News from Vietnam

[alexc]

In case you missed it, here is an update from our friends in Vietnam (Thu & Co): http://www.googlelunarxprize.org/lunar/ ... om-vietnam

Also, congratulations to Thu for taking his ham radio exam - he now has callsign XV9AA

[thuvt]

Thanks for your post, Alex.

Although for me the nanosat project now has the highest priority but I still visit the forum everyday and will continue to support team Frednet. Optimistically, by successfully completing the nanosat project I can introduce my team members, they are all excited learning about this competition

P/S: I own your a beer, please remind me should we have a chance to meet each other someday

[alexc]

Hopefully we will be able to organize an open team summit/conference at least once per year, moving it around the world! So I'm sure we'll meet at some point

By the way, if you and your team wishes, you can use our existing infrastructure (forum and wiki) for your nanosat project. We might be able to share designs for various subsytems - you never know.

[AndersFeder]

By the way, if you and your team wishes, you can use our existing infrastructure (forum and wiki) for your nanosat project. We might be able to share designs for various subsytems - you never know.

That's an interesting thought. Even if we can't directly share designs, we should still be able to learn a thing or two from each other by just watching what considerations are being made.

[alexc]

Indeed. Personally, I'd love to explore the possibility to gather several projects/programs under the same umbrella. The SourceForge of space? SpaceForge?

Our existing infrastructure consisting of the wiki and forum may not be scalable to this extent. That's why I hope we can get experience with the https://launchpad.net/ - I particularly like its feature to create teams and sub-teams, which pretty much reflects our current organization in groups, how bugs are shared across projects using shared components, etc. The whole infrastructure seems well geared towards community contributions.

[AndersFeder]

Indeed. Personally, I'd love to explore the possibility to gather several projects/programs under the same umbrella. The SourceForge of space? SpaceForge?

There is DevelopSpace, though not extremely active at the moment.

Our existing infrastructure consisting of the wiki and forum may not be scalable to this extent. That's why I hope we can get experience with the https://launchpad.net/ - I particularly like its feature to create teams and sub-teams, which pretty much reflects our current organization in groups, how bugs are shared across projects using shared components, etc. The whole infrastructure seems well geared towards community contributions.

Indeed. I also like Blueprints - since it is possible to make dependency trees of blueprints, and flag particular blueprints of being of high priority, it looks like a good way to provide an overview for a community audience of what exact parts of an project that is in need of attention.

[tristancho]

I like the idea of meet at some point someday...
Joshua

[thuvt]

It's a good idea if we can share our idea and experience since both project are space missions so they have many things in common.

Currently our main communication method is face to face team meeting since we're sitting right to each other so it's unlikely that we'll switch to online meeting. However I've talked to my team members about GLXP competition and Team Frednet and they're all excited. How can we do to benefit both parties?

For example we aim to complete the nanosat and launch it by the end of 2010, most likely before any launch attempt by team FredNet. We can take advantage of this chance to test the distributed ground station data collection system or even test flight a component? (currently we have some room for spare within the nanosat)

Just thinking of the nanosat to be the first step to the Moon make me feel so excited

[AndersFeder]

For example we aim to complete the nanosat and launch it by the end of 2010, most likely before any launch attempt by team FredNet. We can take advantage of this chance to test the distributed ground station data collection system or even test flight a component? (currently we have some room for spare within the nanosat)

Dude, that would be so cool. Only thing I wonder, though, is how are you funded? If by an university, for instance, there is the usual stuff with only 10% government funding for the GLXP - but it's definitely worth considering, IMO.

[tristancho]

Anders,

I disagree. Thu can validate some technology and Tean FREDNET or any people can use the same technology. There is no government stuff in this technology transference. It is doesn't matter if he or his team is from Team FREDNET.

In example, I need to validate a low cost and commercial available IMU (Inertial Reference Unit). If this nanosat needs an IMU and they use the same model, it is space tested and validated. Then any Rover group or Propulsion group can use the same model for our purposes; in fact any team can do.

Best regards,
Joshua

[AndersFeder]

If we are favorized in the selection of which technology is validated for public funds then, yes, it do matter.

[tristancho]

If we are favorized in the selection of which technology is validated for public funds then, yes, it do matter.

