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-   -   What "weed need" is a space mission! (https://www.mersenneforum.org/showthread.php?t=17609)

Uncwilly 2012-12-27 02:28

What "weed need" is a space mission!
 
For all of you space buffs and fans, it is time to vent!

What is the most overlooked mission that you think should happen now?
What is a mission that you think should be given priority?
What mission would fill in some vital piece of knowledge or provide a new window of insight or explore new territory?

The rules:[LIST][*]It must be an unmanned mission.[*]It must not be directly overlap any current or currently [U][COLOR="DarkRed"]planned[/COLOR][/U] mission. This includes ESA (and all other European space agencies), NASA, RSA, [URL="http://b612foundation.org/"]B612[/URL], JAXA, and all other national agencies.[*]You have ~$1billion to work with.[*]No breakthrough tech allowed.[*]Must launch within 7 years and flight time to destination must be under 10 years. Primary Mission time is open, but must be covered by the funding.[*]Launch vehicles must be near term available (no SLS, but Falcon Heavy is ok), max of 2 launches, and the cost of the launches are part of the $1B. (Assume that the launched craft can auto-dock if needed).[*]A nominal amount of Deep Space Network support is available for a token charge.[/LIST]
Surprise us. Be creative.

chappy 2012-12-27 02:58

I suppose it would be out of line to suggest that NASA should send a craft to the nearest star: Sol.

We waste a great deal of time and energy studying boring lumps of rock like the moon. It is time for that [STRIKE][URL="http://www.youtube.com/watch?v=3JdWlSF195Y"]mass of incandescent gas[/URL][/STRIKE] [URL="http://www.youtube.com/watch?v=sLkGSV9WDMA"]miasma of incandescent plasma[/URL] to be studied.

And since cost is an issue we could save money on heat shielding by going at night.

[SPOILER]Sorry, I actually think this is a great thread. Though I'm for putting that Billion toward the space elevator. [/SPOILER]

chalsall 2012-12-27 03:25

[QUOTE=Uncwilly;322773]Surprise us. Be creative.[/QUOTE]

Let us assume there is a non-zero probability that a relatively massive asteroid might impact Earth within the next 100 years.

Somewhat minor private funding (only a few hundred million dollars or so) would be able to detect this, using spacecraft located at Lagrangian points.

Might be a bit better than NASA funded scientists noting after the fact "oh, look, that asteroid just missed us yesterday"....

Uncwilly 2012-12-27 03:29

[QUOTE=chalsall;322778]Somewhat minor private funding (only a few hundred million dollars or so) would be able to detect this, using spacecraft located at Lagrangian points.[/QUOTE]Please see the following:
[QUOTE=Uncwilly;322773][LIST][*]It must not be directly overlap any current or currently [U][COLOR="DarkRed"]planned[/COLOR][/U] mission. This includes [URL="http://b612foundation.org/"]B612[/URL][/QUOTE]:bangheadonwall:

LaurV 2012-12-27 05:01

Landing on Mercury. I mean, manned mission. I still believe Mercury will be the next celestial body the mankind will walk on (this means, after the already trodden Moon, and before March, Venus, other things). Colonize may be not, but walk on, for sure! That is first because of the lower gravity (easier to come back) and then because of the temperature (contrary to popular beliefs that Mercury is very hot, because is close to the Sun, its polar caps are frozen, due to its orbital tilt, some area is never reached by the Sun, there is even ice there - i.e. solid, frozen water). As its equator is very hot, there is a "convenient" area somewhere in the middle, the "dew point", where the humans could live with only an oxygen mask for a while, dig some holes, take some stones, boo hoo, come back, happy ending...

Dubslow 2012-12-27 05:07

[QUOTE=LaurV;322785]where the humans could live with only an oxygen mask for a while, dig some holes, take some stones, boo hoo, come back, happy ending...[/QUOTE]

No, you'd still need a full-fledged suit. Humans can't survive in a (near) vacuum, even with an oxygen mask.

Uncwilly 2012-12-27 05:27

[QUOTE=LaurV;322785]Landing on Mercury. I mean, manned mission. [/QUOTE][U]To costly.[/U][QUOTE=Uncwilly;322773]The rules:[LIST][*]It must be an unmanned mission.[/LIST][/QUOTE]
Beside that, it takes a lot of energy to get to Mercury and if you want to get back, it takes a lot of energy to get back to earth.
"A trip to Mercury requires more rocket fuel than that required to escape the Solar System completely." - [URL="http://en.wikipedia.org/wiki/Mercury_(planet)#Research_with_space_probes"]wikipedia[/URL] And a manned mission is [B]much[/B] heavier that an unmanned mission.

LaurV 2012-12-27 05:34

whoops...

you are destroying my dreams :yucky:
:smile:

I know everybody is terrified by descending into this "solar well", the ship gets faster and faster, and if it does not do something (like active changing velocity) then it will pass Mercury fast... Think about a parachute, in the Earth's atmosphere. It does not get faster as it descends.
Now think that the parachute is a big solar sail and the Earth's atmosphere is the solar wind... This can be quite interesting (and cheap, close to free) when it comes back. With a little planning, it may lift the mercurial module without (much) other fuel...

Uncwilly 2012-12-27 05:35

My current personal preference is to plant some (2 or 3) radio telescopes on the moon. This would be for Extremely Long Baseline Interferometry. Ideally they would be about 10 meters in diameter once unfolded and contain an atomic clock, a generous amount of solar cells, and an RTG to provide a bit of power and some heat for the long nights.

ixfd64 2012-12-27 07:12

Not a "space mission" per se, but I'd really like to see a working Heim drive.

Xyzzy 2012-12-27 07:13

[QUOTE]you are destroying my dreams :yucky:[/QUOTE]Not exactly relevant, but a good movie:

[URL]http://www.imdb.com/title/tt0448134/[/URL]

[I]Edit: An excellent song on the soundtrack as well:

[url]https://itunes.apple.com/us/album/adagio-in-d-minor-2012-remaster/id579343029[/url][/I]

Xyzzy 2012-12-27 07:27

Our dream for a space mission is:

A small robotic outpost on the Moon, with all sorts of gadgets and building blocks.

Then, kids from all around the world, working with real scientists, perform remote experiments using the robotic outpost. When we say "working with real scientists", we mean this literally. The real scientists shift gears and mentor the kids using the Socratic method. ([URL="http://en.wikipedia.org/wiki/Socratic_method#Harkness_education"]Or this.[/URL]) The real scientist probably can guess the outcome, but it is much more important for the child to discover the outcome and to feel that sense of discovery.

The result generates interest in the field and gets kids involved. (The biggest goal!)

Imagine a catapult contest between teams of kids. Seriously!

It also establishes a base on the Moon. As experiments get more complicated more stuff is sent to the outpost. After a few years we have a bunch of stuff up there, chosen for reliability and endurance, to maybe begin supporting a manned outpost.

We were, until recently, heavily involved in model rocketry. It is unfortunate that this hobby is so neglected today.

When we think back on our life we remember the big "Aha!" moments, and they are all related to independent discovery, whether guided or not. (Quite a few of ours were independent discovery after miraculous survival!)

:smile:

xilman 2012-12-27 08:19

Hot air ballooning.
 
Not sure that budgetary constraints would allow this one, but it may be worth exploring further.

Fly a hot air balloon in the Jovian atmosphere. Standard trip to Jupiter, followed by aerobraking for stopping in the stratosphere. Drop what's left of the thermal protection, unfold the envelope and inflate by burning an on-board oxygen supply. Keep topped up by the waste heat from a small fission reactor which also provides the science and communications package with oodles of electrical power.

Not sure whether a comsat in high-Jovian orbit would be needed --- that's part of the cost constraint, but not the <= 2 launches constraint.

The main probe should fit on a Ariane-5 or its near-future upgrade.

