A lunar lander is not in any NASA plans or proposals, nor is there any budget for one.
Quote from: whitelancer64 on 02/16/2018 05:59 pmA lunar lander is not in any NASA plans or proposals, nor is there any budget for one.Is it possible with SLS though?
"Build it, they will come."I wish the focus wasn't being directed back to Luna, but if we're to plant flags and footprints on the Moon again, so be it.Orion with some landing legs and an OMS engine should work.NASA just released an RFI for a Shuttle'like OMS engineArticle by Chris Gebhardthttps://www.nasaspaceflight.com/2018/02/nasa-releases-rfi-new-orion-service-module-engine/Here's Endeavours edit:LEFT side OMS pod. .
Quote from: Hog on 02/16/2018 08:43 pm"Build it, they will come."I wish the focus wasn't being directed back to Luna, but if we're to plant flags and footprints on the Moon again, so be it.Orion with some landing legs and an OMS engine should work.NASA just released an RFI for a Shuttle'like OMS engineArticle by Chris Gebhardthttps://www.nasaspaceflight.com/2018/02/nasa-releases-rfi-new-orion-service-module-engine/Here's Endeavours edit:LEFT side OMS pod. .Orion's already using an OMS for its service module. It would need about 20X more fuel to land on the Moon, though, and more to lift off again and break lunar orbit.
{snip}Quote from: whitelancer64 on 02/16/2018 05:59 pmA lunar lander is not in any NASA plans or proposals, nor is there any budget for one. Well, the new budget request has $100 million+ for lunar landing tech(starting with <200 kg landers, expanding to 5000-6000 kg eventually) and $200 million+ for lunar surface missions under the science division.
Is it better to build a ~5 km/s reusable lander that can go directly to the surface or break the trip into stages?
Quote from: Joseph Peterson on 02/18/2018 12:05 amIs it better to build a ~5 km/s reusable lander that can go directly to the surface or break the trip into stages?An expendable system gets you to the Moon faster and with less hardware, since you don't need to build a gateway and the lander can be smaller, since it only needs to do 4 km/s from LLO instead of 5 km/s from NRO. You also don't need to worry about maintaining the lander and transferring propellants and cargo to the lander. The disadvantage is that you need a new lander for every mission, but if you are only going every six months or so, that might not be so bad.
I am trying to figure out how a Lunar surface exploration program could work with SLS/Orion/DSG. Obviously not having to design build permanent infrastructure should speed up the process. That is not the path we are currently on.
The DSG's Power and Propulsion Element (PPE) is a solar powered space tug. A second one can be used to push consumables like food, water and power from LEO to a spacestation orbiting the Moon. Heavy items like habitat building and lunar rovers can also be transferred.Since payload, propellent and lander can arrive separately heavier items can be landed on the Moon from a spacestation than in a single launch.The ideal orbit for the DSG during construction of a Moon Base is probably very different from the orbit of the ship yard for the Mars Transfer Vehicle. Fortunately the DSG's orbit can be changed or a second one built.People could go on direct SLS/Orion flights to the DSG. Most cargo could be launched to LEO on commercial launch vehicles.
Good analysis. For extra credit, cost the same set of operations using FH launches and Dragon spacecraft instead. Don't worry, Congress won't, so SLS/Orion is safe, but it's an interesting exercise.
While this is an interesting thought exercise, I don't see how it gets us closer to the specifications a Lunar lander designed to work with SLS/Orion requires.
Quote from: Joseph Peterson on 02/18/2018 07:17 pmWhile this is an interesting thought exercise, I don't see how it gets us closer to the specifications a Lunar lander designed to work with SLS/Orion requires.The solution is an upgraded Orion service module made in the United States. Bump the solar power capability to 20 kw from 11 kw to match NeMO, add Next-C or AEPS engines. Acting as a lunar lander, It could self ferry itself ahead of crew to whatever orbit Orion can reach(might even be considered LLO) with the upgraded service module utilizing the extra lift capability of the Block 1B. The descent modules get re-used on the surface for power, consumable storage, fuel storage. Once you get some sort of fuel production going on the surface, you could look at fueling them and sending them back up to orbit. Orion would just use ESMs until this is available, freeing up Europe to focus on other stuff (like a European lunar hab equivalent to their contribution to ISS).Either that or base the lander at DSG like what seems to be the plan. The difference between 4.5 km/s and 5.5 km/s for a lander isn't exactly a deal breaker.
