NASA SLS/Orion/Payloads

[PB666]

4 hours ago, wumpus said:

Er, I get 8.5 months for Hohmann transfer to Mars.  The idea that BFR could cut this down seems impossible (nor crew taking a longer path).  https://www-istp.gsfc.nasa.gov/stargaze/Smars1.htm

That's just for zero-gee, although your "atrophied astronaut" would only have to deal with Mars' .375g gravity, so recovery (to Mars levels) would hopefully be quick.  Expect hospitalization when returning to Earth (8 months of 0g after "normalizing" to .375g won't do well at all at full Earth gravity).  Radiation is another story.  I've seen plenty of work done on "building with lunar concrete" but nothing about Mars (presumably thanks to no return samples, although some meteors appear to be martian).  I'd be curious if you could cover your Mars base with martian rock/dirt (or at least the sleeping quarters) in an effort to reduce radiation.

Note that in zero-g, Apollo astronauts could deal with incredibly cramped quarters.  If astronauts spent a significant amount of time (possibly just sleeping) in small, fixed locations then shielding them would be far easier.  I'd expect that ISS data is key for this type of thing.

So an earth Year is 12 months and half a year is 6 months. Half a martian year is 11.28 months the average is an easy approximation in months. 8.64 months. The period is determined by a, the major axis. P = 2πa^1.5/[mu]^0.5
It takes half the period of a transfer orbit to go from its periapsis to apoapsis. a_transfer =  (a_earth + a_mars).  Therefore transfer T_transfer = π(a_earth/2 + a_mars/2)^1.5/[mu]^0.5 = 22,700,000 secs = 8.52 months.

The lowest natural transfer from Earth would occur close to its periapsis to the martian periapsis (a diifuclt proposition), it better to plan targets years in advance to match the martian periapsis (since its orbit is more accentric than earths) by doing this one increases the dV requirement by 30 m/s but lower the transfer time to 7.79 months.  
There is a semi natural transfer that can be done. If we pretended that we could get folks easily to L1 or L2 (we can't and it would not be worth the added dV) you can shave about 2 million km off the average transfer time. In this case you again target the Martian pe. This would take 7.6 months. The problem with this orbit that both require movements at right angles to the direction of travel first. But on the other hand during the departure days on earth speed is substantially higher than average transfer velocity (both sun relative) and likewise speed at Mars is substantially higher than speed just out side of SOI. In addition you lose the benefit of two Oberth-like effcts effects.

 

2 hours ago, tater said:

There are plenty of transfers that can be done in substantially lower times. Some under 100 days, many at ~120 days.

Mess with the NASA trajectory browser.

Unfortunately, the threat sensing software (two types) on my computer report the site as being improperly secured from hacking and block me from using NASA's trajectory browser.

I plugged in with a different browser and got it. Its giving the same result that I got, 208 days for the lowest.
I tried and got 177 days as the shorted out to 2040 using a cap of 5700 dV. The best being in April of 2033.
Using 7000 dV there is one at 3.72 months.
Using 8000 dV and filtering for 100 day there is one for 96 days. 

These are not true Hohman transfers in that the apo and pe of the transfer orbits are not tangential to the orbits of mars or earth at the intersect. These are ;"star trek' transfer.
OK so given 6000 dV for the transfer, just a little above that required for a standard transfer to Martian Pe, lets see the best.

Mars     SPK-ID 499
   
Orbit Condition Code
Size 6779 km
   
Semi-major axis 1.524 AU
Eccentricity 0.093
Inclination 1.85°

Earth Departure Jul-28-2035
4.29 km/s
C3 = 24.6 km2/s2
DLA = -22°

128-day transfer
Mars Arrival Dec-03-2035
1.42 km/s*

* ΔV to/from a C3 = 0 km2/s2 local planetary orbit.

Edited December 4, 2017 by PB666

[Green Baron]

1 hour ago, DAL59 said:

Zubrin says that is completely false.    

