KiwiSAT, Status Report

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KiwiSAT, a project of AMSAT-ZL

Progress report - November 2008

by Fred Kennedy ZL1BYP – KiwiSAT Project Leader

Just before the Christmas period a very successful funding appeal was launched on the <amsat-bb> by AMSAT-ZL President – Terry (ZL3QL) and I note with pleasure that the build fund swelled to 30% of the $10k target in a very short time. This is a brilliant response that boosts not only the financial resource but also the morale of the team! Believe me, building a bird is "mega" hard work (ask those that have done it before) and support from the eventual benefactors is very well received. The feeling that it’s all worth while is restored – at least for a while!

In addition to the actual cash donations we also have a number individuals offering to sponsor a specific item – as did we (AMSAT-ZL) in the pre launch build-up for Phase 3D. Doing that provides a “personal input” to the project and we’re looking into suitable identifiable sub-units.

In the last Status Report mention was made of the Solar Cell problems faced by the team. VERY recent events have, however, meant that this is no longer an impediment to progress! See later!

KiwiSAT DEVELOPMENT STATUS

Satellite Antennas.
Despite several changes requiring rebuilds, all antenna are flyable units, although final tuning awaits completion of the satellite to full flight configuration. All the necessary splitters and phasing loop to link them to the various receivers are now completed and ready for final integration.

The late decision to fly an additional beacon on U band, required some changes to the U Band antenna design. There is insufficient room on the bottom (Z-) face to use a measuring tape based stub so both U band antennas are now brass tubes using TNC connector bases.

The L band folded dipoles are now plated, assembled and tested, with their phasing loop ready for final integration.

The V band antennas are unchanged using "measuring tape". They remain normal to the bottom plate sides and at 45 degrees to the bottom face when in flight. The furl arrangement has been exhaustively tested and has been discussed and cleared with Kosmotras for a standard drum type launch adaptor. (See lead video on the Media - gallery page.)

The GPS Receiver has its own patch antenna close mounted on the Scientific Attic.

Completion date = Construction & testing complete - awaiting final integration.

 

The Horizon Sensor
A change to the sensor head has been made to accommodate the selected thermopile I/R sensor. In a TO-5 can, it has both a “U/V proof” (silicon based) diffractive lens and an inbuilt 9 degree Field Of View (FOV) restrictor. Two will be used.

The combined I/R plus visible light head (the black anodised unit in the image to the right) has been replaced with a white Delrin I/R sensor and a new machined aluminium head for the visible-light photo diodes. Two aluminium machined heads have been made (only one will fly) and they are also shown in the image. (Since taking the image the visible-light heads have been black anodised ready for assembly.)

All units are now with Clayton ZL3TKA who is carrying out the circuit design work needed to integrate the outputs into the sensor telemetry stream. Clayton will also layout the PCB's and assemble and test the flight units.

Completion date for the flight unit = 26th September.

 

The Sun Sensor
A (proto-flight) Sun Sensor head, using a Hamamatsu PSD - type S5991-01, has been operational for some time. The body for a second unit is now ready for assembly.

The “penny sized” prototype PCB in the sensor head was developed for the prototype version and again, courtesy of ZL3JVX and ZL3TKA new boards are now to hand. The required flight PSD’s are also held. The two sensor heads will be assembled and tested shortly.

Work is currently underway on the PCB for the Flight version of the Sun Sensor main electronics PCB and was scheduled for completion by the end of May.

The necessary components for the Sun Sensor main electronics computational circuit are being procured by Terry (ZL2BAC).

Completion date for the flight unit = 3rd week October.

 

The Camera
The camera system is similar to that used to very good affect on the University of Tokyo Cubesat “XI-IV” and we thank Akito from the “XI-IV” Team for providing our start point.

In Christchurch Mark (ZL3JVX) prepared and provided the initial imaging module requirements, along with the first commercial sample, for our current solution

Clayton (ZL3TKA) has taken over the development of the Camera and has populated the new PCB while Fred (ZL1BYP) has produced a camera body/lens unit to which the PCB has now been fitted.

The camera has now been bench tested, and despite the poor lighting conditions produced very good results. PC software to interface to a similar camera module was used for this initial test.

To follow is the writing of new PC interface software to fully test the camera. This software will ultimately be ported into the KiwiSAT IHU. Changes to the camera firmware will also be considered if found desirable.

There were a few minor PCB errors on the original board - mostly related to the solder resist clearances. Whilst these could be worked round it was decided to layout a new (Mk2) board. This has been done and the new board is now made and ready to be populated and tested. On completion a new, lighter camera body will be produced by Fred (ZL1BYP) and the whole will go into the vacuum chamber for a formal bake-out.

