dino peer review 20 september 2015 tip mass presentation anders fornberg – team lead/imaging kate...

DINO Peer Review April 19, 2023

Tip Mass Presentation

Anders Fornberg – Team Lead/ImagingKate Worster– Power

Siddharth Shetty – CommJen Getz & Terry Song – Structures

Joshua Stamps – Thermal

Colorado Space Grant Consortium 2


Overall Mission of the tip-mass

• Main Mission– Provide gravity-gradient stabilization for DINO

• Functions– Capture and send pictures

• Deployment of FITS

• Deployment of Aero-fins

• DINO main module

Tip-Mass



Top-Level Requirements

• 5kg mass

• Tip-Mass shall not connect to DINO other than via the boom• Separate power system• Wireless communications from DINO to Tip-

Mass module

• Tip-Mass shall meet all NASA safety requirements



General Layout of Tip Mass

5 V COMM

Serial Camera

PowerImaging-FPGA

RS

-232

802.11b

Trigger5 V

On

RS

-232

5 VCounter



Overall Tip Mass Subsystem Test Plan

• Proper operations of the tip mass when given specific commands– Triggering of camera– Resetting of camera’s memory– Receiving image for camera’s memory– Initialization of power save mode– Return to non-power save mode– Accomplished with software that simulates commands that the

flight computer would send to the tip mass

• “Initial on” counter can initially activate the tip mass subsystem– Accomplished by connecting counter to power subsystem and

running multiple test to ensure reliability



COMM Tip-Mass SubsystemSiddharth Shetty



COMM System Requirements

• Fast and reliable wireless link • Transmit over 6 meter distance (tested over >33m

distance successfully without packet loss)• Utilizes 5 V DC power line• RS-232 Compatible



TPS Options

• Infrared– Very low range

– Line of sight required

• Bluetooth– Recommended Receiver sensitivity: -70dBm

– Standard not as open as compared the IEEE 802.11

– Operates in license-free band

• IEEE 802.11b– Open and widely used standard

– Recommended Receiver sensitivity: -90dBm (higher range)

– Operates in license-free band



Processor with a serial RS-232 port FPGA Chip

Serial port of processor

802.11 air interface

Wiser 2400 unit (OTC wireless)

RS-232 serial interface port of WISER 2400

Serial RS232 port terminating on the FPGA chip

Main sat module Tip Mass

Communication system

Wiser 2400 is the interface between the wireless 802.11 link and the RS232 serial port on the FPGA Chip



Features - WISER 2400

• Operates In the ISM band (2.4GHz – 2.495GHz), no FCC license required

• No driver on the host device is required for radio operation

• Independent of the operating system on the host equipment or device as long as a RS232 port is properly supported

• Industry standard IEEE 802.11b-compliant wireless interface; Interoperable Client radios from other vendors



Specifications-WISER 2400

• Frequency: ISM band (2.4GHz – 2.495GHz) • Link Distance: ~6 meters in open space • Voltage, current: 5v, max 480mA (in transmit mode)• Data rate: Capable of supporting up to 115K baud

(possible limitation on the digital camera side to transmit data)

• Weight : 3.7ounces:the radio with case,1.7 ounces is the weight of the case

• Antenna type: Integrated dipole antenna (omni-directional) with ~2dBi gain



Implementation details

• One Wiser unit will act as the Access Point and the other will play the role of a station

• ‘Beacon’ packets show supported data rates of 1,2,5.5,11 Mbps

• Cap on the serial interface; a 9600 baud rate is currently set (default value), which can be increased up to 115K



Agilent Tool



Radio test results

Distance(m)

wiser1-V, wiser2-V

wiser1-H, wiser2-H

wiser1-V, wiser2-H

wiser1-H, wiser2-V

signal level (dbm)

signal level (dbm)

signal level (dbm)

signal level (dbm)

12 -71 -67 -76 -62

20 -71 -71 -72 -72

33 -78 -78 -75 -75

•Preliminary radio tests conducted over distances up to 30m with error-free communication



