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All Systems Go for NASA's Mission to Jupiter Moon Europa (nasa.gov)
249 points by Thorondor on June 18, 2015 | hide | past | favorite | 102 comments

The most interesting bit to me was learning why the mission involves orbiting Jupiter rather than orbiting Europa directly. Though the text doesn't make it clear, the video explains (starting at 0:59) that directly orbiting Europa would mean too much time spent in the most intense parts of Jupiter's radiation belts. Making 45 Europa fly-bys apparently avoids radiation-related issues and allows for making observations over an extended period of time to detect changes.

EDIT: The Wikipedia article on Jupiter's Magnetosphere [1] has great details on the impact of Jupiter's radiation on previous missions. For example, Pioneer 11 lost most of its images of Io, and Galileo had total data loss on three of its orbits.

[1] https://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter#Explo...

Does anyone know how this radiation affects the chance of life on the moon?

Not an expert, but in this specific case I suspect the radiation has no impact, because any life on Europa is most likely to exist tens of miles beneath the ice surface in the hypothesized warm oceans beneath.

The way I heard it described is that the ice is basically an atmosphere except it is solid instead of gaseous. It apparently provides similar benefits to our atmosphere like stabilizing temperature and shielding from radiation.


Does the "solid atmosphere" provide any unique benefits for Europa?

Do we have any information on the magnetosphere of Europa? I wonder how much protection it's providing, if any?

For comparison, Venus and Mars have magnetospheres that are smaller than their atmospheres, allowing the solar wind to blow away lighter molecules, such as water. Earth, by contrast, has a magnetosphere that's much larger, and provides significant protection.

phyugin, your comment is marked [dead] for some reason.

Real magnetospheres are created by an active core, which Venus, Mars and Europa don't have. Venus and Europa have induced magnetospheres, which are basically just the result of their ionospheres (the ionized upper atmosphere) interacting with the magnetism surrounding them (from the sun and jupiter respectively).

Mars is actually an interesting case because it used to have an active core (and hence a true magnetosphere) a long time ago but it has since died out. The latent magnetism still remaining in its iron rich crust is what protects it from the solar wind now and if you look at a 3d map from orbiting magnetometers it's all lumpy and not symmetrical in the least.

But yeah, anything below the ice in europa would be fine. Ice is an electric and thermal insulator so it doesn't even need an atmosphere to protect from dangerous radiation.

Under kilometers of ice? A non-issue.

Yep. I loved the sprinkler analogy. It's a nice solution (lots of sightseeing opportunities on an orbit that wide) and one that could only be made by very patient people.

I find it surprising we still have such a hard time shielding electronics from radiation in space. The issues the Mars rover teams have had to deal with (even with redundant systems) have been pretty crazy.

Jupiter's radiation belts are extremely strong. If you were on a spaceship orbiting around, say, Io, for example, you'd experience radiation sickness in a matter of minutes. And you'd die from radiation exposure within around a day, maybe two. That radiation environment is also very difficult for computers to cope with because it means that there is a constant rain of penetrating high-energy particles which can potentially interfere with electronic components.

Imagine a clock-work computer with exposed parts attempting to operate in an unrelenting rain of sand and gravel. That's the sort of environment that computing equipment has to deal with around Jupiter, in some ways it's surprising that they work at all.

There's a LOT of radiation in those belts around Jupiter - "Europa receives about 5.40 Sv of radiation per day.[19] (5.0 Sv is already considered lethal acute dose) from Jupiter's large radiation belts (10 times stronger than Earth's Van Allen radiation belts), and is a severe health threat to colonists without adequate radiation shielding. The satellite has only a very weak magnetosphere, which leaves it exposed to radiation by Jupiter and also the solar wind."

From Wikipedia https://en.wikipedia.org/wiki/Terraforming_of_Europa#Magneti...

Shielding electronics 'in space' is mostly solved. It does give headaches and increase costs. But orbiting Jupiter is another game entirely.

This is great news. I can't wait for this mission.

> If proven to exist, this global ocean could hold more than twice as much water as Earth.

I really wish we were past the "is there water there" stage and onto the "Lets drop a submarine and see what's down there" stage. I imagine getting through 15 miles of ice might be a wee challenging.

I know there is a very good reason for this, but it seems like we're sending a lot of satellites to these moons and planets to perform VERY similar missions. Orbit around, take photos and readings.

Why are we creating a new spacecraft every time this happens? Why are they not "mass producing" the same generic exploration sat, with a generally useful set of features, then slightly modifying it for any specifics?

Launch in 2020's? snooze. Just launch the same sat from the last mission and start getting data now.

Boy, where to start. First of all the conditions around various planets and bodies are very different. Jupiter for example is oozing with ugly radiation so we can't just put a "stock" probe into orbit around Europa, it would fry.

Second, these missions aren't actually that frequent. It takes months or years for a spacecraft to arrive at its destination, and its design had to be finalized and tested rigorously years before its launch. That means by the time we even get a close up picture of Ceres, for example, the science of spacecraft building will have advanced by several years and we now can include new sensors and improve fuel efficiency and so on.

Third, what do you think science is? Taking photos and readings. That is a huge, huge part of basic science, especially when it comes to astrophysics, astrogeology, astrochemistry, and so on. Landing on a planet provides further opportunities to take photos and readings, but it's phenomenally difficult to do.

