Stuff in Space

Discuss life, the universe, and everything with other members of this site. Get to know your fellow polywell enthusiasts.

Moderators: tonybarry, MSimon

paperburn1
Posts: 2379
Joined: Fri Jun 19, 2009 5:53 am
Location: Third rock from the sun.

Re: Stuff in Space

Postby paperburn1 » Mon Jul 24, 2017 8:00 am

I have been pondering your question about seeing things in orbit at 20 LY away.
Even our space station is puny when compared to our planet. Measuring 357 feet end-to-end, the International Space Station largest object orbiting the Earth. That isn’t large enough to register on Earth-observing instruments such as the DSCOVR satellite's EPIC camera, which takes pictures of the Earth from a million miles away. The smallest objects EPIC's camera can make out are about eight to 10 kilometers wide. At that range, the ISS wouldn’t even register as a blip in an image of the Earth.
Even with closer satellites and higher resolutions are out of luck. NASA's Terra and Aqua satellites carry the MODIS (or Moderate Resolution Imaging Spectroradiometer) instrument and operate only about 440 miles above the Earth’s have a resolution of one kilometer you would probably only get a few pixels of resolution.
There are a few military objects in space that can do better but they are optimized for the other direction and right now I am focusing on commercial systems. The new James Webb long-wavelength (orange-red) visible light, through near-infrared to the mid-infrared (0.6 to 27 micrometers). While the Hubble Space Telescope has a 2.4-meter (7.9 ft) mirror, the JWST features a larger and segmented 6.5-meter-diameter (21 ft 4 in) primary mirror and will be located near the Earth–Sun L2 point . In theory it should be able to image exo-planets with 8 to 10 pixels of resolution .( This is a guess does anyone have better info?) and it is still not optimized for UV. It might pick up a orbital power generation station that was very large (Gigawatts?).

It seems once again we will need a bigger telescope. Good news if James Webb proves out we then could have something that big built up there.
I am not a nuclear physicist, but play one on the internet.

hanelyp
Posts: 2237
Joined: Fri Oct 26, 2007 8:50 pm

Re: Stuff in Space

Postby hanelyp » Mon Jul 24, 2017 12:25 pm

The telescopes I'd like to see in space would be far too large to launch from Earth in one piece and deploy in orbit. They'd have to be constructed in space. And probably in deep space, as tidal effects in low Earth orbit would distort the structure far too much.
The daylight is uncomfortably bright for eyes so long in the dark.

Tom Ligon
Posts: 1870
Joined: Wed Aug 22, 2007 1:23 am
Location: Northern Virginia
Contact:

Re: Stuff in Space

Postby Tom Ligon » Mon Jul 24, 2017 1:29 pm

The thing about shiny metal is that it is not the size of the object that counts, its how good a mirror is it.

If I were to hold up a playing card ten miles away from you, you would not see it. You would not see it with a good pair of binoculars. With a good telescope, you might make out that I was holding my arm up. With the Hubble, and no atmosphere, you could easily read the card.

If I held up my signal mirror, a square of shiny metal two inches per side, I looked thru the hole in the center at the sighting tool, and lined that up on your position, you would clearly see the flashes, naked eye. From experience, at two miles, you'd be asking me to cut it the hell out, because it is bright enough to be annoying.

Per the suggested resolution of a 3300 mile diameter planet being visible, an object like the ISS is orders of magnitude too small. But as a flashing mirror, maybe not. The fact that they could theoretically see the body heat from a bumblebee at lunar distances suggests that my signal mirror should be clearly visible at the same distance with a good space telescope. You might not resolve a good image, but the flash should be easier to detect than, for example, ambient light on a grey rock.
Last edited by Tom Ligon on Mon Jul 24, 2017 1:37 pm, edited 2 times in total.

Tom Ligon
Posts: 1870
Joined: Wed Aug 22, 2007 1:23 am
Location: Northern Virginia
Contact:

Re: Stuff in Space

Postby Tom Ligon » Mon Jul 24, 2017 1:35 pm

hanelyp wrote:The telescopes I'd like to see in space would be far too large to launch from Earth in one piece and deploy in orbit. They'd have to be constructed in space. And probably in deep space, as tidal effects in low Earth orbit would distort the structure far too much.