It is not a question of favorizing the selection, is a question of trade of. In my example you can use an expensive IMU, is your decision, but I prefer give to the world a low cost product accessible for many people, not only for rich companies. This is our mission in the open space philosophy: give a solution feasible for everybody in the world in order to reach the moon and explode its resources. In some cases we must advance the technology as proposed in my IMU example.

Other example; for recording we can use Elphel HD camera or an expensive camera. Rover group we have decided use Elphel HD camera and believe me, it is not ‘favorizing’ nothing, is just selecting the best adequate product.

Regards,
Joshua

[alexc]

If everybody - not just a particuklar team - can benefit from a validated technology, then I don't see why it should be a problem.

The purpose with the government funding clause in the rules is to ensure that the prize winning solution is commercially feasible. So, if a government funded entity has developed a prototype something and gives that to a team, that counts in the 10%. On the other hand, if they don't give it to anybody but publish the design as open source, then everybody can benefit from it equally.

[AndersFeder]

Is the purpose to ensure that it is commercially feasible to reproduce the technological solution only, or is the purpose to ensure that it is commercially feasible to repeat the entire mission, including research and development? In the former case, I agree we have a good case, but in the latter, maybe not.

[alexc]

If you can reproduce the technical solution you can repeat the whole mission, no? Otherwise I'm not sure I understand what you mean.

The goal with the GLXP is to develop the commercial space industry and make it cheaper. So using heritage hardware that can not be manufactured today is not okay. Using breakthrough R&D technology that can be turned into a commercial product is okay, provided that the R&D was privately funded or it is available to everybody under the same terms.

[AndersFeder]

If you can reproduce the technical solution you can repeat the whole mission, no? Otherwise I'm not sure I understand what you mean.

Perhaps I'm using the word 'mission' incorrectly, but I mean there is a development phase and an operations phase. Must both phases be commercially feasible to repeat, or only the operations phase? (I consider construction etc. as a part of the operations phase here, or as somewhere in between - by development I mean R&D, space validation etc., i.e. the things that only have to be done once)

[alexc]

If you can reproduce the technical solution you can repeat the whole mission, no? Otherwise I'm not sure I understand what you mean.

Perhaps I'm using the word 'mission' incorrectly, but I mean there is a development phase and an operations phase. Must both phases be commercially feasible to repeat, or only the operations phase?

I understand, but that's not what is meant by reproducability... Well, to some extent yes, in that if somebody would want to reproduce the mission of the winning team, they should be able to buy the solution from the winning team - I just don't think anybody would be interested in that.

No, the objective is to make space exploration "cheaper". The X PRIZE idea is to motivate private teams to invest their own time and money for developing ideas and solutions that may turn into commercial products. So, the solutions must be suited for production. The more commercial products on the market, the cheaper will it eventually become. So, 5 years from now, if I want to send a payload to the Moon, I know that in addition to the government space agencies, there are now a few private organizations that have the capability to bring my stuff to the moon and that can only make the price lower. Other possiblities would include that I build my own spacecraft using cheap components developed by GLXP teams.

[AndersFeder]

So, could the Iranian government set up an Iranian GLXP team to demonstrate their nation's space capability, fund it 100%, and still win the prize, as long as the fruit of those funds are marketed subsequently?

[thuvt]

@AndersFeder: we are funded by a private company, my former employer.

@tristancho: that's what I meant. At the moment my team is discussing on the conceptual design of the nanosat and most of the components are COST devices. So if these components work with the nanosat, it can be used in the lunar bus or the lander with greater confident.

[alexc]

So, could the Iranian government set up an Iranian GLXP team to demonstrate their nation's space capability, fund it 100%, and still win the prize, as long as the fruit of those funds are marketed subsequently?

No, only 10%.

[tristancho]

@tristancho: that's what I meant. At the moment my team is discussing on the conceptual design of the nanosat and most of the components are COST devices. So if these components work with the nanosat, it can be used in the lunar bus or the lander with greater confident.

Good news. You may consider to use this IMU in order to test it in space. This is the best trade of. Low cost ($670) Lower weight, High accuracy:
3 AXIS ANGULAR RATE: +/- 400 º/s
3 AXIS ACCELERATION: +/- 10 g
1 TEMPERATURE: -55 to +125 ºC
SIZE: 30.5 X 31.75 X 15.62mm
WEIGHT: 7g
Spec.



Regards,
Joshua

[thuvt]

Thanks Joshua for your recommendation, it looks like a good one with low weight and small size. We'll take this into account for our next ADS team meeting on the nanosat conceptual design.

