I am still not sold on the Lunar Gateway. It doesn’t cut the required delta V and adds one extra docking requirement to each mission.
A lunar orbit station would certainly be needed if lunar industrialization gets underway, and I can see one as a radiation shelter during early stages of exploration. I can even see a use for an orbital casino so Michael Collins can play blackjack while Neil and Buzz are goofing off on the surface.
But I”m really not sure what the proposed one is for, other than being a heavy government object that requires a really big launcher over a span of several years.
In Pace’s speech, he says that the essential element of the Gateway is its propellant depot in order to make thenlansers reusable. I would wonder if just doing rendezvouses and transferring prop & cargo/crew would be sufficient. However, he crew component of the Gateway would not be so much for the Moon as it would be a step towards developing a reusable, in-space craft for Mars missions. But I suspect that the Starship will be successfully operating by then.
–In Pace’s speech, he says that the essential element of the Gateway is its propellant depot in order to make thenlansers reusable.–
Make the lunar landers reusable.
At what costs?
It seems you want a depot to be able to operate robotically.
And it seems you will get reusable lunar landers, when you get lunar water mining.
It not certain one can mine lunar water in near term.
Though NASA could spend a lot time, pretending it’s mining lunar water.
To determine if lunar water can be mined, exploration of lunar surface is needed.
And NASA can’t mine lunar water, nor mine anything.
NASA needs to determine if and where in lunar poles lunar water could be mined.
This should not require much time nor cost much. And then NASA should explore Mars. Exploring Mars will be harder and require more time.
Before NASA starts exploring Mars, it going to need some solution regarding ISS.
NASA Mars exploration program needs depots.
And commercial lunar water mining needs depots.
As it probably will require exporting lunar rocket fuel to low lunar orbit. If lunar water is mineable, one will have to make about 1000 tons of rocket fuel per year with time period of 5 year years. And in terms of decades, thousands of tons per years.
Making merely 100 tons per year for decades is “not worth it”.
Commerically it doesn’t work, and having NASA doing this doesn’t change the reality that it’s just a waste time and money.
{Though NASA has inherent “skill” of wasting more time and money doing just about anything].
I not believer is idea that settling Mars just require cost per seat to Mars to be a low cost. Instead what is needed is same as what needed in terms of the Moon- one needs exploration.
It not clear to me that Mars settlements at this time, would anything but a death trap. Or we need exploration of Mars to find viable areas of future settlements.
What important in terms of mars settlement is cost of living on Mars- cost of shelter, cost of electrical power, and cost of water.
What seems obvious, if there is lunar water mining, Mars settlement will be more viable. And if there is Mars settlements, lunar commercial activity will be more viable.
It is possible that a station far enough away from mother earth to prevent a retro burn and landing in a couple hours will encourage development of the capability to actually travel past LEO more than once every 52 years. It has to be a bit dis-heartening for the Vice President to order one of his employees to do something, (telling Bridenstine to go to the moon), something NASA did long, long ago, just to be told it can’t be done. It’s not like they have to break new ground here. All the hardware has been developed, tested, and successfully used several times. But I digress. It is also possible the administration sees what commercial space companies are going to do and they need something to justify spending 847 billion since we last went beyond LEO. A lunar orbiting station would at least be a step in the right direction. They could stay out of the way of the people actually landing on the moon, while claiming some purpose for being there.
Well, the ISS was left unoccupied for the first two years of construction, and wasn’t very functional until it had two more years worth of work and weighed around 200,000 lbs
Assuming the Lunar Gateway is a given, even if it’s mostly an excuse to launch big things, I’d avoid routing much through it because it exacts a delta V penalty.
I think a more optimal architecture using a Gateway is to have a crewed lander that is as light and bare bones as possible, basically a pop-up tent with engines, that has the sole task of getting a crew to and from the surface with near 100% reliability. It could also return some rocks.