Quote from: A_M_Swallow on 02/18/2018 10:21 amThe DSG's Power and Propulsion Element (PPE) is a solar powered space tug. A second one can be used to push consumables like food, water and power from LEO to a spacestation orbiting the Moon. Heavy items like habitat building and lunar rovers can also be transferred.Since payload, propellent and lander can arrive separately heavier items can be landed on the Moon from a spacestation than in a single launch.The ideal orbit for the DSG during construction of a Moon Base is probably very different from the orbit of the ship yard for the Mars Transfer Vehicle. Fortunately the DSG's orbit can be changed or a second one built.People could go on direct SLS/Orion flights to the DSG. Most cargo could be launched to LEO on commercial launch vehicles.So your saying we should operate two stations then?{snip}
{snip}I should probably make it clear that I am not arguing against the use of L1/2 stations in the future. Once Lunar sourced propellant is available in sufficient quantity, they make perfect sense. I'm not trying to plan an inner solar system transportation network using existing Lunar propellant production capacity though. What I am trying to understand is how DSG actually helps locating, then building, Lunar production capacity. It would seem to me that it is hard to compete with LLO when SEP can replace ~25% of cargo lander chemical Dv using LLO.
Quote from: Joseph Peterson on 02/18/2018 07:17 pmQuote from: A_M_Swallow on 02/18/2018 10:21 amThe DSG's Power and Propulsion Element (PPE) is a solar powered space tug. A second one can be used to push consumables like food, water and power from LEO to a spacestation orbiting the Moon. Heavy items like habitat building and lunar rovers can also be transferred.Since payload, propellent and lander can arrive separately heavier items can be landed on the Moon from a spacestation than in a single launch.The ideal orbit for the DSG during construction of a Moon Base is probably very different from the orbit of the ship yard for the Mars Transfer Vehicle. Fortunately the DSG's orbit can be changed or a second one built.People could go on direct SLS/Orion flights to the DSG. Most cargo could be launched to LEO on commercial launch vehicles.So your saying we should operate two stations then?{snip}More like 3 spacestations.LEO gateway spacestation to load SEP and chemical tugs.LLO spacestation to garage lunar lander.EML-1/2 spacestation for loading and repair of Mars transfer vehicles.I think the manned Mars trip is 20-30 years away.
I suspect that the DSG, or replacement e.g. Bigelow/ULA depot, will end up in LLO.For the Moon base a Bigelow B330-MDS module would mass 20-30 tonnes. That is payload to the transportation system since the mass of the lander and propellant are additional to that.https://en.wikipedia.org/wiki/B330
Quote from: ncb1397 on 02/18/2018 08:01 pmQuote from: Joseph Peterson on 02/18/2018 07:17 pmWhile this is an interesting thought exercise, I don't see how it gets us closer to the specifications a Lunar lander designed to work with SLS/Orion requires.The solution is an upgraded Orion service module made in the United States. Bump the solar power capability to 20 kw from 11 kw to match NeMO, add Next-C or AEPS engines. Acting as a lunar lander, It could self ferry itself ahead of crew to whatever orbit Orion can reach(might even be considered LLO) with the upgraded service module utilizing the extra lift capability of the Block 1B. The descent modules get re-used on the surface for power, consumable storage, fuel storage. Once you get some sort of fuel production going on the surface, you could look at fueling them and sending them back up to orbit. Orion would just use ESMs until this is available, freeing up Europe to focus on other stuff (like a European lunar hab equivalent to their contribution to ISS).Either that or base the lander at DSG like what seems to be the plan. The difference between 4.5 km/s and 5.5 km/s for a lander isn't exactly a deal breaker.That isn't the current plan though. NASA's RFI requested drop-in replacements for Shuttle OMS engines. I guess the SM tanks could be stretched but that will cut into payload capacity. How long would it take and how much would it cost before an upgraded Orion would be available? How many more SLS launches are needed to send cargo?https://www.nasaspaceflight.com/2018/02/nasa-releases-rfi-new-orion-service-module-engine/Why are you adding a ~20% margin for LLO to surface and back compared to a minimum margin of ~9% for L2 halo orbits?
If Congress actually cared about humans on Mars, they'd shovel a couple billion per year in SpaceX's direction and get out of the way.