Link Budget

• Free space loss in space• Lp(dB)= 92,45 + 20log10 F+20 log10d • For 10m L~ 60dB at 2.45GHz and ~70dB for 30m• Power at Rx (20m)= 14dBm + 2dBm – 70dB + 2dB =

-52dBm ( > Receiver sensitivity of -80dBm)



Power Drain

• Beacons transmitted at 100msec intervals by Access Point (Infrastructure mode)

• Effective time of transmission of beacon frames ~ 3.8sec per hour

• Power drain in Receive mode higher ~250mA• Support for power-save mode available• Circuitry to cut off power at times of ‘No use’



Future tests

• Exhaustive radio test to be carried out by attaching the wiser units behind isogrids to simulate actual working conditions and also takes into account the orientation of units

• Throughput calculations to be performed using programs to transfer bulk data over these units and observing the transmit success rate



Power Tip-Mass SubsystemKate Worster



Requirements on other TM systems

Equipment• 4 A-hr NiCad Cells @ 1.2V ea.

– Charge time 14-16hrs or 1hr

• MAX1672 DC/DC Power Converter

• Structure to contain and support battery

• Fuse, derated; appropriate-sized wires, also derated

• FET’s or relays for inhibit switching

• Requirements imposed by TM-EPS• Battery must be maintained between 0 and 45º Celsius• Battery cannot be drawn below 0.9V• Cell dimensions (DxH) 33mmx60mm• Structure must not damage TM-EPS during thermal cycling

• Mating battery to structure will need attention• Any commands to TM-EPS must come from C&DH on main

S/C• Leads for monitoring cell voltage and temperature, as well as

inhibit status from the GSE must be provided



Power Safety and Operations

• Safety• Two-fault tolerant battery inhibit

system • No shunt diodes• Battery case must contain any leaks

and prevent shorts in the battery• Fuse must be provided on ground

leg of battery• System will be un-powered until

TM separation from DINO• Launch with fully charged

battery• Need shunt diodes on ea. cell• All cell vents must be oriented

upward during launch

• Operations

• System will switch on and off via a photo-sensor

• C&DH will turn the system back off if no images are to be taken on a given orbit

• Inhibit switches open until the boom is deployed

• Separation switches detect boom deployment

• 2 MOPS scenarios



Power System Requirements

• Tip Mass Electrical Power System (TM-EPS) must provide 5V regulated line to TM subsystems

• 802.11b wireless transceiver

• Digital Camera

• TM-EPS must provide power for at least 180 minutes

• Will need to image on at least 3 different orbits

• Boom deployment

• FITS deployment

• Aero-fin deployment

• TM-EPS will meet all NASA safety requirements

• TM-EPS will share as many components as possible with DINO main S/C

• Inhibits and monitors must be able to be verified from Ground Support Equipment (GSE)



TM-EPS Block Diagram

1.2V, 4A-hrNiCad

Cell

5V DC/DCConverter

Inhib2

Inhib3?

Inhib1 Sub-

Systems

Sep Sw.#1

Sep Sw.#2

System linesInhibit lines

Ground(Version 1)



Power System Overview

clock

FPGA counter

EPS

SCICOMM

(Version 2)



Power System Action Items

Accomplished Action Items•Performed battery profile•Trade study for charging scenarios•Determined battery choice – NiCad•First version of power budget•Preliminary EPS system schematic

Upcoming Action Items•Trade study for inhibits•Finish power distribution design•Final version of power budget•Prototype EPS



Power Tip Mass Test Plan

• Proper power levels to each subsystem– Communication’s wiser 2400 unit is given a controlled 5 Volt line– Imaging’s Jam-Cam is given a controlled 5 Volt line– Accomplished using a multi-meter and slightly varying the input

voltage to simulate noise

• Inhibits are operating properly• Receives and can initialize power save mode

– Software that simulates a “power save” command given to power by the FPGA

• Receives and can initialize non-power save mode– Software that simulates a “non-power save” command given to

power by the FPGA



Imaging Tip-Mass SubsystemAnders Fornberg



Science TP Sub-System Requirements

• Take clear pictures of FITS and Aero-Fins Deployment and main DINO module

• Serial connection to FPGA Chip

• Powered by 5 Volt line

• Pass all NASA specification on materials

– No ABS material



Trade Study (Jam-Cams in Tip-Mass)