Finally, if you are bored by cutting-edge space travel and the study of distant worlds that may hold the possibility of life... I don't even know. I'm mystified by your perspective on the universe we live in.

To amplify your comment, here's a web page with documents from the science definition team -- the panel that decides what exactly the mission will study:


A key document is the very granular "Science Traceability Matrix" which is very focused on "can instruments be made to satisfy these science goals" (zoom in to notice a lot of requirements flow-down from science goals):


And regarding Europa, one particular item of concern has been, can markers of life be detected in a plume as sampled by an orbiter. Here's a recent workshop on the subject:


It's a colossal understatement to say that a standard design plus tailoring isn't really going to lift the burden of figuring out if detecting life in the plume is possible.

But that said, there are re-usable components. Some of the spectral radiometers ("take photos") are largely re-used, also communications devices, etc.

Apart from being extremely interesting from space perspective, this matrix seems like a great instrument to help manage a project of this complexity and uncertainty. I wonder what other things software industry can learn from NASA about this stuff.

> I wonder what other things software industry can learn from NASA

they take their software seriously. This is just one shallow article describing their process: https://rhodecode.com/blog/code-review-learn-nasa-codes/

But i recall reading that they do simulation testing of their rocket firing software - by exhaustively running through all possible input ranges from all their sensors, and add in invalid ranges to boot, and their software _musts_ pass it. Takes days to run i heard.

Well, NASA did run a software engineering laboratory for 25 years https://www.cs.umd.edu/~basili/publications/proceedings/P94....

But what's stopping us from making exact copies of this probe/sat (say... 10) and launching them all at once?

Or at an interval of say 6 months a piece? That way we will have low cost since the r&d will be basically 0 for all the extra models and we get 10x the data and larger time span of coverage. Plus we won't be putting all our eggs in the same basket.

The day (or month, or year) you want to send a probe to Pluto and the day you want to send one to Mercury, not to mention the direction, are going to be totally different, and aren't easy to schedule — you might have a 3-day window to be sure something can get to Saturn, since you're relying on a gravity assist from Mars and a configuration of the planets that only happens every couple decades. Also, even if such a thing could be organized, there's simply no way the budget will support 10 missions launching at once. They have to be tracked, developed, and funded separately for a lot of really good reasons. Stuff that's shared (launch vehicles, software) can be co-developed but each mission has wildly different timelines and requirements.

Because of budget.

The closest thing to what you are describing that NASA has done recently was sending 2 rovers to Mars at the same time (Spirit and Opportunity). It cost nearly $1B dollars in 2003 money to do it [1].

Nasa's entire budget for 2015 is $17.5B

In contrast, NASA only spent a further ~$130M keeping the rovers going for the last decade. R&D, as well as getting stuff into space, is incredibly expensive.

[1] - https://en.wikipedia.org/wiki/Mars_Exploration_Rover

Having two rovers turned out to be insanely popular. Yes, it was expensive and NASA's budget is too small. But let's separate out the marginal cost here, because I'm pretty certain that if we had (for example) sent 4 rather than 2, it wouldn't necessarily have cost twice as much.

Many of us abide in disbelief of NASA's inability to leverage economies of scale. But like SpaceX and other private agencies have taught us, maybe this inability is a governmental-culture issue, not some sort of weird space-related issue.

You could build and launch probes at regular intervals to L4 and L5, and dispatch them from there via low-energy transfer.

It would take months for each probe to get there, but once one arrives, you can transfer it from there to anywhere else in the universe far more easily than from the Earth's surface. And since those points are more stable than L1, L2, and L3, you can just leave the probe there for months or years until a good transfer opportunity comes up.

Other responses nearby are good. I'd just like to point out that the instruments on the craft are unique and hand-assembled, and hand-tested through several phases (thermal, vacuum, radiation), so costs don't really go down with small multiples.

Here's a picture to get the flavor: http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA12021

It's interesting to look at India's Mangalyaan Mars probe, which cost $74M, or about a tenth of the NASA orbiter sent at the same launch window. This was largely because Mangalyaan was made out of completely standard parts; it was a tech demo for ISRO's satellite bus. (And it only carried 15kg of instruments.) It also only took 15 months to build.

So it's certainly _possible_ to build cheap spacecraft using mass production. You won't get anything specialised, so they're unlikely to work beyond the inner solar system, but you'll get cheap, simple and tested probes.

Whether this is _worthwhile_ is a very difficult question. Spacecraft cost money to run, and you're going to have to do very careful cost-benefit analysis as to what's the most efficient use of your money long-term. Plus, standard parts only work in standard environments; Jupiter's radiation belts would most likely kill Mangalyaan stone dead, even if had enough delta-V to get there, even if there was enough sunlight to run it.

But it's certainly worth considering designing a standardised long distance spacecraft bus, especially for missions to the outer solar system. Maybe someone's already done that...

(Mangalyaan is still in orbit, still collecting science data, still has years' worth of propellant, and AFAICT from the internets, has been an utterly textbook mission. They're sending another one at the next transfer window.)

Are launch costs still high?

It will be a long while before launch costs are brought down. They aren't all that different than what they were a few decades ago.

Different missions require vastly different hardware.

> Orbit around,

Orbiting Europa requires a different amount of propellant than orbiting Mars. Solar panels that power a probe at Mars won't power one farther away from the sun. Radio that can talk with Earth from the Mars orbit won't be able to do that from Jupiter.