And we will.

That could be delayed if we ever get enough junk in space that one collision sets off a cascade that turns LEO into a cage of frag, or if we suffer a war or economic collapse that throws us back into the 19th century.

paperburn1
Posts: 2379
Joined: Fri Jun 19, 2009 5:53 am
Location: Third rock from the sun.

Re: Stuff in Space

Postby paperburn1 » Mon Jul 24, 2017 2:30 pm

I see your point, I don't think it would be possible with anything smaller than James Webb but I am far from being and expert. Don't we have someone out there that could chime in?
I am not a nuclear physicist, but play one on the internet.

Tom Ligon
Posts: 1870
Joined: Wed Aug 22, 2007 1:23 am
Location: Northern Virginia
Contact:

Re: Stuff in Space

Postby Tom Ligon » Tue Jul 25, 2017 3:10 am

I think the James Webb or larger.

We're still thinking small. I have been willing for some years to let Hubble go. Its old. We need a new one. The Webb will be a good instrument but they screwed around with it, wound up spending more by trying to delay it. The price is badly bloated.

I think we should have at least six large space telescopes, much further out than Hubble, capable of being arranged into very long baseline arrays that can resolve pimples on the arse of Ming the Merciless at 20 LY. Or at least spotting Earth-sized planets and getting something like an image. We should put one up every couple of years and get more observing done. And we should have enough transportation capacity that sending a crew up to service them is not a Big Deal.

kunkmiester
Posts: 866
Joined: Thu Mar 12, 2009 3:51 pm
Contact:

Re: Stuff in Space

Postby kunkmiester » Tue Jul 25, 2017 5:18 am

With Falcon Heavy the price of big stuff is dropped like a hot rock. You could probably throw ten small telescopes up for the price of one big one, and with modern controls, it will be easy to make arrays even in the visible spectrum.

There's also the fact that you'd not be looking for just one object. A civilization like ours will have thousands of objects in orbit, adding up tona much larger reflective "surface" than just the ISS. Once again, quantity has quality.
Evil is evil, no matter how small

Tom Ligon
Posts: 1870
Joined: Wed Aug 22, 2007 1:23 am
Location: Northern Virginia
Contact:

Re: Stuff in Space

Postby Tom Ligon » Tue Jul 25, 2017 1:46 pm

There's a conundrum with going to telescopes with more and more "power". Since our goal is to be able to resolve smaller objects, we typically use the larger aperture for more resolution instead of more light gathering for faint objects. This means we're narrowing the field of view. Observing extrasolar planets is clearly in this narrow-field class.

There are exceptions. Wide field astronomy has yielded some marvelous results, and we've got swarms of small telescopes looking for asteroids and scanning for supernovae.

But the "sexy" telescopes are looking at narrower and narrower patches of sky. This has been the emphasis since Galileo pointed his first crappy first telescope at Jupiter. Better optics and more power.

But we are now building instruments to scrutinize objects Galileo never suspected were there, and now have vastly more galaxies to look at than he had stars to look at. The more powerful these scopes get, the more prospective targets there are, and the fraction of them we can study with a single instrument plummets. There may be a few planets in range that have orbiting satellites making detectable flashes. But we might never see them because we don't know they are there, and we built one huge telescope used primarily to look at galaxies from 13+ billion years ago. We might not afford the time to observe specific systems to spot flashes around a likely planet ... too much observation time on a valuable instrument. We could have a planet swarming with satellites around Eta Cassiopeia, and never spot it because we're too interested in supernovae and colliding black holes at the edge of the Universe. I predict the users will be in fisticuffs, fighting for a chance to use it.

More powerful scopes means a need for more of them to cover more area.

