Wouldn't the James Webb Space Telescope be able to get a picture of this planet? The star is just a red dwarf.
Quote from: scienceguy on 08/25/2016 04:49 pmWouldn't the James Webb Space Telescope be able to get a picture of this planet? The star is just a red dwarf.Maybe. It depends on the apparent distance to the star. JWST does have coronagraphs that might enable a direct image to be taken of Proxima b, but if it can only distinguish Proxima b when it's at the furthest from the star from our perspective, it might be tricky to get the timing right.
Quote from: whitelancer64 on 08/25/2016 05:31 pmQuote from: scienceguy on 08/25/2016 04:49 pmWouldn't the James Webb Space Telescope be able to get a picture of this planet? The star is just a red dwarf.Maybe. It depends on the apparent distance to the star. JWST does have coronagraphs that might enable a direct image to be taken of Proxima b, but if it can only distinguish Proxima b when it's at the furthest from the star from our perspective, it might be tricky to get the timing right.With an 11.2 day orbit, a well planned observation campaign should be able to catch Proxima b, assuming JWST can image it.
Quote from: RonM on 08/25/2016 05:42 pmQuote from: whitelancer64 on 08/25/2016 05:31 pmMaybe. It depends on the apparent distance to the star. JWST does have coronagraphs that might enable a direct image to be taken of Proxima b, but if it can only distinguish Proxima b when it's at the furthest from the star from our perspective, it might be tricky to get the timing right.With an 11.2 day orbit, a well planned observation campaign should be able to catch Proxima b, assuming JWST can image it.We do have a couple of years to nail down the orbital inclination, distance, and time more precisely, and I'm certain that Proxima Centauri will be getting some intense scrutiny by many people!
Quote from: whitelancer64 on 08/25/2016 05:31 pmMaybe. It depends on the apparent distance to the star. JWST does have coronagraphs that might enable a direct image to be taken of Proxima b, but if it can only distinguish Proxima b when it's at the furthest from the star from our perspective, it might be tricky to get the timing right.With an 11.2 day orbit, a well planned observation campaign should be able to catch Proxima b, assuming JWST can image it.
Maybe. It depends on the apparent distance to the star. JWST does have coronagraphs that might enable a direct image to be taken of Proxima b, but if it can only distinguish Proxima b when it's at the furthest from the star from our perspective, it might be tricky to get the timing right.
Let's see here. Inclination will be an issue, which means we would definitely, absolutely have to execute a solar slingshot in order to get a free inclination change. The easiest way to do a solar slingshot, of course, is to do a Jovian slingshot. In order to actually get a gravity assist from Jupiter, you'd need to set it all up with a Martian slingshot.So we have the beginnings of a mission profile. Let's limit ourselves to three LEO BFR launches and just two on-orbit robotic assembly events. Generously, let's say this gives us 900 tonnes in LEO.From a mass basis, is it cheaper to use SEP or a solar sail to do the burn for the martian slingshot, or should chemical propulsion be used?Once the slingshots begin, maximum propulsive capacity should be saved for the periapse of the solar slingshot for Oberth reasons. Chemical propulsion is nice here because it can permit very high thrust, which is ideal for an oberth maneuver, but would an ablative solar sail be a better use of mass? Or would it be better to have a combination of chemical propulsion at periapse followed by the deployment of a solar sail?Remember that your whole system needs to be broken up into 300-tonne blocs in order to fit on three BFR launches.
Quote from: sevenperforce on 08/25/2016 07:11 pmLet's see here. Inclination will be an issue, which means we would definitely, absolutely have to execute a solar slingshot in order to get a free inclination change. The easiest way to do a solar slingshot, of course, is to do a Jovian slingshot. In order to actually get a gravity assist from Jupiter, you'd need to set it all up with a Martian slingshot.So we have the beginnings of a mission profile. Let's limit ourselves to three LEO BFR launches and just two on-orbit robotic assembly events. Generously, let's say this gives us 900 tonnes in LEO....none of this is relevant for an interstellar mission lasting less than a century. Inclination not an issue AT ALL. Are you referring to a gravitational focus mission?
Let's see here. Inclination will be an issue, which means we would definitely, absolutely have to execute a solar slingshot in order to get a free inclination change. The easiest way to do a solar slingshot, of course, is to do a Jovian slingshot. In order to actually get a gravity assist from Jupiter, you'd need to set it all up with a Martian slingshot.So we have the beginnings of a mission profile. Let's limit ourselves to three LEO BFR launches and just two on-orbit robotic assembly events. Generously, let's say this gives us 900 tonnes in LEO.
