Ambasat-1  -  Launch a sprite class satellite for a few hundred bucks. - Page 1
Forum section: electronics / general

author: mrpackethead
author_rank: Super Contributor
timestamp: May 11, 2019, 11:04:07 pm
content: This one really excited me! They seem to check out and it seems fesible. :-) I backed it! The idea of being able to put something in space.. wow.https://www.kickstarter.com/projects/ambasat/ambasat-1-an-educational-space-satellite-kit/Disclaimer. I'm just an excited backer for this project!

author: mrpackethead
author_rank: Super Contributor
timestamp: May 11, 2019, 11:29:59 pm
content: Quote from: blueskull on May 11, 2019, 11:09:31 pmYes, of course. Its good for about 3 to 3 1/2 months. But on the flip side of that, its only USD$300. There are some compromises that you have to accept!

author: mariush
author_rank: Super Contributor
timestamp: May 12, 2019, 01:00:41 am
content: I'm not seeing the point of it... you get a 4Mhz micro that's solar powered and a super limited selection of sensors you may use... no originality.What's the point if 100 tiny sats all do same shit, read temperature for example.

author: mrpackethead
author_rank: Super Contributor
timestamp: May 12, 2019, 03:05:00 am
content: For me the point is "Just because i can, and its way cool ".

author: Cyberdragon
author_rank: Super Contributor
timestamp: May 13, 2019, 11:03:27 am
content: Quote from: mrpackethead on May 12, 2019, 03:05:00 amNo, it's not. Useless junk is space pollution and crap like this if it gets too dense can endanger real satellites. We have enough crap in space already, no need for thousands of temp sensors adding to the litter, even if they burn up eventually.

author: mariush
author_rank: Super Contributor
timestamp: May 13, 2019, 01:11:05 pm
content: They're released at 250km and fall down into atmosphere in max 3 and a half months.So you're paying 300$+ (because you also have to ship back to them the circuit board) just to have the board send a few characters back to you for 3 months, if you're lucky.

author: PlainName
author_rank: Super Contributor
timestamp: May 13, 2019, 06:30:36 pm
content: QuoteThere are a lot of things that some couldn't see the point of before they became ubiquitous - the internet, GPS, digital cameras, mobile phones, etc. I would think that in this case there could well be a few kids that grow up to become space engineers, just as those who built electronic organ kits grew up to become electronics engineers. It's not so much what you can do with this now, it's what it's promoting for the future.QuoteThey won't all do the same shit (you can add your own sensors if you want), and they'd be doing it in different ways anyway. Plus, if you buy in then it's YOUR shit that it's doing. YOUR code which is (hopefully!) doing this thing that not so long ago only government agencies with funding in the billions could envision doing.

author: ogden
author_rank: Super Contributor
timestamp: May 13, 2019, 08:30:05 pm
content: They claim that you may track your sprite satellite using worldwide Things Network. Fine.Now "fun fact", ordering info for one of the LoRa gateways:LG01-P-XXX-YYYXXX: Frequency Band433: For Bands: EU433, CN470868: For Bands: EU868,IN865915: For Bands: US915,AU915,AS923,KR920They also claim successful 700km+ range tests for that little PCB with whip and +14dBm Tx power. Would be great to see evidence of that.

author: hendorog
author_rank: Super Contributor
timestamp: May 13, 2019, 09:07:55 pm
content: Quote from: Cyberdragon on May 13, 2019, 11:03:27 amYes it is.Just doing something like this inspires, and often opens doors to more purposeful opportunities. Any sensible launch company will be doing their homework to ensure the risk of harm is mitigated.Life is full of stupid things that should be outlawed due to some small potential for harm. Thankfully there are still some fun things left.

author: mrpackethead
author_rank: Super Contributor
timestamp: May 13, 2019, 09:11:07 pm
content: Lorawan has a link budget of 151db. The world record is 702km ( well verified )https://www.thethingsnetwork.org/article/ground-breaking-world-record-lorawan-packet-received-at-702-km-436-miles-distanceThese devices will be operating at 250km. It is challenging, but acheiveable.