> take photos and

Different cameras required due to different amount of light, expected distances for imaging, filters optimized for materials being imaged, etc.

> readings.

What readings? Basically no two probes carry the same set of scientific instruments. Often, the instruments carried are one-of-a-kind, specifically designed for the specific thing the mission wants to investigate.

Basically no two probes carry the same set of scientific instruments.

That's the problem. Great as those are, by continually making one- or two-of-a-kind devices we are endlessly prototyping. What if we picked one or a few different designs, selecting for greatest generality, and then worked to get the costs very low by manufacturing a lot of them, accepting that they will be suboptimal for almost every target?

Of course crappy probes would give crappy results, and many of them would fail altogether. But what if we deployed hundreds of cheap crappy probes on a regular basis - ie build a shotgun instead of a series of sniper rifles? Obviously finding a good general-purpose design is easier said than done.

We have I think 3 lunar probes in orbit at the moment, and a few more on the way, as well as various probes that have gone to the moon, sent back a bit of data, and then crashed into it by design. That's not very many at all. The moon's not that far away, why not try putting 50 low-cost probes around it with the same instrumentation and see what we learn from that? If we can get better astronomical observations from arrays of relatively low-power telescopes, surely we will get better planetary observational data from arrays of low-quality probes? Simply getting an array of probes up there and running and learning hwo to handle the networking, data flow, and and the inevitable variety of unexpected failure modes will provide us with a vast amount of experience, not to mention a vast amount of additional data about the moon that can be benchmarked against a whole lot of excellent data we have already for accuracy.

I don't mean this as a dig at you or the other commenters critiquing this proposal, but you remind me of Thomas J Watson suggesting that "I think there is a world market for maybe five computers" (not withstanding the apocryphal nature of this quote, similar sentiments were expressed by other experts around that period, eg https://en.wikipedia.org/wiki/Thomas_J._Watson#Famous_misquo...).

You're ignoring the lifting costs. The cost of lifting a payload into space and putting it into orbit is non-trivial compared to the cost of developing the probe. Can you imagine the cost of trying to put 50 probes into Julian orbit? Or even Lunar orbit? It would be cost-prohibitive. It gets worse if you use a bunch of mass-produced designs because you'd have a bunch of instruments of marginal value to the mission increasing lifting costs.

I also think you're assuming its possible to reduce to a general set of equipment that can answer the scientific questions that we're trying to answer. If you consider, for example, the difference between the things that Philae, Curiosity, New Horizons, Dawn, and this Europa probe are testing and the conditions that they are testing them in, then its hard to arrive at a common design that can handle all these conditions.

Edit: Another thing to consider is launch windows. You typically don't want to just regularly launch stuff to put near Mars or Jupiter whenever. You time your launches such that you can get them there within a certain amount of dV budget, otherwise you're dramatically increasing your deployment costs. This means that you only have a short window in which you can send out your shotgun probes -- you can't send them out constantly even if the lifting costs were feasible.

Let's focus on the lunar orbit idea as a relatively straightforward objective, since it is practically in our backyard and we have so much experience there.

I am not suggesting we perform 50 different launches into space. That would be hopelessly wasteful. But suppose we did one launch, sent one ship towards the moon, and then have it release 50 probes as it got close, each with a small amount of propellant sufficient get itself into orbit.

I am not suggesting a common design that is adequate to handle all the different conditions of the different missions you mention. I said specifically that we should focus some effort on developing cheap probes, accepting that they will be suboptimal in almost every case.

Let's consider one of the most basic things we like to do, which is to simply take pictures of things. Pictures help sell science to the public because most people are interested in how things look, and they are scientifically useful. When we aggregate multiple pictures of the same subject we often get even more useful scientific data. Downsides, the data transmission requirements are large and visual spectrum is just a small slice of the information we'd like to collect. Upsides, you can buy a COTS camera that takes 4k video or ~50mp stills for a few thousand $. Likewise you can buy a fast lens of high optical quality very cheaply, and record onto very cheap solid-state media. Let's accept that it will fail in some situations and that we don't expect it to keep working for ever, but we would like it to work for a while. so we need some power (onboard or renewable or some combination of the two), an antenna of some sort to transmit the data back and listen to requests from our end, some shielding to protect it against the slings and arrows of outrageous fortune, some sort of propulsion to get it into position and point it roughly where we want it to look, and a little control system to run it all.

Technologically this is no longer a tall order. We can stick a consumer video camera & phone in a lunchbox, attach it to a balloon, send it up to the stratosphere, and retrieve it afterwards for only hundreds of dollars, it's a middle-school project by now. I think that we could make a pretty decent camera probe that would take relatively high resolution pictures at a relatively low frame rate and last for at least a year for a marginal cost of $100,000, maybe quite a bit less. 50 of those would be $5 million, which is the sort of sum you can raise on Kickstarter. Now, the fixed costs of launch, building a deployment module and numerous other things would be a lot higher, let's say they started at $50 million. Well, that's quite a lot of money but you could still raise it pretty easily. Donald Trump plans to waste twice that amount on promoting himself as a public figure while pretending he wants to be President, a summer blockbuster movie has launch costs of about $200m including marketing. There are lots of people in Silicon Valley who could write checks for that whole amount if they really wanted to. I pick $50 million as a benchmark because India managed to get a probe going around Mars for ~$75 million, so I don't think it's a totally outrageous idea to think we could deploy a bunch of lunar microsatellites for 2/3 of that.

