Spaceships of the future: ChipSats?

[Frida Space]

So, NASA is spending $500 mln in developing a mission concept to Jupiter's moon Europa involving a CubeSat and a swarm of tiny chips called ChipSats. These chips could just detach from the mothership and land wherever they wanted, allowing scientist to react to real-time events happening down on Europa's mysterious surface. Aside from that, it would have obvious financial benefits.

What do you think of this concept? Certainly interesting, huh?

PS: Excuse for my bad English

Links:

www.astrobio.net/news-exclusive/swarm-tiny-spacecraft-explore-europas-surface-rapid-response/

www.pollucenotizie.com/2014/10/7.html [italian]

[Streetwind]

The nice thing about the rocket equation is that it works at all scales of size

So basically, if they can miniaturize the science instruments enough, they can just keep downsizing their mission "vehicles" without dV becoming a problem. The main challenge at Jupiter is getting power, and surviving the extreme radiation environment.

[megatiger78]

just ass long as there in boes so they look nice for the shool pictures and education programs..... -nasa mission approval

[xenomorph555]

I personally don't see chipsats being the super future of space exploration, just too small to do much, plus problems with other things like radiation and heat/freeze damage. While it may work in the future, I think nasa are going to encounter loads of problems for the time being, the project will be plagued with delays and become over budget and then get cancelled.

[-Velocity-]

The rocket equation doesn't scale with any dimension, but the power required to transmit data remains the same, at least, using traditional methods of communications. So you can only make a spacecraft so small before you run into the problem that the majority of your spacecraft's mass is communications gear- energy storage and antennas.

So you can't have a bunch of tiny little spacecraft flying around the solar system by themselves because and they can't transmit very much data or they can't transmit with very much power because they can't store much energy. They'll need to stay within transmitter range of the "mothership", and that range won't be very big because their transmitters are so weak.

Perhaps the problem could be somewhat mitigated if we made cute, tiny little RTGs. However, your antenna still needs to be a certain size...

So yea, I also don't see these as being the future of space exploration. They may be useful in some settings, but we'll still need big spacecraft.

Besides the difficulty in scaling communications gear, not every sensor can be minimized; for example if you shrink the size of a lens, you reduce the resolution of the imaging system.

[Nuke]

idk you get a ccd, a mems gyro/accelerometer, magnetometer, a transceiver and of course a microcontroller to run the show. you could probibly arrange all those chips on top of a quarter and still have some space over for some tiny solar cells. you could also cram all that stuff into a single radhard package.

only thing you really need is micro thrusters. we could probibly do chemical engines on a chip, tiny gas turbines have already been demoed. we know how ion engines can scale up, i wonder how much they scale down. perhaps you can use tiny piezo nozzles (like whats used in inkjet cartridges) to squirt hydrazine into a tiny combustion chamber, react with a tiny bit of catalyst and fire thrust out a tiny little nozzel. this sounds like the best bet. feep on a chip can come later.

so i do some electronics and have a few dev boards all over the place. one is an imu board, which is about a square inch of area and is less than 3 grams, it has 4 chips (not counting the regulator and logic level converter) and support components. it doesnt have an mcu, camera, or transciever on it, but ive seen those in miniscule packages that could fit if you used both sides of the board (and would likely add a quarter gram to the board at most). obviously this board is not designed for space, its pcb is pretty thick and it has a bunch of headers on it for breadboard mounting. a self contained spacecraft on a chip would not need those, so im going to assume this extra weight will actually represent the weight of our engines.

so we got a 3 gram space ship. say we have 4 quarter-millinewton hydrazine thrusters for a total of 1mn thrust. then you can make a little tiny hydrazine tank about the size of a typical capacitor, say with 2 cubic centimeters of volume. hydrazine has a density of 1.021 g/cm^3, so this tank has 2g of fuel. so our ship weights 5 grams fully loaded. hydrazine engine usually have an isp in the neighborhood of 250s. throw this into the rocket equation and i get 1252 m/s of delta-v. thats probibly enough for checking out the area around a space craft or small asteroid. but dont expect to make escape velocity. you could use a bigger tank, 20 grams of fuel gets you 5km/s of deltav. you can make it bigger but eventually you loose the benefits of a micro ship and are better off getting a full size probe.

Edited October 9, 2014 by Nuke

[-Velocity-]

...

And again, how do you send a message all the way back to Earth? The signal must be strong enough to be received. You can't build a small high gain antenna because the size of such antennas are determined by wavelength- and that's something that's fixed. That makes your required transmit power even higher, because now you're transmitting more isotropicly.

Maybe it would be better to go with some kind of laser communications system to receive data from the spacecraft- and now you need a LARGE optical or UV or IR telescope to be able to receive the very low power laser signal. Oh and you'd still need to send it commands via radio, because you can't put a large telescope on the spacecraft.

[Nuke]

you aren't. what you can do is talk to your mother ship and use that as a relay to the deep space network. i dont think these will be able to operate independently of another spacecraft. they wont have the deltav to go very far either. they would be useful for spacecraft/space station inspection, and possibly be useful for asteroid mining, they can form a positioning and communications network for asteroid operations. so its kind of has its niche, but were probibly not yet at a point to make it a useful one.

[Tery215]

If it's just the chips, then I bet they would get really hurt by pretty much anything that happens in space.

[Rakaydos]

Perhaps the problem could be somewhat mitigated if we made cute, tiny little RTGs. However, your antenna still needs to be a certain size...

http://www.betabatt.com/

It's totally happening.

[Tommygun]

Can you get away with smaller probe antennas and broadcast power by having large dish arrays back on Earth to receive their weaker signals?

Edited October 9, 2014 by Tommygun

[Nuke]

http://www.betabatt.com/

It's totally happening.

betavoltaics are kind of weak (microwatts). might have a use for standby power. perhaps charge up a cap enough to fire a thruster and get the tiny solar cells pointing at the sun. they are nice because the idea is to have them in chip sized packages that can just be soldered to the board.

Can you get away with smaller probe antennas and broadcast power by having large dish arrays back on Earth to receive their weaker signals?

if you have a swarm you might be able to set up an array to boost the range of the transmission. the swarm needs to be in radio range of its individual nodes to do this, since it needs to coordinate the transmission (sync up clocks, exchange data, account for relative position of each node, etc). it would likely be a tight burst with low throughput because of power limits.

you might also have an assortment of different chip ships. some could pack extra xmit power, others could have mission specific sensors, some might boast additional processing power. live for the swarm.

Edited October 9, 2014 by Nuke

[Kryten]

Can you get away with smaller probe antennas and broadcast power by having large dish arrays back on Earth to receive their weaker signals?

DSN already uses 70m antennae-and they already cost $4000 an hour to operate. You're going to hit a point where expanded capability costs more than you could possibly save pretty quickly.