By the way, we are evaluating the possibility of putting a magnetic sensor onboard our nanosat. Currently we are looking at those supplied by Honeywell http://www.magneticsensors.com/products.html?id=421. Although the magnetic sensor is of no use in the lunar environment, do you have any recommendation on magnetic sensor for us?

[tristancho]

It is interesting. I will take in account this link for Propulsion Group.

In 2006, for the design of a pico-satellite we have used the TFM100S respect to others due to the light weight ratio and high accuracy (Range ± 100 µTesla). But I don't know what are your requirements for the magnetic sensor.

Regards,
Joshua

[thuvt]

Joshua, this magnetometer is a little bit long (3.66 x 3.58 x 15.44cm) and not so lightweight (200 grams) for use in our nanosat.

At the moment, we are favoring Honeywell's HMR2300 sensor for its small size (3 x 7.5cm), lightweight (28g PCB only) and digital output www.ssec.honeywell.com/magnetic/datasheets/hmr2300.pdf

If anyone has a comment or suggestion please feel free to chime in.

[tristancho]

Yes I see.
TFM100G2 is 3.51 cm x 3.23 cm x 8.26 cm and weights 105 grams but of course it depends on purpose and specifications for the mission. Sorry.
Joshua

[thuvt]

Hi buddies,
Recently I've been occupied with my project so I was lazy to keep you updated but there's been quite good progress with our nanosat project: we've successfully presented our phase 1 result (receiving satellite signal) to the company's board of director and we've got the green light to go ahead with phase 2 (detailed design of the F-1 satellite). Our team has also moved to a new workplace which has better conditions and we're more confident and eager to continue on the quest for space. Here are some of our new photos:
New work place
http://farm4.static.flickr.com/3610/333 ... 52.jpg?v=0

Testing solar cell with the Halogen lamp "Sun simulator"
http://farm4.static.flickr.com/3583/333 ... 23.jpg?v=0

Discussion
http://farm4.static.flickr.com/3592/334 ... 8c.jpg?v=0

Ad luna!

[alexc]

Good news, Thu - thanks for the update!

[tristancho]

Great!
This is amazing. You have acquiring real experience that you can use in the Team FREDNET. This experience is very closer to our real development, it's to say: Cheap, small, fast, etc.
I like this Team!

Congratulations Thu!

Regards,
Joshua

[thuvt]

Thanks for praising, this is just the first step and we still have a lot of things ahead to do. I've also added another photo of our new workplace to my previous post

@tristancho: it was this team - team FredNet's spirit which gave us the confident to carry on our nanosat project. I always consider the nanosat to be a small part of our big plan to reach for the Moon and we can share knowledge/experience to achieve that goal.

By the way, here's a list of components used in the conceptual design of our nanosat. Most of are COTS products to reduce development cost & time. Perhaps some of them are similar to what will be included in the lunar lander and the picorover so we can test their performance in space

Power Supply Unit:
- Solar cells: TBD, depends on power budget calculation
- Voltage control and Battery Charger: HESC-104 (Tri-M) http://www.tri-m.com/products/engineering/hesc104.html
- Rechargeable battery: BAT-NiMH104 (Tri-M) http://www.tri-m.com/products/engineering/bat104nimh.html
- Battery heater: not decided yet but we favor Minco products (http://www.minco.com/products/heaters.aspx?id=71)

OnBoard Computer (from Diamond Systems):
- OBC: Helios Single Board Computer HLV300-128DV http://www.diamondsystems.com/products/helios
- Storage: 1G flashdisk FD-1G-XT (Linux OS included)
- DAQ: possibly DMM-32-DX-AT (Autocalibrating 32-channel 16-bit A/D + 16-bit D/A, ext. temp.)
- Relay control: OPMM-XT or IR104
- Low-res camera: TBD
- Hi-res camera: TBD but we wonder if this commercial rugged digital camera Olympus Tough 8000 (http://www.olympusamerica.com/cpg_section/product.asp?product=1448&fl=4) can work in space?
- Temperature sensor: LM35
- Gyro sensor: Gyrocube ONI-23503 http://www.o-navi.com/Gyrocube3A_4.pdf
- Magnetic sensor: Honeywell HMC2300 http://www.ssec.honeywell.com/magnetic/datasheets/hmc2003.pdf
- Current sensor: MAX4072