OK, let's say we even went overbudget by a factor 2 but we managed to do it. We have 50 probes in lunar orbit sending back, i dunno, 43 4k photographs of the lunar surface at the rate of 1 frame/minute (7 of them failed to deploy properly). None of them works properly for longer than 18 months. Within a few years they have all fallen out of orbit and are space junk on the lunar surface. Well, I think that we'd get a ton of useful knowledge from doing that.

> Technologically this is no longer a tall order. We can stick a consumer video camera & phone in a lunchbox, attach it to a balloon, send it up to the stratosphere, and retrieve it afterwards for only hundreds of dollars, it's a middle-school project by now. I think that we could make a pretty decent camera probe that would take relatively high resolution pictures at a relatively low frame rate and last for at least a year for a marginal cost of $100,000, maybe quite a bit less.

Where are you getting the $100k from? I would guess that a control system, communication system, reaction control system, propellant, batteries, solar panels, and a camera would cost much more than that if you're designing it to withstand space. The Indian probe you mentioned was 15 kg and cost $24 million. If you normalize that down you're talking $1.6 million per kg for a mission notable for its low cost. The LRO cost $504 million total, and Atlas V costs around 230 million If we take $250 million to be conservative, then it cost $2.5 million per kg of scientific instruments.

Note that the Indian orbiter had a dry mass of 500 kg and a launch mass of 1,337 kg to support that payload. The LRO has a dry mass of 1,018 kg and a launch mass of 1,916 kg. So the LRO had 10 kg of supporting dry mass for every 1 kg of science, and the indian orbiter had about 30 kg of supporting dry mass for 1 kg of science. Lets add Kaguya as another data point that had 1,984 kg dry mass, 2,914 kg launch mass, and the mission payload seemed to be around 300 kg, for a ratio of 6 kg weight for 1 kg of science. In other words, as your satellite gets smaller, the weight of all the other stuff required to keep your satellite ticking and pointing in the right direction becomes dominant. That means that one satellite with 100 kg payload will likely have less total weight than 50 satellites with a 2 kg payload. That increased total weight will come from installing redundant systems on all your satellites. So we're talking higher launch costs and higher part costs. Its certainly going to be difficult to improve upon costs by a literal order of magnitude.

So then the question becomes, what science can we accomplish with 50 satellites that we can't with 1? Is there a benefit to all this added cost and complexity?

I don't have the experience to address any of your points, but I do enjoy learning about this kind of stuff and there are some very smart people with long track records of past success working on these challenges:

"Through the use of multiple ARKYD 300 spacecraft per mission, Planetary Resources will distribute mission risk across several units, and allow for broad based functionality within the cluster of spacecraft.

The ARKYD 300 series spacecraft also demonstrate low-cost interplanetary capability, which is of interest to potential customers such as NASA, scientific agencies or other private exploratory organizations."

[1] Planetary Resources Corporation - http://www.planetaryresources.com/company/roadmap/#harvestin...

"Very often satellites are more expensive than the rocket. So in order for us to really revolutionize space, we have to address both satellites and rockets. We’re going to start off building our own constellation of satellites, but that same satellite technology that we develop can also be for science — Earth science and space science — as well as other potential applications that others may have. We’re definitely going to build our own, but also it’s something we would be able to offer to others."

[2] SpaceX - http://www.geekwire.com/2015/elon-musk-plans-get-mars-via-se...

Again: what would be the benefit of collecting hundreds of mediocre (and probably predictable after the first few samples) data points, without being able to do the kind of science you really want to do?

If we had a few things we knew we wanted to monitor for a long time, then this sort of proposal might make sense. But we don't, and there are always new questions to be answered, necessitating the use of different instruments on different missions. Those are rarely as simple as a camera simply taking pictures.

Moreover, I think you are overestimating the reliability of COTS hardware and underestimating the environment in space -- or underestimating the cost of radiation hardened hardware while overestimating its capabilities. You don't just grab a SD card or a CCD and send it into space. Likewise with lenses/filters (we are more interested in some wavelengths than others), etc.

COTS hardware may work for cute balloon projects that stay within the Earth's atmosphere, or (maybe!) satellites in low earth orbit. Space is a very different environment.

Even with "economies of scale" pushing down the cost per probe, you still have substantial fixed operational and science costs on top of that. Since running a large fleet of probes would be, overall, more complex than a single probe, I'm not sure if it would even be cheaper to operate than a few specialized probes. So you get worse science for, at best, the same cost, with much increased operational complexity. Again: what is the benefit?

I've already explained what the benefits are: practice, because we are going to want to run networks in space sooner or later anyway; the observational benefits from aggregating an array of relatively low-quality observations, which is something we already do for astronomy; and knowledge of failure modes and fault tolerances.

I don't expect COTS stuff to work that well or that long. But I would like to know how well or poorly it does perform. Some kinds of hardware are so cheap that we can afford to waste it on such experiments. Your reference to 'science costs' suggests to me that you've missed the point; I don't want to do any innovative science, I am perfectly happy to try something as simple as taking boring pictures to begin with as proof of concept, so we can concentrate on operational issues. Learning how to do things fast and cheaply even if the results are not especially good is a perfectly worthwhile goal in its own right.