To ensure the "unknown plastic" lens mount was suitable for use on the Mk 2 camera it was decided to subject it to a full bake out/out-gassing check and then test the whole Mk 1 camera (to prove its electronics) even though it wont be flown. The bake-out results were good and the electronics produced the image on the right which speaks for itself!  The camera materials configuration is, therefore, totally satisfactory.

Completion date for the flight unit = imminent.

GPS Receiver
The GPS receiver development has been completed and 3 units are now to hand. These unit have been fully tested using a professional GPS simulation system with little to choose between them. The most sensitive has been earmarked to fly.

The flight and stand-by flight units have been in the vacuum chamber for 72 hours and baked-out at 60º Celsius for 24 hours during that period without any problems.

The additional 2 power boards (attached to the rear of the 9 pin D connector in the picture) will, when populated, be “cooked up” separately. These boards await completion when time permits.

Completion date for the flight unit = Imminent - awaiting final confirmation.

L Band Converter
A proto-flight unit has been designed by Clayton (ZL3TKA) and is currently being tested by Terry (ZL2BAC). This unit is similar to the other receiver boards using SMD components and MMICs where appropriate. Fred (ZL1BYP) milled a housing for this unit from an aluminium block.

The accompanying picture shows the converter mounted in its pre conversion coated housing. The changes required for the flight model have been identified are being incorporated in a new PCB. This board is on the scheduled list of minor boards for production by end of May. (The DB-9 connector will be eliminated in the flight unit.)

Completion date for the flight unit = Imminent - awaiting final confirmation.

 

FM Receiver.
Mark (ZL3JVX) produced the proto-flight FM Receiver which has now been fully tested and proved. As four more units will be required, two of which will fly, this fine piece of work is now being replicated. This will afford us the convenience of have a spare Working Channel receiver and a spare Command Receiver.

The PCB’s, boxes and most parts for the first two flight units are to hand. Parts for the second two are on order and the units are to be be professionally assembled.

(It’s worth noting that the prototype unit was totally un-phased by a long spell heated to 50° Celsius in the Massey vacuum Chamber at -6 Torr pressures! The units will be subjected to formal bake-out tests at 60ºC in a further environment run.)

Completion date for the flight unit = Imminent - awaiting minor components in final preparation for acceptance tests.

 

Linear Receiver (and Pre Amp)
The U/V Linear Transponder has been up and running for some time. Whilst the results obtained were outstanding, a number of changes were identified that reduce the size and weight of the units. The Mk 2 (flight units) developed as a result of the tests are now finished and have been subjected to the appropriate thermal vacuum test with no discrepancies. (See the Transmitter report (below))

The accompanying picture is of the integrated Mk2 flight Transponder (standby unit) mounted on a test plate. This system is currently on the air from the ZL1BYP location giving local amateurs an opportunity to experience live operation prior to orbiting.

The beacon is keyed by a PIC (thanks Kelvin) with the call sign ZL6SAT. This special callsign has been allocated to AMSAT-ZL for identification for all ground tests in the KiwiSAT project.

The Mk 2 unit has replicated the performance of the Mk 1 over a known 295km terrestrial path to the Mount Egmont area to the South.

Our thanks to Phil Wakeman of TMD Consultants for this quality production.

This marks first fully completed and tested flight system unit for KiwiSAT.

Completion date = Completed.

 

Pre Amp & Splitter

The Pre-amp and Splitter have been developed as one unit to fit in the Flight Attic close as practical to the 23cm antenna array.

Completion date = Work in progress.

 

Transmitters
The FM Transmitter proto-flight unit (Designer; Kelvin (ZL3KB)) is complete and has been tested under normal and vacuum conditions. Whilst it performed well there are several issues that required attention for the Flight unit. These are a reduction in current drain so that the transmitter can be run continuously within the available power budget, the overall efficiency, and some close-in spurious emissions. Minor changes are also required to provide a signal source for the new 70CM beacon. Kelvin (ZL3KB) is currently revising the PCB layout to incorporate these alterations. This unit will be flight ready by end of August (08)

As mentioned above, Phil’s Linear Transmitter (married with its Receiver and Pre-amp) is finished and on trial beaming South from Whangaparaoa 25k North of Auckland. Its performance is outstanding and is now awaiting integration into the space-frame.

Completion date for the flight unit = Imminent - awaiting final confirmation.

Magnetometer
As part of the Scientific Experiment, a Honeywell HMC 2003 (3 axis) Magnetometer will be flown to measure the actual magnetic field in both strength and direction. The required on/off switch and re-set function which will be integrated into the system. Terry (ZL2BAC) is currently designing the hardware which was scheduled for completion by the end of May.