Uncwilly 2012-12-27 13:41

[QUOTE=xilman;322795]Fly a hot air balloon in the Jovian atmosphere.
...
The main probe should fit on a Ariane-5 or its near-future upgrade.[/QUOTE]
I like this one.
But why not use a Falcon Heavy? The best Ariane-5 gets you 11,200kg to GTO for an estimated $120M. The Falcon Heavy will get you 19,000kg to GTO for a fixed price of $128M.

BTW, the budget of $1B is a soft number. Stretch it but don't break it.

Flatlander 2012-12-27 15:26

Time to start moving the planets. We might need them.

A craft of maximum mass that repeatedly slingshots Venus and Mars, thus bringing them nearer to the Earth. Shouldn't take too long.:tu:

Not close enough to disturb the moon mind, and someone will tell me it's impossible anyway. (More planets required?)

or, more seriously:

Mars-style rovers at the moon's poles looking for water etc. The start of a long-term plan to make use of the moon as a base for longer missions.

A lander/rover that rides a periodic comet. Should stay gravitationally attached despite any melting? Use the emitted gases as fuel or process the 'ground'? Don't know if it is possible to match the orbit to get on board in the first place.

These just need the details fleshed out!

(As is the nature of mega-projects maybe we should consider $1bn an underestimate just to get the funding. We can multiply by four or something?)

xilman 2012-12-27 16:20

[QUOTE=Uncwilly;322818]I like this one.
But why not use a Falcon Heavy? The best Ariane-5 gets you 11,200kg to GTO for an estimated $120M. The Falcon Heavy will get you 19,000kg to GTO for a fixed price of $128M.

BTW, the budget of $1B is a soft number. Stretch it but don't break it.[/QUOTE]The A5 is a proven launcher.

The forthcoming upgrade raises the maximum payload significantly.

jasong 2012-12-27 18:43

I definitely think we need an un-manned mission to the moon. Haven't read up on this particular topic recently, but there are probably dozens of different goals we could try to achieve.

Seeking water at the poles, digging into the soil(is soil the proper term in this instance?) to see what we can find underneath, seismic studies, mining(if we can find a place super-dense with valuable metals or minerals). All sorts of awesome things we can do on the moon.

The only reason for a manned mission is to appeal to stupid people. You do science, a few people are impressed; but you send a person there, every Tom, Dick and Harry wants to know about it. Intelligent people will be interested in a manned mission for sure, but NASA had them hooked anyway.

Dubslow 2012-12-27 22:07

[QUOTE=jasong;322837]mining(if we can find a place super-dense with valuable metals or minerals).[/QUOTE]
If we ever get fusion figured out, I've heard the moon is chock-full of helium-3.

xilman 2012-12-28 07:31

[QUOTE=Dubslow;322857]If we ever get fusion figured out, I've heard the moon is chock-full of helium-3.[/QUOTE]You've been misinformed.

AFAWK, the top few centimetres of the lunar regolith contains a tiny amount of helium captured from the solar wind. A tiny fraction of that is [sup]3[/sup]He. Extracting the [sup]3[/sup]He would be very expensive. About the only things to the advantage of mining lunar helium is that the moon presents a large collecting area and it's been collecting the solar wind for a loing time. The moon is relatively close by at the bottom of a relatively gentle gravity well but collectors in earth orbit are even better in those respects.

The atmospheres of the gas giants, on the other hand, contain several per cent helium at a pressure or temperature of anything you would like, within reason. They are a long way from here but that impacts only latency, not capacity. The disadvantages are their ferocious gravity wells and the lack of any solid surface which you didn't bring with you.

Did you not realise that I had an ulterior motive in suggesting a mission for a long-term exploration of the Jovian atmosphere?

Uncwilly 2012-12-29 07:02

[QUOTE=chappy;322776]I suppose it would be out of line to suggest that NASA should send a craft to the nearest star: Sol.[/QUOTE]
There have been discussions about this. The idea has been floated, but there is no current mission being planned. I like this one.

Uncwilly 2012-12-29 07:05

Another mission that has been talked about, but not currently in the works that I like:

An asteroid deflection mission. There are suggestions that a practice mission be undertaken so that we can learn how well it might work.

fivemack 2012-12-29 09:25

There is a mission planned to the Sun: Solar Probe Plus [url]http://solarprobe.jhuapl.edu[/url] being built at JHU APL to launch 2018. Interesting trajectory with repeated Venus flybys to lower perihelion to 0.04AU.

fivemack 2012-12-29 09:46

I'd like to put three small satellites 120 degrees apart around Callisto's orbit, to get real-time full-planet-scale imagery of the Jovian atmosphere. Jupiter is about two degrees wide as seen from Callisto-orbit, so a well-corrected six-inch telescope onto a large CCD (e2v offers a 9Mx9M device with 10um pixels) gets you adequate imagery, 20km pixels are about the same as the closest flyby missions have produced to date but this would give coverage comparable to Earth's meteosat network.

(hmm, yes, you'd also want IR imaging since Jupiter is strongly self-luminous and that would mean you didn't waste the time when one and a half of the satellites are looking at the unilluminated side of Jupiter)

Callisto orbit is well outside the radiation belts; I don't know what the gravitational stable points in the Galilean system look like so this may need prohibitively much fuel for orbit control.

xilman 2012-12-29 13:01

I'd like to put something useful in the solar focal sphere but although it just about might be within budget, it would take far too long to get there. Increase both constraints by a factor of a few and it would become possible.

Closer to home, it would be nice to land a technology prototype on Mars which converts atmospheric carbon dioxide into carbon monoxide and oxygen. The products are used as rocket fuel for sample return to earth. Once again, budgetary constraints are likely to be the limiting factor.

science_man_88 2012-12-29 14:23

[QUOTE=Uncwilly;322773]For all of you space buffs and fans, it is time to vent!

What is the most overlooked mission that you think should happen now?
What is a mission that you think should be given priority?
What mission would fill in some vital piece of knowledge or provide a new window of insight or explore new territory?

The rules:[LIST][*]It must be an unmanned mission.[*]It must not be directly overlap any current or currently [U][COLOR=DarkRed]planned[/COLOR][/U] mission. This includes ESA (and all other European space agencies), NASA, RSA, [URL="http://b612foundation.org/"]B612[/URL], JAXA, and all other national agencies.[*]You have ~$1billion to work with.[*]No breakthrough tech allowed.[*]Must launch within 7 years and [B]flight time to destination must be under 10 years.[/B] Primary Mission time is open, but must be covered by the funding.[*]Launch vehicles must be near term available (no SLS, but Falcon Heavy is ok), max of 2 launches, and the cost of the launches are part of the $1B. (Assume that the launched craft can auto-dock if needed).[*]A nominal amount of Deep Space Network support is available for a token charge.[/LIST]
Surprise us. Be creative.[/QUOTE]

this limit and dawns max acceleration in space can give us distances for specific types of mission, d=0 mpd * 3652 d +.5*60mph/d*(3652 d)^2 = 2.5 miles/h/h * (87648 h)^2 = 2.5 miles/h/h * 7682171904 h^2 = 19205429760 miles for a 10 year 1 way mission.

xilman 2012-12-29 15:11

[QUOTE=science_man_88;323017]this limit and dawns max acceleration in space can give us distances for specific types of mission, d=0 mpd * 3652 d +.5*60mph/d*(3652 d)^2 = 2.5 miles/h/h * (87648 h)^2 = 2.5 miles/h/h * 7682171904 h^2 = 19205429760 miles for a 10 year 1 way mission.[/QUOTE]Where do you get those numbers from? I understand the 3652 as being hours per ten years. Though if you insist on using ludicrously precise results, you should use 3652.425 instead. Personally I'd say 3650 is more than adequate precision and your conclusion should be 19G miles.

In particular, where does that "60"? come from?

19G miles is 30G km in more conventional units and 20 AU is even more conventional in this area. It's about the right order of magnitude in that Uranus is about that distance from us and the Voyager probes took about that length of time to get there, though not in a straight line of course. The distance they actually travelled to reach Uranus was significantly greater.

