A $1000 Tiny Personal Satellite

If you ever read any old magazines, you might be surprised at how inexpensive things used to be. A U.S. postage stamp was six cents, a gallon of gas was $0.34, and the same amount of milk was $1.07. Everything is relative, though. The average household income back then was under $8,000 a year (compared to over $53,000 a year in 2014). So as a percentage of income, that milk actually cost about seven bucks.

The same is true of getting into orbit. Typical costs today just to get something into orbit has gone from–no pun intended–astronomical, to pretty reasonable. Lifting a pound of mass on the Space Shuttle cost about $10,000. On an Atlas V, it costs about $6,000. A Falcon Heavy (when it launches) will drop the cost to around $1,000 or so. Of course, that’s just the launch costs. You still have to pay for whatever you want to put up there. Developing a satellite can be expensive. Very expensive.

Satellites are expensive because they have to operate in a very harsh environment. Then there’s the “integration costs” of putting your payload on a launch vehicle, which can run up to $35,000 per pound).

[Jekan Thanga] at Arizona State University wants to reduce the cost of doing space projects. He claims his SunCube can go to the International Space Station for just $1,000. If you want to do something in low Earth orbit, that could run $3,000. Granted, this still isn’t dirt cheap, but how many of us have spent at least that on building a 3D printer or a high-end gaming rig?

If you add in hackerspaces and other groups of builders, the possibilities are even greater. Ham radio operators have done this for years, banding together to build and launch satellites. Keep in mind, though, that at that price, the satellite is tiny: only 35-100 grams, and just over an inch on each side. When the Falcon Heavy launches, the price of getting these in orbit could drop in half.

The SunCube is technically a femtosat. If you want to look at something a little bigger, we covered cubesat design last year.

52 thoughts on “A $1000 Tiny Personal Satellite

  1. Actually, it was really expensive and hard, then cheap and relatively easy, then in between.

    Originally it was one satellite per rocket, really expensive. OSCAR 1 was built in a garage, the cost had to be minimal, and hitchhiked into space in December 1961. It was the first non-government and I think non-commercial satellite to go up, and it proved that a rocket could be used to launch multiple satellites.

    But that success made it harder. Since it could be done, the “useless space” became more viable, and since cheap satellites could be built, there were more to go up, making the “empty space” in the rocket more valuable and thus expensive. It’s no free ride now. And since there are other satellites going up, certain standards have to be met, for fear that they might impact on the other satellites.

    A lot of amateur radio satellites have gone up, but there re some fancy ones waiting for a ride, or money to pay for the launch. And that goes back some time.

    Michael

          1. “Rational people wouldn’t spend 60% of their tax base on military.”

            Who spends 60% of their tax base on defense? The US spends only 20% of it’s annual budget on the military…

          2. Like Ken said, the US certainly doesn’t spend 60% of its tax base on the military. You’re one of the millions that saw a facebook post and neglected to do your research verify, and as a result didn’t discover the difference between mandatory and discretionary spending. The US spends 57% of discretionary spending on the military, of which discretionary spending is itself 34% of the total pie, meaning we spend roughly 20% on the military.

            All these points aside, a rational person absolutely would spend 20%, even more, on the military.

      1. I think some of the ham satellites have deployed antennas, and maybe solar panels, so it’s a matter of scale. But I seem to recall reading of restrictions. Certainly I can see limits placed on what they’ll put in orbit for fear other satellites on the launch won’t be affected. So likely no Rube Goldberg schemes of shot gun shells to blast a panel away to deploy the sail.

        I thought some of the standardization was to allow more into space without worrying that the novice will cause problems. So buy the casing and so long as it all fits, you’re in, kind of like using a CSA ac adapter. You then don’t have to get approval.

        Michael

  2. So, let’s remember that satellites are **lonely pieces of stuff, floating in space with no one to listen unless they transmit**. Then it becomes obvious is necessary to include transmission capabilities into the satellite.

    Aside from power and thermal management, getting any antenna into that size will be hard.

    A quick calculation: The ISS orbits in a height of ca 340km above earth. So the minimum distance your signal will travel is that 340km.

    Free space path loss A (like Attenuation) (simply: Energy spreads over space due to basic geometry; see the intercept theorem) is

    A = (4 * pi * distance * frequency / speed_of_light)²

    filling in the distance and speed of light:

    A = 0.0002 * frequency²

    Or, butting it in terms of decibels, for those more used to them

    A[dB] = -37dB + 2*(frequency[dB])

    Now, filling in a few interesting frequencies

    100MHz: A[dB] = -37dB + 2*80dB = 123dB

    2.4GHz: A[dB] = -37dB + 2*93.8dB = 150.6dB

    10GHz: A[dB] = -37dB + 2*100dB = 163dB

    Which means that even for relatively low frequencies, free space path loss alone is above 120dB. If you want 1mW (=-30dBW=1dBm) to reach your receiver antenna on earth, you will need to send more than 90dBW. That’s 1GW. That’s one hell of a nuclear power plant up there.

    So without antenna gain, this will be complicated. Let’s assume we have much more sensitive receivers, that work at -90dBm. So you must only transmit 30dBm = 1W. That’s still very much for a device that small, but assuming it gets full sun, and has a very efficient power amplifier, sounds actually doable. Remember, that’s the number for 100MHz (or a bit lower). Problem is: at 100MHz, your half-wavelength dipole is 1.5m; nope, not within reach of that size. So we’re definitely working with a short dipole, which has a negligible gain of 1.5dBi on the transmitter side. Increasing frequency will increase antenna gain (in best case, almost linearly), but will quadratically increase path loss, so we’re not going to do that. Problem is that a short antenna is not an efficient one: your transmitter has to be more powerful than with a well-sized antenna, and it will produce additional waste heat, which will be an additional problem!

