Quote from: Zed_Noir on 12/22/2018 01:06 amQuote from: RonM on 12/21/2018 04:49 pmQuote from: whitelancer64 on 12/21/2018 03:41 pmQuote from: Comga on 12/21/2018 03:35 pmSo let's start a different unanswerable debate about Dragon 2Please point out corrections where these assumptions are wrong.SpaceX is building a new Dragon 2 for each manned/crewed flight to the ISS under Commercial Crew.Eventually NASA will allow these to fly, next spring, next fall, before Boeing's CST-100, after Boeing, whatever.They plan on refurbishing capsules and reusing them for CRS-II cargo flights.SpaceX may do one crew rotation per year, and perhaps three cargo flights, as one of three providers, four if we count the modest amount of cargo that can ride with the four passengers on CST-100.Because Dragon is never flown as expendable, SpaceX will start accumulating used Dragons.I would presume that BFS will take a bit longer than some of Musk's predictions to get built, work out the ground system, fly low altitude, low speed tests, build to high speed and altitude, practice the acrobatics of converting from reentry to landing, and fly some test orbits, which will be needed before the DearMoon flight.Given they will have used first stages and capsules complete with proven life support systems, the marginal cost of an independent crew flight to orbit is mostly the second stage and trunk. This is not trivial, but not huge on the scale of SpaceX projects, or even the Boring Company projects.Why wouldn't someone try to arrange a private flight to LEO?Why wouldn't SpaceX agree to make that happen?NASA will have "real astronauts" doing Real Astronaut Stuff (R) on the real space station, so they might not care.SpaceX can "walk and chew gum at the same time". I think this will indeed happen, perhaps in 2021 or 2022.I also hope it does.SpaceX's attitude has generally been, "if someone is willing to pay us, we'll do it," so I would say such a tourist flight(s) would be plausible. That said, they will probably also be re-using crew dragons for flights to Bigelow's space station, whenever they get around to launching it.Skip the second stage for an interesting suborbital flight. Only throwing away the trunk. Should be relatively inexpensive with reusable booster and capsule.If the Dragon is out of the atmosphere does it need a trunk at all? Attached the Dragon to a modified intrastage fairing directly. Actively stablized the Dragon for the short time aloft with the Dracos.Of course you might need down range recovery assets.Dragon 2 needs a trunk for abort scenarios. No need to put solar cells on the trunk. Short flight should work with internal batteries.
Quote from: RonM on 12/21/2018 04:49 pmQuote from: whitelancer64 on 12/21/2018 03:41 pmQuote from: Comga on 12/21/2018 03:35 pmSo let's start a different unanswerable debate about Dragon 2Please point out corrections where these assumptions are wrong.SpaceX is building a new Dragon 2 for each manned/crewed flight to the ISS under Commercial Crew.Eventually NASA will allow these to fly, next spring, next fall, before Boeing's CST-100, after Boeing, whatever.They plan on refurbishing capsules and reusing them for CRS-II cargo flights.SpaceX may do one crew rotation per year, and perhaps three cargo flights, as one of three providers, four if we count the modest amount of cargo that can ride with the four passengers on CST-100.Because Dragon is never flown as expendable, SpaceX will start accumulating used Dragons.I would presume that BFS will take a bit longer than some of Musk's predictions to get built, work out the ground system, fly low altitude, low speed tests, build to high speed and altitude, practice the acrobatics of converting from reentry to landing, and fly some test orbits, which will be needed before the DearMoon flight.Given they will have used first stages and capsules complete with proven life support systems, the marginal cost of an independent crew flight to orbit is mostly the second stage and trunk. This is not trivial, but not huge on the scale of SpaceX projects, or even the Boring Company projects.Why wouldn't someone try to arrange a private flight to LEO?Why wouldn't SpaceX agree to make that happen?NASA will have "real astronauts" doing Real Astronaut Stuff (R) on the real space station, so they might not care.SpaceX can "walk and chew gum at the same time". I think this will indeed happen, perhaps in 2021 or 2022.I also hope it does.SpaceX's attitude has generally been, "if someone is willing to pay us, we'll do it," so I would say such a tourist flight(s) would be plausible. That said, they will probably also be re-using crew dragons for flights to Bigelow's space station, whenever they get around to launching it.Skip the second stage for an interesting suborbital flight. Only throwing away the trunk. Should be relatively inexpensive with reusable booster and capsule.If the Dragon is out of the atmosphere does it need a trunk at all? Attached the Dragon to a modified intrastage fairing directly. Actively stablized the Dragon for the short time aloft with the Dracos.Of course you might need down range recovery assets.
