Quote from: Fequalsma on 01/17/2009 03:24 amWhat are 1.5 launches? Ares I = 1 launch, and Ares V = 1 launch.1+1 = 2 launches. I've got a bridge to sell anyone who buys that "1.5 launch" red herring.F=maQuote from: Will on 01/17/2009 03:11 amAs I understand it, you seem to be bringing together three entirely separable questions:1) Is two launches better than 1.5?I can understand your frustration, but do you have a more concise way to distinguish between:1) two launches on the same size launcher and2) two launches, with one on a much larger launcher and one on a much smaller launcher?Because the costs, LOC and LOM numbers can be very different.Yes, they both launch twice. But what is the most convenient way to distinguish the two options?
What are 1.5 launches? Ares I = 1 launch, and Ares V = 1 launch.1+1 = 2 launches. I've got a bridge to sell anyone who buys that "1.5 launch" red herring.F=maQuote from: Will on 01/17/2009 03:11 amAs I understand it, you seem to be bringing together three entirely separable questions:1) Is two launches better than 1.5?
As I understand it, you seem to be bringing together three entirely separable questions:1) Is two launches better than 1.5?
Quote from: ballew on 01/17/2009 02:45 amWhat size and type of unmanned missions would be possible to Mars or to the outer solar system using a Jupiter 120 or 130 along with an existing US as a launch vehicle that would not be possible using the launch vehicles currently available. I'm thinking that some of the later unmanned test flights could be used to send missions to deep space.For starters, a REAL Mars Sample Return.
What size and type of unmanned missions would be possible to Mars or to the outer solar system using a Jupiter 120 or 130 along with an existing US as a launch vehicle that would not be possible using the launch vehicles currently available. I'm thinking that some of the later unmanned test flights could be used to send missions to deep space.
Just out of curiosity, was the PM article the January 15 surprise, or was there something else that we missed?Also, a few more misc questions:The J232 is rated to carry 100 tonnes to LEO, but all of its proposed missions are for smaller payloads farther out (Moon, Mars, NEAR, etc). Can the stack actually support 110 tonnes through max acc. or is that a purely theoretical maximum for LEO?Will the J120 and J232 need crew access facilities that are different to both each other and the shuttle?Is there any plan for a cryogenic orbital transfer stage that can hold propellant for years instead of weeks, for use in large planetary missions?Does the fuel-for-seats plan for the orbital fuel depot risk turning NASA into a space tourism company? For example, if a very wealthy person bought enough commercial tanker rockets to put the requisite tonnage of fuel up, would that buy him a ticket to the moon?How would losing another shuttle effect DIRECT's chances vs the alternatives?
For starters, a REAL Mars Sample Return.
I can understand your frustration, but do you have a more concise way to distinguish between:1) two launches...and2) two launches...
Quote from: clongton on 01/17/2009 02:47 amFor starters, a REAL Mars Sample Return.How much could a Jupiter 232 send on a trajectory to Mars ?(that's why I asked payload Vs C3 above )
Just out of curiosity, was the PM article the January 15 surprise, or was there something else that we missed?
Also, a few more misc questions:The J232 is rated to carry 100 tonnes to LEO, but all of its proposed missions are for smaller payloads farther out (Moon, Mars, NEAR, etc). Can the stack actually support 110 tonnes through max acc. or is that a purely theoretical maximum for LEO?
Will the J120 and J232 need crew access facilities that are different to both each other and the shuttle?
Is there any plan for a cryogenic orbital transfer stage that can hold propellant for years instead of weeks, for use in large planetary missions?
Does the fuel-for-seats plan for the orbital fuel depot risk turning NASA into a space tourism company? For example, if a very wealthy person bought enough commercial tanker rockets to put the requisite tonnage of fuel up, would that buy him a ticket to the moon?
How would losing another shuttle effect DIRECT's chances vs the alternatives?