The reset function is required to guard against the remote possibility of the Magnetometer being swamped by the magnetorquing coils should the operations overlap, recovery is not automatic.

The magnetometer head is mounted in a dummy structure to plot the response pattern as a confidence check. It does exactly what is expected of it and it is awaiting integration - first into the "flat sat" and then the flight structure.

Completion date for the flight unit = 2nd week October.

The Integrated Housekeeping Unit (IHU) Computer
As could be expected, the IHU (In House Unit) Computer board has given some problems which have been analysed and have now been corrected.

While modifying the circuitry it was decided that, in conjunction with Phil Karn KA9Q, FEC (Forward Error Correction) would be incorporated. This was tested and proven using a small daughter board wired to the two prototypes. All changes have now been incorporated into a revised schematic which is now with a specialist PCB assembler in Christchurch, Assembly Specialists Ltd (ASLtd).

Terry (ZL3QL) is working with ASLtd on production of the final boards. They have taken on the task of completing the units to flight ready status using their expertise to design and populate the PCBs. This is being done to "Space Qualification" standards without, however, the use of Mil Spec components. Considering the history of reliability of amateur satellites using standard components, this step is deemed unnecessary.

Some parts, such as the I/O plugs and sockets, will be of the highest quality available. ASLtd will obtain the components using their buying privileges and expect to complete the work by the end of August(08). A rigorous test regime and period of testing/ evaluation will follow. The IHU is expected to be married with its tray in the “flat-sat” early September '08.

Our thanks to the Howick Radio Club for the generous donation that has made this possible. Truly superb, guys.

Progress: 2 November 08
Unit is 98% completed awaiting special inter-board connectors. Insertion of final EPROM chip awaits completion of software development.

The Battery
Thanks to the excellent cooperation of our friends at AMSAT-DL, a complete flight battery of 10 NiMH cells has been obtained. These 4000mAh cells from Suppo in China have been matched for flight and will give a nominal 12.5 rail voltage. The cells will be fastened down to support frames which have been machined and prepared from flight acceptable plastic (Delrin).

The appropriate Kapton tape has been obtained and the existing heat shrink insulation around the cells is being replaced with this prior to insertion into the vacuum chamber for the required bake-out test. (An out-gassing precaution.)"

The battery compartment also features the Z Axis torque coil and the coil drivers for all three coils for the active ADAC system. The coil has been wound along with the others for the attitude control system and all have been baked ready for installation. The Z Coil will be incorporated in the battery tray when the board driver PCB has been received. This (along with those for the X and Y coils) has been completed and populated by Clayton (ZL3TKA) ready for bake-out. The thermal chamber check will take place with other miscellaneous boards during July/August.

Completion date = Construction & testing complete - awaiting final integration.

The Battery Charge Regulator
Work on the Battery Charge Regulator, in the hands of Hans (ZL1HB), is now well advanced. The prototype will be ready for initial tests in the next couple of weeks. No are problems foreseen to having the flight board finalised by the end of June'08.

The first prototype board - populated by Hans using normal soldering equipment - is shown in the image.  The unit is undergoing extensive tests to make sure that the BCR design and product - a flight critical item - is 100% in all respects.  So far results are up to full design specifications. The necessary hot plate/hot air soldering equipment, for the assembly of the flight unit to the highest standard possible, is being obtained.

Flight unit build underway on track for the end September.

Power Switches
Two power switches that will be held open by a projection on the launch adaptor are situated in the Transmitter Tray. Mil Spec micro switches of the same type as used (successfully!) in the original Microsats are held for this task. These will switch the electronics on after satellite separation. A requirement of the launch is that the systems are not to be powered up until after orbit insertion.

These are undoubtedly the most Mission Critical items. They only operate once, and they have to work!

Progress = Integration consideration.

The Structure
Work on this has taken several forms with models, wooden mockups, prefabricated aluminium trays (‘engineering mock-ups’) and dozens of drawings/sketches in support as the final dimensions have changed. These changes have been driven by many factors including the addition of the extra beacon, solar cell development, and minor modifications as the various modules are developed.

Mike Jack of Stanier Engineering (our CNC machining expert) is now working on the outline software program and awaiting details on the last small changes. To confirm the final major proportions, Fred (ZL1BYP) produced a full size mock-up which is now with Phil Wakeman.

For minimum weight and maximum stiffness the 'trays' forming the satellites structure will be CNC machined from solid 6061-T651 Aluminium blocks. This material is now available in New Zealand. Although funds are held for its purchase, this would make an excellent sponsor project. Cost is expected to be NZ$1,000 for the quantity required.

