The thread for space cadets!

Not that I disagree with you that building cost efficient instruments would be a good thing, but I think you are underestimating the difficulty of refilling Herschel with liquid Helium. Liquid Helium cryostats are difficult enough to work with on earth (see: LHC), doing it in space seems like a really daunting task. I also expect that adding the option to refill would greatly increase the complexity of the design of Herschel, making it more expensive and offsetting the gains you would get from the increased longevity.
 
Dutchfire hit it on the head. We already design our spacecraft to be as redundant as possible, but certain "simple" tasks such as refueling or swapping out some parts are anything but, and expensive to boot.
 
Not that I disagree with you that building cost efficient instruments would be a good thing, but I think you are underestimating the difficulty of refilling Herschel with liquid Helium. Liquid Helium cryostats are difficult enough to work with on earth (see: LHC), doing it in space seems like a really daunting task. I also expect that adding the option to refill would greatly increase the complexity of the design of Herschel, making it more expensive and offsetting the gains you would get from the increased longevity.

Which brings us back to the wrong mentality. In what universe do we think that developing and building an incredibly sophisticated space telescope (just one, which is another problem) without the possibility of seriously prolonging its service lifespan in space is a good idea?

As a general point, if we had an in-space refuelling/repair infrastructure, we could build cheaper and more reliable satellites. In the end, we could have large complexes the size of ISS in geostationary orbit, providing high speed internet and mobile phone coverage to the entire planet without the need of having much of a ground infrastructure. The benefits of being able to service our in-space assets would be countless.

/rant ;)
 
Which brings us back to the wrong mentality. In what universe do we think that developing and building an incredibly sophisticated space telescope (just one, which is another problem) without the possibility of seriously prolonging its service lifespan in space is a good idea?

On the bolded point: each one of these satellites needs its own ground crew, sometimes hundreds strong. Multiple telescopes requires multiple ground crews. It seriously increases cost in money and manpower.

As a general point, if we had an in-space refuelling/repair infrastructure, we could build cheaper and more reliable satellites.

Yes. Give us more money. :gripe:
 
On the bolded point: each one of these satellites needs its own ground crew, sometimes hundreds strong. Multiple telescopes requires multiple ground crews. It seriously increases cost in money and manpower.

Excellent. Having three of them for the same (or only slightly larger) ground crew would be far more cost effective. I argued for this principle before - let's adopt a bit more quantitative approach towards space science.

Hershel will of course be obsolete in 12 years time (and its mirror will be too cratered to be of any use anyway), but that doesn't justify this mission-prototype-discard approach I am talking about.

BTW, see the Hubble Space Telescope. It's been up for ages because it's been serviced. Yes, the cost was high, but the scientific return was worth it, IMO.

Yes. Give us more money. :gripe:

Whom? It's the private sector that has to see the light, with some (inter)governmental help/prodding, of course.

In the podcast I linked, the guys are discussing how a sensible cislunar infrastructure would benefit everyone and how historical examples of public-private partnership (railroads, air mail, etc.) could be used as a model for creating it.
 
Excellent. Having three of them for the same (or only slightly larger) ground crew would be far more cost effective. I argued for this principle before - let's adopt a bit more quantitative approach towards space science.

What? You would need a separate ground crew for each satellite. You would need a separate ground crew for each Mars rover as well. It's just one reason why we don't produce more than one in either instance - others, of course, being dubious RoI and increased overhead that doesn't improve risk-return ratio.


NASA. They're already working with (read: completely sustaining) private space as is.
 
Which brings us back to the wrong mentality. In what universe do we think that developing and building an incredibly sophisticated space telescope (just one, which is another problem) without the possibility of seriously prolonging its service lifespan in space is a good idea?

As a general point, if we had an in-space refuelling/repair infrastructure, we could build cheaper and more reliable satellites. In the end, we could have large complexes the size of ISS in geostationary orbit, providing high speed internet and mobile phone coverage to the entire planet without the need of having much of a ground infrastructure. The benefits of being able to service our in-space assets would be countless.

/rant ;)

I suppose you would also prefer the LHC to be replaced by a hundred copies of an inferior accelerator?
 
How much would refueling cost vs. sending up a new device? As well, do these satellites benefit from some type of Moore's law?
 
When considering refueling, I think you need to take into account that it doesn't just mean getting a new batch of liquid helium into space (relatively easy), but also means that you to make the He container in such a way that it can (easily) be refueled. This means it needs to have a shutable opening. That needs to shut well enough so the He doesn't get out in space, and so that heat can't get in. And of course, adding such a feature increases the risk that it will break somewhere along the road, wrecking the whole project.

I think the experience gained during these projects will make it invariably easier to make the next model a lot better. Trying to design the perfect thing the first time around seems overambitious. I guess the peripherals (data uplink technology to earth, solar panels, imaging technology) follow some usual lawlike predictable increase in capacity, for specifics it is more of a hit and miss thing, with huge advances in some decade and standstill in another.

Herschel weighed 3300 kg, launching stuff into space costs 10.000s of euros per kg according to the Interwebs, so launching it would cost like $33 million. The total cost of the Herschel is $1.1 billion.
 
http://arxiv.org/abs/1210.7757
...planetesimal accretion can be inhibited even in the outer disk (4-10 AU) far from the central binary, a location previously thought to be a plausible starting point for the formation of circumbinary planets.
:mad:
 
On the bolded point: each one of these satellites needs its own ground crew, sometimes hundreds strong. Multiple telescopes requires multiple ground crews. It seriously increases cost in money and manpower.:

Not necessarily. Surely the scientific data output would require a more manpower, but things like techs who know the systems could probably stay the same size. Commonality has its benefits.
 
I'm not saying there couldn't be some crossover, but for monitoring telemetry, orbital adjustments/calculations, and other transient tasks you'd need a new ground crew for each satellite.
 
As much as I like the idea, I'm not sure if 100 years is enough time, or if this is even the right idea when there's still quite a bit to do within our own system.
Then again, Clarke's second law.

It would be nice to get back on some type of historical trendline for "human travel in space". i.e., a geometric series of somesort.
 
I suppose you would also prefer the LHC to be replaced by a hundred copies of an inferior accelerator?

What? :confused: No. What I am saying is that if you develop something useful, you shouldn't throw it away after one mission. This principle applies to what I said about Hershel AND to what I said a few months ago about planetary probes.

I believe the mission driven approach that makes us constantly produce prototype craft to perform one specific mission and be discarded afterwards is contributing to the high cost of space exploration. That's all. I am not saying we should have stopped moving forward with technology, I am not saying that 100 Viking landers would be better than one MER, or whatever other misinterpretation people here will come up with.
 
I guess I don't see how producing three prototypes instead of one is cheaper. Materially or logistically.
 
Then you propose a full production run? :huh: These aren't iPhones, you know.
 
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