SETI research has a similar problem. You'd be surprised just how little observing time they get. They'll get a little sliver of observing time on the Allen Array, or Green Bank, etc, covering a small patch of sky, and spend years analyzing that. Some alien signal could be blasting at us from another direction, outside their band, not when they're listening, and we'd be clueless. The odds of them missing such a signal vastly outweigh the odds of them detecting one. So there's an amateur SETI League, with the goal of creating a network of small, inexpensive radiotelescopes (based on ICOM microwave receivers available for a few hundred $ on e-bay, plus old satellite dishes and an obsolete PC). Their sensitivity is sufficient to pick up the "WOW!" signal, but nowhere near what the Allen Array can. But they are dedicated SETI instruments, and could be operated in vast numbers, covering more of the sky.

ladajo
Posts: 6194
Joined: Thu Sep 17, 2009 11:18 pm
Location: North East Coast

Re: Stuff in Space

Postby ladajo » Tue Jul 25, 2017 3:16 pm

kunkmiester wrote:With Falcon Heavy the price of big stuff is dropped like a hot rock. You could probably throw ten small telescopes up for the price of one big one, and with modern controls, it will be easy to make arrays even in the visible spectrum.

There's also the fact that you'd not be looking for just one object. A civilization like ours will have thousands of objects in orbit, adding up tona much larger reflective "surface" than just the ISS. Once again, quantity has quality.



As I stated earlier, this is where my thinking is. I don't think we are that far from it. Think of the possibility of placing some linked sensors at a couple of Lagrange Points, and playing 'I have a massive interferometer', or 'massive synthetic aperture array'?

We are already playing with this on the ground...
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

KitemanSA
Posts: 6113
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Re: Stuff in Space

Postby KitemanSA » Wed Jul 26, 2017 7:53 pm

Tom Ligon wrote:The Webb will be a good instrument but they screwed around with it, wound up spending more by trying to delay it. The price is badly bloated.
Reminds me of the USS Gerald R. Ford. When NewNews Shipbuilding first provided an estimate for the Ford, it was ~7 years and $7billion." The Navy said "that is too much per year, what happens if we spread it out over 10 years?" NewNews replied, "that would then be 10 years and $10 billion".

Face it folks, it takes a certain amount of money every year to keep a capability intact. It seems that the cost to keep a supercarrier construction capability intact is ~$1B/a.

ladajo
Posts: 6194
Joined: Thu Sep 17, 2009 11:18 pm
Location: North East Coast

Re: Stuff in Space

Postby ladajo » Fri Aug 04, 2017 12:46 pm

We are almost there in regards to detecting signatures of orbital stuff...

Nature Article on Detecting Atmospheres
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)

What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

paperburn1
Posts: 2379
Joined: Fri Jun 19, 2009 5:53 am
Location: Third rock from the sun.

Re: Stuff in Space

Postby paperburn1 » Mon Nov 13, 2017 4:48 am

We talked about this once, now the first step for setting a legal colony
An odd but intriguing experiment in technology, diplomacy, governance and space exploration, among other things, has officially begun its journey.

After being delayed one day, an Orbital ATK Antares rocket carrying a cubesat named Asgardia-1 launched from NASA's Wallops Flight Facility in Virginia early Sunday. The milk carton-sized satellite makes up the entirety of territory of the self-proclaimed "Space Kingdom" of Asgardia.

"Asgardia space kingdom has now established its sovereign territory in space," read an online statement.

Over 300,000 people signed up online to become "citizens" of the nation over the last year. The main privilege of citizenship so far involves the right to upload data to Asgardia-1 for safekeeping in orbit, seemingly far away from the pesky governments and laws of Earth-bound countries.
[url]/https://www.cnet.com/news/asgardia-1-space-kingdom-nasa-orbital-atk-launch-nation/[url]
I am not a nuclear physicist, but play one on the internet.

hanelyp
Posts: 2237
Joined: Fri Oct 26, 2007 8:50 pm

Re: Stuff in Space

Postby hanelyp » Tue Nov 14, 2017 12:37 am

paperburn1 wrote:The milk carton-sized satellite makes up the entirety of territory of the self-proclaimed "Space Kingdom" of Asgardia.