Zubrin and his text on the "Mars Society" page fits completely in the conspiracy theme, seeing enemies where there are none and scoffing at the work of others without presenting a concrete solution. Ignore the guy, stick to science, in the long run you will be right ;-)

If you willingly follow the likes of him you will sooner or later be disappointed.

1 hour ago, DAL59 said:

Thats not how transfers work.  8.5 months is the worst possible transfer.  Without too much extra fuel, it could be reduced to 6 months, but past 4 months it grows exponentially. SpaceX has done its math. 

The "worst possible transfer" dV wise would be at a phase angle between the planets where you had to completely cancel out the orbital speeds, like Mars behind Earth. The "worst possible transfer" time wise could be several years long (Earth or Mars, totally banana), depends on how many times you want to orbit the Sun until you finally get too close to Mars. There is, i'd think, no practical time limit ... (must be checked whether that is true).

The fastest possible transfer would be the Brachistochrone, where you'd accelerate ~50% of the time towards and the other ~50% backwards. That'll be amost a straight line (try it out in the open source game "Pioneer"). With chemical propulsion that is, of course, impractical, if i may say so :-)

I think (but i am not sure), that 8.5 months(*) is the Hohmann transfer that raises the AP from Earth just to Mars orbit at a time when the phase angle between the planets is near optimum (every +/-2 years or so, writing this without a check.). You'll arrive at Mars with a v-inf that reflects the orbital differences between Earth and Mars - Hohmann - Oberth(**). If the ship has more dV than are necessary for this classical Hohmann maneouver than it can shorten the trip, as said above, by accelerating longer, thus raising the AP above Mars orbit, but then it'll have to perform a mor radical braking maneouver there. KSP standard :-)

(*) edit: yes, it is :-)

(**) speak Obert, not Oberth

Edited December 4, 2017 by Green Baron

[tater]

There are loads of trajectories possible. For DST (the LM concept, presumably) the transfer has to be a rendezvous to martian orbit. We'd have to check on the dv of the proposed "2 of everything" system to know what the transfer might look like. BFS can be faster because it skips martian orbit in favor of direct entry at up to at least 7.5 km/s (according to the simulation shown for it). In the trajectory browser you can look at flybys with that as the velocity it passes with, limited by the fully fueled dv of the craft (~9km/s for a flags and footprints sort of cargo load).

The SLS/Orion/DST varieties will be longer transfers, but the LockMart concept has the habs surrounded by LH₂ tanks.

[Green Baron]

1 minute ago, tater said:

... loads of trajectories possible ...

Spock would say, the number is infinite, and add a lecture in Vulcanian philosophy.

Just sayin' :-)

[PB666]

2 minutes ago, Green Baron said:

Spock would say, the number is infinite, and add a lecture in Vulcanian philosophy.

Just sayin' :-)

There are an infinite number of women you could ask out on a date, but how many could you afford that wont also turn you into wreck.

[tater]

1 minute ago, Green Baron said:

Spock would say, the number is infinite, and add a lecture in Vulcanian philosophy.

Just sayin' :-)

Loads of fairly optimum trajectories. There are obviously an infinite number, but the NASA software prioritizes them so that you can look at as few as a handful of optima, or maybe a hundred or so useful ones. They are going to all be "cloud" values where small changes in parameters result in small changes in trip time, intercept relative velocity, etc. Effectively families of solutions.

[Green Baron]

Just now, PB666 said:

There are an infinite number of women you could ask out on a date, but how many could you afford that wont also turn you into wreck.

I don't have dV time for this ... *waveshand*

 

:-)

1 minute ago, tater said:

Loads of fairly optimum trajectories. There are obviously an infinite number, but the NASA software prioritizes them so that you can look at as few as a handful of optima, or maybe a hundred or so useful ones. They are going to all be "cloud" values where small changes in parameters result in small changes in trip time, intercept relative velocity, etc. Effectively families of solutions.

Yeah, i wasn't that serious.