Quote from: whitelancer64 on 12/21/2018 03:41 pmQuote from: Comga on 12/21/2018 03:35 pmSo let's start a different unanswerable debate about Dragon 2Please point out corrections where these assumptions are wrong.SpaceX is building a new Dragon 2 for each manned/crewed flight to the ISS under Commercial Crew.Eventually NASA will allow these to fly, next spring, next fall, before Boeing's CST-100, after Boeing, whatever.They plan on refurbishing capsules and reusing them for CRS-II cargo flights.SpaceX may do one crew rotation per year, and perhaps three cargo flights, as one of three providers, four if we count the modest amount of cargo that can ride with the four passengers on CST-100.Because Dragon is never flown as expendable, SpaceX will start accumulating used Dragons.I would presume that BFS will take a bit longer than some of Musk's predictions to get built, work out the ground system, fly low altitude, low speed tests, build to high speed and altitude, practice the acrobatics of converting from reentry to landing, and fly some test orbits, which will be needed before the DearMoon flight.Given they will have used first stages and capsules complete with proven life support systems, the marginal cost of an independent crew flight to orbit is mostly the second stage and trunk. This is not trivial, but not huge on the scale of SpaceX projects, or even the Boring Company projects.Why wouldn't someone try to arrange a private flight to LEO?Why wouldn't SpaceX agree to make that happen?NASA will have "real astronauts" doing Real Astronaut Stuff (R) on the real space station, so they might not care.SpaceX can "walk and chew gum at the same time". I think this will indeed happen, perhaps in 2021 or 2022.I also hope it does.SpaceX's attitude has generally been, "if someone is willing to pay us, we'll do it," so I would say such a tourist flight(s) would be plausible. That said, they will probably also be re-using crew dragons for flights to Bigelow's space station, whenever they get around to launching it.Skip the second stage for an interesting suborbital flight. Only throwing away the trunk. Should be relatively inexpensive with reusable booster and capsule.
Quote from: Comga on 12/21/2018 03:35 pmSo let's start a different unanswerable debate about Dragon 2Please point out corrections where these assumptions are wrong.SpaceX is building a new Dragon 2 for each manned/crewed flight to the ISS under Commercial Crew.Eventually NASA will allow these to fly, next spring, next fall, before Boeing's CST-100, after Boeing, whatever.They plan on refurbishing capsules and reusing them for CRS-II cargo flights.SpaceX may do one crew rotation per year, and perhaps three cargo flights, as one of three providers, four if we count the modest amount of cargo that can ride with the four passengers on CST-100.Because Dragon is never flown as expendable, SpaceX will start accumulating used Dragons.I would presume that BFS will take a bit longer than some of Musk's predictions to get built, work out the ground system, fly low altitude, low speed tests, build to high speed and altitude, practice the acrobatics of converting from reentry to landing, and fly some test orbits, which will be needed before the DearMoon flight.Given they will have used first stages and capsules complete with proven life support systems, the marginal cost of an independent crew flight to orbit is mostly the second stage and trunk. This is not trivial, but not huge on the scale of SpaceX projects, or even the Boring Company projects.Why wouldn't someone try to arrange a private flight to LEO?Why wouldn't SpaceX agree to make that happen?NASA will have "real astronauts" doing Real Astronaut Stuff (R) on the real space station, so they might not care.SpaceX can "walk and chew gum at the same time". I think this will indeed happen, perhaps in 2021 or 2022.I also hope it does.SpaceX's attitude has generally been, "if someone is willing to pay us, we'll do it," so I would say such a tourist flight(s) would be plausible. That said, they will probably also be re-using crew dragons for flights to Bigelow's space station, whenever they get around to launching it.
So let's start a different unanswerable debate about Dragon 2Please point out corrections where these assumptions are wrong.SpaceX is building a new Dragon 2 for each manned/crewed flight to the ISS under Commercial Crew.Eventually NASA will allow these to fly, next spring, next fall, before Boeing's CST-100, after Boeing, whatever.They plan on refurbishing capsules and reusing them for CRS-II cargo flights.SpaceX may do one crew rotation per year, and perhaps three cargo flights, as one of three providers, four if we count the modest amount of cargo that can ride with the four passengers on CST-100.Because Dragon is never flown as expendable, SpaceX will start accumulating used Dragons.I would presume that BFS will take a bit longer than some of Musk's predictions to get built, work out the ground system, fly low altitude, low speed tests, build to high speed and altitude, practice the acrobatics of converting from reentry to landing, and fly some test orbits, which will be needed before the DearMoon flight.Given they will have used first stages and capsules complete with proven life support systems, the marginal cost of an independent crew flight to orbit is mostly the second stage and trunk. This is not trivial, but not huge on the scale of SpaceX projects, or even the Boring Company projects.Why wouldn't someone try to arrange a private flight to LEO?Why wouldn't SpaceX agree to make that happen?NASA will have "real astronauts" doing Real Astronaut Stuff (R) on the real space station, so they might not care.SpaceX can "walk and chew gum at the same time". I think this will indeed happen, perhaps in 2021 or 2022.I also hope it does.
Quote from: Zed_Noir on 12/22/2018 01:06 amIf the Dragon is out of the atmosphere does it need a trunk at all? The onboard batteries are very short-lived. Power is normally supplied by the solar cells on half the trunk body. Cooling for the onboard electronics is supplied by the radiators on the other half of the trunk body.
