ICE/ISEE-3 to return to an Earth no longer capable of speaking to it | Hacker News Reader

ICE/ISEE-3 to return to an Earth no longer capable of speaking to it

planetary.org

162 pointsrmason65 comments

I think I see the next natural progression in the open-source movement:

1) Open-Source Software

2) Open-Source Hardware

3) Open-Source Spacecraft

So ... if NASA and the other space agencies aren't willing to make use of this spacecraft, would they be willing to cede ownership to a group of hackers dedicated to helping the hardware continue its mission?

I've got quite a bit of ancient hardware in my basement, and while I was a broad-band RF engineer (in the cable industry), I know the theory behind narrow-band transmission. Anyone think we should start a Github project?

UPDATE:

It looks like the highest bit-rate that would be required would be 2048 bps:

"Tracking and telemetry support have been provided by the DSN (Deep Space Network) since January 1984. The ISEE-3/ICE bit rate was nominally 2048 bps during the early part of the mission, and 1024 bps during the Giacobini-Zinner comet encounter. The bit rate then successively dropped to 512 bps (on 9/12/85), 256 bps (on 5/1/87), 128 bps (on 1/24/89) and finally to 64 bps (on 12/27/91)."

This should be pretty easy to achieve with any UART. Now to find the frequencies used during communication.

UPDATE 2:

I'm currently working at the Pennsylvania State University and just sent an e-mail to a friend who's the Flight Operations Team Lead of the SWIFT Mission Operation Center here (http://www.swift.psu.edu/). More information as I hear back from those I've contacted!

> 1) Open-Source Software

> 2) Open-Source Hardware

> 3) Open-Source Spacecraft

Turns out that 3 is really just 1 and 2, plus Open Source mechanical engineering as well: http://psas.pdx.edu/

True ... and in this case, you don't have to worry about getting the spacecraft into space. The mechanical challenges are quite a bit simpler (steering antennas to track the space-craft). Perhaps we should make a high-level list of what needs to be done?

1) Find/track the spacecraft

2) Steer antennae to follow the spacecraft

3) Create transmitter and receiver hardware capable of communicating with the spacecraft's radio equipment (perhaps software radios).

4) Write software capable of handling the transmit and receive protocols.

5) Write software that captures the state of the spacecraft.

6) Write software that can control the spacecraft.

7) Decide where the spacecraft should go (hopefully, if we were to reestablish communications, perhaps NASA would help with the physics).

I think the bulk of the project consists of performing the research required to actually "speak the spacecraft's language". Fortunately, this part of the project is most conducive to crowd-sourcing and collaboration.

The problem is, how do you intend to introduce collaboration in this? It may be worth the shot, but it'd expect there's a big chance you won't be able to achieve that -- the "control space" of valid commands is likely very large and unstructured. You can't risk brute forcing it and seeing what happens because of the low rate and risk of failure from a bad command. There's also the responsibility of issuing a bad command. For such a scientific reverse-engineering you also need proper tools to observer the aircraft behavior which I imagine can be quite difficult -- what if a command sets the rotation rate of the aircraft to +1 arcsec/hr and that causes an antenna misalignment?

Unless, of course, you get full specification from relevant agencies and check with them before issuing any command. But that implies they're willing to apply resources on this project, which is another though barrier.

Anyway, sounds like quite an adventure. My sincere good luck.

Good points ... I don't intend to try this devoid of all NASA input (I've already reached out to a contact I have at SWIFT). I'm assuming two things right now:

1. That the documentation for the commands exists and that it's available to the project.

2. That NASA (or someone with sufficient knowledge) helps avoid issuing dangerous commands (e.g. running the spacecraft into the ISS).

Otherwise, it's probably better to do nothing. As I noted above, I view this more as crowd-sourcing the expensive "reengineering".

5.5) Determine how much fuel it still has. Per Wikipedia, "a [2008] status check revealed that all but one of its 13 experiments were still functioning, and it still has enough propellant for 150 m/s of ΔV. ".

I'm guessing that is not much. (Amazing that it still had any at all)!