[tater]

 

[PB666]

The problem is that many Martian landings make the assumption that you are going to be able to aerobrake in the martian atmosphere.
However if your transfer has too great of a Vrad relative to the ||Sun-Mars then what happens is you will have to spend extra dV to carry a comparable heat shield.

[Green Baron]

5 minutes ago, PB666 said:

The problem is that many Martian landings make the assumption that you are going to be able to aerobrake in the martian atmosphere.
However if your transfer has too great of a Vrad relative to the ||Sun-Mars then what happens is you will have to spend extra dV to carry a comparable heat shield.

The guys that calculate that probably are aware i'd guess and weigh between the options.

EM-2, that would mean 2022 as earliest date, if the evaluation and reality are in favour ...

 

Edited December 4, 2017 by Green Baron

[PB666]

July 28th 2035  buy your tickets now. lol. 128 days to mars, then I guess Elon will have a chance to wait on Mars for a ride back.

Mars
Earth Departure May-07-2033 4.13 km/s
C3 = 20.7 km2/s2, DLA = -19°,   
120-day transfer

Mars Arrival Sep-04-2033 2.78 km/s*

Mars Departure Sep-24-2033 3.92 km/s*
 210-day transfer

Earth reentry
Apr-22-2034
14.72 km/s reentry

   350-day total mission
10.83 km/s (add an additional 0.5 km/sec for other stuff like rendevous with landers)

Solar range:
0.73 - 1.39 AU
   
Earth range:
0 - 0.95 AU

If we place the lander in Martian Orbit . . .apriori....

Trajectory Itinerary

Earth Departure Jul-12-2035 3.77 km/s
C3 = 12.2 km2/s2 DLA = -20°
176-day transfer

Mars Arrival Jan-04-2036  716 m/s*

Total = 4.48 km/s (allow 0.5 km/s for docking its lander with the Transfer habitat)

If this ship has a lander then the lander needs 1000 to 2000 dV for landing on Mars and 5000+ dV for reattaining orbit.

 

 

 

 

Edited December 4, 2017 by PB666

[tater]

 

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170001347.pdf

 

[PB666]

1 hour ago, Green Baron said:

Zubrin and his text on the "Mars Society" page fits completely in the conspiracy theme, seeing enemies where there are none and scoffing at the work of others without presenting a concrete solution. Ignore the guy, stick to science, in the long run you will be right ;-)

If you willingly follow the likes of him you will sooner or later be disappointed.

The "worst possible transfer" dV wise would be at a phase angle between the planets where you had to completely cancel out the orbital speeds, like Mars behind Earth. The "worst possible transfer" time wise could be several years long (Earth or Mars, totally banana), depends on how many times you want to orbit the Sun until you finally get too close to Mars. There is, i'd think, no practical time limit ... (must be checked whether that is true).

The fastest possible transfer would be the Brachistochrone, where you'd accelerate ~50% of the time towards and the other ~50% backwards. That'll be amost a straight line (try it out in the open source game "Pioneer"). With chemical propulsion that is, of course, impractical, if i may say so :-)

I think (but i am not sure), that 8.5 months(*) is the Hohmann transfer that raises the AP from Earth just to Mars orbit at a time when the phase angle between the planets is near optimum (every +/-2 years or so, writing this without a check.). You'll arrive at Mars with a v-inf that reflects the orbital differences between Earth and Mars - Hohmann - Oberth(**). If the ship has more dV than are necessary for this classical Hohmann maneouver than it can shorten the trip, as said above, by accelerating longer, thus raising the AP above Mars orbit, but then it'll have to perform a mor radical braking maneouver there. KSP standard :-)

(*) edit: yes, it is :-)

(**) speak Obert, not Oberth

I imagined a rescue scenario for Martian expedition. Here is what it was

You burn retrograde from earth (Atp something like 310 to 290) and descend to a submercurial orbit (27 days), then you burn prograde at an appropriate time to intersect with Mars (<136 days), assuming that Mars is say behind earth in its orbit, the craft then wraps around the sun and burns out to Mars intercepting mars with a excess radial motion nearly at right angle to S_{mars, orbital}. Atmosphere entry velocity is ~20 km/sec.