•Pros–Already know software

–Lens is Non-ABS

–Cheap

–Readily Available

•Cons–Not good pictures

–Long storage time

–Not very good at manual controls

–Low camera memory

–Low Resolution



Canon Powershot S-10 for Tip-Mass

•Pros–Can use both serial and USB connection

–High resolution (2.1 MP)

–Better lens and parts

–Short storage and loading times

–Linux Compatible

•Cons–More expensive (≈$120)

–Don’t know software/commands

–Don’t know if lens mounting is ABS plastic



Trade Study Review

• Due to the boom redesign the tip-mass structure will be positioned closer to the main module. This will require a less resolution camera. Also, because of the faster deployment of such a design, storage time is not such an issue.

• The ability of the S-10 to use serial and USB could allow for use in main satellite as well as tip mass module.

• S-10 is a better camera all around except that there are a lot of unknowns



Tip-Mass Camera Decision

• Jam-Cams will be the primary camera at this point

• Will do a dual development with the jam-cams and the Canon S-10

• In the process of purchasing one S-10 to do ABS plastic detection



Preliminary Command list for Science

• All of Jam-Cams operations can be controlled through the serial Port• Camera Power (on/off)• Camera Trigger (take picture)• Receive images• Clear Memory• Ping Camera



FPGA Board

•Studying 3CS Science Jam-Cam FPGA Board•Will have to modify for DINO

•Uses only on camera•Has to be connect to power



Test Plan and future studies

• Reliable serial connection to FPGA board

• Program to test commands given to Jam-Cam

• Test image quality at 6 meters with bright background

• ABS plastic testing on S-10 with help from main science team



Structure Tip-Mass SubsystemTerry Song and Jen Getz



Structures Design Requirements

• Total Mass: 5 kg• Components Mass (estimates):

• Batteries (including structure): 500-600g • Camera (w/o case): 68 g• Comm (w/o case): TBD• Top Half of the Lightband Deployment System: 2.1 kg• Internal Deployment System:

• Mechanism to deploy: 1.0 kg• Attachment Tether: ~1.0 mg

• Internal/External Support Boxes: • Constructed of 6061 Aluminum• Density: 2698.79064 kg/m3

• Ballast will be used as necessary to meet mass requirements.



Structures Design Requirements

• Total Volume: 420.5 in3

– Bottom Plate will have a half inch lip to decrease tension and increase stability.

• Interior Dimensions (estimates):– Battery Box: TBD

– Camera Box: TBD

– Comm Box: TBD

– Boom Deployment System Box: 3.5” x 4.0” x 4.0”

• Center of Mass must be along the z-axis – The boom is parallel to the z-axis

– The length of the boom is 6 meters long



Structures Design Detail

• The main design driver is the mass requirement– The 5kg mass limit is critical in

designing every component

• Maximizing interior space without failing to meet the design requirements– Hexagon shape has been selected

due to its large volume capacity



Structures Design Detail



Subsystem Test Plan for Tip-Mass

• COMM– Transmit and receive from both FPGA and flight computer

• Structures– Keep on improving the design to optimize structural performance

meanwhile meeting mass requirement

– Testing will be done in coordination with the main satellite

• Science– Image quality for objects at 6 meters (~60 feet)

– Proper communications with FPGA

• Power– All system power test to ensure 2 hour operation



Issues and Concerns

• STR– Protection for internal components, necessary?– Exceeding the mass requirement is still possibly an issue

• COMM– Power drain due to continuous “beacon” transmission

• PWR– Effects on power from tether to boom (if any)– MOPS counter vs. switch for initial power on

• SCI– Non-ABS material with Canon S-10– Complications of redesigning camera selection

dino peer review 20 september 2015 tip mass presentation anders fornberg – team lead/imaging kate...

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