And what, beyond good manners, prevents someone from shooting down the self proclaimed sovereign nation?
The daylight is uncomfortably bright for eyes so long in the dark.

williatw
Posts: 1725
Joined: Mon Oct 12, 2009 7:15 pm
Location: Ohio

Re: Stuff in Space

Postby williatw » Thu Dec 21, 2017 4:17 pm

Make of this what you will...



We May Not Be Alone, Former Pentagon UFO Investigator Says

Image
Luis Elizondo, the former head of a Pentagon program to investigate U.F.O. sightings by the U.S. military, says we may not be alone.


The former head of a secret government program to investigate UFO sightings told several media outlets that extraterrestrial life may exist. Simultaneously, the public benefit corporation he is affiliated with has raised more than $2.2 million to research "exotic technologies" affiliated with "unidentified aerial phenomena."

"My personal belief is that there is very compelling evidence that we may not be alone," said Luis Elizondo, the person who formerly managed the Pentagon Advanced Aviation Threat Identification Program, in an interview with CNN.


Elizondo said the program had found "a lot" of strange aircraft while it was in existence. "These aircraft — we'll call them aircraft — are displaying characteristics that are not currently within the U.S. inventory nor in any foreign inventory that we are aware of," he said.


In a separate interview with National Public Radio (NPR), Elizondo added that his remarks don't necessarily mean the craft were extraterrestrial, as his focus was more on learning about any potential problems with national security.

"If you're asking my personal opinion from here, look, I've got to be honest with you, I don't know where it's from. But we're pretty sure it's not here," Elizondo told NPR. "Now does that mean it's 'out there'? Whether or not it's Russian or Chinese inside, or little green men from Mars, or frankly, your neighbor's dog, I wanted to purposely steer away from that [speculation], because I wanted to focus on truly the raw science: What were we seeing, and did it pose a threat to national security?"

Elizondo resigned from the Defense Department program on Oct. 4, writing in his resignation letter that there needs to be more attention paid to "the many accounts from the Navy and other services of unusual aerial systems interfering with military weapon platforms and displaying beyond-next-generation capabilities," according to The New York Times.

Fundraising for "aerial phenomena" research

Elizondo and two other former Defense Department officials — Christopher K. Mellon and Harold E. Puthoff — have created a venture called To the Stars Academy of Arts and Science, which aims to investigate "exotic science and technologies", according to its website.

"We believe there is sufficient credible evidence of unidentified aerial phenomena that proves exotic technologies exist that could revolutionize the human experience," the organization's website states. The company has fundraised more than $2.2 million from nearly 2,500 individual investors.Elizondo's remarks come amid recent revelations that the U.S. government had a secret, $22 million program to seek out UFOs that ran between 2007 and 2012. The Times reports the program is still ongoing, although the Defense Department said a lack of funding shut the effort down.

Also, in recent days, Navy pilots reported that they spotted a UFO during a training mission off the coast of San Diego in 2004. "It accelerated like nothing I've ever seen," said Cmdr. David Fravor in an interview with the Times, adding that he was "pretty weirded out." To the Stars references these reports frequently on its website.

To the Stars' mission is to examine science that was "suffocated by mainstream ideology and bureaucratic constraint," the venture's website says. It plans a fusion of science, aerospace and entertainment to "work collectively to allow gifted researchers the freedom to explore exotic science and technologies," according to the website.


https://www.space.com/39169-aliens-may- ... chief.html

williatw
Posts: 1725
Joined: Mon Oct 12, 2009 7:15 pm
Location: Ohio

Re: Stuff in Space

Postby williatw » Sun Feb 04, 2018 4:38 pm

Commentary: The poles of the moon are the most valuable real estate in the solar system

The lunar poles offer revolutionary spaceflight capabilities and the promise of untold scientific, economic and security benefits.


Image
A super blue blood moon rises behind the 2,500-year-old Parthenon temple on the Acropolis of Athens, Greece, on Wednesday, Jan. 31, 2018. On Wednesday, much of the world will get to see not only a blue moon which is a supermoon, but also a lunar eclipse, all rolled into one celestial phenomenon.