One always has to remember that if we can improve ION drive power systems, there is no ISP limit for ION drives, c is entirely possible for hydrogen (as it is done in a super-collidor). Therefore the fuel requirement can be zero (i.e meaning it could be the fuel waste of a nuclear reactor). Orbits that drop in the direction of the sun can utilize increase insolance and burn in the direction of Mars with very little mission lead time. For example suppose you had a situation were Mars was 120' degrees behind earth, there are 'diving orbits' that intersect Mars.

Here is where ION drives ironically have some ability. Given adequate lead time an ION drive could, in priniciple, burn to nearly match the orbital velocity vectors of the target as it approaches. The problem with exiting earth is not a problem intersecting planets, its just a problem if one wants to insert into an orbit quickly. So that once you get to a planet the rescue ship would need to have some other propulsion. Presumably this would be a lander that would use the atmosphere to break its orbit, while the ION drive very slowly circularizes its orbit. The problem is a rescue ship needs also to leave Mars (maybe there is fuel on Mars?) and reach the same orbit as the rescue ship, whereby it could return to Earth.

[PB666]

I was just watching this

I was a spectacular pile of BS.

1. Earth powered by cis-lunar solar power stations.
Uh, global warming plus GTO solar power stations = global crazy warming.

2. Resourcing space missions from lunar mining buses. Because getting your stuff of them moon is radically better than getting them off of earth.
Ok I not a perfect rocket science, but dV to land on moon is about 3000, the dV to lift off of moon and orbit, also about 3000. Thats 6000 dV. dV required to get stuff off of earth, around 10,300.
a. So at best the moon is like 60% the cost of launching from Earth.
b. Elon already has a system of ships that can be recycled.
c. The worst case scenario for water here on earth is you dip a garden hose about 400 feet away into a briney canal and use reverse osmosis. The best case scenario on the Moon is that you have to grind rocks and heat them to generate steam which you can consense.
d. The worst case scenario of oxygen on Earth is you buy a concentrator from your local medical supply shop and concentrate oxygen from the air. The best case scenario on mars it to create oxygen from electrolysis or heating rocks to very high temperatures.
e. THe worst case scenario of hydrogen on earth is that you have to perform electrolysis, but methane also can be used to generate hydrogen much cheaper. Hydrogen can also be produce by biological reduction processes. There is no biological reduction on mars.
So lunar bases cryogenics are very expensive, much so than earth.

3. Resource gathering from the Moon. Not better than the earth The moon is believed to be composed of the ancient surface of pre-theran earth IOW almost all of the moon's composition is resembles the surface of the earth except without all the separative processes here on earth that make copper, iron, silver, uranium mining work. Somewhere on the moon is a better place than on the surface of the Earth and they are going to map it with satellites. Lets look at the earth.
a. Hydrogen (about 10% of the worlds ocean), helium is rare - but even harder to extract from space, helium is the expected by product of fusion energy. lithium (14,000,000 t reserve), berylium (400,000 t reserve), boron (major component of sea water, common component of detergents), carbon (coal), nitrogen (70% of air), oxygen (29% of air, 80% of sea water),  florine (mostly toxic to humans), sodium (sea water), magenisum (a better source is earth passing asteroids, lower dV requirement), aluminum (29,000,000 t reserves), silicon (beach sand), phosphorous (extensively mined), sulfer (sulfate is a major component of sea water), chlorine (sea salt), potassium (pot ash) calcium (lime stone), . . . . . .None of these elements are cheaper on the moon. The only thing that raises the brow a bit is titanium oxide about 12% of moon rocks. At that percent it might be a tenth as competitive as the price on earth.
b. they better use a very low frequency, the heat of accretion probably put the low level of precious heavy metals at the center of the moon, what kind of drills do they have?