Quote from: Joseph Peterson on 02/19/2018 12:30 am If Congress actually cared about humans on Mars, they'd shovel a couple billion per year in SpaceX's direction and get out of the way.That is not how it works. the congress never directly funds a company.
More like 3 spacestations.LEO gateway spacestation to load SEP and chemical tugs.LLO spacestation to garage lunar lander.EML-1/2 spacestation for loading and repair of Mars transfer vehicles.I think the manned Mars trip is 20-30 years away.
LLO does not seem necessary nor offer any significant advantage.
Quote from: Jim on 02/26/2018 12:24 pmQuote from: Joseph Peterson on 02/19/2018 12:30 am If Congress actually cared about humans on Mars, they'd shovel a couple billion per year in SpaceX's direction and get out of the way.That is not how it works. the congress never directly funds a company.Except of course that it (bizarrely to a European) mandates specific rockets for specific missions, thereby ensuring the manufacturers of those rockets get funded.
Quote from: IRobot on 02/26/2018 02:26 pmLLO does not seem necessary nor offer any significant advantage.It can, if you use it to avoid having to take your TEI fuel (and possibly rocket engine) down to the moon and back.
Wouldn't ELM-1 or 2 be a better location for a station and design a lander to be refueled there? Most companies and countries can reach these locations with existing rockets.
Space activities will always be mass limited. Colonisation will also be very money limited. Astrobotic Technology are currently charging $1,200,000 per kilogram to land a payload on the Moon. Even if larger landers get the price down to $100,000/kg transporting ten tonnes of fuel would cost10,000 * $100,000 = $1,000,000,000Bigelow claims it will sell you a spacestation for that billion dollars (placement extra).
Err...If we're dragging other providers claims into it, SpaceX claims to be able to do it (eventually) for around $50/kg, not $100000/kg.https://forum.nasaspaceflight.com/index.php?topic=41682.msg1731818#msg1731818(Assuming numbers applicable to making passenger transport plausible, and detanking and retanking in LEO and LLO with another vehicle. )Even more near-term launchers (including SLS) can probably comfortably beat $100000/kg.
Quote from: speedevil on 02/26/2018 10:21 pmErr...If we're dragging other providers claims into it, SpaceX claims to be able to do it (eventually) for around $50/kg, not $100000/kg.https://forum.nasaspaceflight.com/index.php?topic=41682.msg1731818#msg1731818(Assuming numbers applicable to making passenger transport plausible, and detanking and retanking in LEO and LLO with another vehicle. )Even more near-term launchers (including SLS) can probably comfortably beat $100000/kg.These figures are to the Moon's surface not to LEO." around $50/kg"Which decade?
For a 20 tonne payload that is $1,562,000,000 / 20,000kg = $78,100/kg
Quote from: A_M_Swallow on 02/27/2018 10:09 amFor a 20 tonne payload that is $1,562,000,000 / 20,000kg = $78,100/kgNo, it is not.See this thread.In short, 100% reusability slashes costs a lot. If it works, which is a more appropriate topic in other threads.
Currently Falcon Heavy is $90M for 63,800 kg to LEO. That is $1,420/kgBlock 1B SLS is ~$1B for 105,000 kg to LEO. That is $9,524/kgThe LEO to lunar surface round trip is 2 * 5.93 = 11.86 km/sAccording to its Wikipedia article the BFR propellant mass is 240,000 kg (530,000 lb) CH4 and 860,000 kg (1,900,000 lb) LOX.So the fuel for the round trip using Falcons and upper stage BFR refuelled in space would cost at least (240,000kg + 860,000kg) * $1420/kg = $1,562,000,000For a 20 tonne payload that is $1,562,000,000 / 20,000kg = $78,100/kg
If you haven't seen it, this is the chart NASA now is using to describe the new exploration plan. #Goddard18
Gerst - Zurbuchen will partner with companies for small lunar landers. NASA will do human lunar landers, but if it turns out industry is more mature and can move faster than us, will reconsider. #Goddard18
This chart shows a lander:Quote from: Marcia SmithIf you haven't seen it, this is the chart NASA now is using to describe the new exploration plan. #Goddard18 https://twitter.com/SpcPlcyOnline/status/973933081819217920
I presume that graphic is talking about Blue Moon and similar initiatives, not a man-rated lander.
