With all of this good conversation about cheap spaceflight, did anyone
ever mess around with the "low-tech" spacecraft design stuff in Hard
Times?
> Roger - a steerable parachute was eventually used for both stages, with
> residual fuel used to get the final deceleration so the stages could land
> on the ground.
>
> Tim - getting to LEO is the hard part. IIRC the total delta-V needed to
> escape the Sun's gravity is 17.75 km/s. However the delta-V needed to
> get to LEO is ~9 km/s. So once you have cargo up in LEO, you are halfway
> to anywhere (in the Milky Way at least), energy-wise.
> As a cost comparison for getting cargo to LEO:Space Shuttle: ($450m/launch
> for 24,400 kg): ~$18,400/kiloDelta IV heavy ($375m/launch for 28,790 kg):
> $13,025/kilo
> Falcon Heavy: ($85m/launch for 53,000 kg): ~$1,600/kilo
>
> The station itself might initially be a giant fuel tank with a command
> center coordinating the activities of multiple drones that use ion drives
> (or similar high-efficiency low thrust engines) to move about the Earth
> orbits. Cheap spacelift carries fuel to orbit, and delivers it to the
> station. The station then handles refueling the pods attached, and the
> drones move the fuel pods to different orbits. The drones may take 1-2
> months to move the payload up or down, but they will do it cheaply.Â
> Passengers will want faster transit.
> So a new Lunar mission might be the following:Rocket launches to orbit,
> delivering the fuel needed for LLO-Earth transit. Fuel attached to
> drones, and sent on 3-4 month journey to LLO. Two sets of fuel might be
> sent, as a 'just in case'.
> Rocket launches to orbit, and delivers Lunar Lander. Lander pod attached
> to drones and sent on 3-4 month trip to LLO.Rockets deliver Fuel for
> LEO-LLO maneuver. This is kept at the station (or nearby, and with a
> drone attached to it).Rockets also deliver Food and water (and other
> consumables) for trip. This is to ensure food doesn't go bad while
> waiting for the crew.
> Rocket delivers Lunar transfer pod. This is fueled from the LEO-LLO fuel
> stockpiles (so you are lifting an empty transfer vessel instead of a
> fuelled one)
> Rockets deliver Crew for Lunar mission. They arrive at the station, and
> board the transfer pod. They thrust to the LLO maneuver, so they can
> rendezvous with the Fuel pods and Lunar Lander already present.Transfer
> pod refuels from LLO-LEO fuel stockpile, and drones begin long lonely
> flight back to the station. Drones attached to the Lunar Lander are
> attached to transfer pod instead (so they aren't left floating around).
> Lunar crew lands on Moon using Lander. They do their thing, then launch
> back to orbit to rendezvous with the Transfer vessel. Drones help
> maneuver Lunar Lander and transfer pod so they attach (or the Lunar crew
> just don spacesuits and transfer via EVA to the transfer pod). Drones
> are left attached to Lunar Lander.
> Lunar Lander is left in Lunar orbit for the next crew, or pushed back to
> Earth via drones. Lunar Crew uses transfer pod to get back to
> station.From station, the Lunar crew return to Earth.
>
> Todd
>
> From: "Tim O'Reilly [Traveller_TNE]"
> <>
>
>
> I'd go for a station that would refuel, or transfer cargo & passengers
> from rockets/shuttle types from earth and those going/coming from higher
> stage orbits, L5, Luna, whatever.
>
>
> On Saturday, March 7, 2015 9:27 AM, "
> [Traveller_TNE]" <> wrote:
>
>
> Â I agree with your ideas for cheap spacecraft except for the vertical
> landing. Here I think I would go with horizontal landing. I can only
> think of two ways to break for landing, thrusters or parachute. I
> think I would rather deal with the shifting mass problem over having to
> haul fuel up to orbit just to bring it back for breaking thrusters. I
> also agree about the shuttle tiles, I was never happy with them, too
> vulnerable by far, but with Earth's TL at the time there was little
> option. Not sure that wood would work either but the idea of having a
> BBQ after landing is amusing. "Hey we made it back alive. Where the
> ship? Lets rip it apart I'm starving." I've always thought of the
> shuttle program as a prototype program and was basely late
> seventy's/early eighties tech program with some upgrades. I would
> dearly like to see a new "advanced shuttle program" with current tech.Â
> It would have to use off the shelf components and be built more like an
> aircraft production line than as a single unit which would help cut costs
> too. The big problem as you pointed out is, what to do with them once
> you have a fleet of twenty or so shuttles and several ones in other
> country's hands? Here with the US/USSR space race gone we would need
> some kind of need to put people into space to validate the shuttles
> viability {Off, did I just say that}. Exploration by robot rovers seems
> to be working well and tourists or people wanting to skydive from orbit
> will not be worth it or the occasional satellite launch. We would need
> orbital factory's, or off planet colonies to need the fleet for
> service. I get a little off topic here, but I can't resist. My idea
> for a first space station would be a habitation ring around a Zero-G
> factory with a shuttle docking bay one end and maybe a ore
> crusher/smelter on the other end.Roger #yiv0507728621 --
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>
>
>
>
>
ever mess around with the "low-tech" spacecraft design stuff in Hard
Times?