 

[Canopus]

18 minutes ago, PB666 said:

I was just watching this

I was a spectacular pile of BS.

1. Earth powered by cis-lunar solar power stations.
Uh, global warming plus GTO solar power stations = global crazy warming.

2. Resourcing space missions from lunar mining buses. Because getting your stuff of them moon is radically better than getting them off of earth.
Ok I not a perfect rocket science, but dV to land on moon is about 3000, the dV to lift off of moon and orbit, also about 3000. Thats 6000 dV. dV required to get stuff off of earth, around 10,300.
a. So at best the moon is like 60% the cost of launching from Earth.
b. Elon already has a system of ships that can be recycled.
c. The worst case scenario for water here on earth is you dip a garden hose about 400 feet away into a briney canal and use reverse osmosis. The best case scenario on the Moon is that you have to grind rocks and heat them to generate steam which you can consense.
d. The worst case scenario of oxygen on Earth is you buy a concentrator from your local medical supply shop and concentrate oxygen from the air. The best case scenario on mars it to create oxygen from electrolysis or heating rocks to very high temperatures.
e. THe worst case scenario of hydrogen on earth is that you have to perform electrolysis, but methane also can be used to generate hydrogen much cheaper. Hydrogen can also be produce by biological reduction processes. There is no biological reduction on mars.
So lunar bases cryogenics are very expensive, much so than earth.

3. Resource gathering from the Moon. Not better than the earth The moon is believed to be composed of the ancient surface of pre-theran earth IOW almost all of the moon's composition is resembles the surface of the earth except without all the separative processes here on earth that make copper, iron, silver, uranium mining work. Somewhere on the moon is a better place than on the surface of the Earth and they are going to map it with satellites. Lets look at the earth.
a. Hydrogen (about 10% of the worlds ocean), helium is rare - but even harder to extract from space, helium is the expected by product of fusion energy. lithium (14,000,000 t reserve), berylium (400,000 t reserve), boron (major component of sea water, common component of detergents), carbon (coal), nitrogen (70% of air), oxygen (29% of air, 80% of sea water),  florine (mostly toxic to humans), sodium (sea water), magenisum (a better source is earth passing asteroids, lower dV requirement), aluminum (29,000,000 t reserves), silicon (beach sand), phosphorous (extensively mined), sulfer (sulfate is a major component of sea water), chlorine (sea salt), potassium (pot ash) calcium (lime stone), . . . . . .None of these elements are cheaper on the moon. The only thing that raises the brow a bit is titanium oxide about 12% of moon rocks. At that percent it might be a tenth as competitive as the price on earth.
b. they better use a very low frequency, the heat of accretion probably put the low level of precious heavy metals at the center of the moon, what kind of drills do they have?

 

The idea isn't to return recources to earth from the Moon but to use them in space without having to lift them from the earth. Also why would Solar power satellites contribute to global warming? All in all this model for a cislunar economy would contribute more to the advancement of humanity than some remote Mars colony that doesn't return any value, atleast in my opinion (also a lot more realistic). This is the wrong thread for Cislunar-1000 though. 

 

Edited December 4, 2017 by Canopus

[_Augustus_]

To build or not to build a new Mobile Launcher Platform?

http://spacenews.com/nasa-weighs-new-mobile-launcher-for-sls/

It's only $300 million; it's not like you could build another MER or buy five Falcon 9s for that price......

[Bill Phil]

11 minutes ago, _Augustus_ said:

To build or not to build a new Mobile Launcher Platform?

http://spacenews.com/nasa-weighs-new-mobile-launcher-for-sls/

It's only $300 million; it's not like you could build another MER or buy five Falcon 9s for that price......

If they can get up to two per year with it, it's probably worth it. 

What do they have that they can launch on five F9s? Nothing. And it turns out that launch costs are less than payload costs. So, to launch 5 more F9s with NASA payloads they'd have to spend 600 million at least, potentially a billion.