Quote from: Robotbeat on 08/25/2016 08:49 pmQuote from: sevenperforce on 08/25/2016 07:11 pmLet's see here. Inclination will be an issue, which means we would definitely, absolutely have to execute a solar slingshot in order to get a free inclination change. The easiest way to do a solar slingshot, of course, is to do a Jovian slingshot. In order to actually get a gravity assist from Jupiter, you'd need to set it all up with a Martian slingshot.So we have the beginnings of a mission profile. Let's limit ourselves to three LEO BFR launches and just two on-orbit robotic assembly events. Generously, let's say this gives us 900 tonnes in LEO....none of this is relevant for an interstellar mission lasting less than a century. Inclination not an issue AT ALL. Are you referring to a gravitational focus mission?I was more saying...given current and near future tech, what's the greatest dV you could get out of three BFR launches for an interstellar flyby mission? If inclination is not an issue that still probably makes no difference since an oberth around the sun is going to be huge regardless.
Quote from: scienceguy on 08/25/2016 04:49 pmWouldn't the James Webb Space Telescope be able to get a picture of this planet? The star is just a red dwarf.Not even close. Proxima b has a separation from it's star of about 20 milli-arcseconds. The band limited Lyot coronagraphs in JWST's instruments have inner working angles varying from 400 mas to 800 mas. So the coronagraphs would not be able to spatially resolve the planet or even come close to it.In addition to that, there is the contrast problem. A terrestrial planet in the habitable zone of a mid M dwarf has a contrast of about 1 X 10^-8 dimmer than its host star. The coronagraphs on JWST are designed for about 1 X 10^-5 contract, since they are simple coronagrpahs without any wavefront control or diffraction suppression.WFIRST would get closer but the inner working angle of the coronagraph would still be too large for this planet.The best bet to study it in detail in the next few years would be if the planet transits its host star, which would allow JWST to use Transmission or Emission Spectroscopy on it.
BFR launches probe that is just large enough to transmit some data and images from Prox b. Stack 4, 5, or more high-energy upper stages on top of the BFR. I wonder how fast the probe would be moving when the final stage drops away? This would be Atlas V 551/New Horizons on steroids+. Alas, I suspect even this scheme would not be enough to reach an appreciable fraction of light speed.
Quote from: AS_501 on 08/25/2016 11:54 pmBFR launches probe that is just large enough to transmit some data and images from Prox b. Stack 4, 5, or more high-energy upper stages on top of the BFR. I wonder how fast the probe would be moving when the final stage drops away? This would be Atlas V 551/New Horizons on steroids+. Alas, I suspect even this scheme would not be enough to reach an appreciable fraction of light speed.Better yet. Parked a stripped down empty BFR core with one Raptor Vac engine at Lagrange point 2. Added combo NEP & SEP cruise module and Proxima probe. Top off and lit the BFR core for the initial boost. Switch to ion thrusters powered by solar arrays & RTGs after separating from depleted BFR core. Jettisoning the solar arrays after going beyond Jupiter orbital distance. Then continuous boost with ion thruster powered by RTGs until Xenon depletion. Finally the probe separated from cruise module and is on ballistic encounter with the Proxima system. Of course presuming the probe lasted long enough for the encounter observation and got a working radio transmitter for a brief data transmission. For a reasonable chance of mission success, a series of probe launches is needed.
Quote from: Zed_Noir on 08/26/2016 02:16 amQuote from: AS_501 on 08/25/2016 11:54 pmBetter yet. Parked a stripped down empty BFR core with one Raptor Vac engine at Lagrange point 2. Added combo NEP & SEP cruise module and Proxima probe. Top off and lit the BFR core for the initial boost. Switch to ion thrusters powered by solar arrays & RTGs after separating from depleted BFR core. Jettisoning the solar arrays after going beyond Jupiter orbital distance. Then continuous boost with ion thruster powered by RTGs until Xenon depletion. Finally the probe separated from cruise module and is on ballistic encounter with the Proxima system. Of course presuming the probe lasted long enough for the encounter observation and got a working radio transmitter for a brief data transmission. For a reasonable chance of mission success, a series of probe launches is needed.No, this is still not nearly good enough. It'll be hundreds (if not thousands) of years before your probe arrives.The usual approaches to exploring our solar system simply do not work.Do the math!
Quote from: AS_501 on 08/25/2016 11:54 pmBetter yet. Parked a stripped down empty BFR core with one Raptor Vac engine at Lagrange point 2. Added combo NEP & SEP cruise module and Proxima probe. Top off and lit the BFR core for the initial boost. Switch to ion thrusters powered by solar arrays & RTGs after separating from depleted BFR core. Jettisoning the solar arrays after going beyond Jupiter orbital distance. Then continuous boost with ion thruster powered by RTGs until Xenon depletion. Finally the probe separated from cruise module and is on ballistic encounter with the Proxima system. Of course presuming the probe lasted long enough for the encounter observation and got a working radio transmitter for a brief data transmission. For a reasonable chance of mission success, a series of probe launches is needed.