> benefits are: practice, because we are going to want to run networks in space sooner or later anyway

As I've said earlier, learning how to manage a fleet of probes is a non-issue until we actually have a legitimate need for a large fleet of probes operating in concert, which won't be for a (very) long time. Note that we already have experience managing satellite constellations in the 50+ range.

> I don't expect COTS stuff to work that well or that long. But I would like to know how well or poorly it does perform. Some kinds of hardware are so cheap that we can afford to waste it on such experiments

TBH, neither do I, but 1) Someone does already, hence why we don't hear about Nikons on interplanetary missions, or even in orbit. 2) We don't need to send dozens of probes up to space to find out. In fact, we don't even need to leave the Earth. 3) Many instruments are not simply cameras, let alone COTS.

> Your reference to 'science costs' suggests to me that you've missed the point

You are moving the goal posts, your original comment was about sending dozens of cheap probes up to do different missions. Quoting:

> What if we picked one or a few different designs, selecting for greatest generality, and then worked to get the costs very low by manufacturing a lot of them, accepting that they will be suboptimal for almost every target?

Even taking your statement that this isn't meant to be good science, beyond the perceived benefits of increased operational experience after the first few batches of probes (using the moon as your example), continuing with the "small, cheap, lousy" form factor is not going to outweigh the loss of spending the money instead on fewer solid science missions -- because, right now, what other purpose do we have for sending probes into space? We don't have the resources or knowledge to do anything else "useful" yet -- the science needs to come first. srdev has made better arguments on why it's still infeasible from a cost and technical perspective.

I am not moving the goalposts at all. I made a general point about what I'd like to happen I wrote an entire post addressing a single example of an initial project with the specific goal of doing nothing more exotic than taking pictures of the moon, our nearest neighbor to see what would be achievable at a low cost. I made it very clear from the outset that I wanted ot explore theidea of leveraging quantity and low cost at the expense of quality and speficity. To claim otherwise is not an honest way to carry on an argument.

Feel free to keep right on arguing about why this is stupid and a waste of time until someone gets around to doing it, which I predict will happen between 2025 and 2030.

"Feel free to keep right on arguing about why this is stupid and a waste of time until someone gets around to doing it"

This is something HN does a lot. Always mystifies me, for a site based around a supposedly disruptive startup industry. Lots of little mental boxes in many of the conversations.

EDIT- To be fair, the reason your proposal hasn't happened yet is that it's still very early days for space exploration. Satellites in Earth orbit are often like you describe, so contrary to some of the arguments against it, obviously it can be done. But even though we have countless photos of Jupiter, it's a lot more mysterious that it seems. So much still totally unknown, so they have to optimize for learning it all. Your approach is actually pretty good for refining general knowledge once the basics are locked in. As such, you're very likely correct that the Moon will be a target of such efforts soon.

"If we had a few things we knew we wanted to monitor for a long time, then this sort of proposal might make sense. But we don't [...]"

I strongly suspect this isn't true.

We generally have to make a choice, and new types of science gathering usually wins. For a variety of reasons, some good, some merely political.

But it's a choice, not a fact of life.

I know of at least one case where the relevant science community would love to have more identical spacecrafts that are launched about one year apart: Follow ups to the very successfull stereo mission. In 2006 we launched two spacecraft that (compared to other science missions) were basically identical, with the goal of having solar observations not just from earth, but two other vantage points. During the mission it we learned that it is quite helpful to combine Stereo data with data from the Soho satellite that is stationed near earth at the L1 Lagrange point. And while having two or three observations from different directions is a start, having a couple more stereo-like satellite would make things like 3d reconstruction of CME fronts possible.

What you're describing is, basically, Pocket Spacecraft:


...except Pocket Spacecraft is even smaller. One of their probes is a CD-sized mylar disk with a solar panel and an Arduino-compatible microcontroller printed on it. The antenna is a wire ring around the outside. Sensors are minimal (I believe one of their models has a single pixel camera) and of course there's no propulsion. They were planning on launching hundreds at a time via cubesats.

They did a Kickstarter last year --- £99 for a vehicle in Earth orbit, £199 for one in lunar orbit --- which failed, but apparently they got funding elsewhere. Their website's short on updates but their twitter feed is active.

(IANA Astronomer) Each probe has a mission, and each instrument has an hypothesis it is designed to test -- that's the scientific method. Given the large fixed costs of space exploration, it's probably a better tradeoff for now to specialize fewer missions rather than risk gathering the same data hundreds of times over, while missing out on opportunities to test other hypotheses. (For example, I'm not sure what the benefit of 50 identical trips to the moon would be.)

Sure, we would learn a lot about managing a fleet of so many probes simultaneously (esp. when it comes to mission control, analyzing the data, etc), but those are operational concerns, which are orthogonal to the science they are trying to accomplish. And it's solving a non-issue: the only time we'll need to figure out to manage a fleet of probes is when we actually have a fleet of probes.

Your statement about missions requiring different types of hardware isn't wrong, but having a generic platform for creating probes with different mission profiles isn't a bad idea. Think of it like a car platform which enables you to put on different bodies, interiors, etc. to suit the tastes and requirements of purchaser. If you had a standardized parts bin you could select whatever you needed to meet your mission objectives.

That said, usually you would do this to leverage economies of scale, and I think there probably isn't the budget or demand for enough space probes to make it viable. Who knows though, if the price of space launches continues to plummet, maybe it starts to make a lot of sense.

