Quote from: IanThePineapple on 07/24/2017 11:48 pmIts LES is pretty much the engines on the bottom of the ship, you can't have an escape system that large.It's similar to the crewed Dream Chaser's abort system.
Its LES is pretty much the engines on the bottom of the ship, you can't have an escape system that large.
By the way, a LAS would add its own risk factors. For instance, if the LAS on Orion fails to separate, the crew dies.And commercial airlines are so safe that if you added a LAS or ejection seats to them, the extra risks would greatly outweigh the abort advantages, and you'd REDUCE overall safety.Again, for those in the back:If BFR is as reliable as Musk wants it to be, adding a LAS would REDUCE safety.
Quote from: Robotbeat on 10/12/2017 01:44 pmBy the way, a LAS would add its own risk factors. For instance, if the LAS on Orion fails to separate, the crew dies.And commercial airlines are so safe that if you added a LAS or ejection seats to them, the extra risks would greatly outweigh the abort advantages, and you'd REDUCE overall safety.Again, for those in the back:If BFR is as reliable as Musk wants it to be, adding a LAS would REDUCE safety.Ejection seats are not practical on any commercial airline because of the wide variation between passengers(300 pound man, baby, elderly woman), number of passengers on a plane(hundreds) and the fact that the passengers would need training. Nobody would think of designing an experimental craft , bomber or a fighter jet without some consideration of escape.In this time period and age BFR is closer to an experimental aircraft than anything else and If the shuttle had lived up to it's safety claims Columbia and Challenger would not have occurred.The first BFR flights will not have such a number of people that it is impossible to put in an LES. In fact I don't think you could find as many people as Elon hopes to travel to the moon, mars or LEO at the price he is offering on any regular bias. The most likely paying passenger at the moment for better or worse is going to be NASA and not private citizens.
Quote from: yg1968 on 10/12/2017 11:47 pmQuote from: IanThePineapple on 07/24/2017 11:48 pmIts LES is pretty much the engines on the bottom of the ship, you can't have an escape system that large.It's similar to the crewed Dream Chaser's abort system....Which they were having problems with, even at Dreamchasers much smaller scale. When DC was dropped from commercial crew, they were in the middle of evaluating new propulsion ideas to replace it. (It was a hybrid system) The cargo DC has no such system.
...The first BFR flights will not have such a number of people that it is impossible to put in an LES. In fact I don't think you could find as many people as Elon hopes to travel to the moon, mars or LEO at the price he is offering on any regular bias. The most likely paying passenger at the moment for better or worse is going to be NASA and not private citizens.
Quote from: pathfinder_01 on 10/13/2017 09:03 am...The first BFR flights will not have such a number of people that it is impossible to put in an LES. In fact I don't think you could find as many people as Elon hopes to travel to the moon, mars or LEO at the price he is offering on any regular bias. The most likely paying passenger at the moment for better or worse is going to be NASA and not private citizens.If there are so few passengers, then they can launch and return on F9R/Dragon 2 until BFR completes hundreds of successful flights.
Quote from: envy887 on 10/13/2017 04:00 pmQuote from: pathfinder_01 on 10/13/2017 09:03 am...The first BFR flights will not have such a number of people that it is impossible to put in an LES. In fact I don't think you could find as many people as Elon hopes to travel to the moon, mars or LEO at the price he is offering on any regular bias. The most likely paying passenger at the moment for better or worse is going to be NASA and not private citizens.If there are so few passengers, then they can launch and return on F9R/Dragon 2 until BFR completes hundreds of successful flights.Bingo. And how much does, say, 300 flights cost of SpaceX gets costs as low as they want? Just $600m, less than developing a LAS.
Quote from: Robotbeat on 10/13/2017 11:07 pmQuote from: envy887 on 10/13/2017 04:00 pmQuote from: pathfinder_01 on 10/13/2017 09:03 am...The first BFR flights will not have such a number of people that it is impossible to put in an LES. In fact I don't think you could find as many people as Elon hopes to travel to the moon, mars or LEO at the price he is offering on any regular bias. The most likely paying passenger at the moment for better or worse is going to be NASA and not private citizens.If there are so few passengers, then they can launch and return on F9R/Dragon 2 until BFR completes hundreds of successful flights.Bingo. And how much does, say, 300 flights cost of SpaceX gets costs as low as they want? Just $600m, less than developing a LAS.The Dragon flights will still be very expensive. They will get lots of experience with the ship before they are ready to put people on it anyway, no need to kludge dragon in there.