I believe this lady may be particularly helpful in this endeavour: http://www.windytan.com/2014/02/mystery-signal-from-helicopt...

That was a great story!

The problem isn't a mater of openness, it is Could new transmitters be built? Yes, but it would be at a price no one is willing to spend. I imagine that it would be feasible to obtain the proper documentation, but there is the matter of building the hardware. More significantly, I suspect that duplicating DSN is a rather monumental task.

The transmitters and receivers that were designed and built in the '70s required lots of discrete components. The up-converters, amplifiers and matching networks will still need to be discrete components, but I'm estimating that the other 80% of the radio equipment can be implemented as a software-defined-radio (SDR - see http://spectrum.ieee.org/geek-life/hands-on/a-40-softwaredef... for an example).

I'll be reaching out to a friend and former colleague who specializes in this type of hardware/software.

I have no expectation that we can replicate even a tiny portion of the DSN, but I'm talking with people that already have big dishes and tracking capabilities. Remember that we don't have to talk to this spacecraft continuously. I think even downloading the last of its collected data would be a win but positioning it to do more science, then collecting data from it again in several months/years would be really cool.

And these are the fellows who could give it a run: http://www.arrl.org/arrlletter?issue=2014-02-06#toc04

Many DB away from what DSN needs, however.

> software-defined-radio

Can you conjure up a software-defined 70-meter parabolic dish?

http://en.wikipedia.org/wiki/Deep_Space_Network#Antennas

https://www.google.com/search?q=virtual+antenna+array

Or, for those who want the production grade stuff:

http://www.vla.nrao.edu/

"The Very Large Array, one of the world's premier astronomical radio observatories, consists of 27 radio antennas in a Y-shaped configuration on the Plains of San Agustin fifty miles west of Socorro, New Mexico. Each antenna is 25 meters (82 feet) in diameter. The data from the antennas is combined electronically to give the resolution of an antenna 36km (22 miles) across, with the sensitivity of a dish 130 meters (422 feet) in diameter. For more information, see our overview of the VLA, and the configuration schedule."

So, yes, with multiple IP-connected software-defined radios, you could provide the required signal strength without a Deep Space Network antenna.

At best, your signal will improve linearly with the number of antennas (N), while the noise will be completely incoherent and scale like sqrt(N). Thus your signal-to-noise ratio will improve like N/sqrt(N)=sqrt(N). You're going to need an awful lot of radios...

See also the Open Source Satellite Initiative (http://opensat.cc/)

There's also a project out there to replace the internet with millions of open source satellites. Can't remember the name of it right now.

As the comments in mention, with authorization from the FCC the HAM community would jump on this, there are lots of folks playing around with software defined radio who can build pretty much an arbitrary transmitter/receiver at any frequency band. Not sure if they would be successful but they would make a heroic effort to get it done.

I was really annoyed to get to the end of this article and not find any information about frequencies, bandwidth, power, or anything else that would enable a practical consideration of the problem. Not only am I annoyed with the journalist (who I presume has a science degree), I'm even more annoyed with NASA for omitting this basic factual information from their statement in favor of pablum that appears to be tailored to small children.

I, too, was annoyed by the omission of any relevant details.

I did a little searching and came up with some nice details about the ISEE-3 communications system here: http://mdkenny.customer.netspace.net.au/ISEE-3.pdf

Thanks for finding that. Apparently the receive antenna has a gain of 0dbi. The use of PCM/FSK for the modulation schemes means you need to achieve a high signal-to-noise ratio on the receiver for the message to be coherent to the spacecraft. I don't know the spectral power density of a PCM/FSK, but this most likely describes everything you'd want to know about the scheme: http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=109174... . The abstract specifically mentions NASA.

I dont see anything really strange about that.

If the issue is that all of the existing gear is wideband and you need to send something narrowband - build a narrowband exciter, use an upconverter to drive the wideband amp.

PCM/FSK-AM/PM doesnt seem to be really a complicated thing. Its a pretty easy way to send data, and should be build-able.

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=109174...

I wish I knew more about what the specific difficulty was.