[DAL59]

"Patch points from the cicular restricted model are iteratively corecxted into a continous, quasi-periodic halo orbit in a high-fidelity force model."  I guess I now know why ksp used patched conics.

33 minutes ago, PB666 said:

Uh, global warming plus GTO solar power stations = global crazy warming

greatly take away from it by eliminating need for fossil fuels.

37 minutes ago, PB666 said:

I was just watching this

I was a spectacular pile of BS.

1. Earth powered by cis-lunar solar power stations.
Uh, global warming plus GTO solar power stations = global crazy warming.

2. Resourcing space missions from lunar mining buses. Because getting your stuff of them moon is radically better than getting them off of earth.
Ok I not a perfect rocket science, but dV to land on moon is about 3000, the dV to lift off of moon and orbit, also about 3000. Thats 6000 dV. dV required to get stuff off of earth, around 10,300.
a. So at best the moon is like 60% the cost of launching from Earth.
b. Elon already has a system of ships that can be recycled.
c. The worst case scenario for water here on earth is you dip a garden hose about 400 feet away into a briney canal and use reverse osmosis. The best case scenario on the Moon is that you have to grind rocks and heat them to generate steam which you can consense.
d. The worst case scenario of oxygen on Earth is you buy a concentrator from your local medical supply shop and concentrate oxygen from the air. The best case scenario on mars it to create oxygen from electrolysis or heating rocks to very high temperatures.
e. THe worst case scenario of hydrogen on earth is that you have to perform electrolysis, but methane also can be used to generate hydrogen much cheaper. Hydrogen can also be produce by biological reduction processes. There is no biological reduction on mars.
So lunar bases cryogenics are very expensive, much so than earth.

3. Resource gathering from the Moon. Not better than the earth The moon is believed to be composed of the ancient surface of pre-theran earth IOW almost all of the moon's composition is resembles the surface of the earth except without all the separative processes here on earth that make copper, iron, silver, uranium mining work. Somewhere on the moon is a better place than on the surface of the Earth and they are going to map it with satellites. Lets look at the earth.
a. Hydrogen (about 10% of the worlds ocean), helium is rare - but even harder to extract from space, helium is the expected by product of fusion energy. lithium (14,000,000 t reserve), berylium (400,000 t reserve), boron (major component of sea water, common component of detergents), carbon (coal), nitrogen (70% of air), oxygen (29% of air, 80% of sea water),  florine (mostly toxic to humans), sodium (sea water), magenisum (a better source is earth passing asteroids, lower dV requirement), aluminum (29,000,000 t reserves), silicon (beach sand), phosphorous (extensively mined), sulfer (sulfate is a major component of sea water), chlorine (sea salt), potassium (pot ash) calcium (lime stone), . . . . . .None of these elements are cheaper on the moon. The only thing that raises the brow a bit is titanium oxide about 12% of moon rocks. At that percent it might be a tenth as competitive as the price on earth.
b. they better use a very low frequency, the heat of accretion probably put the low level of precious heavy metals at the center of the moon, what kind of drills do they have?

 

1. Overall the plan was reasonable, and I agree that the internet is to the early century economy what space will be to the mid century economy.

2. The ITS(or BFR, whatever you want to call it) could do this much quicker and cheaper.

3. Solar power satellites are a very, very, great idea, except for the problems of space debris, and hijacking to hit people with masers

4. Its a good plan, but you can never plan anything 30 years in advance.  SpaceX could do 100 people to the moon in 5 years.

[Bill Phil]

10 minutes ago, DAL59 said:

"Patch points from the cicular restricted model are iteratively corecxted into a continous, quasi-periodic halo orbit in a high-fidelity force model."  I guess I now know why ksp used patched conics.

greatly take away from it by eliminating need for fossil fuels.

1. Overall the plan was reasonable, and I agree that the internet is to the early century economy what space will be to the mid century economy.

2. The ITS(or BFR, whatever you want to call it) could do this much quicker and cheaper.

3. Solar power satellites are a very, very, great idea, except for the problems of space debris, and hijacking to hit people with masers

4. Its a good plan, but you can never plan anything 30 years in advance.  SpaceX could do 100 people to the moon in 5 years.