Quote from: intrepidpursuit on 10/13/2017 11:15 pmQuote from: Robotbeat on 10/13/2017 11:07 pmQuote from: envy887 on 10/13/2017 04:00 pmQuote from: pathfinder_01 on 10/13/2017 09:03 am...The first BFR flights will not have such a number of people that it is impossible to put in an LES. In fact I don't think you could find as many people as Elon hopes to travel to the moon, mars or LEO at the price he is offering on any regular bias. The most likely paying passenger at the moment for better or worse is going to be NASA and not private citizens.If there are so few passengers, then they can launch and return on F9R/Dragon 2 until BFR completes hundreds of successful flights.Bingo. And how much does, say, 300 flights cost of SpaceX gets costs as low as they want? Just $600m, less than developing a LAS.The Dragon flights will still be very expensive. They will get lots of experience with the ship before they are ready to put people on it anyway, no need to kludge dragon in there.We weren't saying kludge a Dragon on there, we were saying launch the Dragon on F9 and transfer crew to the BFR, just like NASA was/is planning for Altair or the Mars transfer vehicle, then return to the Dragon for entry.
Quote from: Robotbeat on 10/13/2017 11:20 pmQuote from: intrepidpursuit on 10/13/2017 11:15 pmQuote from: Robotbeat on 10/13/2017 11:07 pmQuote from: envy887 on 10/13/2017 04:00 pmQuote from: pathfinder_01 on 10/13/2017 09:03 am...The first BFR flights will not have such a number of people that it is impossible to put in an LES. In fact I don't think you could find as many people as Elon hopes to travel to the moon, mars or LEO at the price he is offering on any regular bias. The most likely paying passenger at the moment for better or worse is going to be NASA and not private citizens.If there are so few passengers, then they can launch and return on F9R/Dragon 2 until BFR completes hundreds of successful flights.Bingo. And how much does, say, 300 flights cost of SpaceX gets costs as low as they want? Just $600m, less than developing a LAS.The Dragon flights will still be very expensive. They will get lots of experience with the ship before they are ready to put people on it anyway, no need to kludge dragon in there.We weren't saying kludge a Dragon on there, we were saying launch the Dragon on F9 and transfer crew to the BFR, just like NASA was/is planning for Altair or the Mars transfer vehicle, then return to the Dragon for entry.The objective of BFR is to replace Dragon, Falcon 9 and FH. So it would be strange to have to rely on them.
Quote from: Robotbeat on 10/13/2017 11:20 pmQuote from: intrepidpursuit on 10/13/2017 11:15 pmQuote from: Robotbeat on 10/13/2017 11:07 pmQuote from: envy887 on 10/13/2017 04:00 pmQuote from: pathfinder_01 on 10/13/2017 09:03 am...The first BFR flights will not have such a number of people that it is impossible to put in an LES. In fact I don't think you could find as many people as Elon hopes to travel to the moon, mars or LEO at the price he is offering on any regular bias. The most likely paying passenger at the moment for better or worse is going to be NASA and not private citizens.If there are so few passengers, then they can launch and return on F9R/Dragon 2 until BFR completes hundreds of successful flights.Bingo. And how much does, say, 300 flights cost of SpaceX gets costs as low as they want? Just $600m, less than developing a LAS.The Dragon flights will still be very expensive. They will get lots of experience with the ship before they are ready to put people on it anyway, no need to kludge dragon in there.We weren't saying kludge a Dragon on there, we were saying launch the Dragon on F9 and transfer crew to the BFR, just like NASA was/is planning for Altair or the Mars transfer vehicle, then return to the Dragon for entry.The kludge is making it a part of the system, whether it is built into the rocket or not. It is impossible for BFR to be cheaper than Falcon 9 if you still have to launch a Falcon 9 (or several). They won't put people on BFR until they are comfortable launching them along with it.