By Paul Spudis |

I’ve been reading with interest the recent exchanges in The Salt Lake Tribune on the moon’s utility. I’m grateful for this opportunity to add some facts and analysis to the conversation.


To recap briefly, after space author Mark Whittington encouraged potential Senate candidate Mitt Romney to reconsider his earlier disparagement of lunar return, University of Utah Professor Emeritus of chemical engineering Noel de Nevers chided Whittington for advancing such a fantastic concept.


Permanent human presence on the moon is essential to any future spacefaring infrastructure. Data from lunar orbital missions have revealed locales at the Moon’s poles that will permit habitation of the moon, where access to constant power from solar illumination is located near permanently shadowed crater floors holding deposits of water-ice.


Finding permanent sunlight is critical, as power is essential for human or robotic presence on the moon. Due to the orientation of the moon’s spin axis, the sun skirts and circles around the polar horizon. On certain mountain peaks, or elevated crater rims, the sun shines 80 percent to 95 percent of the year, with short periods of darkness easily bridged by temporary power sources, such as fuel cells. These oases of “quasi-permanent” sunlight permit continuous power production and surface operations, unlike the harsh lunar nights lasting fourteen, 24-hour Earth days over the rest of the Moon.


With the sun circling around the horizon, the interiors of craters near the poles remain dark and cold — only a few tens of degrees above absolute zero. Over the past 4 billion years, these “cold traps” have accumulated significant amounts of water molecules from comets and asteroids. Remote sensing techniques, including neutron mapping, UV spectroscopy, radar and near-infrared spectra, all indicate substantial amounts of water ice reside there.


In 2009, water vapor and ice particles were detected in soil ejected when an upper stage rocket was slammed into the south pole of the Moon. Analysis suggests over 10 billion metric tons of water is available at each pole — each, roughly equivalent in volume to the Great Salt Lake.


Water is the most useful material in space. As a consumable in liquid form, we can drink it, use it for food reconstitution and for sanitation. A water barrier is excellent shielding against hard radiation in space and on the lunar surface. Disassociated into its component elements of hydrogen and oxygen, it provides breathable air. These same gases combined in a fuel cell generate electricity, producing water as a by-product. Thus, lunar water is a medium to store energy for use when needed. Finally, hydrogen and oxygen condensed into liquid form is the most powerful chemical rocket propellant known. With ready access to power and water, the poles offer us unique places for the development of spacefaring logistics depots.


In contrast to Professor de Nevers’ comments, this is not magical or futuristic technology. Most resource processing needed will use mining techniques and chemical engineering perfected in the 18th Century — digging the feedstock from the upper couple of meters of soil, heating the soil to vaporize the ice, collecting the water (and other volatile) vapors, fractionally distilling them to make various products and, finally, cracking the water into its component elements. Moreover, because the moon is close (3 seconds round trip light time), we can accomplish much of this early mining work using robots controlled by operators on Earth.
Because more than 80 percent of a rocket’s mass is propellant, having the availability and ability to utilize lunar polar water and solar resources creates a new template for spaceflight. Currently this great mass must be lifted from Earth’s surface — the deepest gravity well in the inner solar system. The moon has one-sixth Earth’s gravity — provisioning spacefarers with resources from the moon, while at the same time assuring the continuous re-supply of space-based assets with consumables and propellant, beckons humanity to dream big and travel far.

Ponder for awhile on the valuable real estate residing just above us — the lunar poles offer revolutionary spaceflight capabilities and the promise of untold scientific, economic and security benefits for our nation and the world, for many generations to come. This is the place where we will realize our dreams and ambitions of becoming a spacefaring species.


Paul D. Spudis, Ph.D., is a planetary scientist and has spent more than 40 years studying the moon. He is the recipient of several professional awards, most recently the 2016 Columbia Medal of the American Society of Civil Engineers. He blogs at Air & Space Magazine and at his own site, Spudis Lunar Resources. His latest book is “The Value of the Moon: How to Explore, Live, and Prosper in Space Using the Moon’s Resources.”


Return to “General”

Who is online

Users browsing this forum: Google [Bot] and 12 guests