author: mairo
author_rank: Unknown
timestamp: May 13, 2019, 09:40:07 pm
content: So it will be just bareboards floating in 'space'? Wouldn't they need any thermal / radiation protection of the system? When I look at theirs components list that they are suggesting, I am wondering if they can withstand the operating temperatures at that altitude, launch vibrations, possible radiation ...I am not a space electronics expert, but thought you would need abit more specialised components, or at least versions of them that are manufactured to handle the harsh conditions. ATMEGA328P-AU, LSM9DS1, BME680, etc seems all to be only rated at -40 to 85'C.. I am also interested in the crystal specs, which are not shown, I would guess it would need to be a special crystal that can withstand the launch?Another thing that worries me is the fact that they are selling a DIY kit to assemble it yourself? If you are experienced in soldering you can do it, but what about a kid, which I am sure is a market (schools, STEM ...) that they are trying to catch, is trying to assemble it .. one bad joint and the system may fail during launch ... I cannot see flux, or solder wick in the package, why do I need that desoldering pump?

author: ogden
author_rank: Super Contributor
timestamp: May 13, 2019, 10:23:45 pm
content: Quote from: mrpackethead on May 13, 2019, 09:11:07 pmThank you, did not know about this excellent LoRa demonstration.My point is that particular world record was not made using "this wonderful piece of kit" as they (literally) say. I can't find any info/photographs of the world record event to check antenna, but I would use quality 6dB vertical dipole antenna. I bet this is what they most likely did. 915MHz free space loss @700km is 148.6 dB which is very close to 151dB budget, it means good antennas needed for sure, at both ends. Ambasat-1 small PCB with that thin wire whip gain is far from 6dB, in space they most likely will not be positioned properly against receive antenna. Each loss of 6dB means 1/2 distance loss. Ambasat creators shall launch their test weather balloon with string of randomly oriented satellites and only then make distance and`/or any other "spaceworthy" claims.

author: ogden
author_rank: Super Contributor
timestamp: May 13, 2019, 10:37:45 pm
content: Quote from: mairo on May 13, 2019, 09:40:07 pmApparently not. One good example ishttp://www.50dollarsat.info/.It was launched 21/11/13 and went silent 19/07/15.

author: hendorog
author_rank: Super Contributor
timestamp: May 13, 2019, 10:45:29 pm
content: Quote from: ogden on May 13, 2019, 10:23:45 pmIt's a good point too. The space antenna will need to be close to isotropic - i.e. no usable gain.However the terrestrial antenna could have gain which will compensate. You know where the satellites need to be to be within a few hundred km's, so point the gain there. (i.e. well above the horizon)The problem may be their use of an existing LoraWan network. Do these existing stations have antennas with a null above them? That is obviously where you need some gain if you want to talk to a satellite.

author: polyfractal
author_rank: Newbie
timestamp: June 17, 2019, 10:18:34 pm
content: Long time lurker, first time poster. Felt compelled to mention this: their launch provider is Interorbital Systems. Interorbital is, if not an outright scam, close enough to be indistinguishable.The company is 20+ years old and has yet to do more than launch sounding rockets and do simple motor tests. They've been selling cubesat and "tubesat" packages to people for years but their NEPTUNE rocket is still just vaporware. They have done some testing of the components of the NEPTUNE, but still aren't ready to do a full-scale rocket (e.g. NEPTUNE is made of many smaller rockets, and they've only launched individual portions of the total NEPTUNE. The full design still remains entirely theoretical).Comparing their launch price (~$10k per 1U cubesat) to other low-priced competitors (~$70-200k) should also be a strong indicator that there's something not quite right. Perhaps the company isn't a scam, merely very very slow... but that doesn't bode well for this Kickstarter either way.So either this Kickstarter is a scam itself (sell cheap PCBs to people, collect launch fees and vanish into the night), or they've been taken by Interorbital Systems as well and everyone is going to have a bad day. In either case, there's no way IS is launching anything in the next year, or probably even next five years.