Verify conformance of all flight units with strength requirements delineated in Section 8.1. Determine stiffness of flight and qualification units in all six degrees of freedom. PSC’s strength and stiffness test fixture will be used for this testing. Strain, deflection and applied load will be recorded.
10.1.3Retaining Line Strength And Creep
A sampling of three retaining line assemblies (the only single use component of the Lightband) from each lot and an entire lot of 10 retaining line assemblies shall be tested for ultimate strength. The reduction in preload over time will be measured and verified to be in conformance with requirements of Section 8.1.
10.1.4Deployment Reliability
This test will verify conformance with specifications delineated in Sections 8.1, 9.1 and 9.2.1:
1.Deployment energy and their statistical variation (to be used in predicting V)
2.Disturbance torques and their statistical variation (to be used in predicting tip-off rates)
3.Separation initiator current and their statistical variation
4.Time to separate and their statistical variation
Both flight units and the qualification unit will be exposed to this testing. PSC will perform these tests on lab bench tops, in thermal vacuum chambers and on its five degree-of-freedom air bearing. Tip-off, V, initiator current and voltage, and time to separate will be recorded for all tests.
10.1.5Thermal Vacuum
Verify operation of all flight units in vacuum at temperature extremes. Both flight units and the qualification unit will be exposed to this testing.
Test Item / Lower Limit / Upper Limit / Number of cycles / Cycle duration(minutes) / Separation Test in Vacuum
Flight unit / Flight lower limit (8.1) / Flight Upper Limit (8.1) / 8 / 60 to 240 / 1 (Each unit)
Qualification Unit / Flight lower limit –11 C / Flight upper Limit +11 C / 8 / 60 to 240 / 1
Thermal profile (five Lightbands are tested simultaneously):
Figure 2: Thermal Vacuum Test Profile
± 2 °C
dT/dt: as fast as practical
Pressure, 1x10-5 Torr
10.1.6Mechanical Shock
Shock generation of the qualification Lightband will be measured at the bolted interface between Lightband and adjoining vehicles. Shock tolerance of the qualification unit will also be measured to verify specified function of the Lightband during and following the input shock. This will only be done on the qualification unit. The input shock levels are shown in 12.5. The largest source of shock to the Lightband is estimated to come from the stack separation system and / or the SHELS/MSDS separation system.
10.1.7Fracture Control
Lightband will conform to NASA-STD-5003, Fracture Control Requirements for Payloads Using the Space Shuttle.
10.1.8 Random Vibration
Verify conformance of all flight units to survive random vibration spectrum shown in 12.2, taken from NASA GEVS-SE. Both flight units and the qualification unit will be exposed to this testing.
Test Item / Level / Axes (as shown in Section 12.3) / Duration, Each Axis (Minutes)Flight unit / Acceptance level (Section 12.3) / X,Y,Z / 1.0
Qualification Unit / Qualification level (Section 12.3) / X,Y,Z / 1.0
10.2Electrical Test Requirements
Electrical tests will be conducted by PSC on all flight hardware to verify conformance with electrical specifications. Expanded testing will be completed on a separate, not-for-flight qualification unit.
10.2.1High Potential (Voltage)
All pinned junctions in separation connectors will be exposed to a high potential (9.1) to verify conformance to leakage specification.
10.2.2Electrical Conductivity Of Joined Separation System
Measure DC resistance across mated Lightband to verify conformance with resistance specifications of Section 9.1. Test will be performed on at least one flight unit.
10.2.3Conductivity Of Electrical Connectors
All pinned junctions in separation connectors will be exposed to currents to verify conformance with current carrying specifications of section 9.1
10.3Test Sequence
Completion of all mechanical tests will be nested as follows:
Sequence / Test / Qualification Unit / Flight Unit1 / Strength and stiffness / X / X
2 / Deployment reliability / X / X
3 / Strength and stiffness / X
4 / Random Vibration / X / X
5 / Deployment Reliability / X / X
6 / Thermal Vacuum / X / X
7 / Deployment reliability / X / X
8 / Strength and Stiffness / X / X
Strength and stiffness testing will include all six degrees of freedom. Deployment reliability will include a subset of the required number of cycles.
10.4Testing Of The Lightband At Higher Levels Of Spacecraft Integration
It will be prudent to test the Lightbands while they are attached to the satellites. In some cases it will be necessary.
As a minimum the Lightband will see repeat testing during stack level tests. These tests include:
Thermal and Thermal Vacuum
Sine burst
Random Vibration
Shock
Mechanical Function (Deployment Reliability)
11.Deliverable Items
11.1Hardware
11.1.1Flight Hardware
Flight hardware consists of all hardware bounded by the 2.125-inch dimension shown in Section 12.1.
11.1.2Consumable Items
All consumables necessary to re-set each delivered Lightband 10 times. More consumables will be provided upon request.
11.1.3Ground Support Equipment
The following items will be provided with each Lightband:
1. Electrical connector to mate to electrical connectors on the separated Lightbands for use during ground testing
2. Lightband Tension Indicator, which provides a readout of retaining line tension in pounds.