gewing Posted May 23, 2015 Report Share Posted May 23, 2015 Well, at least until we know more it is a great basis for forerunner relics, crashed alien ships or crystalline alien colonies. ;-) Quote Link to comment Share on other sites More sharing options...
tkdguy Posted May 24, 2015 Author Report Share Posted May 24, 2015 This is what an astronaut sees during an aborted spaceflight Quote Link to comment Share on other sites More sharing options...
tkdguy Posted May 24, 2015 Author Report Share Posted May 24, 2015 Balloon space launch system L. Marcus 1 Quote Link to comment Share on other sites More sharing options...
Christopher Posted May 25, 2015 Report Share Posted May 25, 2015 Balloon space launch system I do see two reasons it might not be as good as it sounds: 1. We kinda need the escape velocity to put that sattelite into a semi-stable and easy to maintain orbit 2. Baloons are highly affected by winds, so you never get to quite choose where your orbit will be. Trying to get a single sattelite into a specific orbit with this might be like trying to snipe someone with a shootgun on 1 km. But for a bunch of short lived, low cost, low precision stattelites it could be ideal. Quote Link to comment Share on other sites More sharing options...
Lucius Posted May 25, 2015 Report Share Posted May 25, 2015 Mysterious space plane blasts off for secretive US air force mission Source: Guardian Web Publication date: 2015-05-20 A mysterious robotic space plane launched its secretive mission for the US air force on Wednesday, its fourth long orbital flight in five years. The X-37B launched from Cape Canaveral, Florida , for the reusable spacecraft's fourth mission. Its third mission lasted a record-breaking 675 day s in space, and ended when it landed at an air force base in California in October 2014 . The spacecraft's mission, including the technology on board and what its objectives are, are secret, but the air force has revealed at least one detail. In a statement, the air force said the X-37B will test a new electric engine called a Hall thruster, described as an "electric propulsion device that produces thrust by ionizing and accelerating a noble gas, usually xenon". Major General Tom Masiello , the commander of the air force research laboratory, space and missile systems center, said the X-37B mission would test a wide range of technologies. The higher-powered electric thruster could improve the efficiency of those technologies. "Secure comms, [intelligence, surveillance and reconnaissance], missile warning, weather prediction, precision navigation and timing all rely on [space science], and the domain is increasingly contested," Masiello said in a statement . "Less fuel burn lowers the cost to get up there, plus it enhances spacecraft operational flexibility, survivability and longevity." Captain Christopher Hoyler , an air force spokesman, said that the vehicle's mission "cannot be specified" but that it will enhance "the development of the concept of operations for reusable space vehicles". In a statement, the director of the air force rapid capabilities office, Randy Walden , said: "With the demonstrated success of the first three missions, we're able to shift our focus from initial checkouts of the vehicle to testing of experimental payloads." The Pentagon has consistently denied over the years that X-37B missions test space weapon capabilities. Built by Boeing's Phantom Works division, the spacecraft resembles Nasa's classic space shuttle design in miniature; it is a fourth of the size of the original shuttles, at about 9.5ft tall and 29ft long, and is operated robotically. It runs partially on solar power, and probably tests a wide range of avionics, advanced spacecraft design technology and experimental spy sensors. Nasa has also joined the X-37B experiment, sending dozens of material samples, including thermal coatings, ink and window substitutes, up in the shuttle's payload. The Nasa experiment will test how those materials withstand the hazards of space, such as radiation and extreme temperatures. The original X-37A shuttle was of Nasa's design, but the program was cancelled in 2006, at which point the air force and the military technologists at Defense Advanced Research Projects Agency (Darpa) adopted the program. Also launched into space are 10 small satellites called CubeSats, including one known as the LightSail , developed by the nonprofit Planetary Society . The tiny satellite will unfurl four solar-powered Mylar sails after a month in space, for a first short test of solar sailing near Earth. Other CubeSats will perform propulsion and communication experiments for the US Naval Academy , California Polytechnic State University and the Aerospace Industries Association . Lucius Alexander Palindromedary Enterprises denies all knowledge of alleged experiments involving spaceborne palindromedaries Christopher and tkdguy 2 Quote Link to comment Share on other sites More sharing options...
IndianaJoe3 Posted May 25, 2015 Report Share Posted May 25, 2015 Balloon space launch system It reminds me of the old rockoon concept from the 1950s. gewing 1 Quote Link to comment Share on other sites More sharing options...
Zeropoint Posted May 26, 2015 Report Share Posted May 26, 2015 It's not a terrible idea. From having played enough Kerbal Space Program to get a rudimentary but experience-based understanding of orbital mechanics, I know that the biggest chunk of delta-v for an orbit is horizontal velocity, not altitude. Obviously, balloons won't provide that. However, shoving a launch stack through the thick air near the surface is also quite a bit of work--go too fast, and you waste fuel fighting drag. Go too slow, and you waste fuel counteracting gravity*. I've thought about using air-breathing first stages to deal with this, but the balloons just might do the trick. * For example, consider the worst-case scenario in which the rocket puts out exactly 1 g of thrust and merely hovers over the pad, not gaining any speed or altitude--ALL the fuel burned like that is wasted. It reminds me of the old rockoon concept from the 1950s. Like some sort of . . . rocket raccoon? Quote Link to comment Share on other sites More sharing options...