> Basically no two probes carry the same set of scientific instruments. Often, the instruments carried are one-of-a-kind, specifically designed for the specific thing the mission wants to investigate.

Whatever these things are, I'm assuming 3 facts:

1. They require some type of electricity to operate.

2. They require a data interface for output.

3. They occupy a finite amount of space.

Based on these, can't we modularize the scientific instruments? Provide common power and data ports within a common frame? So they can fit into the same bays, like a blade server, or even like Hubble's 4 bays.

Your assumptions are correct. And this is how the spacecraft industry operates. In fact, like rack units, CubeSats have "1U", "3U", etc. Spacecraft components and instruments are modular. Data interfaces vary, but 1553, SpaceWire, and RS-422 UART are all quite popular. The part that all the instruments and components bolt to are called the bus. Aerospace companies have standard buses.

The huge variable is the mission itself. Your blade server analogy is too narrow. Look at applications of computers on the ground. If you want to put a computer on a collar to track wolves, a blade server doesn't work. If you want a computer to take with you on a jog, a smartphone is appropriate. If you want to run a data center, a blade is great.

Spacecraft vary just like this. JWST is the size of a tennis court. KickSat was the size of a cracker. The environments they operate in are crazy. The Voyagers are in deep space a light day away. Some spacecraft are just a few hundred kilometers over your head. A one-size fits all approach doesn't work.

Science instruments aren't generic, you have to choose a scientific payload that gives you a chance to attain your objectives while operating both under monetary and power constraints. The instruments have also improved tremendously over the last couple of decades.

Here is an overview of what we know about the mission now: http://futureplanets.blogspot.se/2015/06/nasa-goes-first-cla...

"Galileo’s camera and spectrometers revealed that the icy crust is fractured and frequently covered with material that appears to have originated in the ocean below. The Clipper’s radar instrument (Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) – principal investigator Dr. Donald Blankenship of the University of Texas, Austin) will see below the surface to investigate the structure of the shell, potentially all the way to the interface with the ocean below."

"The MAss SPectrometer for Planetary EXploration/Europa (MASPEX) (principal investigator Dr. Jack (Hunter) Waite, of the Southwest Research Institute (SwRI)) will measure the composition of gasses, ices, and organic molecules."

"The wide angle camera in the Europa Imaging System (EIS) (principal investigator Dr. Elizabeth Turtle of APL) will map the surface of Europa at 50 meter resolution in color to document the surface structure."

"During each of the planned 45 flybys, the spacecraft will travel close to the surface of Europa. At each encounter, the wide and narrow angle EIS cameras will record the surface geology in high resolution recording details as small as one meter."

The spacecraft itself isn't a particularly big deal on these missions. They will usually use an existing bus or put together existing subsystems. So basically they already do as you suggest. Cassini, currently around Saturn, is directly descended from the Mariner/Voyager/Viking line, as were Galileo and Magellan. MAVEN, MRO, and Mars Odyssey are all basically the same type. Mars Observer was a comsat, and most Earth observers use a commercial sat bus. Historically the Explorer, Mariner/Voyager/Viking, Pioneer, Ranger, Venera, Zond, and other families shared quite a lot.

Most of the effort goes into novel and usually hand-made sensors to deal with specific scientific questions. There's not particularly a point in sending the same instruments to the same places again, and the accessible parts of the solar system are fairly well studied from a generic standpoint. If you're going through the (fairly expensive) effort at all, you want better or different instruments, and that's what takes so long. There's a reason all these programs are led by a "principal investigator" and not a "head engineer".

I do think a common design with fairly generic instruments would be useful for a pair of ice-giants orbiters. Uranus and Neptune are basically unstudied up close, compared to all the other planets. But two does not mass production make.

A lot of the time there are good reasons, but the funding structures of this kind of large-scale science also generate some perverse incentives. No-one's employed full-time to "be a scientist" at the kind of scale that a space mission takes - at best some of the people will be tenured researchers, but their loyalty tends to (reasonably) belong to their specific institution. Usually at least some of the people involved will be commercial contractors who will then move elsewhere once the money goes away - and it will, as soon as the probe is launched. Finally, science tends to be funded on a grant basis, and these grants are always for specific things.

So imagine someone working on the Foo Mars Orbiter. They're probably employed by the University of Bartown, and their work is being funded by an NSF grant for the Foo Mars Orbiter project. Neither of those bodies is interested in making something reusable for another satellite ten years down the line: the university may well not be involved in the next one, and they're unlikely to get much academic prestige from having their designs reused, they'd rather their professor spend time making their paper nicer and getting it in better journals. Meanwhile the NSF wants its grant to be used for the grant's specific purpose, not as a general slush fund, and will be hostile to any expenditure that's not directly related to getting the Foo Orbiter into orbit. Even if the team did put together something reusable, the team's going to be dissolved as soon as it launches (with a skeleton crew remaining to check when it arrives) or at very best once the primary mission completes, so no-one's going to be in a position to handover the assets to the team making the next satellite. If you've ever tried to reuse some code that was written two years ago by someone who thought it was a one-off and has since left the company, you get the idea.

The destinations the probes go to are drastically different, and generally the things you want to study aren't identical. What's more is that the mission plans for probes need to be extremely detailed, which impacts the design of the actual probes. The extreme level of detail necessary for a mission is also one of the reasons probes aren't launched on short timeframes.