Masers aren't dangerous enough in most proposals to damage anything. The intensity in watts may be just as high as the sun ( or lower), and optimized to be as safe as possible.

[_Augustus_]

40 minutes ago, Bill Phil said:

If they can get up to two per year with it, it's probably worth it. 

The reason for a new MLP would be to replace the old one made for ICPS. They'd retire the old one after just one flight (EM-1).

[PB666]

27 minutes ago, DAL59 said:

"Patch points from the cicular restricted model are iteratively corecxted into a continous, quasi-periodic halo orbit in a high-fidelity force model."  I guess I now know why ksp used patched conics.

greatly take away from it by eliminating need for fossil fuels.

1. Overall the plan was reasonable, and I agree that the internet is to the early century economy what space will be to the mid century economy.

2. The ITS(or BFR, whatever you want to call it) could do this much quicker and cheaper.

3. Solar power satellites are a very, very, great idea, except for the problems of space debris, and hijacking to hit people with masers

4. Its a good plan, but you can never plan anything 30 years in advance.  SpaceX could do 100 people to the moon in 5 years.

The patching they are referring to are semi-continuously fired SEP devices to keep orbits from, well, slamming into a hard object, like the moon.

1. Adding power to the earth does not take away global warming already created. It only adds to it. By the time this things gets going the carbon usage will already be on the fall.
2. We already have potentially all the non-carbon producing electric power we need, Wind, Solar and Nuclear. The only countries that can afford "maser" power are the countries that already have enough money to create their own carbon-free power. The countries that don't wont be able to afford space maser power. Finally, the life of solar panels in space is not infinite, the larger panels are subject to damage from sun-spot activity (the larger the panel the greater the cross-panel voltage potential).
3. The plan was only reasonable to a fool or a politician.
4. SpaceX will not have 100 people on the moon in five years. SpaceX has yet to place a single person in space.

[Bill Phil]

Just now, _Augustus_ said:

The reason for a new MLP would be to replace the old one made for ICPS. They'd retire the old one after just one flight (EM-1).

They're thinking seriously about Europa Clipper and other Block 1 flights. Wasting the time to build an MLP and a whole upper stage and using it once is insane. Of course, NASA isn't that logical... but Block 1 may see future use. It's not likely, but possible.

[_Augustus_]

Just now, Bill Phil said:

They're thinking seriously about Europa Clipper and other Block 1 flights. Wasting the time to build an MLP and a whole upper stage and using it once is insane. Of course, NASA isn't that logical... but Block 1 may see future use. It's not likely, but possible.

Europa Clipper has to fly on Block 1B so they can human rate it. 

Also, Delta production is going to be shut down, so they can't get more ICPSes anyway.

[Bill Phil]

Just now, _Augustus_ said:

Europa Clipper has to fly on Block 1B so they can human rate it. 

Also, Delta production is going to be shut down, so they can't get more ICPSes anyway.

Not necessarily. EC can fly on Block 1. And it just may do that. It may not, but we don't know for sure. It probably will be if they build a second MLP.

Delta II is getting shut down. Delta IV will be eventually. But, if need be, ICPS production can be extended. After all, it isn't DCSS anymore.

[DAL59]

33 minutes ago, Bill Phil said:

Masers aren't dangerous enough in most proposals to damage anything.

Yay.  

13 minutes ago, PB666 said:

Adding power to the earth does not take away global warming already created. It only adds to it.

Energy production itself does not significantly cause warming, its the byproducts that make the greenhouse effect.  Solar panels in space don't make carbon.  The masers won't be powerful enough to heat up the Earth.  

15 minutes ago, PB666 said:

Solar

Clouds and nighttime

15 minutes ago, PB666 said:

Wind

Takes up too much space, and wind isn't constant

16 minutes ago, PB666 said:

Nuclear.

Meltdowns