Some of the proposals instead use huge one or two stage re-usable landers, which seems to me to be an incredibly inefficient use of fuel. There’s hardly any structures or equipment on the moon, so why, after landing those, would we want to fly them away again, just to land them again?
Some proposals try to make a long duration reusable vehicle that has everything, including beds and a kitchen sink. Given the enormous fuel requirements of the landing/ascent phase of the missions, the Airstream RV approach is not optimal. Some of the Mars architectures make much more sense, landing the equipment and structures separately from the crew.
So along those lines, the big lander shouldn’t have an ascent stage. It should be like a building that flies unmanned from LEO to LLO, using the minimum delta-V profile, even one that takes months, and then it lands in a designated spot. Cryogenics would be the way to land the maximum possible payload, considering that higher risks are acceptable for a robotic landing attempt.
Then the crew flies from Earth to the Gateway, hops in the teeny hypergolic lander, and lands a hundred feet away from the building. They go to the building, inspect it, unfurl any extra solar cells, deploy all the deployables, unhook any rovers, and go about their business. When they’re done, days or months later, they go back to their teeny lander’s ascent module and head back to the Gateway, get back in their capsule, and return home.
All the heavy stuff that landed is permanent infrastructure, whether re-occupied and reused or not. Everything going through the Gateway or going to the surface and back is shaved down to be as light and minimal as possible, so that each crewed mission requires the cheapest possible launch system. That ups the attainable flight rate on a given budget. By not reflying any of the heavy landers, the surface infrastructure build-up is highly efficient. Everything heavy that lands, stays.
In this concept, the Gateway serves as a reliable abort destination, whether left manned or unmanned, a safe parking spot for return capsules, and a lifeboat if there are problems.
The teeny hypergolic lander isn’t sufficient cheap, crazy, and quick, so here’s version 2.0.
The dry weight of the ascent module is 4,600 lbs, the same as Apollo’s. The ascent engine is a 5,250 pound solid rocket motor with a 300 sec ISP and a 400 pound casing. The descent motor responsible for almost all the dV from LLO to landing is an 11,600 pound solid rocket motor whose casing accounts for 850 pounds of its weight. The descent engine is almost exactly the Boeing Inertial Upper Stage used by Titan IV and the Shuttle.
The all up vehicle weight is 21,500 pounds, which is far less than early Apollo’s 33,500 pounds. That’s because instead of using the Apollo’s 4,780 pound dry weight descent stage, this vehicle drops its 800 pound descent engine casing prior to the final landing burn, making a fresh crater, and the landing legs are on the lighter ascent stage, which no longer needs a ladder. There really is no descent module, just a big staging motor that gets discarded. The nearly 4,000 lbs advantage of not having a descent module translates into an 8,000 lb difference in wet weight.
The delicate landing work is handled by the ascent maneuvering engines, and the dV requirements would be much less than a launch abort system on Earth. If it’s landing using oversized maneuvering thrusters out on posts, the landing legs could be replaced by airbags.
Refueling is the sample process of sliding the old ascent motor out and sliding a new one in, then plugging up the ignition circuit. Then just attach a new descent motor and refill the RCS tanks.
The question is whether orbital mechanics can find a landing trajectory compatible with a solid’s entry burn.
I’d prefer hypergolics, I’d prefer lots of better ways to do it, but realistically, I don’t see anybody whose going to put boots on dirt by 2024 if they have to develop those better systems within the available time constraints, so time to punt.
SpaceX.
“Although only minimal capabilities are needed in the next 5 years, the Gateway and other facilities will grow over time to support “never-ending firsts,” not just flags and footprints.”
“Firsts” are flags and footprints, and Gateway is a useless waste of resources.
” On March 26, Pence announced the goal of landing humans at the South Pole of the Moon in 2024. NASA had notional plans to land in 2028. The White House has not yet submitted an amended FY2020 budget request to Congress showing how much more it will cost and where the money will come from.”
Which means they are not serious about the project.
Actual speech at https://www.youtube.com/watch?v=YVnBxWKJAcw
I am still not sold on the Lunar Gateway. It doesn’t cut the required delta V and adds one extra docking requirement to each mission.