Construction awaits final flight units completion and Flat-Sat integration.

Launch Adaptor. – Prototype
The advanced status of the project now requires our turning attention to the launch hardware, specifically the Launch Adapter. This aligned with a need for a suitable test support for the satellite.

A number of alternatives where considered but what better than “the real thing” if it could be produced at a reasonable cost. From material costs there was little difference so a fabricated “drum” was decided upon – if facilities could be found for its manufacture. They could!

After extensive research a number of part dimensioned sketches were obtained and from these - and AMSAT photographs - a Dnepr style launch adaptor designed. The basic ‘drum’ shaped support was recently completed in the Massey University Engineering Workshop in Albany. It will be used to confirm our “fit-up” plate and to support the flight version of the completed satellite for the pre flight vibration, shock and balance testing.

Our thanks to Dr Johan Potgieter for approving and assisting with its manufacture and in particular to Eddie Rogers (Workshop Manager) and Clinton Darsch for their skill and effort in turning the aluminium plate supplied into the superb adaptor framework as pictured. Alongside is a shot of the launch adaptor for AO-51 fitted to its Dnepr LV third stage. (Thanks, Chuck.)

Completion = Development at prototype stage awaiting final launch confirmation.

Solar Panels
Procurement problems of suitable high efficiency solar cells was a continuing headache until we received a heads up from David, (G0MRF ) just before Christmas. Some “substandard satellite gallium arsenide cells” had appeared on eBay. We immediately started investigating whether or not we would have problems under US export restrictions(ITAR) in bringing the cells to New Zealand.

To cut a long story short; with the help of Reinhold Bauer of The Aerospace Corporation - whom I had the good fortune to meet at the Asian Space Conference in Singapore last year and who has been an absolute fund of information - and Bill (N6GHZ) of High Sierra Microwave (who had already supported us with a set of Hotweezers for the wiring loom work) we now have enough cells to complete the flight solar panels.

Not only that but we can also produce one panel of each type as a spare AND we have enough to offer to another small project once KiwiSAT is complete. To both Reinhold and Bill we offer our sincere thanks for stepping up to the plate and giving KiwiSAT a magnificent start for 2008. (Such effort from already busy guys is terrific. The ‘ZL hospitality suite awaits when you pay a visit to us down here!)

Completion = final design awaiting structure confirmation. Initial integration tested and completed as far as possible.

General Comment

Science Package
Visitors to this site will have noticed a reference to an enhancement to the satellites systems with the addition of a U Band beacon. This we plan to use for ionospheric Faraday Rotation experiments which, in a way, is a replacement for the ozone measurement experiment originally considered. That, we decided, was a “bridge too far” and of rather limited value. The additional beacon is feasible and will be a useful tool. The beacon has now been incorporated into the design and we have approval to use 437.425 MHz. More details of this will be given later.

This is a cutting edge endeavor and we know that the transmissions will be monitored both in and outside of the Amateur Satellite Service. Monitoring assistance will certainly be needed by radio amateurs and we know that your support will be forthcoming. (The ability to receive 9600 data on 2m and 70cm simultaneously plus a good sound card is expected to be the requirement – and, of course – an enquiring mind and a concern for the environment!!)

It’s expected - on a global data base scale – the results will lead to a better understanding of some propagation aspects ultimately aiding global warming research through the development of better tools for important measurements. If it does it’s well worth the additional effort.

A vote of thanks to the AMSAT-ZL RF Team – and the IARU Amateur Satellite Frequency Coordinator - for making this possible.

Completion = Mechanical work completed to integration stage. Development of software etc. will continue throughout he life of the project.

ADAC Experiment
A vast amount of work has been put in on the ADAC package by KiwiSAT Project Team member Dr. Jon Henderson and what was very much a ‘vision’ at the start of the 2006 is now a mathematically proven system. However, though the principle of Active Magnetic Control has been established, uncertainties about its application make it absolutely vital that it be proved by means of computer simulation.

This will involve marrying together three MATLAB based software components which have been individually proven and found accurate. These are: Orbit Prediction using NORAD generated KEPS, Earth's Magnetic Field (strength and direction) at points along the orbit using World Magnetic Model 5/10 and the Rotational Equations of Satellite Dynamics. The integrated computer model will then enable the development and testing of robust algorithms for determining and controlling satellite attitude.

Jon’s work was the subject of a meeting at the Massey University School of Technology and Engineering on July 6th (2007) and our thanks to Professor Ian Maddox (Industrial BioScience) and Dr Tom Moir (Computer Engineering), who have offered to increase Massey’s current support effort by helping in this very complex area. The upshot is that we are expecting to have additional support starting October/November this year and, with Jon’s very capable direction and supervision, the ‘bones’ will be fleshed out to a fully working system.