If you want to go as far as possible outwards you should be able to do significantly better by bouncing off at least two of the Moon, Venus, the Earth, Jupiter and Saturn en route, especially if you use a long-duration low-thrust ion engine during the cruise phases. Voyager was constrained by having to visit Uranus after its earlier and compulsory gravity assists from Jupiter and Saturn. A long distance mission to the middle of nowhere doesn't have that limitation.

The science from such a package would, in my view, best be devoted to observing charged particles, magnetic fields and ultra low frequency radio. Put cameras on board if you wish for the planetary fly-bys, but heading out into interstellar space is likely to be better served by using a significant fraction of the payload for electrical power, reaction mass (presumably Xe or Hg0, a very large comms antenna and even longer ULF radio antennae. If the comms antenna is large enough, in the 20 to 100m class, it could do double duty for radio astronomy and, in particular, enable mult-AU baseline interferometry. I haven't yet worked out the numbers but it may be possible to detect parallax shifts for the nearest quasars which would get the cosmologists excited.

Uncwilly 2012-12-29 17:40

[QUOTE=Uncwilly;322994]There have been discussions about this. The idea has been floated, but there is no current mission being planned. I like this one.[/QUOTE][QUOTE=fivemack;323007]There is a mission planned to the Sun: Solar Probe Plus [url]http://solarprobe.jhuapl.edu[/url] being built at JHU APL to launch 2018. Interesting trajectory with repeated Venus flybys to lower perihelion to 0.04AU.[/QUOTE]
Did not know that had moved from the thought about to the doing phase.

[QUOTE=fivemack;323008]I'd like to put three small satellites 120 degrees apart around Callisto's orbit, to get real-time full-planet-scale imagery of the Jovian atmosphere.[/QUOTE]This would also be really cool for seeing asteroid strikes. Imagine if this was out there when Shoemaker-Levy 9 arrived. :smile:

[QUOTE=xilman;323024]The science from such a package would, in my view, best be devoted to observing charged particles, magnetic fields and ultra low frequency radio. Put cameras on board if you wish for the planetary fly-bys, but heading out into interstellar space is likely to be better served by using a significant fraction of the payload for electrical power, reaction mass (presumably Xe or Hg0, a very large comms antenna and even longer ULF radio antennae. If the comms antenna is large enough, in the 20 to 100m class, it could do double duty for radio astronomy and, in particular, enable mult-AU baseline interferometry. I haven't yet worked out the numbers but it may be possible to detect parallax shifts for the nearest quasars which would get the cosmologists excited.[/QUOTE]I like this mission. Which direction would you send this probe? Note in [URL="http://www.redshift-live.com/binaries/asset/image/20024/image/The_flight_paths_of_the_Voyager_and_Pioneer_space_probes.jpg"]this image[/URL], that 3 of the four interstellar probes have gone off in one general direction.

xilman 2012-12-29 17:59

[QUOTE=Uncwilly;323039]I like this mission. Which direction would you send this probe? Note in [URL="http://www.redshift-live.com/binaries/asset/image/20024/image/The_flight_paths_of_the_Voyager_and_Pioneer_space_probes.jpg"]this image[/URL], that 3 of the four interstellar probes have gone off in one general direction.[/QUOTE]It depends very much on where the planets are located at time of launch.

An attractive proposition is to send it significantly out of the plane of the solar system but that can only be done at the final planetary encounter, for obvious reasons. If the interferometry idea pans out, a vector at right angles to (the maximum number of) the interesting point sources would also be indicated. I don't yet know what that might be.

xilman 2012-12-29 18:09

Recent supernovae detection
 
Another mission: fly a soft-gamma ray observatory with a high-resolution (arcsec or better) telescope optimized for the 1.809MeV gammas emitted by the decay of [sup]26[/sup]Al. This isotope is created a few earth-masses at a time in supernovae explosions and has a half live approaching a million years. Current observations have an angular resolution measured in degrees so it's possible to say that there have been quite a lot of SN towards the galactic centre (big surprise!) and a clump out Cygnus way, but not much more than that can be deduce.

Being able to map the locations, ages, distribution and velocities of supernovae and, especially, their ejecta would be rather useful.

This one could fly in relatively low earth orbit and wouldn't need excessive fuel and comms requirements, so several tonnes could be used for the telescope if desired.. It could even be designed to be user-serviceable.


Do you yet get the idea that I could propose missions at the rate of a few a week for a significant length of time if I set my mind to it? There's no shortage of ideas, only a shortage of cash.

Uncwilly 2012-12-29 19:23

[QUOTE=xilman;323042]Do you yet get the idea that I could propose missions at the rate of a few a week for a significant length of time if I set my mind to it? There's no shortage of ideas, only a shortage of cash.[/QUOTE]Indeed. The pair of scopes that NASA received from the NRO. Those would be fun to play with. Put them out near one of the Lagrange points. Tie them together as far apart as practical to make a full time space based optical interferometer.

fivemack 2012-12-29 21:47

I'm afraid I do get a bit annoyed by the way that, whenever someone mentions space telescopes in quantities greater than one, someone else mentions interferometry. Particularly with the NRO telescopes, which are short focal length and optimised for very-wide-field work in the visual in almost exactly not the way that you'd want for interferometer elements.

NASA put about a billion dollars into space interferometry development, to discover that building an exciting space interferometer cost more than they would be prepared to spend ... planet-hunting by interferometric astrometry is so much more expensive than Kepler.

VLBI with an actually-long baseline is more interestingly practical - big deployable antenna are off-the-shelf, JAXA has launched a test comsat with a 17-metre one. Regrettably the very biggest ones are off the NSA's shelf and so you probably have to pay for the development again.

With current 10,000km baselines you can get 10-microarcsecond precision, which allows pretty good parallax measurements out to 10kpc within the Milky Way, and direct measurements of Keplerian motion of water masers to 60Mpc - there are admittedly issues of getting enough signal for those fairly weak sources. So you probably do need a billion-kilometre baseline for direct parallax to quasars, but the water-maser work might well be possible with sufficiently large dishes at Earth-Sun L4 and L5.

tServo 2012-12-29 21:58

EUROPA !! We must go to this moon of Jupiter for the obvious reason that it may harbor life in its oceans. Even if not, it is one of the most interesting places in the solar system. Anyway, we've got to check it out to see if one of A.C. Clarke's monoliths stands guard there !

Uncwilly 2012-12-29 22:40

[QUOTE=fivemack;323053]Particularly with the NRO telescopes, which are short focal length and optimised for very-wide-field work in the visual in almost exactly not the way that you'd want for interferometer elements.[/QUOTE]Yes, but they are FREE.

science_man_88 2012-12-29 23:07

[QUOTE=xilman;323024]Where do you get those numbers from? I understand the 3652 as being hours per ten years. Though if you insist on using ludicrously precise results, you should use 3652.425 instead. Personally I'd say 3650 is more than adequate precision and your conclusion should be 19G miles.

In particular, where does that "60"? come from?

19G miles is 30G km in more conventional units and 20 AU is even more conventional in this area. It's about the right order of magnitude in that Uranus is about that distance from us and the Voyager probes took about that length of time to get there, though not in a straight line of course. The distance they actually travelled to reach Uranus was significantly greater.

If you want to go as far as possible outwards you should be able to do significantly better by bouncing off at least two of the Moon, Venus, the Earth, Jupiter and Saturn en route, especially if you use a long-duration low-thrust ion engine during the cruise phases. Voyager was constrained by having to visit Uranus after its earlier and compulsory gravity assists from Jupiter and Saturn. A long distance mission to the middle of nowhere doesn't have that limitation.

