3 ms·

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

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.
- jallmann 11y ago
  > 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.
  - anigbrowl 11y ago
    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.
waterlesscloud 11y ago
"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.
- petschge 11y ago
  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.

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.

jallmann 11y ago
> 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.
- anigbrowl 11y ago
  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.

waterlesscloud 11y ago

"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.

petschge 11y ago
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.