Yeah, it could be implemented inexpensively in SDR using GNU Radio and a USRP. Of course you'd still need the front end hardware; high gain antenna, LNA, and PA. Not something out of the ordinary for some hams though. It's probably NASA not having the manpower to devote to it.

Apparently the highest gain antenna NASA has is 61.7 dbi at the relevant frequency. If they used 5 watt transmitters, that would be like running 4.5 megawatts into a conventional dipole antenna. The reality is NASA probably used many tens or even hundreds of watts to contact the spacecraft. As an amateur radio operator I assure that is out of reach for most of us.

> Apparently the highest gain antenna NASA has is 61.7 dbi at the relevant frequency.

Don't forget angular resolution. Because of the antenna's geometry, it's misleading to describe its gain without also mentioning that the gain applies to a very small angle -- which, depending on the circumstances, may be a great advantage if it needs to reject interfering sources.

61.7dbi, while it represents a peak rather than a more descriptive statistic, does go a ways toward describing 'angular resolution', or rather, how tight you can make the beam of the transmitter.

It's easiest to think about it thusly: You steal part of the power that would normally go out equally to a sphere ("isotropic radiator") and you redirect that power to a smaller part of the sphere. If you can successfully redirect the entire power into only half of the sphere (1 hemisphere), you get +3db. Keep slicing that in half and you add +3db each time.

61.7dbi gain necessarily means that the power felt at the center of the target is 1545883 times as powerful as it would be if you were using an isotropic radiator, given the same number of input watts. If you have successfully concentrated the power that much, something at the target's range isn't going to detect sidelobes much at all.

This isn't a technical summary - radiation patterns are never absolute step functions and there is indeed a distinction between peak power and usable area... it's just not as relevant as the huge number represented by 61.7dbi, for any remotely gaussian distribution of signal.

Would you even need a 61.7 db gain antenna? It's going to be doing a near earth flyby.

They say they need to use the DSN to do the comms. This is a set of three stations, in the US, in Spain, and in Australia, that has a 70 meter dish each, plus some 34 meter dishes.

Here is a pic of the 70 meter dish:

http://deepspace.jpl.nasa.gov/dsn/images/picture_70_bw_lg.jp...

It's not regular ham equipment in many ways, obviously. Besides power, aperture, and accurate pointing, which have been mentioned here, there is also the need to hand off transmitting/receiving as the Earth rotates. You also need a receiver and transmitter velocity model to adjust for Doppler.

People are not giving the difficulty of this problem adequate respect.

How hard would it be for access to be granted to the DSN? The challenge to build the transmission equipment does not seem insurmountable nor even particularly hard.

It's the logistics and red tape to make it happen.

I'd also like to point out, that this satilite will be doing a near earth flyby - you could probably get away with something smaller, maybe even a 3.5m dish versus a you know, 70m dish.

The engineers at GSFC say you will need the DSN. The smallest DSN antenna is 26m and that is used only for LEO (a couple thousand km).

You talk about "red tape" like moving a huge radio telescope is some kind of formality, and you quoted a figure of 3.5m with no apparent engineering basis. I find this ridiculous.

The red tape isnt moving the dish - its getting someone to agree to let them mount a feedhorn for the proper band, and the needed radio hardware.

Moving the dish to me seems like the least difficult part, as it pales in the complexity to mounting the hardware.

For what its worth both Voyager probes feature S-Band Antennas - I have trouble believing we cant talk to those either on S-Band.

There are lots of other issues involved, but the DSN picked up the carrier signal in 2008, and it's much closer now. The article also mentioned that people can listen to the carrier as it goes by. I don't think dish size is one of the problems.

well, other than 0db gain antenna on the sat. But, ideally, if we can hear it, all we need to do its match the equivalent ERP on this end that the sat is sending (gain of the TX antenna on the sat, plus the minimum gain of the RX antenna required to successfully receive) it should work.

The previously linked pdf puts the up/downlinks around 2.0/2.2GHz; the same band used for the Apollo missions, which figures given the era (http://en.wikipedia.org/wiki/Unified_S-band).

Currently, the entire Deep-Space Network is on ~8.4GHz.

Re-equipping a multinational network for S-band could quite possibly a significant budgetary issue given how little love have been NASA getting in recent years.