> Roger - a steerable parachute was eventually used for both stages, with
> residual fuel used to get the final deceleration so the stages could land
> on the ground.
>
> Tim - getting to LEO is the hard part. IIRC the total delta-V needed to
> escape the Sun's gravity is 17.75 km/s. However the delta-V needed to
> get to LEO is ~9 km/s. So once you have cargo up in LEO, you are halfway
> to anywhere (in the Milky Way at least), energy-wise.
> As a cost comparison for getting cargo to LEO:Space Shuttle: ($450m/launch
> for 24,400 kg): ~$18,400/kiloDelta IV heavy ($375m/launch for 28,790 kg):
> $13,025/kilo
> Falcon Heavy: ($85m/launch for 53,000 kg): ~$1,600/kilo
>
> The station itself might initially be a giant fuel tank with a command
> center coordinating the activities of multiple drones that use ion drives
> (or similar high-efficiency low thrust engines) to move about the Earth
> orbits. Cheap spacelift carries fuel to orbit, and delivers it to the
> station. The station then handles refueling the pods attached, and the
> drones move the fuel pods to different orbits. The drones may take 1-2
> months to move the payload up or down, but they will do it cheaply.Â
> Passengers will want faster transit.
> So a new Lunar mission might be the following:Rocket launches to orbit,
> delivering the fuel needed for LLO-Earth transit. Fuel attached to
> drones, and sent on 3-4 month journey to LLO. Two sets of fuel might be
> sent, as a 'just in case'.
> Rocket launches to orbit, and delivers Lunar Lander. Lander pod attached
> to drones and sent on 3-4 month trip to LLO.Rockets deliver Fuel for
> LEO-LLO maneuver. This is kept at the station (or nearby, and with a
> drone attached to it).Rockets also deliver Food and water (and other
> consumables) for trip. This is to ensure food doesn't go bad while
> waiting for the crew.
> Rocket delivers Lunar transfer pod. This is fueled from the LEO-LLO fuel
> stockpiles (so you are lifting an empty transfer vessel instead of a
> fuelled one)
> Rockets deliver Crew for Lunar mission. They arrive at the station, and
> board the transfer pod. They thrust to the LLO maneuver, so they can
> rendezvous with the Fuel pods and Lunar Lander already present.Transfer
> pod refuels from LLO-LEO fuel stockpile, and drones begin long lonely
> flight back to the station. Drones attached to the Lunar Lander are
> attached to transfer pod instead (so they aren't left floating around).
> Lunar crew lands on Moon using Lander. They do their thing, then launch
> back to orbit to rendezvous with the Transfer vessel. Drones help
> maneuver Lunar Lander and transfer pod so they attach (or the Lunar crew
> just don spacesuits and transfer via EVA to the transfer pod). Drones
> are left attached to Lunar Lander.
> Lunar Lander is left in Lunar orbit for the next crew, or pushed back to
> Earth via drones. Lunar Crew uses transfer pod to get back to
> station.From station, the Lunar crew return to Earth.
>
> Todd
>
> From: "Tim O'Reilly [Traveller_TNE]"
> <>
>
>
> I'd go for a station that would refuel, or transfer cargo & passengers
> from rockets/shuttle types from earth and those going/coming from higher
> stage orbits, L5, Luna, whatever.
>
>
> On Saturday, March 7, 2015 9:27 AM, "
> [Traveller_TNE]" <> wrote:
>
>
> Â I agree with your ideas for cheap spacecraft except for the vertical
> landing. Here I think I would go with horizontal landing. I can only
> think of two ways to break for landing, thrusters or parachute. I
> think I would rather deal with the shifting mass problem over having to
> haul fuel up to orbit just to bring it back for breaking thrusters. I
> also agree about the shuttle tiles, I was never happy with them, too
> vulnerable by far, but with Earth's TL at the time there was little
> option. Not sure that wood would work either but the idea of having a
> BBQ after landing is amusing. "Hey we made it back alive. Where the
> ship? Lets rip it apart I'm starving." I've always thought of the
> shuttle program as a prototype program and was basely late
> seventy's/early eighties tech program with some upgrades. I would
> dearly like to see a new "advanced shuttle program" with current tech.Â
> It would have to use off the shelf components and be built more like an
> aircraft production line than as a single unit which would help cut costs
> too. The big problem as you pointed out is, what to do with them once
> you have a fleet of twenty or so shuttles and several ones in other
> country's hands? Here with the US/USSR space race gone we would need
> some kind of need to put people into space to validate the shuttles
> viability {Off, did I just say that}. Exploration by robot rovers seems
> to be working well and tourists or people wanting to skydive from orbit
> will not be worth it or the occasional satellite launch. We would need
> orbital factory's, or off planet colonies to need the fleet for
> service. I get a little off topic here, but I can't resist. My idea
> for a first space station would be a habitation ring around a Zero-G
> factory with a shuttle docking bay one end and maybe a ore
> crusher/smelter on the other end.Roger #yiv0507728621 --
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