Backup computer:
- PIC16F877A

Communication:
- Main transceiver: dualband (2m/70cm) handheld transceiver Kenwood TH-D7AG with built-in AX.25 TNC
- Backup transceiver, beacon transmitter, DTMF decoder (used in emergency cases): TBD

Please feel free to have a look and let me know if you have any questions. Comments are also welcome

[tristancho]

Ok Thu, I will check one per each after the meeting. I will tell you something ASAP but it looks like nice!
Regards,
Joshua

[alexc]

...
Communication:
- Main transceiver: dualband (2m/70cm) handheld transceiver Kenwood TH-D7AG with built-in AX.25 TNC
- Backup transceiver, beacon transmitter, DTMF decoder (used in emergency cases): TBD

Please feel free to have a look and let me know if you have any questions. Comments are also welcome

I never personally though of using an OTS hand-held for onbard radio, but it sounds like an interesting idea if it provides all the required functionality like the TH-D7AG does. However, I am concerned about too much excess power and weight wasted in components that you do not need but cannot remove, e.g. display driver, audio amplifier (for speaker and microphone) and so on. In any case, I would compare it to other options like existing designs from prior cubesats - you can find many of them on the net.

[tristancho]

Yes,
Every time it seams easy to space qualify the near to people technology.
You can buy a high integrated MCU with so many functionalities whit a very low weights. Why don't waste some grams if you are validating the entire component?

This is a new approach never seen before.

Regards,
Joshua

[thuvt]

I never personally though of using an OTS hand-held for onbard radio, but it sounds like an interesting idea if it provides all the required functionality like the TH-D7AG does. However, I am concerned about too much excess power and weight wasted in components that you do not need but cannot remove, e.g. display driver, audio amplifier (for speaker and microphone) and so on. In any case, I would compare it to other options like existing designs from prior cubesats - you can find many of them on the net.

In fact we learned this approach by studying some prior cubesats such as Tokyo Institute of Technology's Cute 1.7 where they modified the Alinco DJ-C5 and Kenwood TH-59 transceivers for use onboard their cubesat. Per this design they needed 2 separate modems since they're not included the transceivers as the TH-D7AG does. Of course we'll have to remove (or disconnect) the LCD, speaker, case, buttons... to reduce power consumption & weight as much as possible.

If this works, it can save us a lot of time and effort since the TH-D7AG can interface directly with the Helios board via the PG-4W serial cable.

Anyway, I've noted your comments and our team will research & discuss on other options before we finalize our design. Thanks

[alexc]

Cool. I didn't know about that.

[thuvt]

Hi, just to keep everybody informed on our nanosat project. Recently there's been a lot of discussion on the COM module design and here's our decision:
The nanosat will be equipped with 02 Yeasu handheld transceivers VX-3R http://www.universal-radio.com/catalog/ht/3003.html. In normal operation mode (full duplex), one VX-3R will listen on VHF band while the other transmits on UHF band. If one of the transceivers fails, we hope to switch to half duplex mode using the remaining one. This is kind of redundancy for the COM system

We also agreed on this modem TNC from Baypac to connect the onboard computer with the transceivers http://www.tigertronics.com/bp2info.htm

On a side note, we also want to experiment with a more advanced transceiver (on a higher frequency) and the MHX2400 from Microhard seems to be a good choice http://www.microhardcorp.com/MHX2400.htm

Have a nice weekend!

[scasey]

Thanks for the update and keep up the good work!

[tristancho]

On a side note, we also want to experiment with a more advanced transceiver (on a higher frequency) and the MHX2400 from Microhard seems to be a good choice http://www.microhardcorp.com/MHX2400.htm

Hi Thu,
Thanks for updating.

MHX could be a good option. We have selected this transceiver for our Picosat design.
Regards,
Joshua

[thuvt]

MHX could be a good option. We have selected this transceiver for our Picosat design.

Joshua et al,
I've contacted Microhard and here's a few thing you may find useful:
- MHX2400 is now obsolete and replaced with MHX2420. Function of both the radios is same. MHX2420 ($425 - http://www.microhardcorp.com/MHX2420.htm) radio has some new added features.
- Besides the MHX2420 there're also the MHX910A ($225 - http://www.microhardcorp.com/MHX910A.htm) and MHX920A ($325 - http://www.microhardcorp.com/MHX920A.htm). I looked at their specs and found out that the 3 are pretty much the same (920A seems to be an improved version of 910A), the most apparent difference is frequency (900Mhz vs 2.4Ghz).
- As far as I know, higher frequency tends to be more absorbed by the atmosphere (free space path loss) so I wonder if the MHX920A outperforms the MHX2420 in reality? Is there any advantage of using frequency 2.4Ghz vs 900Mhz?

