I love panels where people discuss the pros and cons of things but so far I am not impressed with this one. Reminds me of a religious program I used to watch years ago where they would try to present a discussion, but really the “panelist” were on the same side of the issues or the panelist who was on the opposite side was rarely given equal time or seemed equally prepared.
The panel assumed you would use vasmir as the main propulsion of a manned mission, when you might not use it in that fashion at all. The panel also assumed the 39 day trip was all one could do with it. Juzz, what is it. You would think the mars society would welcome anything that could be helpful for a mars trip.
The part where is discusses that spending on EDL(are capture ect.) helps reduce mass in other systems is a bit like taking a 500 pound man and a 100 pound man and putting them on a diet. They both loss ten pounds, but since the 500 pound man only loss 2% of his weight while the 100 pound man lost 10% you conclude the diet was ineffective on the 500 pound man. Of course reducing mass via areocapture helps reduce the mass of a chemical stage more than an electrical one. The chemical rocket needs more mass of propellant per mass of payload than the electric one. In short every pound you save on the payload of a chemical rocket reduces the in space mass of the chemical rocket more than the electric one but that is solely due to the inefficiency of the chemical rocket.
The part where he discusses the question of wither or not there is a net thrust and how much of one is a good one, but could have been presented better. This is a critical question about this technology. Also I though with rockets accelerating the mass out the rear was what caused it to go forward. I can understand that a charge on the ship will short the process (i.e. despite accelerating the plasma out the back there is no net mass loss because the plasma and rocket attract each other), but I don’t see this whole “plasma needs to push on metal parts for thrust” for this process to happen.
The part about the thrust to weight ratio adds nothing. Electric propulsion has a low thrust to weight ratio. That is known. However how long the trip time takes depends on more than just the thrust to weight ratio (i.e. The turtle vs. the hare) and even if the trip time is slower there are advantages to not taking a much lower amount of propellant(i.e. a 1-1.5 year trip time for mars cargo could be just fine if doing so means you need ten times less propellant in orbit).
The part on the mass of nuclear vasmir is a good part, but you might not need nuclear power for this to be useful.
The reason why we can’t go to mars today is because I as tax payer am not willing to pay for mars direct if every time we send a mission there we need to throw everything away. Mars direct was a move in the right direction over previous ones, but not enough. I really don’t want to pay for a new habitat complete with a nuclear reactor for each and every mission as well as two nuclear thermal escape stages. If we keep spending money on throw away stuff, how on earth can we afford to achieve anything expect wave a flag at mars?
The panel assumed you would use vasmir as the main propulsion of a manned mission, when you might not use it in that fashion at all. The panel also assumed the 39 day trip was all one could do with it. Juzz, what is it. You would think the mars society would welcome anything that could be helpful for a mars trip.
The part where is discusses that spending on EDL(are capture ect.) helps reduce mass in other systems is a bit like taking a 500 pound man and a 100 pound man and putting them on a diet. They both loss ten pounds, but since the 500 pound man only loss 2% of his weight while the 100 pound man lost 10% you conclude the diet was ineffective on the 500 pound man. Of course reducing mass via areocapture helps reduce the mass of a chemical stage more than an electrical one. The chemical rocket needs more mass of propellant per mass of payload than the electric one. In short every pound you save on the payload of a chemical rocket reduces the in space mass of the chemical rocket more than the electric one but that is solely due to the inefficiency of the chemical rocket.
The part where he discusses the question of wither or not there is a net thrust and how much of one is a good one, but could have been presented better. This is a critical question about this technology. Also I though with rockets accelerating the mass out the rear was what caused it to go forward. I can understand that a charge on the ship will short the process (i.e. despite accelerating the plasma out the back there is no net mass loss because the plasma and rocket attract each other), but I don’t see this whole “plasma needs to push on metal parts for thrust” for this process to happen.
The part about the thrust to weight ratio adds nothing. Electric propulsion has a low thrust to weight ratio. That is known. However how long the trip time takes depends on more than just the thrust to weight ratio (i.e. The turtle vs. the hare) and even if the trip time is slower there are advantages to not taking a much lower amount of propellant(i.e. a 1-1.5 year trip time for mars cargo could be just fine if doing so means you need ten times less propellant in orbit).
The part on the mass of nuclear vasmir is a good part, but you might not need nuclear power for this to be useful.
The reason why we can’t go to mars today is because I as tax payer am not willing to pay for mars direct if every time we send a mission there we need to throw everything away. Mars direct was a move in the right direction over previous ones, but not enough. I really don’t want to pay for a new habitat complete with a nuclear reactor for each and every mission as well as two nuclear thermal escape stages. If we keep spending money on throw away stuff, how on earth can we afford to achieve anything expect wave a flag at mars?
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