If the Dragon is out of the atmosphere does it need a trunk at all?
Quote from: clongton on 12/22/2018 06:20 pmQuote from: Zed_Noir on 12/22/2018 01:06 amIf the Dragon is out of the atmosphere does it need a trunk at all? The onboard batteries are very short-lived. Power is normally supplied by the solar cells on half the trunk body. Cooling for the onboard electronics is supplied by the radiators on the other half of the trunk body.Emphasis mine.From what I hear from sources: H*ll no those batteries are not short-lived. On a fully charged set Crew Dragon can go for nearly two days without them being recharged.Theoretically Crew Dragon can go from launch to docking to the ISS without having the need for the solar cells at all.
Would adding fixed fins on the Dragon do the same function as the trunk aerodynamically?
Quote from: Zed_Noir on 12/23/2018 08:39 amWould adding fixed fins on the Dragon do the same function as the trunk aerodynamically?No, the center of pressure needs to be sufficiently aft of the center of gravity for the vehicle to be aerodynamically stable.
Quote from: RonM on 12/23/2018 04:27 pmQuote from: Zed_Noir on 12/23/2018 08:39 amWould adding fixed fins on the Dragon do the same function as the trunk aerodynamically?No, the center of pressure needs to be sufficiently aft of the center of gravity for the vehicle to be aerodynamically stable.The trunk separates from Dragon after re-entry "burn" (RCS), but before atmospheric "interface", so the trunk has no aerodynamic function on re-entry. I assume any affect during launch can be mitigated.Edit: The purpose of the trunk is, external storage, photovoltaic platform, and radiator platform, and mounting to second stage. No aerodynamic purpose I think.
Quote from: RDMM2081 on 11/15/2018 07:27 pmI agree it is a stretch at this point. I was merely trying to come up with reasons for the existence for a manual abort switch/lever/button. I am well past my instinct that there should be manual "flight controls" and just trying to poke the corners of the envelope to (dis)prove the need for some who seem to insist in favor of these manual controls.Emphasis mine.Neither the original design for Crew Dragon, nor the original design for Starliner, had manual abort capabilities. Manual abort capabilities were added because NASA asked the CCP providers to do so.
I agree it is a stretch at this point. I was merely trying to come up with reasons for the existence for a manual abort switch/lever/button. I am well past my instinct that there should be manual "flight controls" and just trying to poke the corners of the envelope to (dis)prove the need for some who seem to insist in favor of these manual controls.
The grip of the astronaut "pilot (sorry, need to stop here for a second and just say that I have to use stupid words to get my point across. I know that means I must have a weak argument, but that's why I use bad words)." over NASA human spaceflight is strong but loosening. Thankfully it will be gone soon.
Quote from: Lars-J on 12/27/2018 02:36 amThe grip of the astronaut "pilot (sorry, need to stop here for a second and just say that I have to use stupid words to get my point across. I know that means I must have a weak argument, but that's why I use bad words)." over NASA human spaceflight is strong but loosening. Thankfully it will be gone soon.What the... oh yeah, Chris put in that autocorrect for the M-word
Late to the party here...what's the M-word? What does it rhyme with?
Quote from: zubenelgenubi on 12/27/2018 05:18 amLate to the party here...what's the M-word? What does it rhyme with? Criminal organization originated from Italy...Anyway, NASA explains T-38 is needed to train astronauts to do technical work under stressful situations, I don't disagree.
Quote from: zubenelgenubi on 12/27/2018 05:18 amLate to the party here...what's the M-word? What does it rhyme with? Criminal organization originated from Italy...
Quote from: woods170 on 11/16/2018 08:33 amQuote from: RDMM2081 on 11/15/2018 07:27 pmI agree it is a stretch at this point. I was merely trying to come up with reasons for the existence for a manual abort switch/lever/button. I am well past my instinct that there should be manual "flight controls" and just trying to poke the corners of the envelope to (dis)prove the need for some who seem to insist in favor of these manual controls.Emphasis mine.Neither the original design for Crew Dragon, nor the original design for Starliner, had manual abort capabilities. Manual abort capabilities were added because NASA asked the CCP providers to do so.NASAs gotta have a few manual controls. It helps to justify the fleet of NASA owned and maintained twin-engine supersonic T-38's for all the NASA pilot astronauts."NASA T-38’s “put to bed” for the holidays....... Looks just like an aircraft carrier hangar deck!"Tweet and photo by @Astro_Maker Scott D. Tingle
Neither the original design for Crew Dragon, nor the original design for Starliner, had manual abort capabilities. Manual abort capabilities were added because NASA asked the CCP providers to do so.
I hear Staples can give you a good deal on an "Easy" button.More seriously a "manual abort" really means telling the computer to change plans, no? And what it does in response depends on where you are in the ascent profile?