    On earth, going for such low frequencies is disastrous, because they are really, really crowded with high power interferers (at 100MHz, you’d be competing with local FM stations with kWs of power, and bare kilometers of distance, and even in the 144MHz band you’re not alone), so having a high gain antenna to aim at your satellite is obligatory. I don’t know about you, but my girlfriend has little to no understanding for me mounting an 8m length yagi out of my window, or me operating a 2.5m satellite dish from our door. So it’s not “just ${cost of hardware design + cost of hardware + cost of testing + cost of launch} for the satellite”; you’ll have to take ground station costs into account, too.

    TV satellites and the like actually use the higher frequencies, and live with the necessities of both having large satellite dishes and powerful, large, high-risk-of-getting-hit-by-space-particles sun sails, just because they need more than half a Gigahertz of bandwidth to transmit their programming. So that’s the other end of the design range.

    Femtosats like these will thus have little bandwidth, bad SNR, and hence, very low data rates. There’s not going to be “cheap fast internet from the clouds” via femto LEOs.

    1. So, we need some way of fitting big antennas into a small space. The antennas don’t need a particular thickness, do they? Maybe some sort of foil, or some clever mechanism with metal rods. This is where the genius comes in! Fortunately sophisticated electronics don’t take up much space any more.

      Sounds like an origami problem, maybe the Japanese have an advantage.

    2. Did none of you not have an 80’s -90’s car with an telescoping radio antenna? a similar mechanism would easily solve the antenna size problem. It would have some weight to it, but could be dealt with using lighter materials.

    3. 1 mW at the receiver? What kind of uselessly insensitive receiver do you have? :]

      Received power only goes down with frequency squared if both TX and RX antennas are dipoles. More likely you have some fixed area dish for reception, in which case the received power is independent of frequency (because gain of a dish is \propto frequency^2). So your damping is basically the ratio between the solid angle painted by the transmitting antenna to the solid angle taken up by your receiving antenna. For 340 km and a 1m dish this is 123 dB. The 916FSK (first receiver I found in a search) has a sensitivity of -112 dBm at 2.4 kbps. So 1 W gets you 30-123+112 = 19 dB above that (or around 190 kbps, give or take)

    4. I am not an expert in this, but from some googling, it appears a shockingly small transmitter can provide useful telemetry. The amateur radio satellites seem to use transmitters in the 100mw range!

      Full size satellites often have signifigant ability to transform in space – fold open solar panels, unravel antenna, etc.

      Small cubesats have off the shelf components available. Some of these components are antennas that fold open.

      1. Exactly and those small sats can be received with handheld radios and “rubber duck” antennas.

        I received Fox-1A (500mW 10cm cubesat) with a 10cm rubber duck. If I can do that you can receive 10mW with a decent tracked directional antenna.

    5. I am 99 44/100% positive your calculations are wrong, because small amateur radio satellites manage to receive signals from modest earth-borne stations and send signals to those same small earth stations using well, wel under a single watt of RF power.

  3. Emerging wireless technologies can greatly improve the link budget at low data rates. Perhaps the most promising is Semtech’s UHF LoRa™ ( = “Long Range”) => http://www.instructables.com/id/Introducing-LoRa-/.
    Terrestrial trials show range boosts near an order of magnitude over classical techniques, while HAB (High Altitude Balloon) trials with a 10 mW (milli Watt) transmitter at 433 MHz gave reiiable signals out to 600+ km, with LoS (Line of Sight) reception only limited by the earth’s curvature.

      1. Most of these smaller sats are usually going to or near the ISS and encounter significant aero drag. I think most micro sats last a few months before falling back into the atmosphere.

        1. I want to know given their small size and mass what the possibility of them surviving reentry would be. If they had some type of mini “drouge” could the upper atmosphere slow it enough not to burn up?

          1. As I understand it, no. The problem is, the speed it comes in at. It’s well above Mach 1, which means air can’t get out of the way fast enough. It bunches up, compresses, which creates a shitload of heat. To avoid that you’d have to get below a certain speed before you encountered much atmosphere, which is impossible, far as I know. Well, unless you had a very big retro-rocket.

            Word is “drogue” btw.

        2. And being small, and home made, they won’t have rockets to keep them in place.

          They can’t have much space for solar cells, so life will be limited by battery life too. Early amateur radio satellites had days or week of life, it came as a pleasant surprise when Oscar 6 went up and it had month of operation.

          A lot of these tiny satellites are for the sake of doing it, or specific experiment. So life span wouldn’t matter th much, compared to a communication satellite.

          Michael

  4. Before everyone starts the antenna design you need to survive the ride up so lets strap that thing to a vibration table and see what it’s made of. Now for the antenna. The Hubble antenna is made of molybdenum wire, gold plated and woven by a panty hose company. It’s folded like an umbrella, 5 meter Ka-band.

  5. “If you ever read any old magazines, you might be surprised at how inexpensive things used to be. A U.S. postage stamp was six cents, a gallon of gas was $0.34, and the same amount of milk was $1.07. Everything is relative, though. The average household income back then was under $8,000 a year…”

    Care to share WHEN you are comparing current prices to?

  6. Hams should start launching APRS digipeater satellites & high altitude balloons that operate in the 23cm ham band for the uplink frequency. The satellite / ballon downlink frequency would remain on 145.825MHz. This would allow really compact / portable directional and hemispherical antennas to be used for transmitting up to APRS satellite and balloon digipeaters. Imagine being able to walk around while transmitting APRS beacons up to a satellite or ballon and not lugging around a cumbersome antenna.

    http://forums.qrz.com/index.php?threads/23cm-33cm-geosynchronous-aprs-digipeater-satellite-idea.536671/

    KH2SR

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