The science from such a package would, in my view, best be devoted to observing charged particles, magnetic fields and ultra low frequency radio. Put cameras on board if you wish for the planetary fly-bys, but heading out into interstellar space is likely to be better served by using a significant fraction of the payload for electrical power, reaction mass (presumably Xe or Hg0, a very large comms antenna and even longer ULF radio antennae. If the comms antenna is large enough, in the 20 to 100m class, it could do double duty for radio astronomy and, in particular, enable mult-AU baseline interferometry. I haven't yet worked out the numbers but it may be possible to detect parallax shifts for the nearest quasars which would get the cosmologists excited.[/QUOTE]

I found a source that said dawn's fastest acceleration (and apparently the fastest) in space was at 60 mph/ day as for the formula it's just my way of working with d=vi*t+.5at^2, admittedly I didn't quite think of gravity assist in this scenario.

chalsall 2012-12-29 23:25

[QUOTE=fivemack;323053]NASA put about a billion dollars into space interferometry development, to discover that building an exciting space interferometer cost more than they would be prepared to spend ... planet-hunting by interferometric astrometry is so much more expensive than Kepler.[/QUOTE]

Yeah. Funny. It worked great here on Earth (where everything is relatively fixed). Didn't work so well is space (where everything is relatively moving)...

[QUOTE=fivemack;323053]So you probably do need a billion-kilometre baseline for direct parallax to quasars, but the water-maser work might well be possible with sufficiently large dishes at Earth-Sun L4 and L5.[/QUOTE]

Synthetic stereo vision and reconstruction is OTC now-a-days in the Computer Vision space.

fivemack 2012-12-29 23:47

[QUOTE=Uncwilly;323060]Yes, but they are FREE.[/QUOTE]

They are free white elephants - the missions they'd be really useful for are ones where they're pointed at Earth, and that's explicitly forbidden by the terms of the deal handing them over. Building a spacecraft to put them on, and launching it, will run into high hundreds of millions of dollars ... for mirrors that big you need pointing to 100-milliarcsecond over the course of multi-hour exposures, and whilst entirely possible that's not a cheap thing to design into a spacecraft.

They're not capable of being run cold enough to work in the cosmologically-interesting bits of the infra-red; they could do awesome sky-survey work in the optical because of the size of the field of view, if you could afford the focal plane array (focal length is about 20 metres, field of view about one square degree so 30cm on a side, tiling that with 10um pixels is 64 4k x 4k arrays at about a million dollars each for space-qualified hardware), but the data rates are getting high enough to be inconvenient.

I expect they'll get launched because it would be such awful PR not to launch them.

fivemack 2012-12-29 23:52

[QUOTE=chalsall;323064]Yeah. Funny. It worked great here on Earth (where everything is relatively fixed). Didn't work so well is space (where everything is relatively moving)...[/QUOTE]

I think you need to read some of the SIM white papers; the space interferometry proposals that got developed were ones in which the spacecraft consisted of various pieces mounted very solidly to an extremely solid optical bench. The ESO's [i]Messenger[/i] magazine has some very good articles about the difficulties of getting the VLTI working, in an environment where you can work on the real hardware after it was designed and where you can bolt things to foundations sunk into Andean bedrock.

Nobody's got close to a design which would get wavefront combining between free-flying spacecraft; microwave ranging between free-fliers has been done quite effectively for GRACE and GRAIL, but that's a hundred times worse precision than would be needed to get fringes.

[QUOTE]Synthetic stereo vision and reconstruction is OTC now-a-days in the Computer Vision space.[/QUOTE]

Interferometry is very, very different from synthetic stereo vision.

chalsall 2012-12-29 23:59

[QUOTE=fivemack;323066]I think you need to read some of the SIM white papers; the space interferometry proposals that got developed were ones in which the spacecraft consisted of various pieces mounted very solidly to an extremely solid optical bench. The ESO's [i]Messenger[/i] magazine has some very good articles about the difficulties of getting the VLTI working, in an environment where you can work on the real hardware after it was designed and where you can bolt things to foundations sunk into Andean bedrock.[/QUOTE]

Links would be appreciated.

[QUOTE=fivemack;323066]Nobody's got close to a design which would get wavefront combining between free-flying spacecraft; microwave ranging between free-fliers has been done quite effectively for GRACE and GRAIL, but that's a hundred times worse precision than would be needed to get fringes.[/QUOTE]

But, as you say, NASA spent a billion dollars trying to do this.

WTF?

[QUOTE=fivemack;323066]Interferometry is very, very different from synthetic stereo vision.[/QUOTE]

I'm very aware of that.

What has produced the better results?

fivemack 2012-12-29 23:59

[QUOTE=xilman;323042]Another mission: fly a soft-gamma ray observatory with a high-resolution (arcsec or better) telescope optimized for the 1.809MeV gammas emitted by the decay of [sup]26[/sup]Al[/QUOTE]

Does anyone know how to make optics for that line? NuSTAR is state of the art with depth-graded multilayers, and manages 40 arc-second resolution at 80keV; the papers about unexpectedly high refractive indices of silicon lenses at 2MeV suggest that the 'unexpectedly high' value is still something like n=1+1e-6, at which point you're talking separate lens and detector spacecraft at the very least.

fivemack 2012-12-30 00:19

[QUOTE=chalsall;323068]Links would be appreciated[/QUOTE]

[url]http://arxiv.org/pdf/0807.1668.pdf[/url] is quite a nice overview of the SIM-Lite mission concept design. [url]http://arxiv.org/pdf/0708.3953v2.pdf[/url] is more a summary of the things that astronomers would be able to do given SIM-Lite or equivalent.

The 'PIONIER' article in [url]http://www.eso.org/sci/publications/messenger/archive/no.146-dec11/messenger-no146.pdf[/url], the GRAVITY article at [url]http://www.eso.org/sci/publications/messenger/archive/no.143-mar11/messenger-no143-16-24.pdf[/url] and the earlier article at [url]http://www.eso.org/sci/publications/messenger/archive/no.137-sep09/messenger-no137-25-29.pdf[/url] give some idea of the technical difficulties of getting the VLTI to work; VLTI interferometry has
resolved the disc of the red-giant component in symbiotic binary systems. Probably the most visually appealing optical-interferometry example is the CHARA Array image of the eclipsing disc at Epsilon Aurigae: [url]http://www.gsu.edu/41129.html[/url]


NASA spent a lot of money (it was in fact nearer $200 million than $1 billion) doing technology development for microarcsecond astrometry from large optical-bench structures; interferometry between free-flying spacecraft was always running at much more of a wish-list level.

chalsall 2012-12-30 00:45

[QUOTE=fivemack;323072][url]http://arxiv.org/pdf/0807.1668.pdf[/url] is quite a nice overview of the SIM-Lite mission concept design. [url]http://arxiv.org/pdf/0708.3953v2.pdf[/url] is more a summary of the things that astronomers would be able to do given SIM-Lite or equivalent.

NASA spent a lot of money (it was in fact nearer $200 million than $1 billion) doing technology development for microarcsecond astrometry from large optical-bench structures; interferometry between free-flying spacecraft was always running at much more of a wish-list level.[/QUOTE]

OK. Cool. Thanks.

Did anyone run an analysis as to what is more effective -- interferometry between closely spaced observers (the closer, the more error) or synthetic observations greatly distanced?

Uncwilly 2012-12-30 00:58

[QUOTE=fivemack;323065]They are free white elephants - the missions they'd be really useful for are ones where they're pointed at Earth, and that's explicitly forbidden by the terms of the deal handing them over.[/quote]How about putting one into lunar orbit and looking down there?
Take the other one, put it out in an orbit around E-M L2. Have it dedicated to Hubble deep field type projects. The data thus accumulated could integrated on-board before transmission.
[QUOTE=fivemack;323072]NASA spent a lot of money (it was in fact nearer $200 million than $1 billion) doing technology development for microarcsecond astrometry from large optical-bench structures; interferometry between free-flying spacecraft was always running at much more of a wish-list level.[/QUOTE]That is part of the reason that I suggested that they be physically linked together.

xilman 2012-12-30 08:31

[QUOTE=fivemack;323069]Does anyone know how to make optics for that line? NuSTAR is state of the art with depth-graded multilayers, and manages 40 arc-second resolution at 80keV; the papers about unexpectedly high refractive indices of silicon lenses at 2MeV suggest that the 'unexpectedly high' value is still something like n=1+1e-6, at which point you're talking separate lens and detector spacecraft at the very least.[/QUOTE]Grazing incidence reflectors? Masks?