And one last question that I previously forgot:The DIRECT lunar launch schedule is pretty ambitious. Is there enough funding available to build meaningful payloads for all of those launches? If not, you'll lose some of your economy of scale.
Yes, they both launch twice. But what is the most convenient way to distinguish the two options?
TMI 3,800m/s : 35.7mTTMI 4,100m/s : 31.9mTWith the a top-off at an orbital Depot the size of a single J-232 Upper Stage though, the limit for TMI is above 200mT -- and the vehicle can't lift that much on a single launch.
With the a top-off at an orbital Depot the size of a single J-232 Upper Stage though, the limit for TMI is above 200mT -- and the vehicle can't lift that much on a single launch.
Hey,Not to get off topic, but I had a question about Jupiter120.It can boost about 45ton into LEO right? Roughly twice the weight of Orion? Could it launch Orion, fully fueled, with another 20 ton "service module"?
Of course, to fill the depot you`d have to launch J-232 several more times...
Quote from: Lobo on 01/17/2009 12:42 amHey,Not to get off topic, but I had a question about Jupiter120.It can boost about 45ton into LEO right? Roughly twice the weight of Orion? Could it launch Orion, fully fueled, with another 20 ton "service module"?AFAIK, Direct have proposed a number of uses for that extra weight (whixch could be as great as the shuttle's maximum cargo payload). These include:* ISS resupply using an autominous re-entry version of the MPLM* ISS or satellite maintenance using an autominous re-entry mission module based on the shuttle's Payload Suppot Frame (SSPSF), which would also be equipped with a small remote manipulator system arm, based on a squinting close consideration Phillip's illustrations of an Orion/SSPSF delivering the Advanced Microwave Spectrograph to the ISS.* Trans-Lunar fly-around, with the Orion sitting on top of a Centaur upper stage, which would act as an EDS.
Quote from: Eerie on 01/17/2009 01:14 pmOf course, to fill the depot you`d have to launch J-232 several more times...DIRECT's proposal, if I recall correctly, is that you would require other launches from Atlas, Delta, Soyuz, Ariane, Falcon, etc., etc. to fill your depot.You probably need another Jupiter launch to get your depot up there to start with (though who says you couldn't launch an empty depot on a smaller launcher, too), but the point isn't to refill the depot with Jupiter launches.
I'm personally not sold on the depot concept yet. I understand the reasoning, but I'm having trouble believing that having X launches to refuel a depot ends up costing less than just launching the fuel as part of the mission, especially if those fuel launches are getting spread out among a number of vendors.
i.e. Would one J-23x and ten (pick your favorite LV) fuel launches actually end up costing less that 2-J232 launches, one with all the fuel you need?
I'm also not sold on the "fuel for seats" concept. If NASA says "you can have a seat to Mars if you orbit $20 worth of fuel", my response might be "can I just give you the $20?"
Now if you have a competitive contract for a company to provide depot-refueling services, I could see that resulting in lower cost. Maybe similar to the COTS model, except they're carrying up fuel to depots rather than cargo to ISS.
If you need 100mT of fuel for your upcoming mission, them compete out a contract to supply that fuel at your depot. If the contract winner's proposal is for 5mT, 10mT, or 25mT fuel launches depending on the vehicle they use? If the single contractor knows they will get X dollars for Y launches, they can build a solid business plan around that, and you might begin to see some economies in scale using smaller launchers.
What are 1.5 launches? Ares I = 1 launch, and Ares V = 1 launch.1+1 = 2 launches. I've got a bridge to sell anyone who buys that "1.5 launch" red herring.F=ma
Quote from: Stephan on 01/17/2009 07:59 amQuote from: clongton on 01/17/2009 02:47 amFor starters, a REAL Mars Sample Return.How much could a Jupiter 232 send on a trajectory to Mars ?(that's why I asked payload Vs C3 above )Assuming 3.8 km/s dv from LEO, about 35 mt. Not including the JUS itself.