I wonder if the russians might have something helpful for this task, or have something already fitted out for S-Band.

What are you on about? All the relevant information is there. What need is there for details? That would be interesting, sure, but it is not in any way necessary when simply reporting on the state of this mission. Something the linked article does.

Not everything needs to always contain all information.

Agreed I've been sitting here trying to figure out what relevancy frequencies, bandwidth and power have to the primary issue which is cost. The article described the problem and why there isn't a solution quite clearly to me.

So to translate: 'Don't you worry about space communications, let me worry about blank.'

The cost is a function of the technical criteria, and we have no idea what the cost is either. It might be quite small, just not within the unallocated budget at NASA. Without specifics, there's no way to gauge the economic question.

It's not uncommon for NASA to include a list of TV satellites and frequencies that stream their video releases in a press release, so why not for research satellites as well?

It's also missing basic information about orbital approach.

Just how far away is it going to be on this 'return'? What would be the dV to an Earth capture?

edit: It will apparently "enter the earth-moon system" in August of 2014.

edit2: After its second or third serendipitous mission, it was deliberately put into an orbit that would put it on a Lunar flyby-capable trajectory with closest approach August 10, 2014.

I seem to have run into a wall - further research requires locating this resource:

http://biblioteca.universia.net/html_bura/ficha/params/title...

Which seems to be paper-copy-only conference proceedings, despite the claim that it's located on NTRS (whose search function seems to be embargoing my IP, but whom friends note says "No Digital Version Available").

Maybe it was one of the things removed when NTRS was mysteriously taken offline in March due to some sort of security concerns?

Can you provide the source for that information?

It might be a little harder than you think. Satellites typically use some kind of encryption on the command channel, since no one wants to find their satellite has been hijacked. Even back in 1978 that was likely the case. So when they say 'decommissioned the transmitters' what they probably mean is 'threw out the data encryption hardware.' If they also threw out the design files (and remember these are the people who shredded the Saturn 5 engineering plans), there's pretty much no chance of talking to ISEE-3. No matter how many enthusiastic and capable hams try. Radio transmitters and antennas are easy. Yes, hams could do that part. But the packet structure and encryption - not easy.

It's not a case of hacking a protocol, or breaking the encryption on a given stream of data. There's no data stream. Unless the encryption is correct in commands sent to it, there'll be no response at all.

There might not be any encryption on the return data channel. Nothing anyone can do with that which harms the mission, so why bother adding more circuitry to the satellite?

Give NASA another brown star.

Based on the article, the more accurate title would be "ICE/ISEE-3 to return to an Earth not interested in spending money to reenable transmitter to it"

I'm not so sure how much it's "reenable" and not "re-engineer". I can certainly understand why it would take many millions of dollars to develop and implement a transmitter no longer in use in 7 months.

One day, I tacked up a quote from the "Max Headroom" TV show. The dialogue it was from went like this:

Blank Reg: "Here, take this." Kid: "What is it?" Blank Reg: "It's a book." Kid: "What is it?" Blank Reg: "It's a non-volatile storage medium. You should have one." Kid: "Shove off!"

I explained this to a coworker, and after laughing he told a story about how, decades ago, a few folks had made a computerized "repository of all human knowledge". Semi-recently, some folks tried to read the data on this massive storage device; technology had advanced and changed so much... they couldn't. However, we can still read "ancient books" like the Gutenberg bible.

Note: The Gutenberg bible was just an example of a really old book; religion was incidental at best.

Reminds me of the Domesday Project http://en.wikipedia.org/wiki/BBC_Domesday_Project

That may have been it, I can't quite remember.

It's pretty amazing we have a deep space array that is capable of finding and listening to a signal that weak and far away.

Couldn't we please just swap the NASA and military budgets for one year? Just one.

>Couldn't we please just swap the NASA and military budgets for one year? Just one.

No, but we could just give DARPA to NASA, since they should both be doing roughly the same thing anyway, and the gov't probably loses some few hundreds of millions of dollars maintaining a superfluous bureaucracy to manage DARPA.