A lunar orbit station would certainly be needed if lunar industrialization gets underway, and I can see one as a radiation shelter during early stages of exploration. I can even see a use for an orbital casino so Michael Collins can play blackjack while Neil and Buzz are goofing off on the surface.
But I”m really not sure what the proposed one is for, other than being a heavy government object that requires a really big launcher over a span of several years.
In Pace’s speech, he says that the essential element of the Gateway is its propellant depot in order to make thenlansers reusable. I would wonder if just doing rendezvouses and transferring prop & cargo/crew would be sufficient. However, he crew component of the Gateway would not be so much for the Moon as it would be a step towards developing a reusable, in-space craft for Mars missions. But I suspect that the Starship will be successfully operating by then.
–In Pace’s speech, he says that the essential element of the Gateway is its propellant depot in order to make thenlansers reusable.–
Make the lunar landers reusable.
At what costs?
It seems you want a depot to be able to operate robotically.
And it seems you will get reusable lunar landers, when you get lunar water mining.
It not certain one can mine lunar water in near term.
Though NASA could spend a lot time, pretending it’s mining lunar water.
To determine if lunar water can be mined, exploration of lunar surface is needed.
And NASA can’t mine lunar water, nor mine anything.
NASA needs to determine if and where in lunar poles lunar water could be mined.
This should not require much time nor cost much. And then NASA should explore Mars. Exploring Mars will be harder and require more time.
Before NASA starts exploring Mars, it going to need some solution regarding ISS.
NASA Mars exploration program needs depots.
And commercial lunar water mining needs depots.
As it probably will require exporting lunar rocket fuel to low lunar orbit. If lunar water is mineable, one will have to make about 1000 tons of rocket fuel per year with time period of 5 year years. And in terms of decades, thousands of tons per years.
Making merely 100 tons per year for decades is “not worth it”.
Commerically it doesn’t work, and having NASA doing this doesn’t change the reality that it’s just a waste time and money.
{Though NASA has inherent “skill” of wasting more time and money doing just about anything].
I not believer is idea that settling Mars just require cost per seat to Mars to be a low cost. Instead what is needed is same as what needed in terms of the Moon- one needs exploration.
It not clear to me that Mars settlements at this time, would anything but a death trap. Or we need exploration of Mars to find viable areas of future settlements.
What important in terms of mars settlement is cost of living on Mars- cost of shelter, cost of electrical power, and cost of water.
What seems obvious, if there is lunar water mining, Mars settlement will be more viable. And if there is Mars settlements, lunar commercial activity will be more viable.
It is possible that a station far enough away from mother earth to prevent a retro burn and landing in a couple hours will encourage development of the capability to actually travel past LEO more than once every 52 years. It has to be a bit dis-heartening for the Vice President to order one of his employees to do something, (telling Bridenstine to go to the moon), something NASA did long, long ago, just to be told it can’t be done. It’s not like they have to break new ground here. All the hardware has been developed, tested, and successfully used several times. But I digress. It is also possible the administration sees what commercial space companies are going to do and they need something to justify spending 847 billion since we last went beyond LEO. A lunar orbiting station would at least be a step in the right direction. They could stay out of the way of the people actually landing on the moon, while claiming some purpose for being there.
Well, the ISS was left unoccupied for the first two years of construction, and wasn’t very functional until it had two more years worth of work and weighed around 200,000 lbs
There is a very long forum thread at NASA Space Flight discussing all the pro’s, con’s, and delta V’s, which I guess I’ll have to read.
Assuming the Lunar Gateway is a given, even if it’s mostly an excuse to launch big things, I’d avoid routing much through it because it exacts a delta V penalty.
I think a more optimal architecture using a Gateway is to have a crewed lander that is as light and bare bones as possible, basically a pop-up tent with engines, that has the sole task of getting a crew to and from the surface with near 100% reliability. It could also return some rocks.
