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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 prob

by srdev 11y ago

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.

anigbrowl 11y ago
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.
- jallmann 11y ago
  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?
  - anigbrowl 11y ago
    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.

by srdev 11y ago

anigbrowl 11y ago

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.

jallmann 11y ago
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?
- anigbrowl 11y ago
  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.