 April 8, 2009 - 11:27am | Here is another gap that has annoyed me about SF... How do probes work? What kind of gadgets can you drop into an atmosphere to gauge the planet's characteristics? Are they robots? If so, what levels, etc? How big are they and how much do they cost? Can any of these measurements be done from a ship without needing a probe? I always noticed in Star Trek they just glanced at a computer panel (or Spock's Blue Thang) and knew a great deal about the planet - even life forms. Obviously, that level of knowledge is silly, but how much can be gleaned from a ship, and what instruments would it need? Advanced spectrum analysis should be able to detect atmospheres and measure levels of gas quite accurately, given a little "Star Frontiers boost"... |
 April 8, 2009 - 11:51am | Kngiht Hawks has some information about probes. Look in remastered Knight Hawks pg 48-49 Look for Eploration Equipment and Scientific Research Equipment. Basically there are: Atmoprobes; one shot items that crash though an atmosphere, gather and transmit data as they go. usually non-recoverable item. Landing Drones: Big as an aircar, descends slowly, gathers atmosphere information, lands and gathers geological data. It send information back the entire time. It is a recoverable item. Remote Probes: much more sophisticated thingy that is for more hazerdous areas that living beings cant enter. Gathers lots of information. Finally, there is the Laboratory: makes it much easier to interpret data gathered via probes or physically in the field. Time flies when your having rum. Im a government employee, I dont goof-off. I constructively abuse my time. |
 April 8, 2009 - 3:08pm | Star Trek uses "broad spectrum analysis" to determine those things. In other words, they image the planet with various spectrums of light. Through those spectrums they can determine life, kinds of life, and volumes of life, and they can distinguish flesh from concrete and heat from cold. With just 50 years of practice, we have satalites that can do the same thing. Is it really that far fetched that 300 years in the future they can do it from a little further out in space and without having to do 100 mile wide square-by-square coverage? In the 60's, Spock's station that he stared into was voo-doo. Today it's real tech. View my profile for a list of articles I have written, am writing, will write. "It's yo' mama!" —Wicket W. Warrick, Star Wars Ep. VI: Return of the Jedi "That guy's wise." —Logray, Star Wars Ep.VI: Return of the Jedi Do You Wanna Date My Avatar? - Felicia Day (The Guild) |
 April 8, 2009 - 6:01pm | Nice topic title, by the way  .It should be totally possible to get basic information, even from a distance, with just your basic astrogation equipment (which I've always assumed included at least a small (~8") telescope, CCD imager and spectrograph that works both in the visible and near IR). As Ascent said, the basics of that are here today. Any decent spectrograph will be able to tell you the composition of the atmosphere of a planet or the surface if you can resolve it. In the end the limit is how big of a telescope you have to work with. You will be limited by the diffaction limit of your optics at the wavelength you want to take measurements in and the amount of light you can gather. The further away or smaller your telescope, the longer you'll have to observe to get enough signal and less resolution you'll have to make out features. As an example, think of Hubble images of the planets in our solar system. That is the kind of resolution you could get given similar distances and sizes. But remember, the Hubble has a 2.4m (8 ft) diameter mirror. You're not going to get that size of a telescope on a HS 3 exploration ship. It would definitely take something larger (In fact the Hubble space telescope is bigger than a HS 1 KH ship if I remember the dimensions correctly). The diffraction limit for blue (300nm) light on an 8" telescope is 0.0000018 radians. This scales directly with wavelength and inversely with diameter (i.e going to reddish light at 600 nm makes the limit 0.0000036 and doubling the size of the mirror makes the limit at blue 0.0000009). This is the simple Rayleigh criteria which you can beat but it is a good starting point for discussion. What does this mean? Multiply this number by the distance to the object and that gives you the size of the smallest feature you can see. So if you are 384,000 km from an object (distance from earth to moon), the smallest feature you can see is 0.7 km (and that assumes there is no atmosphere in the way  ).If you wanted to look at something the distance of Mars at opposition (closest approach to Earth, about 80,000,000 km), the smallest feature you could see with that 8" telescope in blue light is about 146 km across. In red light it would be about 300 km across. For comprison, Mars is about 6800 km in diameter so in red light your resolution element is about 4.5% of the planet's diameter. And it just gets worse the further you are away. The bottom line is that it can be done, you just have to get close or have big glass on your ship to do it from a distance. Ad Astra Per Ardua! My blog - Expanding Frontier Webmaster - The Star Frontiers Network & this site Founding Editor - The Frontier Explorer Magazine Managing Editor - The Star Frontiersman Magazine |
April 8, 2009 - 7:43pm | And then there's the light return method, normally used for measuring the distances of extraplanetary bodies, in this instance can be used for enhancing imaging and determining chemical compositions. View my profile for a list of articles I have written, am writing, will write. "It's yo' mama!" —Wicket W. Warrick, Star Wars Ep. VI: Return of the Jedi "That guy's wise." —Logray, Star Wars Ep.VI: Return of the Jedi Do You Wanna Date My Avatar? - Felicia Day (The Guild) |
 April 9, 2009 - 12:44am | the other thing to remember about optical functions: Double the distance, get 1/4th the intensity. See mars from .6AU and from 1.2AU (with the same relative solar incidence on mars), and you not only double the size of the minimum resolution element, but you also get 1/4th the energy, so either you need 4x the expsoure time, or 4x the sensitivity (or 2x each) to get the same quality of image, (but that image will still have 1/4th the data due to larger size per pixel). Or you can sacrafice even more resolution and concentrate the light on a smaller number of sensor pixels. |
April 9, 2009 - 6:52am | True Rum... I just thought they could use a little more fleshing out... |
April 9, 2009 - 11:12am | True Rum... I just thought they could use a little more fleshing out... Yeah... I wasnt thinking along that lines when I read your post. I definatley agree. A ship should be able to do alot of what the probes while in orbit. Time flies when your having rum. Im a government employee, I dont goof-off. I constructively abuse my time. |
 January 11, 2010 - 5:51pm | Check into imaging interferometers. I designed the auto alignment for the moving mirror in one. Our pitch to NOAA was that the satallite in geosynchronous orbit could watch a full hemisphere of the Earth and measure atmospheric composition, temperature, and movement (pressures and winds) by doing fourier analysis of the interferogram array and sequences of interferogram captures. Check out Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) for the satellite. Grabbed this from the Space Dynamics Lab site that is developing the instrument: "The GIFTS instrument can measure the distribution, change, and movement of atmospheric moisture, temperature, and certain pollutant gases with the high vertical and temporal resolution typical of low?earth?orbit sensors. Its mission could provide the observations needed to predict where and when severe thunderstorms, and possibly tornados, would occur before they are visible on radar or in satellite cloud imagery." Thus I think that we are well on the way to a space ship being able to orbit a planet and analyse the atmosphere to determine if it was hospitable. -iggy |