Some of the proposals instead use huge one or two stage re-usable landers, which seems to me to be an incredibly inefficient use of fuel. There’s hardly any structures or equipment on the moon, so why, after landing those, would we want to fly them away again, just to land them again?
Some proposals try to make a long duration reusable vehicle that has everything, including beds and a kitchen sink. Given the enormous fuel requirements of the landing/ascent phase of the missions, the Airstream RV approach is not optimal. Some of the Mars architectures make much more sense, landing the equipment and structures separately from the crew.
So along those lines, the big lander shouldn’t have an ascent stage. It should be like a building that flies unmanned from LEO to LLO, using the minimum delta-V profile, even one that takes months, and then it lands in a designated spot. Cryogenics would be the way to land the maximum possible payload, considering that higher risks are acceptable for a robotic landing attempt.
Then the crew flies from Earth to the Gateway, hops in the teeny hypergolic lander, and lands a hundred feet away from the building. They go to the building, inspect it, unfurl any extra solar cells, deploy all the deployables, unhook any rovers, and go about their business. When they’re done, days or months later, they go back to their teeny lander’s ascent module and head back to the Gateway, get back in their capsule, and return home.
All the heavy stuff that landed is permanent infrastructure, whether re-occupied and reused or not. Everything going through the Gateway or going to the surface and back is shaved down to be as light and minimal as possible, so that each crewed mission requires the cheapest possible launch system. That ups the attainable flight rate on a given budget. By not reflying any of the heavy landers, the surface infrastructure build-up is highly efficient. Everything heavy that lands, stays.
In this concept, the Gateway serves as a reliable abort destination, whether left manned or unmanned, a safe parking spot for return capsules, and a lifeboat if there are problems.
The teeny hypergolic lander isn’t sufficient cheap, crazy, and quick, so here’s version 2.0.
The dry weight of the ascent module is 4,600 lbs, the same as Apollo’s. The ascent engine is a 5,250 pound solid rocket motor with a 300 sec ISP and a 400 pound casing. The descent motor responsible for almost all the dV from LLO to landing is an 11,600 pound solid rocket motor whose casing accounts for 850 pounds of its weight. The descent engine is almost exactly the Boeing Inertial Upper Stage used by Titan IV and the Shuttle.
The all up vehicle weight is 21,500 pounds, which is far less than early Apollo’s 33,500 pounds. That’s because instead of using the Apollo’s 4,780 pound dry weight descent stage, this vehicle drops its 800 pound descent engine casing prior to the final landing burn, making a fresh crater, and the landing legs are on the lighter ascent stage, which no longer needs a ladder. There really is no descent module, just a big staging motor that gets discarded. The nearly 4,000 lbs advantage of not having a descent module translates into an 8,000 lb difference in wet weight.
The delicate landing work is handled by the ascent maneuvering engines, and the dV requirements would be much less than a launch abort system on Earth. If it’s landing using oversized maneuvering thrusters out on posts, the landing legs could be replaced by airbags.
Refueling is the sample process of sliding the old ascent motor out and sliding a new one in, then plugging up the ignition circuit. Then just attach a new descent motor and refill the RCS tanks.
The question is whether orbital mechanics can find a landing trajectory compatible with a solid’s entry burn.
I’d prefer hypergolics, I’d prefer lots of better ways to do it, but realistically, I don’t see anybody whose going to put boots on dirt by 2024 if they have to develop those better systems within the available time constraints, so time to punt.
SpaceX.
“Although only minimal capabilities are needed in the next 5 years, the Gateway and other facilities will grow over time to support “never-ending firsts,” not just flags and footprints.”
“Firsts” are flags and footprints, and Gateway is a useless waste of resources.
” On March 26, Pence announced the goal of landing humans at the South Pole of the Moon in 2024. NASA had notional plans to land in 2028. The White House has not yet submitted an amended FY2020 budget request to Congress showing how much more it will cost and where the money will come from.”
Which means they are not serious about the project.