It would also be nice if the next revolutionary rocket technology were to be used primarily to go to other planets and explore space, rather than to kill peasants in Asia, but that is a secondary consideration.

NSF might correspond to DARPA, but not NASA. DARPA's remit is far wider than NASA's is.

For example Solar Designer's work on a password-based key derivation function has a DARPA funding component, but would hardly make sense for NASA.

What would interest me: does the comm protocol of (interstellar) satellites include any form of authentication or was it assumed at build time that only government-level entities would ever be able to build transmission equipment powerful enough to reach the probes?

They probably have some sort of crypto on the communication, you could could probably break it on your iPhone :) 1978 was a long time ago and security wasn't nearly as well developed as it is now.

Even if the security protocol was "append this number to the messages you send me", it wouldn't be very easy to break since you don't have a successful transcript, any information about the implementation, or the ability to cheaply try keys.

Call up Travis Goodspeed and tell him "Open Season" on ICE/ISEE-3.

I'd bet on successful bi-directional communications within 18 months.

If they had planned for it to still be functioning at this point, they would have maintained the capability to communicate with it.

This is the key point. It completed its mission. Someone forgot to turn it off. Nobody ever expected to do anything more with it.

Opportunity had a planned 90-sol mission duration but continues to be useful. Maybe there isn't any useful task this bird could be used for, but I'd be surprised if the wider scientific community can't think up anything.

This thing was built in the 1970's. It has no locomotive power. It aint no Mars rover.

The NRAO has telescopes that have been used to communicate with spacecraft. But the are out of money, too.

http://NRAO.edu

I am interested in anyone with serious attempts at communicating with this space craft. I think NASA decided they have no interest because they need to focus the deep space network antenna at the craft during data collection due to no local memory on the space craft.

The answer is to launch a cubesat translater to shadow the space craft. However the cubesat translater is only of use if the space craft is headed somewhere interesting. That involves a time window of only a few months. Also the cubesat is only practical if the ISEE-3 still has functioning instruments which are being broadcast.

The combination of interesting places being far enough away from earth that only very large antennas can transmit and the logistics of launching a cubesat mission that can escape earth's orbit which has never been done are why I think nasa is bowing out.

I would be interested in the cubesat mission if the legal aspects of the initial communication and trajectory change are ironed out. If there is a serious attempt within the law I am willing to donate my time as an electrical engineer.

darrin.taylor@gmail.com

PS I think the only way there can be a legal effort is if NASA and FCC bless it.

I'm mad at politicians and people in power : it seems they always find billions to fund foreign wars or stock market shenanigans but when it comes to great scientific projects that can help understand our universe better, there's not a cent.

what is the value in communicating with it? it sounds as if it has very little propellant left. is there any meaningful science that it can do that we otherwise could not?

from http://www.thespacereview.com/article/1697/1

Recycling an existing spacecraft that has already completed its original mission makes good sense for a number of reasons. The spacecraft has already been designed, built, and launched in the course of its original mission. These are typically the most expensive parts of any mission. For the price of a little on-board propellant needed to nudge a craft on a new trajectory and a modest amount of additional funding for mission operations and science, an existing spacecraft can sometimes be sent to another target of interest. ... On September 18, 2008, ICE, which had finally begun drifting closer to the Earth, was located and successfully reactivated. It was found that all but one of its 13 instruments were still functioning and enough propellant remained on board for a velocity change of 150 meters per second (320 miles per hour). There appeared to be enough life left in the old probe to perform more useful science. ICE should return to the Earth-Moon system again around August 10, 2014—over three decades after it left. NASA scientists, including a team lead by Robert Farquhar, are considering several options for the future of ICE, including redirecting it towards additional comet encounters in 2017 or 2018. Still other missions are possible for this robust, reused spacecraft before it once again drifts back into interplanetary space and subsequently returns to the vicinity of the Earth sometime in the 2040s.

This seems like a good place for a kickstarter?

indiegogo :P

If only they'd reached out to the ham radio community two years ago. There has to be some retiree out there someplace who could provide enough info to get volunteers started. But you can't begin to pull something together like this on the current timeline.

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