However, they are absolutely used for more than one purpose, and this is part of the reason the mission plans are so detailed. We generally try to get as much usable science out of what we send. For example, the mission for Cassini Huygens[1] included Venus, Jupiter, and obviously Saturn and its moons. Some of the other easy examples... Voyager[2] I and II, Spirit and Opportunity[3].

[1] https://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens

[2] https://en.wikipedia.org/wiki/Voyager_program

[3] https://en.wikipedia.org/wiki/Mars_Exploration_Rover

Because we know what happens when you try to make an expensive thing that takes the place of several somewhat related other expensive things and can perform all of their capabilities:

https://en.wikipedia.org/wiki/Joint_Strike_Fighter_program#C... https://en.wikipedia.org/wiki/Joint_Tactical_Radio_System#Pr...

You end up with a super duper expensive thing that takes 15 years longer than you expected to build and ends up not being able to do the job of any one of the things it was intended to replace.

There's a lively discussion on the front page about one of the examples above.

> I know there is a very good reason for this, but it seems like we're sending a lot of satellites to these moons and planets to perform VERY similar missions. Orbit around, take photos and readings.

I think you're overly abstracting the missions. It may seem similar at such a high level, but the actual readings being taken are likely very different and require very different hardware.

The same reason every modern automobile is not a model T ford and every computer is not just an Apple 2?

Also, space missions do not have the luxury of activities on earth where if things go wrong one can quickly try again if funds are available. Thus, much more preparation is needed.

> I imagine getting through 15 miles of ice might be a wee challenging.

Just drop a nuclear probe that can melt through: http://news.bbc.co.uk/2/hi/science/nature/3548139.stm

Getting under the surface of the ice might not be too bad, but getting a signal back up would definitely be.

easy, pack 10km of fibre.

oh wait...

Sometimes I feel like the aerospace industry is in a race to make the most phallic objects possible. I wonder how hard it is to get a signal through all the ice.

There's one design that's a very effective perpetrator. Works in biology; works in space.

I imagine that the probe would set up a transmitter on the surface, and drag a cable behind it through the ice-hole, then deploy another relay at the bottom - probe signals underwater relay, relay passes it onto the surface transmitter, transmitter phones home.

Plans exist.

Here's one for a submarine on Titan - https://www.nasa.gov/content/titan-submarine-exploring-the-d...

There was another Titan boat proposal a couple years ago, but it lost NASA's internal funding battles to Yet Another Mars Lander. http://www.universetoday.com/96924/mars-lander-wins-out-for-...


Just to be clear, the Titan "boat" was really a buoy. It would have dropped into a lake and drifted. That still would have been amazing (imagine video from a lake on another world!), but the science would have been limited by the cost of dealing with the environment and the tight budget of the Discovery program.

The biggest issue, however, was the problematic development of the needed power supply[1].

There is another option for these missions, of course. A nominal increase in NASA funding to increase the number of missions we can fly.

[1] https://en.wikipedia.org/wiki/Advanced_Stirling_radioisotope...

Even these "cheap" missions are a half billion each, so it's a little more than nominal. Choices have to be made, even if NASA's budget was doubled.

TiME was always a longshot proprosal, but I'd personally rather see the lower budget Discovery Program missions doing riskier stuff. And while I love a good Mars mission, Mars gets all the marquee missions anyway. It's kind of a shame to see it eat the resources of the lesser missions too.

> Even these "cheap" missions are a half billion each, so it's a little more than nominal

over a decade or more, though :) I just wish we could have more.

Mars is easily the lamest planet in the solar system. I don't understand why we need to keep going there.

Mars is the Ohio of the Solar System. Important for political purposes, but otherwise boring and unfulfilling.

Because there is actually a chance people could live there for extended periods of time.

by being "lamest" it is most reasonable for humans to go to, and most likely to actually be useful to us.

Thousands of experts disagree?

Nonsense, just put a chunk of something radioactive at the bottom and let it melt its way through, and then drop it when you get to water

Might make more sense to put the RTG in the nosecone; why ship something radioactive and useful all that way just to throw it away?

Oh great, let's hose up the environment on our first visit...we will end up doing this anyway, but radioactive chuncks on the sea floor?

It's probably substantially less damage than the rocket required to launch the extra mass that would be required if we used an alternative, heavier, method.

Water is so good at blocking radiation, that an RTG dropped into that ocean would be absolutely nothing. It would be dangerous to anything within 5 meters of it, which again - is absolutely nothing.

Just make sure that we drop it near a black smoker and accelerate evolution for the Europans. I doubt there is much background radiation on the bottom to stimulate random mutations.

hmm, let's hope it turns out better this time http://www.imdb.com/title/tt2051879/

If you want to get hyped, I recommend the movie Europa Report.

Seconded. A great little film.

No lander?? :-(

June 17, 2015


All Systems Go for NASA's Mission to Jupiter Moon Europa

Could a liquid water ocean beneath the surface of Jupiter’s moon Europa have the ingredients to support life? Here's how NASA's mission to Europa would find out.

Credits: NASA/JPL-Caltech Beyond Earth, Jupiter’s moon Europa is considered one of the most promising places in the solar system to search for signs of present-day life, and a new NASA mission to explore this potential is moving forward from concept review to development.

NASA’s mission concept -- to conduct a detailed survey of Europa and investigate its habitability -- has successfully completed its first major review by the agency and now is entering the development phase known as formulation.