It's not something I've put any great resources into finding out the best technology so arcsec resolution may be impractical within budget. Even arcmin would be orders of magnitude better than what we have now.

xilman 2012-12-30 08:46

[QUOTE=xilman;323024]19G miles is 30G km in more conventional units and 20 AU is even more conventional in this area. It's about the right order of magnitude in that Uranus is about that distance from us and the Voyager probes took about that length of time to get there, though not in a straight line of course. The distance they actually travelled to reach Uranus was significantly greater.[/QUOTE]
Oops! Major cock-up :redface:

One AU is 0.15G km, so 30G km is 200AU, not 20AU as posted and used in subsequent burblings.

It doesn't make too much difference to the maximum solar distance as much of the velocity is tangential (as I did note for the Voyager missions) but it's still an embarrassing OoM error. :doh!:

Uncwilly 2012-12-31 00:11

A sun observing probe that orbits the Earth-Sun L3 point. This would help seeing the dark side of the sun, giving us a complete view.


A small cluster of seismographs dropped around on the moon (not unlike the Ranger missions). Then smack the moon 3 different times at different locations with significant different energies.

retina 2012-12-31 01:01

[QUOTE=Uncwilly;323138]A sun observing probe that orbits the Earth-Sun L3 point. This would help seeing the dark side of the sun, giving us a complete view.[/QUOTE]How will you communicate with the probe? There is a rather large ball of hot plasma that gets in the way of any signals you might want to transmit between the probe and Earth.

Uncwilly 2012-12-31 01:08

[QUOTE=retina;323141]How will you communicate with the probe? There is a rather large ball of hot plasma that gets in the way of any signals you might want to transmit between the probe and Earth.[/QUOTE][QUOTE=Uncwilly;323138]A sun observing probe that orbits the Earth-Sun L3 point. This would help seeing the dark side of the sun, giving us a complete view.[/QUOTE]The probe would not be stationed directly at L3, rather it would orbit the point. It is not crazy. Please read the section on L3 at wikipedia: [url]http://en.wikipedia.org/wiki/Lagrangian_point#L3[/url]

axn 2012-12-31 03:17

[QUOTE=Uncwilly;323138]the dark side of the sun[/QUOTE]
The what? :shock:

Uncwilly 2012-12-31 03:45

[QUOTE=axn;323149]The what? :shock:[/QUOTE]
From [url]http://science.nasa.gov/science-news/science-at-nasa/2009/23jan_darkside/[/url]
[QUOTE]"This is a perspective we've never had before," says STEREO mission scientist Lika Guhathakurta of NASA headquarters.
"We're now monitoring more than 270 degrees of solar longitude—that's 3/4ths of the star."

"After all these years," she laughs, "we're finally getting to see the [COLOR="Teal"]dark side of the Sun[/COLOR]."

(Editor's note: The Sun has no dark side. That was a solar physics joke.)[/QUOTE]

retina 2012-12-31 04:35

[QUOTE=Uncwilly;323143]The probe would not be stationed directly at L3, rather it would orbit the point. It is not crazy. Please read the section on L3 at wikipedia: [url]http://en.wikipedia.org/wiki/Lagrangian_point#L3[/url][/QUOTE]Thanks for the link. I think at a minimum the orbit has to be double the diameter of the Sun so that we can peek at the probe around the Sun's edges on a continuous basis. But practically I would expect the orbit needs to be larger than that to make signal reception more reliable.

xilman 2012-12-31 07:59

[QUOTE=fivemack;323053]I'm afraid I do get a bit annoyed by the way that, whenever someone mentions space telescopes in quantities greater than one, someone else mentions interferometry. Particularly with the NRO telescopes, which are short focal length and optimised for very-wide-field work in the visual in almost exactly not the way that you'd want for interferometer elements.

NASA put about a billion dollars into space interferometry development, to discover that building an exciting space interferometer cost more than they would be prepared to spend ... planet-hunting by interferometric astrometry is so much more expensive than Kepler.

VLBI with an actually-long baseline is more interestingly practical - big deployable antenna are off-the-shelf, JAXA has launched a test comsat with a 17-metre one. Regrettably the very biggest ones are off the NSA's shelf and so you probably have to pay for the development again.

With current 10,000km baselines you can get 10-microarcsecond precision, which allows pretty good parallax measurements out to 10kpc within the Milky Way, and direct measurements of Keplerian motion of water masers to 60Mpc - there are admittedly issues of getting enough signal for those fairly weak sources. So you probably do need a billion-kilometre baseline for direct parallax to quasars, but the water-maser work might well be possible with sufficiently large dishes at Earth-Sun L4 and L5.[/QUOTE]While in the sauna yesterday I came across a flaw in my original mission profile. It may be reparable.

The original had the large antenna doing double duty for down link and astronomy. The former requires that it point at the Earth; the latter that it point almost anywhere but. There's too much noise coming from these parts to be able to see faint astronomical objects. Even if that limitation is overcome, by listening in a particularly quiet band for instance, the geometry is not conducive to parallax measurements.

As I see it, the best solution would be to use a 2-5m dish for comms while near the Earth, up to 30 AU away say, switching over to the big dish once the bandwidth gets too low for the interferometry data. Thereafter, for as long as the spacecraft lasts and anyone cares to listen, there will be adequate bandwidth for the other science packages. The switchover would be done with the same manoeuvring subsystem used to point the big dish at the astronomical sources, possibly augmented by attitude control rockets.

I still wouldn't bother with cameras, though.

xilman 2012-12-31 09:54

Like bananas
 
Another project came to mind while in the sauna yesterday. This one needs to be flown in relatively low earth orbit.

Quite a few studies have been made of long-term effects on orbiting organisms. Relatively little has been done on genetic adaptability to weightlessness. Ground-based studies of radiation adaptation have been widespread.

The breeding cycle for Drosophila melanogaster is approximately two weeks, though it can vary significantly with living conditions. In stressful environments, thirty to fifty generations is likely long enough for Darwinian evolution to become noticeable. There is probably enough background radiation in earth orbit to induce mutations anyway but a mutagen could be included if needed.

The satellite initially contains 30-50 samples of wild-type Dmel eggs in separate containers each of which are big enough to let them (try to) fly around and indulge in relatively normal behaviour. As Dmel are only a couple of millimeters long, this isn't actually a very large volume. Needless to say, the interior of the space craft has to be fly-rated, so kept warm, lit on a diurnal cycle, pressurized, oxygenated, etc. Every two weeks, or so, one of the remaining containers is depressurized and cryogenically frozen. A mechanism to move it into a permanently shaded part of the craft should be enough to keep it cold.

When all the containers are ready, they are returned to earth for detailed study in the lab.

As you can easily work out, this is a 18-24 month mission.

Dubslow 2012-12-31 10:07

[QUOTE=xilman;323175]Another project came to mind while in the sauna yesterday. This one needs to be flown in relatively low earth orbit.
[/QUOTE]

Ooooohh, good one. It can essentially be done now, at hardly any (extra) cost, and the results would be quite interesting to a significant population of the Earth (where by significant I mean like above 0.001% or so, maybe even more depending on exactly how "interesting" you mean).

xilman 2012-12-31 10:25

[QUOTE=fivemack;323053]With current 10,000km baselines you can get 10-microarcsecond precision, which allows pretty good parallax measurements out to 10kpc within the Milky Way, and direct measurements of Keplerian motion of water masers to 60Mpc - there are admittedly issues of getting enough signal for those fairly weak sources. So you probably do need a billion-kilometre baseline for direct parallax to quasars, but the water-maser work might well be possible with sufficiently large dishes at Earth-Sun L4 and L5.[/QUOTE]Here's a quick order of magnitude computation.