IndianaJoe3 Posted May 26, 2015 Report Share Posted May 26, 2015 Like some sort of . . . rocket raccoon? I think it came from ROCKet ballOON. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted May 27, 2015 Author Report Share Posted May 27, 2015 Instruments for Europa mission selected Quote Link to comment Share on other sites More sharing options...
tkdguy Posted May 29, 2015 Author Report Share Posted May 29, 2015 Salty water on Mars? Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted May 29, 2015 Report Share Posted May 29, 2015 Arrh! Quote Link to comment Share on other sites More sharing options...
Christopher Posted June 3, 2015 Report Share Posted June 3, 2015 Perhaps not news, but I randomly stumbeled over it: Hey Gravity, aren't you supposed to be a constant? http://en.wikipedia.org/wiki/Flyby_anomaly The flyby anomaly is an unexpected energy increase during Earth-flybys of spacecraft. This anomaly has been observed as shifts in the S-Band and X-Band Doppler and ranging telemetry. Taken together it causes a significant unaccounted velocity increase of up to 13 mm/s during flybys Quote Link to comment Share on other sites More sharing options...
tkdguy Posted June 5, 2015 Author Report Share Posted June 5, 2015 Uranus' Moon Umbriel (error in the title) Pluto System's Weird "Dance" Test Flight for NASA's "Flying Saucer" Today (2nd attempt) Quote Link to comment Share on other sites More sharing options...
Cancer Posted June 8, 2015 Report Share Posted June 8, 2015 Pluto System's Weird "Dance" Here's the abstract of the Nature paper (this week's issue) with the results. Very weird system. Four small moons—Styx, Nix, Kerberos and Hydra—follow near-circular, near-equatorial orbits around the central ‘binary planet’ comprising Pluto and its large moon, Charon. New observational details of the system have emerged following the discoveries of Kerberos and Styx. Here we report that Styx, Nix and Hydra are tied together by a three-body resonance, which is reminiscent of the Laplace resonance linking Jupiter’s moons Io, Europa and Ganymede. Perturbations by the other bodies, however, inject chaos into this otherwise stable configuration. Nix and Hydra have bright surfaces similar to that of Charon. Kerberos may be much darker, raising questions about how a heterogeneous satellite system might have formed. Nix and Hydra rotate chaotically, driven by the large torques of the Pluto–Charon binary. More information is likely to come in the coming couple of months, as New Horizons approaches the system. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted June 10, 2015 Author Report Share Posted June 10, 2015 Articles on Mercury and Ceres Quote Link to comment Share on other sites More sharing options...
DShomshak Posted June 12, 2015 Report Share Posted June 12, 2015 This month's Scientific American has an article about an attempt to assay the Extragalactic Background Light. And what is Extragalactic Background Light? The abstract at the beginning of the article explains: "The night sky may look dark, but it is actually filled with the accumulated light of all the galaxies that have shone in the universe's history. "This extragalactic background light is difficult to detect because it has spread out throughout the expanding cosmos and because it is outshone by brighter nearby sources of light. "Astronomers have finally been able to measure this light by observing how gamma rays from distant bright galaxies called blazars are dimmed when they collide with photons of the extragalactic background light. "Studying the background in this way allows scientists to examine the record of cosmic history that the light preserves." To show the difficulty, the article notes that the EBL is much fainter than the Cosmic Microwave Background. Preliminary results are not particularly surprising: The EBL seems strongest in higher frequencies suggestive of bright, hot, newly formed stars and another peak in the infrared, suggestive of dust. Lots and lots of dust, to the extent that there might be lots of "dust-obscured galaxies" (DOGs) that our telescopes can't see at all. The astronomers involved in this project hope they can detect how the spectrum of the EBL has changed over time, as another line of evidence in reconstructing the history of the universe. Dean Shomshak Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted June 14, 2015 Report Share Posted June 14, 2015 Philae wakes up! http://blogs.esa.int/rosetta/2015/06/14/rosettas-lander-philae-wakes-up-from-hibernation/ tkdguy 1 Quote Link to comment Share on other sites More sharing options...
tkdguy Posted June 15, 2015 Author Report Share Posted June 15, 2015 Farewell, Lightsail Quote Link to comment Share on other sites More sharing options...
Old Man Posted June 15, 2015 Report Share Posted June 15, 2015 Philae wakes up! http://blogs.esa.int/rosetta/2015/06/14/rosettas-lander-philae-wakes-up-from-hibernation/ Best news all day. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted June 17, 2015 Author Report Share Posted June 17, 2015 Mars lost an ocean's worth of water Lockheed Martin's laser test Russia's answer to US laser testing Microwave gun Quote Link to comment Share on other sites More sharing options...
tkdguy Posted June 22, 2015 Author Report Share Posted June 22, 2015 Polar winds on Titan Quote Link to comment Share on other sites More sharing options...
tkdguy Posted June 25, 2015 Author Report Share Posted June 25, 2015 Mars had lots of water 500,000 years ago Quote Link to comment Share on other sites More sharing options...
tkdguy Posted June 27, 2015 Author Report Share Posted June 27, 2015 Time for breakfast Christopher 1 Quote Link to comment Share on other sites More sharing options...
Christopher Posted June 27, 2015 Report Share Posted June 27, 2015 Time for breakfast As long as it does not come over because the neighbours keep watching it via telescopes when it tries to eat in peace. tkdguy 1 Quote Link to comment Share on other sites More sharing options...
tkdguy Posted June 28, 2015 Author Report Share Posted June 28, 2015 Venus, Jupiter to Converge in Night Sky Quote Link to comment Share on other sites More sharing options...
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