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View Full Version : Space exploration without space travel.....



marsbug
2014-Feb-16, 07:13 PM
I'd like to try a thought experiment, an exercise in odd thinking about how we might explore space: Let us imagine that some bizarre force is lurking in Earths upper atmosphere and preventing anything physical leaving. It can't stop radiation like radio signals, and it doesn't mind things entering the atmosphere. Globally space agencies have the same budgets (it's thought experiment, so the politics doesn't have to make sense), so how do they go about exploring the universe now? What could be done to explore with a $17 billion a year NASA (for example) budget that wasn't putting anything physical into space?

iquestor
2014-Feb-16, 11:01 PM
radio telescopes and spectrometers.

marsbug
2014-Feb-16, 11:48 PM
I was thinking of something along the lines of a super Aricebo? I was also wondering if modern adaptive optics would be good enough to allow a ground based laser to divert small NEO's to hit other celestial objects (E.G. the moon or a well placed comet) and use big *** optical telescopes to study spectral lines of the ejecta.

swampyankee
2014-Feb-17, 12:24 AM
Well, we explored space for several hundred years before spacecraft, aircraft, or balloons. There would be a lot of phenomena that would be difficult or impossible to detect, like anything that emits in the X-ray.

What's the altitude limit? Does it permit sounding rockets? How about high-altitude balloons?

Noclevername
2014-Feb-17, 12:51 AM
I would think in that scenario that examining what phenomenon holds us Earthbound would be as big an area of study as examining space.

marsbug
2014-Feb-17, 10:15 AM
The upper limit is 100km, with a grace zone of 10km where 'it' will ignore something that is clearly not trying to permanently leave the atmosphere. Oh, and it will ignore anything which remains supported by the earths surface, although if you built a space tower and tried to launch from the top of that it'd destroy what you launched. I expect that we would spend 90% of or time and energy studying and working out a way around it, but for the sake of this thought experiment we've concluded we're at least fifty years away from beating it.

Glom
2014-Feb-17, 07:22 PM
Wasn't that the plot of a Voyager episode?

Well anyway, the politics are important because if it is impossible for anything to be launched into space, then the Space Race never happens.

NEOWatcher
2014-Feb-17, 07:29 PM
Wasn't that the plot of a Voyager episode?
Not quite. Their problem was the time, not the space limitation. They were able to launch warheads fairly easily.

ST-VOY: The Weird Planet Where Time Moved Very Fast And So Did The People Who Lived There.

marsbug
2014-Feb-17, 07:47 PM
To be honest I tuned out of Voyager after the one where an engine accident on a shuttle turned Paris and Janeway into poo-lizards.

RE the politics: I'm not world or alternate history building here, I'm fishing to see if anyone has, or knows of, any interesting left-field ides for how space might be explored without actually travelling through it. As a F'rinstance: IIRC the ice at Mercury's poles was first suspected from the results of a radar probe by Aricebo. How much further could 'active' radio astronomy be pushed? And could the general principle be applied to other forms of radiation - for example could a really big ground based laser be used to vaporise part of the surface of a NEO coming in for a close pass of Earth so we could get a spectrum of the plume of its surface material?

Or: If we wanted to launch an X-ray observatory, is there any way it could be suspended at the 100km mark for a reasonable duration, say a few hours?

Or: At 20km altitude you're already above most of the atmophere: Are there any proposed schemes for building a structure of that range of height that might be used as a platform for UV and gamma ray observatories?

And so on. I'm not wondering how the world would have turned out if actual space access was somehow prohibited, I'm wondering how we could still explore if space access became prohibited tomorrow.

Edit: We could re-phrase it like this: How hard would it be to do the things we do with access to orbit (and beyond), without being able to actually launch things into orbit? Are there even any realistic plans that could replace basic in-space capabilities? Look it as an exercise in measuring how dependant we are on space launch capability, by looking at what the alternatives might be. What technologies would we need to develop?

JustAFriend
2014-Feb-17, 08:45 PM
Well as we were clawing into the Space Age, we were sending up small observatories into
the stratosphere with giant balloons and large airplanes: http://en.wikipedia.org/wiki/Airborne_observatory

We still do occasionally: http://en.wikipedia.org/wiki/Sunrise_(telescope)

swampyankee
2014-Feb-17, 09:32 PM
Well as we were clawing into the Space Age, we were sending up small observatories into
the stratosphere with giant balloons and large airplanes: http://en.wikipedia.org/wiki/Airborne_observatory

We still do occasionally: http://en.wikipedia.org/wiki/Sunrise_(telescope)

NASA converted a C-141 to an I/R observatory, and there were many balloons and sounding rockets used to observe astronomical phenomena. Maybe a dozen aircraft like SOFIA.

marsbug
2014-Feb-18, 01:33 AM
Thanks guys, Sunrise and SOFIA are exactly the kinds of alternative-design missions I was thinking of.....If we were somehow deprived the ability to travel space there are other routes (harder to use true) by which we could still explore the universe. I find that comforting in the face of politicians frequently capricous treatment of space program funding!

Now, if anyone can think of way to do a Mars sample return mission without the need for rockets.....:D :D ;D

publiusr
2014-Feb-21, 11:02 PM
Well, there are the SNCs. But I'd rather push for the rockets.

Dave12308
2015-Feb-26, 10:13 PM
There might not be such a push to explore space to begin with, though; if it were impossible for us to make use of any of the resources found there.

Noclevername
2015-Feb-26, 10:33 PM
There might not be such a push to explore space to begin with, though; if it were impossible for us to make use of any of the resources found there.

I disagree, exploration is also done out of curiosity. FOR SCIENCE!

Dave12308
2015-Feb-26, 11:24 PM
I disagree, exploration is also done out of curiosity. FOR SCIENCE!

That's true. I only wish we'd do more actual exploration. Our space program used to be so much braver than it is now. The moon should be a regular target of science missions, given our technology today it should be relatively cheap compared to Apollo. Heck, people should be taking real honeyMOONs. On the MOON.


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Ara Pacis
2015-Feb-27, 05:19 AM
If you want some basic tech ideas, start with towers and balloons (see Dark Sky station (http://en.wikipedia.org/wiki/JP_Aerospace#Dark_Sky_Station)) or you could use a large kite in the polar jet stream.. At the poles the atmosphere is lower, so you should be able to get above it at a higher altitude and/or get above even more at the same altitude. Moreover, you'd be able to rotate the telescope to see things with a long exposure. Since cold air is denser, a warm balloon would have better buoyancy. Alternately, you could do something fancy and complicated, like levitating against the magnetic field instead of using balloons.