Assume the first position measurement is taken at 1G km from the earth (7AU, or half-way between Jupiter and Saturn, probably at a decent period after a Jovian gravity assist). That's 1e5 times the current baselines, so the positional measurements could be good to 10e-6 / 1e5 == 1e-10 arcsec. Wait a few more years and the probe will be over twice as far away so the parallax baseline will be 10AU. Note that this is still well within the orbit of Neptune and is easy to reach even with 40-year old technology.

A parsec is defined as the distance at which a length of 1AU subtends an angle of one arcsec, so a 10AU baseline subtends 1 arcsec at 10pc and 1e-10 arcsec at 1e11pc. 100Gpc is way beyond the edge of the observable the universe and so nearby quasars at a few gigaparsec should show useful parallax.

This pretty much determines the probe trajectory to be as normal as possible to the directions of the largest number of radio-bright quasars.

chappy 2013-07-28 14:05

You space nuts have been [URL="http://news.yahoo.com/nasa-flooded-asteroid-exploration-ideas-180717913.html"]busy.[/URL]

TheMawn 2013-07-28 18:27

*GASSP*

Oh thank god I made it out of there alive. I started reading the comments and was almost choked by the stupid.

In all fairness, this does sound like a pretty amazing idea. As a mechanical engineer to be, working on asteroid mining would easily be my number 1 dream job. Could be pretty lucrative too, by the sounds of it.

tha 2013-07-28 18:54

This is the kind of mission that could really outdo the others:

[URL="http://odyssey.onera.fr/"]http://odyssey.onera.fr/[/URL]

ewmayer 2013-07-28 19:40

[QUOTE=TheMawn;347608]*GASSP*

Oh thank god I made it out of there alive. I started reading the comments and was almost choked by the stupid.[/QUOTE]

I think they fully expect over 99% of submissions to be either stupid and/or infeasible - it's the rare bright idea their own experts might not have come up with they are angling for here.

chappy 2013-07-28 21:40

[QUOTE=ewmayer;347616]I think they fully expect over 99% of submissions to be either stupid and/or infeasible - it's the rare bright idea their own experts might not have come up with they are angling for here.[/QUOTE]

I saw Don Blazys on the forum earlier, you want I should send him NASA way?

kracker 2013-07-28 22:46

[QUOTE=chappy;347629]I saw Don Blazys on the forum earlier, you want I should send him NASA way?[/QUOTE]

[URL]http://www.youtube.com/watch?v=umDr0mPuyQc[/URL]

chappy 2013-07-29 03:16

1 Attachment(s)
we need to get off this rock.

chappy 2013-11-01 17:42

[url]http://www.news.com.au/technology/science/saudi-sheikh-ali-al-hemki-declares-fatwa-against-manned-missions-to-mars/story-fnjwlcze-1226750128434[/url]

chappy 2013-12-13 03:46

[YOUTUBE]d0PtWLPmnTg[/YOUTUBE]

kladner 2013-12-13 04:52

Do you want fries with that? :smile:

chappy 2013-12-14 16:34

[URL]http://www.space.com/23968-china-moon-rover-historic-lunar-landing.html[/URL]

jasong 2013-12-18 19:22

[QUOTE=chappy;362048][URL]http://www.space.com/23968-china-moon-rover-historic-lunar-landing.html[/URL][/QUOTE]
lol, no, we want someone on OUR side doing that.

I think the optimal situation would be for a country that isn't the United States, but is allied with us, doing something similar. Then everybody can get excited about it without American politics being a big problem.

Flatlander 2013-12-19 15:54

1 Attachment(s)
...

LaurV 2013-12-19 17:05

Nice post Flatulander!

xilman 2013-12-23 18:06

Keep banging those rocks together guys
 
Here's another mission I would like to see flown. It (probably) takes two launches.

The first mission lands several seismometers on the lunar surface to complement the ones left behind in the Apollo era. Ideally there should be at least four, one at each vertex of an regular tetrahedron but then at least one would be on the dark side and we'd need a comsat to listen to what it has to say. Perhaps the spacecraft bus carrying the sub-probes could stand in. Otherwise, at least five at the visible vertices of an octahedron (slighty distorted so that all are visible from earth except perhaps at times of extreme libration).

The other mission contains nothing but dumb missiles, likely made of tungsten to get the mass up and the volume down, in high lunar orbit. They would be of various masses and fitted with rockets of varying power so that a wide range of impact velocities, momenta and kinetic energies are available. This half of the mission could take a long time to get there if necessary. The launcher should be optimised to getting as much mass into high lunar orbit as possible without worrying about journey time.

When everything is in place, start practising tomography and get a good 3-d picture of the lunar interior. Try not to hit anything important and/or of sentimental value.

Uncwilly 2013-12-23 19:59

[QUOTE=xilman;362717]Here's another mission I would like to see flown. [/quote][QUOTE=xilman]at least one would be on the dark side and we'd need a comsat to listen to what it has to say.[/quote]"Back side" we must eliminate that other term for the sake of scientific literacy.

An Earth-Moon L2 halo orbiting comsat is on many peoples' wish lists: for people on the far side, for radio telescopes on the far side, your idea, etc.

[QUOTE=xilman]The other mission contains nothing but dumb missiles,[/quote] Thinking off the cuff, why not leave them in the highly eccentric orbit that is a result of the orbital transfer? Taking the slow boat over there should leave them in an orbit that almost touches L1. From there, the nudge to make it an impactor might be much smaller than from a circular high orbit.

There are objects to shipping explosives to space in quantity. But using high explosives either in place of or with the tungsten might be fun (blasting a new crater on the front side when the moon is above the horizon for Jodrell Bank and the Keck's, would garner some attention of the lay community.)

My 10 pesos. :two cents:

only_human 2013-12-23 20:15

[QUOTE=xilman;362717]Here's another mission I would like to see flown. It (probably) takes two launches.

The first mission lands several seismometers on the lunar surface to complement the ones left behind in the Apollo era. Ideally there should be at least four, one at each vertex of an regular tetrahedron but then at least one would be on the dark side and we'd need a comsat to listen to what it has to say. Perhaps the spacecraft bus carrying the sub-probes could stand in. Otherwise, at least five at the visible vertices of an octahedron (slighty distorted so that all are visible from earth except perhaps at times of extreme libration).

The other mission contains nothing but dumb missiles, likely made of tungsten to get the mass up and the volume down, in high lunar orbit. They would be of various masses and fitted with rockets of varying power so that a wide range of impact velocities, momenta and kinetic energies are available. This half of the mission could take a long time to get there if necessary. The launcher should be optimised to getting as much mass into high lunar orbit as possible without worrying about journey time.

When everything is in place, start practicing tomography and get a good 3-d picture of the lunar interior. Try not to hit anything important and/or of sentimental value.[/QUOTE]Why not throw Moon rocks at the Moon? That would accomplish your seismographic tomography goal and offer a test-bed for the development of a [URL="http://en.wikipedia.org/wiki/Lunar_space_elevator"]Lunar space elevator[/URL] that could afford to misdeliver a few loads:[QUOTE]A lunar space elevator is similar in concept to the better known Earth-based space elevator idea, but since the Moon's mass and rotational speed are much lower than the Earth's, the engineering requirements for constructing a lunar elevator system can be met using currently available materials and technology. The primary difference in the design of a lunar elevator is that the cable, or tether extends considerably farther out from the lunar surface into space than one that would be used in an Earth-based system. However, the main function of a space elevator system is the same in either case; both allow for a reusable, controlled means of transporting payloads of cargo, or possibly people, between a base station at the bottom of a gravity well and a docking port in outer space.