If you are going to take BFR to the moon or mars then you are relying on it not to fail anyway. Adding in a Dragon, a Falcon 9, and two crew transfers isn't going to make the system appreciably safer.NASA will either accept the BFR for human use or not. I don't see any helpful middle ground other than just using it for cargo only.(keeps telling me the body is empty if I try reply with the quoted thread)
Quote from: woods170 on 10/11/2018 10:34 amQuote from: Darkseraph on 10/11/2018 10:31 amIt shows the importance of having a launch escape system. They may only ever be used on rare occasions but when they do they save a crew's life! After this, I don't think NASA will certify BFR for astronaut transport and will demand Dragon 2 be kept online for the foreseeable future.Don't be silly. NASA isn't in the process of certifying BFS for use by NASA astronauts. And BFS was never going to replace Crew Dragon for ISS crew rotation missions. BFS is way too massive for that. The docking-loads, imparted on the aging ISS structure, alone were a showstopper for "BFS-to-ISS".It does bring up a good point though, not having a launch abort system is a critical flaw in BFS.
Quote from: Darkseraph on 10/11/2018 10:31 amIt shows the importance of having a launch escape system. They may only ever be used on rare occasions but when they do they save a crew's life! After this, I don't think NASA will certify BFR for astronaut transport and will demand Dragon 2 be kept online for the foreseeable future.Don't be silly. NASA isn't in the process of certifying BFS for use by NASA astronauts. And BFS was never going to replace Crew Dragon for ISS crew rotation missions. BFS is way too massive for that. The docking-loads, imparted on the aging ISS structure, alone were a showstopper for "BFS-to-ISS".
It shows the importance of having a launch escape system. They may only ever be used on rare occasions but when they do they save a crew's life! After this, I don't think NASA will certify BFR for astronaut transport and will demand Dragon 2 be kept online for the foreseeable future.
I think what is missing from the discussion is that the Soyuz escape tower was already jettisoned when the abort occurred, so the spacecraft basically aborted by itself, just like BFS is supposed to do in case the BFB has an issue.
Bump this thread due to all the BFR abort discussion triggered by the Soyuz accident, such as this:Quote from: Khadgars on 10/11/2018 04:14 pmQuote from: woods170 on 10/11/2018 10:34 amQuote from: Darkseraph on 10/11/2018 10:31 amIt shows the importance of having a launch escape system. They may only ever be used on rare occasions but when they do they save a crew's life! After this, I don't think NASA will certify BFR for astronaut transport and will demand Dragon 2 be kept online for the foreseeable future.Don't be silly. NASA isn't in the process of certifying BFS for use by NASA astronauts. And BFS was never going to replace Crew Dragon for ISS crew rotation missions. BFS is way too massive for that. The docking-loads, imparted on the aging ISS structure, alone were a showstopper for "BFS-to-ISS".It does bring up a good point though, not having a launch abort system is a critical flaw in BFS.I think what is missing from the discussion is that the Soyuz escape tower was already jettisoned when the abort occurred, so the spacecraft basically aborted by itself, just like BFS is supposed to do in case the BFB has an issue.
The point of BFR isn't just to be cheaper than F9.NASA has no way to get to Mars orbit, Mars surface, or Moon surface. BFR solves that. If for the first Mars trip, NASA insists on a LAS, then SpaceX will be happy to launch the crew on the reusable Falcon 9 and Dragon.This really isn't that hard to understand.
Quote from: su27k on 10/11/2018 04:56 pmBump this thread due to all the BFR abort discussion triggered by the Soyuz accident, such as this:Quote from: Khadgars on 10/11/2018 04:14 pmQuote from: woods170 on 10/11/2018 10:34 amQuote from: Darkseraph on 10/11/2018 10:31 amIt shows the importance of having a launch escape system. They may only ever be used on rare occasions but when they do they save a crew's life! After this, I don't think NASA will certify BFR for astronaut transport and will demand Dragon 2 be kept online for the foreseeable future.Don't be silly. NASA isn't in the process of certifying BFS for use by NASA astronauts. And BFS was never going to replace Crew Dragon for ISS crew rotation missions. BFS is way too massive for that. The docking-loads, imparted on the aging ISS structure, alone were a showstopper for "BFS-to-ISS".It does bring up a good point though, not having a launch abort system is a critical flaw in BFS.I think what is missing from the discussion is that the Soyuz escape tower was already jettisoned when the abort occurred, so the spacecraft basically aborted by itself, just like BFS is supposed to do in case the BFB has an issue.Why people assume only 1st stage will fail on BFR, upper stage has same engines and fuel, both are capable RUD. Even in 1st stage RUD, upper stage is useless as it can't power up and boost away from exploding 1st stage in time.