[alexc]

- As far as I know, higher frequency tends to be more absorbed by the atmosphere (free space path loss) so I wonder if the MHX920A outperforms the MHX2420 in reality? Is there any advantage of using frequency 2.4Ghz vs 900Mhz?

Atmospheric attenuation becomes significant above 10GHz, but the exact effects depend on what modulation you use, i.e. whether your link is sensitive to fading or phase shifts, etc. Galactic noise, on the other hand is stronger on VHF/UHF than on microwaves. Free space loss is independent of atmosphere, hence the name free space. It is simply an expression for the energy density decreasing as you "wave sphere surface" expands. The free space loss increases with frequency, but on the other hand, the gain of an antenna increases. For parabolic dishes these two effects cancel each other.

Finally you should be careful with radio equipment for the ISM bands. First, the regulations are different in the US, EU, and Asia, and something that is legal in one region may be illegal in another region. In particular, there are limits on max allowed radiated power (i.e. including antenna gain) and I suspect it is not even allowed to use license free ISM transmitters for space applications.

On 2.4GHz you can also use amateur radio license, but you should be prepared for strong terrestrial interference from ISM equipment. Also, I don't know if spread spectrum is allowed under amateur radio license.

Just a few heads up

[tristancho]

Good approach Alex.

The MHX2420 -108dBm @ 115.2kbps link rate 1 W 50 km
The MHX920A -108dBm @ 172kbps link rate 1 W 100 km

You will need a good antenna gain for uplink in LEO orbit. As per down-link you will need a good ground station.

The ionosphere introduces high disturbance when is day and less disturbance in the night due to the sun activity. The FSL depends on the frequency but better antenna gain your satellite antenna gain could be achieved with a directive beam antenna or just down the link rate for better range.

Thu, good job,
Joshua

[thuvt]

Some updates from Hanoi: a big Japan-Vietnam culture exchange event called "Sakura festival" is being held in Hanoi and fortunately, we managed to get a booth for FSpace to present our nanosat project to the public. The event runs till Sunday and we expect to receive as many as 20,000 visitors, time for some PR

FSpace booth


FSpace team with Ms LienBH - our new CEO


GLXP & team FREDNET posters


Here comes the Dragonfly!



@admin: pls help me to display the photos on the forum, I tried but unsuccessful

[scasey]

Thu,

Not sure about the pictures - but how about recruiting some more people for the team - Team FREDNET? Can you get the photos posted on your web site. Is there a fliker folder with photos?

How did the Asia Times article work out? Perhaps you can post the article too during the meeting?

Cheers,

SC

[AndersFeder]

FSpace booth


FSpace team with Ms LienBH - our new CEO


GLXP & team FREDNET posters


Here comes the Dragonfly!


(For some reason, removing the part after the '?' from the URL's made it work)

[tristancho]

The event runs till Sunday and we expect to receive as many as 20,000 visitors, time for some PR

Thu, congratulations for the Sakura festival participation. This is very important people know what we are doing!
Regards,
Joshua

[thuvt]

Thanks Anders for correcting the pictures' links.

@scasey and Joshua:
We posted these photos on our website as well http://fspace.fsoft.com.vn/index.php?op ... &Itemid=23

I've been also introducing about GLXP with mention to the Asia Times article to some people, mostly curios young ones. To most of them it's the first time they've heard about the competition. Though there's still a long way to go, at least we raised public awareness about our project

[alexc]

Nice website, Thu. Those of you interested can run it through http://translate.google.com/

[tristancho]

he he,
Yeah. Very complet web site.
Joshua

[alexc]

If you go for VHF/UHF, another option is the ultra lightweight linear transponder designed by William Leijenaar PE1RAH. It's a mode V/U linear transponder, very small, 22g, gives 23dBm, 30kHz bandwidth. Here is a demonstration video.

[tristancho]

Interesting. Also useful for Cubesat!
Joshua

[alexc]

It is designed for cubesats