A lunar elevator could significantly reduce the costs and improve reliability of soft-landing equipment on the lunar surface. For example, it would permit the use of mass-efficient (high specific impulse), low thrust drives such as ion drives which otherwise cannot land on the Moon. Since the docking port would be connected to the cable in a microgravity environment, these and other drives can reach the cable from low Earth orbit (LEO) with minimal launched fuel from Earth. With conventional rockets, the fuel needed to reach the lunar surface from LEO is many times the landed mass, thus the elevator can reduce launch costs for payloads bound for the lunar surface by a similar factor.[/QUOTE]Instead of LEO to Moon, just get loads from the Moon and then drop them at trajectories that will land them back there. That way the Moon won't be too polluted with terrestrial sources. Then the need for refined, lighter loads that hit at high velocity may not as necessary if we have plenty of (albeit lower velocity) mass to sling around. If some of all that material gets piled up for building material or shielding: bonus.[QUOTE]In 2005 Jerome Pearson completed a study for NASA Institute of Advanced Concepts which showed the concept is technically feasible within the prevailing state of the art using existing commercially available materials.[6]

In October 2011 on the LiftPort website Laine announced that LiftPort is pursuing a Lunar space elevator as an interim goal before attempting a terrestrial elevator. At the 2011 Annual Meeting of the Lunar Exploration Analysis Group (LEAG), LiftPort CTO Marshall Eubanks presented a paper on the prototype Lunar Elevator co-authored by Michael Laine.[7]

In August 2012, Liftport announced that the project may actually start near 2020.[8][9][10][11][/QUOTE]One thing I would like all the Google cars that run around with Call of Duty game playing minders scarfing up rocks on the Moon to do is be on the lookout for Earth rocks that may have landed on the Moon in the past.
[URL="http://science1.nasa.gov/science-news/science-at-nasa/2002/18oct_earthrocks/"]Earth rocks on the Moon[/URL][QUOTE]When a large body strikes Earth, impact debris can be accelerated to orbital speed and achieve Earth orbit. Four billion years ago Earth was probably surrounded by debris ejected in this way. (The Moon itself is a big piece of Earth that sundered when a Mars-sized planetestimal hit 4.5 billion years ago.) During the Period of Heavy Bombardment, the Moon was considerably closer to the Earth than it is now, perhaps 3 times closer. This placed the Moon in an ideal position to sweep up some of the terrestrial debris.

Because the Moon lacks weather or tectonic activity, that debris might still be there. While some has undoubtedly been destroyed by subsequent impacts of asteroids or comets on the Moon, some might have survived in the lunar soil. A recent study by Univ. of Washington graduate students John Armstrong and Llyd Wells, in collaboration with Guillermo Gonzalez at Iowa State, suggests that as much as 20,000 kg of Earth material could cover every 100 square kilometers of the Moon.

David McKay, an astrobiologist at NASA's Johnson Space Center, notes that "the Moon was in a unique position to be a collector of ejecta from Earth. If we look in the right places, we could find a reservoir of materials for study."[/QUOTE]

chalsall 2013-12-23 20:29

[QUOTE=jasong;362410]lol, no, we want someone on OUR side doing that.[/QUOTE]

Interesting how you frame this discussion with regards to "sides". Aren't all "humans" on the same side against the "aliens" (or incoming energy...)?

Would you agree that it would be a /really/ good idea to get a "backup copy" of the human race (independently viable) established off earth sometime soon?

[QUOTE=jasong;362410]I think the optimal situation would be for a country that isn't the United States, but is allied with us, doing something similar. Then everybody can get excited about it without American politics being a big problem.[/QUOTE]

Already happening. Oh, except for the USA thing.... :wink:

ewmayer 2013-12-23 21:03

Actually, in space (or in a frictionless environment of any kind) flatulence might prove a valuable propulsion mechanism.

[Mission control to astronauts: Stop farting around up there, you guys!]

Batalov 2013-12-23 22:13

[QUOTE=ewmayer;362741]Actually, in space (or in a frictionless environment of any kind) flatulence might prove a valuable propulsion mechanism.

[Mission control to astronauts: Stop farting around up there, you guys!][/QUOTE]
Spoiler alert! [SPOILER]You must have watched Gravity 3D. Giving away everything, you![/SPOILER] ;-)

chalsall 2013-12-23 22:31

[QUOTE=Batalov;362750]Spoiler alert! [SPOILER]You must have watched Gravity 3D. Giving away everything, you![/SPOILER] ;-)[/QUOTE]

You guys have of course thought about sex in zero gravity, right...

She'll wrap her legs around you... You'll do your thing... She'll respond accordingly...

Sorry, I have to go... The wife is in orbit....

kladner 2013-12-23 22:57

[QUOTE=chalsall;362755]You guys have of course thought about sex in zero gravity, right...

She'll wrap her legs around you... You'll do your thing... She'll respond accordingly...

Sorry, I have to go... The wife is in orbit....[/QUOTE]

I recommend a short story by Rudy Rucker: "Rapture in Space". It is in a collection named "[SIZE=2]Semiotext(e) SF".
[url]http://en.wikipedia.org/wiki/Semiotext%28e%29_SF[/url]
[QUOTE][/SIZE][B]Semiotext(e) SF[/B] is a [URL="http://en.wikipedia.org/wiki/Science_fiction"]science fiction[/URL] anthology released in 1989 and edited by [URL="http://en.wikipedia.org/wiki/Rudy_Rucker"]Rudy Rucker[/URL], [URL="http://en.wikipedia.org/wiki/Peter_Lamborn_Wilson"]Peter Lamborn Wilson[/URL] and [URL="http://en.wikipedia.org/wiki/Robert_Anton_Wilson"]Robert Anton Wilson[/URL]. It includes short stories and other works by the likes of [URL="http://en.wikipedia.org/wiki/J._G._Ballard"]J. G. Ballard[/URL], [URL="http://en.wikipedia.org/wiki/William_S._Burroughs"]William S. Burroughs[/URL], [URL="http://en.wikipedia.org/wiki/Kerry_Thornley"]Kerry Thornley[/URL], [URL="http://en.wikipedia.org/wiki/William_Gibson"]William Gibson[/URL], [URL="http://en.wikipedia.org/wiki/Bruce_Sterling"]Bruce Sterling[/URL], and others.
USA [URL="http://en.wikipedia.org/wiki/Special:BookSources/0936756438"]ISBN 0-936756-43-8[/URL] UK [URL="http://en.wikipedia.org/wiki/Special:BookSources/1873176813"]ISBN 1-873176-81-3[/URL]
[SIZE=2][/QUOTE]

w00t! We are in luck! Rudy's stories are online!

Rapture in Space- Link is ~20 down the page.
[url]http://www.rudyrucker.com/transrealbooks/completestories/#_Toc24[/url]


[/SIZE]

ewmayer 2013-12-24 00:24

[QUOTE=chalsall;362755]You guys have of course thought about sex in zero gravity, right...[/QUOTE]

To quote a long-ago pal who quoth thusly after having hooked up with a girl after several years of abstinence: "Blew 'er across the room, dude."

And for my next 0G docking maneuver...

@Serge: Have not seen [i]Schwergewicht: The Max Schmeling Story[/i], so any spoilerage is entirely unintended.

Technical note #1: In order for a safe (i.e. not one-shot-only-then-you're-dead) [i]Vakuumfurzantriebsystem[/i] one would need a safe way of venting the gases into the void while preserving at least a decent fraction of their impulse. A kind of "pass-through airlock for farts". I await a selection of trial designs for such from the engineering staff on my work desk by week's end.