“Today we’re taking an exciting step from concept to mission, in our quest to find signs of life beyond Earth,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “Observations of Europa have provided us with tantalizing clues over the last two decades, and the time has come to seek answers to one of humanity’s most profound questions.”

NASA’s Galileo mission to Jupiter in the late 1990s produced strong evidence that Europa, about the size of Earth’s moon, has an ocean beneath its frozen crust. If proven to exist, this global ocean could hold more than twice as much water as Earth. With abundant salt water, a rocky sea floor, and the energy and chemistry provided by tidal heating, Europa may have the ingredients needed to support simple organisms.

The mission plan calls for a spacecraft to be launched to Jupiter in the 2020s, arriving in the distant planet’s orbit after a journey of several years. The spacecraft would orbit the giant planet about every two weeks, providing many opportunities for close flybys of Europa. The mission plan includes 45 flybys, during which the spacecraft would image the moon's icy surface at high resolution and investigate its composition and the structure of its interior and icy shell.

NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, has been assigned the responsibility of managing the project. JPL has been studying the multiple-flyby mission concept, in collaboration with the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, since 2011.

Instruments selected for the Europa mission's scientific payload were announced by NASA on May 26. Institutions supplying instruments include APL; JPL; Arizona State University, Tempe; the University of Texas at Austin; Southwest Research Institute, San Antonio and the University of Colorado, Boulder.

“It’s a great day for science,” said Joan Salute, Europa program executive at NASA Headquarters in Washington. “We are thrilled to pass the first major milestone in the lifecycle of a mission that will ultimately inform us on the habitability of Europa.”

NASA's Science Mission Directorate in Washington conducts a wide variety of research and scientific exploration programs for Earth studies, space weather, the solar system and the universe.

For more information about NASA's mission to Europa, visit:



Dwayne Brown / Laurie Cantillo

Headquarters, Washington

202-358-1726 / 202-358-1077

dwayne.c.brown@nasa.gov / laura.l.cantillo@nasa.gov

Elizabeth Landau / Preston Dyches

Jet Propulsion Laboratory, Pasadena, Calif.


elizabeth.r.landau@jpl.nasa.gov / preston.dyches@jpl.nasa.gov

Last Updated: June 18, 2015

Editor: Sarah Ramsey

(For those on older / non-JS browsers)

What programming languages / operating systems do these systems use?

Is there any chance they could be open sourced?

Why is the hardware on them so weak? Why is the bandwidth so low?

Why can't we just spend a billion dollars for more bandwidth, CPU power and hard drive space? Why don't we just build an army of orbiters and send them into space?

https://github.com/nasa and http://ti.arc.nasa.gov/opensource/ and https://code.nasa.gov/

Hardware has to be radiation hardened and redundant.

Bandwidth is so low because it has to send radio waves 500 million miles, and that's not an exaggerated number.


Edit: The Deep Space Network is currently down, might be aliens, good luck everybody.

We have billions of dollars. USA already is experts at making complex, reliable and complicated hardware with complex manufacturing processes.

Why can't we just craft that hardware we need in bulk? We have billions of dollars in funding. Make a factory production out of it.

Why don't we send 300 mars rovers? We can make 5000 tanks. We can build 5000 fighter jets. Why do we just build one rover?

My impression with astronomy is it has nowhere near the fervor or seriousness that defense has. Why are we not dumping supply ships in the moon in anticipation of colonization?

I wrote a very detailed reply for this with lots of sources, but deleted it because it would only invite more questions that you can find out the answers to yourself. Really what you are asking requires several books worth of information to fully explain.

Basically just read everything on Wikipedia about DARPA, NASA, CIA satellites, the NRO, the Apollo missions, Sputnik, Voyager 1 / 2, the Curiosity rovers, KH-9, KH-11, Hubble, etc. then come back and criticize NASA if you still think that they are not doing their job properly.

You have the answers to all of these questions and more at your fingertips via Google.

NASA has another Curiosity rover, but the cost/benefit of sending it to Mars isn't worth it in their expert opinions.

See responses to similar question here: https://news.ycombinator.com/item?id=9740777

I don't know for recent missions but from a short stint at working with a space agency I remember there were a number of factors. One of them was how long it is from the moment the systems are designed to the moment they are launched. Another was how reliable and well known the hardware had to be, brand new hardware was not a good candidate. Other issues were with radiation resistance, smaller circuits are more sensible, the amount of redundancy that had to be built in and the little amount of power that was really available. In the case of a mission such as this one, I believe transmission is an issue given how far the spaceship is.


sounds like a dare...

Why the downvotes? It's a benign(albeit groan-worthy) reference

Anything that starts with "obligatory" probably doesn't contribute to the discussion.

Ah, fair enough.

if only i cared what about my +/- is in a popularity contest. thanks for asking about it, though. :)

hm. seems like we're not fans of 2001 here.

that was the plot of 2061...

The quote comes from 2010... Which was 5 years ago. PSHEW! (As my mind explodes.)

BAH! you're right. i'm more ashamed that i misattributed it than the fact that i went boilerplate on HN.

And look how that turned out.

First thing that came to my mind, too. Came here to post this. :)

Don't sweat the votes. HN mashes the down button for anything confusing or foreign to it.

HN doesn't like boilerplate.

This web site optimized for ... arguing with users.

Nondismissable "upgrade your browser" dialog. Which, of course, I can't actually do.

I thought we learned this was a bad thing in the 1990s.


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