Quote from: sevenperforce on 03/15/2018 05:55 pmI presume that graphic is talking about Blue Moon and similar initiatives, not a man-rated lander.Nope.Someone dusted off the LM truck plans.
Quote from: speedevil on 03/15/2018 06:05 pmQuote from: sevenperforce on 03/15/2018 05:55 pmI presume that graphic is talking about Blue Moon and similar initiatives, not a man-rated lander.Nope.Someone dusted off the LM truck plans.Why build and transport a pressurized rover?I know it extends the eva range extremely but I feel like unless you have a lunar base or your going to reuse it on a different mission then it feels like a waste of payload compared to a light unpressurized rover.This is my opinion though
ESA had FISO presentation few months back where plan was to have two RTG+Solar powered 2man rovers. These could support crew for up to 6 weeks, lander was only for transport to and from DSG. The 6 weeks is hopefully enough time to see how body reacts to 1/6g. With this concept we are free to explore all moon, rovers have life of years and can travel to new locations 100kms if not 1000s apart between missions. This without all the overheads of developing and supporting lunar base. NB lander and rovers still need to be developed even if planning lunar base. Non RTG rovers while cheaper would limit range to 1 weeks radius from base.
Not sure how crew get from lander to rover. Docking is ideal, but landers height may not allow this. Crew could step onto roof of rover and enter from top, avoids dust from ground. Would avoid need for heavy bulky EVA suits. NB Pod access EVAs would already be on rovers.
Quote from: TrevorMonty on 03/16/2018 04:24 pmNot sure how crew get from lander to rover. Docking is ideal, but landers height may not allow this. Crew could step onto roof of rover and enter from top, avoids dust from ground. Would avoid need for heavy bulky EVA suits. NB Pod access EVAs would already be on rovers.How about going more skycrane-style? Something like this (see attachments).Reusable space truck is a platform with 4-6 drop tanks around the perimeter, a payload adapter underneath, and multiple engines mounted around the perimeter. It can be used to deliver virtually any payload (high capacity when used expendable; lower capacity when used reusable). It can also accept a crew vehicle attached to the aft payload adapter, holding the vehicle just above the surface and allowing plenty of clearance for a rover to drive up and dock.It drops unneeded tanks in the order they are emptied during descent and ascent but retains all other hardware. It is sized to be able to deliver a crew vehicle to the surface and bring it back up to lunar orbit with about half a reserve tank remaining.You would need something like a Canadarm at a station to replace the drop tanks with new articles after each sortie.
There are no bridges on the Moon so rovers are not height constrained.
Quote from: A_M_Swallow on 03/16/2018 08:09 pmThere are no bridges on the Moon so rovers are not height constrained.Centre of gravity is still an issue, plus crew area structural weight goes (more or less) with pressurised volume.
Quote from: sevenperforce on 03/16/2018 04:54 pmReusable space truck: platform with 4-6 drop tanks around the perimeter, a payload adapter underneath, and multiple engines mounted around the perimeter. It can be used to deliver virtually any payload (high capacity when used expendable; lower capacity when used reusable). It can also accept a crew vehicle attached to the aft payload adapter, holding the vehicle just above the surface and allowing plenty of clearance for a rover to drive up and dock.It drops unneeded tanks in the order they are emptied during descent and ascent but retains all other hardware. It is sized to be able to deliver a crew vehicle to the surface and bring it back up to lunar orbit with about half a reserve tank remaining.You would need something like a Canadarm at a station to replace the drop tanks with new articles after each sortie.DSG (or whatever they are calling the lunar station now) was supposed to have a canadarm on it but I don't know if it has changed
Reusable space truck: platform with 4-6 drop tanks around the perimeter, a payload adapter underneath, and multiple engines mounted around the perimeter. It can be used to deliver virtually any payload (high capacity when used expendable; lower capacity when used reusable). It can also accept a crew vehicle attached to the aft payload adapter, holding the vehicle just above the surface and allowing plenty of clearance for a rover to drive up and dock.It drops unneeded tanks in the order they are emptied during descent and ascent but retains all other hardware. It is sized to be able to deliver a crew vehicle to the surface and bring it back up to lunar orbit with about half a reserve tank remaining.You would need something like a Canadarm at a station to replace the drop tanks with new articles after each sortie.