Technical note #2: This one is in form of a question to the members of the aforementioned [i]Ingenieurstab[/i] -- Neglect for now the need for a fart-airlock for safe venting and assume a simple bare-buttocked venting into space. Would the human nether orifice provide for a sufficient converging-diverging nozzle geometry so as to allow for acceleration of the flow to supersonic speeds, or are we dealing with an effectively converging-only nozzle and thus a Mach-1 upper limit? Is the result variable by person, and if so, should maximal "personal Mach number" be a factor in selection to the astronaut training program?

xilman 2013-12-24 08:48

[QUOTE=only_human;362733]Why not throw Moon rocks at the Moon? That would accomplish your seismographic tomography goal and offer a test-bed for the development of a [URL="http://en.wikipedia.org/wiki/Lunar_space_elevator"]Lunar space elevator[/URL] that could afford to misdeliver a few loads:Instead of LEO to Moon, just get loads from the Moon and then drop them at trajectories that will land them back there. That way the Moon won't be too polluted with terrestrial sources. Then the need for refined, lighter loads that hit at high velocity may not as necessary if we have plenty of (albeit lower velocity) mass to sling around. If some of all that material gets piled up for building material or shielding: bonus.One thing I would like all the Google cars that run around with Call of Duty game playing minders scarfing up rocks on the Moon to do is be on the lookout for Earth rocks that may have landed on the Moon in the past.
[URL="http://science1.nasa.gov/science-news/science-at-nasa/2002/18oct_earthrocks/"]Earth rocks on the Moon[/URL][/QUOTE]Wouldn't meet the original mission requirements, specifically the financial constraint and, almost certainly, the <= 2 launches constraint.

xilman 2013-12-24 08:50

[QUOTE=Uncwilly;362730] Thinking off the cuff, why not leave them in the highly eccentric orbit that is a result of the orbital transfer? Taking the slow boat over there should leave them in an orbit that almost touches L1. From there, the nudge to make it an impactor might be much smaller than from a circular high orbit.[/QUOTE]Who said anything about a circular orbit?

only_human 2013-12-24 10:51

[QUOTE=xilman;362794]Wouldn't meet the original mission requirements, specifically the financial constraint and, almost certainly, the <= 2 launches constraint.[/QUOTE]Yeah, I know. Eventually we (for some definitions of we) are going to {do,build,exploit} things on the Moon and will have *-ologists vitally interested in the resources and costs of extracting or delivering them from here to there or there to there or elsewhere to there. So I subsumed the survey into the controlled chaos of getting things done with all those deliveries happening. All the products that get delivered by terminal velocity Amazon delivery drones provide seismic data points worth observing.

chappy 2014-01-10 21:55

[url]http://howmanypeopleareinspacerightnow.com/[/url]

chappy 2014-02-04 21:17

[url]http://www.independent.co.uk/life-style/gadgets-and-tech/goodnight-earth-goodnight-humanity-chinas-jade-rabbit-rover-tweets-its-own-death-9103864.html[/url]

This makes me very sad. Yutu was a great step forward by the Chinese.

kladner 2014-02-04 22:00

That's a real shame.

cheesehead 2014-02-05 17:31

[QUOTE=Uncwilly;362730]"Back side" we must eliminate that other term for the sake of scientific literacy.[/QUOTE]... or "far side". ("Farside" is used in some sci-fi.)

Pro: sounds enough like "dark side" so as to make switching ones terminology habit easy

Con: sounds enough like "dark side" so as to let "dark side" habitués think they heard one say "dark side" instead of "far side"

chappy 2014-02-05 18:51

Pro: sounds like an extremely funny comic.

firejuggler 2014-02-05 19:29

sad sad sad robot...
This call for a nice song...called sad sad robot

[url]http://www.youtube.com/watch?v=u7Dg3LrhmIY[/url]

Ken_g6 2014-02-07 00:18

I've seen some headlines lately that might be relevant to this.

If you can get your budget down by several orders of magnitude, and can fit it in a small package, [url=https://www.fbo.gov/index?s=opportunity&mode=form&id=ec040a31b16194f877d1034ccefdda40&tab=core&_cview=0]NASA might fund your mission[/url]!

If you can't, maybe [url=https://experiment.com/]you can get the public to fund your mission[/url]. :wink:

chappy 2014-02-18 00:35

A bit off-topic, but I highly recommend [URL="http://www.amazon.com/The-Martian-Novel-Andy-Weir-ebook/dp/B00EMXBDMA"]The Martian [/URL]by[URL="http://www.galactanet.com/writing.html"] Andy Weir[/URL]

Hard SF, pro space exploration, pro science, it has an in-your-face writing style that takes some getting used to, but in the end Andy Weir is a steely-eyed missile man.

[URL="https://www.goodreads.com/review/show/853252895"]My review.[/URL]

[URL="http://forum.dansimmons.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=153828&fpart=1"]Dan Simmons review.[/URL]

kladner 2014-04-26 14:52

SpaceX confirms successful Falcon 9 soft landing on the Atlantic Ocean
 
[url]http://www.gizmag.com/falcon-9-landing/31797/[/url]

[QUOTE]SpaceX CEO Elon Musk has confirmed that the first stage of the Falcon 9 rocket that boosted the [URL="http://www.gizmag.com/crs-3-launch-spacex/31671/"]CRS-3[/URL] Dragon spacecraft into orbit made a controlled power landing on the surface of the Atlantic Ocean. The historic first controlled landing of a liquid booster was tracked by telemetry and recorded on video. Unfortunately, heavy seas destroyed the rocket before recovery operations could retrieve it.[/QUOTE]

(With 20 foot waves, not even the Coast Guard would put out.)

chappy 2014-09-17 03:44

[url]http://arstechnica.com/science/2014/09/the-little-known-soviet-mission-to-rescue-a-dead-space-station/[/url]

cool article on something I had never heard of--or at least I don't remember this happening.

Nick 2014-10-28 22:39

[QUOTE]
[B]Orbital Evaluating Mission Status[/B]

[COLOR=#292f33]Orbital Sciences Corp. is currently evaluating the status of its mission. Visit [/COLOR][URL="http://t.co/6Bo6KBRWnG"]http://1.usa.gov/1r42Ssu [/URL][COLOR=#292f33] for the latest information.[/COLOR]



[/QUOTE]
That usually means the rocket blew up, doesn't it?
Fortunately, this one has no people aboard.

firejuggler 2014-10-29 02:45

[youtube]MZ0SgAU9LXI[/youtube]
view from the press site, might be nsfw as coarse language is used

Nick 2014-10-29 08:27

Good pictures! There is now a statement on the NASA website:
[URL]http://www.nasa.gov/mission_pages/station/structure/launch/orbital.html[/URL]

xilman 2014-10-29 09:32

Another viewpoint from the Beeb, starting with a close-up of the launch itself.

[url]http://www.bbc.co.uk/news/world-us-canada-29813109[/url]

Uncwilly 2014-10-29 12:35

[QUOTE=Nick;386392]Good pictures! There is now a statement on the NASA website:
[URL]http://www.nasa.gov/mission_pages/station/structure/launch/orbital.html[/URL][/QUOTE]
I wonder if the RSO had criteria that they followed to let the rocket fall if it was below a specific height. Once it goes pop and begins to fall, I would think that that is the time to hit the button.

Nick 2014-10-31 19:16

[QUOTE]
At least one person is dead and another injured after Virgin Galactic's SpaceShipTwo space tourism craft crashed in a California desert, the California Highway Patrol has said.
The craft was undergoing manned testing when it experienced what the company described as "a serious anomaly".
Television images shot from a helicopter showed what appeared to be wreckage bearing the Virgin logo.
SpaceShipTwo is carried aloft by a jet, then launched into sub-orbit.
In a statement, Virgin Galactic said the "vehicle suffered a serious anomaly resulting in the loss of SpaceShipTwo".
[/QUOTE][URL]http://www.bbc.com/news/world-us-canada-29857182[/URL]
[URL]http://www.virgingalactic.com/news/item/statement-from-virgin-galactic/[/URL]

xilman 2014-11-19 18:50

[URL="http://www.bbc.co.uk/news/science-environment-30102343"]Boldly going where 12 men have been before.[/URL]

To be serious, I hope they get this thing off the ground. A £600K (approx $1M) kickstarter sounds eminently reasonable.


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