As part of the software package (providing the hardware aspects are incorporated into the space-frame) this can continue right up to and after the launch.

Completion = Test-ready phase; 26 September.

Software
Attention to the software for KiwiSAT has really taken off during the last couple of months with ideas free flowing right across the Project Team. Additionally, following Ian’s (ZL1AOX) hard work preparing and delivering our KiwiSAT Paper at the AMSAT- NA Symposium in San Francisco in October 06, a number of AMSAT-NA folk came forward with offers of help and our thanks to them. The exchange of dialog between Ian, Austin and Phil Karn (KA9Q) on the application of Forward Error Correcting in the software/hardware field has already borne fruit and long may it continue!

I have to report that the problem of non availability of a proven Operating System STILL remains with us but I’m confident an answer will be found. It has to be!

The depth of talent within the KiwiSAT Project Team is such that practically all are contributing to the software effort with Terry (ZL2BAC) leading the general/overall aspects. (That is “all” apart from me! As a non-software guy I can only wonder at the complexity and struggle to keep up with the detail of the task – and with the jargon!)

My understanding is that we just need a 100% guaranteed fireproof boot loader to be finished and loaded into ROM memory on the satellite. Once the basics command structure is taken care of such things as the OS can follow.

Completion = Initial modules completed and are now being burnt into the IHU EPROMS ready for PCB population.

The Clean Room
Last Status Report indicated work was in hand at Massey University on a “KiwiSAT Integration Laboratory” and I’m happy to report that the facility is now complete. As items are put through the thermal vacuum chamber they will remain in the clean area till they are integrated into the satellite.

The clean area (located in and almost filling the small “Wet” Laboratory) was a combination of AMSAT-ZL and Massey University funding. AMSAT-ZL provided the materials and built the room itself with Massey supplying the two HEPA Filters and 5 sets of clean room apparel for use there-in.

The standard achievable in the enclosed area, beyond an airshower entry cubical, will certainly be to 100,000 standard which is quite satisfactory for the satellite. It could well make 10,000 standard but maintaining it would be hard going and probably not worth the required extra time and effort. With a structure that almost fills the space available - and walls that one can see through - it is not the easiest thing to photograph, but I’ve tried.

The PVC tube integration stand is genuine KiwiSAT ground equipment but the satellite is the Mk 2 model – sorry, not for flight. (Impresses the visitors though!)

Whilst the construction of the Clean Room was going on it was necessary to remove the thermal vacuum chamber from the Wet Laboratory and re-site it. Luckily a space was made available by Dr John Harrison of the Massey ( Albany ) Chemistry Department and the unit now sits in his lab. It now sports an additional item that he has made available to us, a Residual Gas Analyser. Not only can we determine that the out gassing is within the prescribed limits but we can, if necessary, also determine what is coming out!

The unit, which was built initially in the days when we were considering the build of a CubeSat, is not capable of holding the completed satellite but is capable of holding the entire contents of KiwiSAT in module form, and at the same time powering it up with antennas etc. attached.

We are still trying to identify a facility for a fully assembled test here in New Zealand should this be called for to present an “overall” thermal vacuum record. (Which is likely!) Should this not be possible we will have to look at a commercial test - in Australia perhaps. We can be assured that it will pass first time however!!

A picture of the unit, with John in attendance, is also below

 

Where from Here?
With flight items now coming on stream we are turning our attention to the program that will take us to serious negotiation with the launch agency to put KiwiSAT into orbit. Initial steps have been taken as mentioned above and we are already talking to ISC Kosmotras and to our friends in SSTL who are our providing much guidance and advice on what to us is a very unfamiliar area.

Our strategy is simple. We shall now complete KiwiSAT to the point where the satellite is all ready to go completely assembled and capable of full operation using a remote “ground-station”.

Hans (ZL1HB) is already working on a simulated power system to feed the solar cell circuits with the currents it would generate with the cells when in space and we plan to have an ‘on screen’ display that will ‘fly the satellite’ as realistically as possible whilst it’s still on the ground.

The object of the exercise is to convince those we approach for support for the big one, the launch costs, that we have a viable product that is worthy of their support. And also that “KiwiSAT” is an Amateur Radio Satellite Service communications satellite, not an ‘amateur’ satellite with the “baggage” that could be conjured up in the minds of those that are in the position of being able to help us.

This is vital. Our own confidence in our teams’ product is not enough. We have to instill that confidence in others who are able to advance the cause and put our hard work into orbit.

 

Full re-edit - 11 November 2008.

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