New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: We've recently made changes to our user database and have removed inactive and spam users. If you can not login, please re-register.

#26 2017-02-14 18:17:34

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,741
Website

Re: Apollo 11 REDUX

Terraformer wrote:

It would demonstrate the ability to do manned deep space flight. They have to do that before they can do a lander, just as they did with Apollo (8, 9, 10). Most importantly, it would show that America still has the ability.

America doesn't. It's starting over from scratch. Every attempt to retain old capability results in contractors going out of their way to destroy everything, to start over from scratch and charge NASA accordingly. All the work and money spent on Ares V is lost; SLS will take as much time and more money than development of Saturn V. And now they have to start with an Apollo 8 redo (redux). That means America has lost that ability. And America is NOT able to land on the Moon.

If you want to demonstrate America hasn't lost it, then send astronauts straight to the Lunar surface. The mission plan I proposed is a modifications of Robert Zubrin's plan, which tests/demonstrates the Mars Direct surface hab on the Moon.

Offline

#27 2017-02-14 21:32:02

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,791

Re: Apollo 11 REDUX

If America has got it its going to need to hussle in order to show that it still can. Knowing this is not just speed but money in the game its probably should be a cooperation to between nasa and all cots providers to make this possible. If not then there will be no aniversary celebration onthe flyby or of the landing....

Gw meantioned a page back using the European ATV that is being mated to the Orion for a Space x service module attachment.
https://en.wikipedia.org/wiki/Automated … er_Vehicle
http://www.esa.int/Our_Activities/Human … o_capacity

The ATV was the last of the production line that is being coverted to be used on Orion and will not have a follow up unit for the next flight of it. Last I recalled Lockheed was trying to americanize it so as to be able to reproduce it for the later flights use.

I would suspect that we can do the same with the Cygnus from Orbital ATK to which they seem to be able to alter it quite quickly....

The dragon and one of these units could make a safe flyby very possible for the time scale that we are looking to work with.

A lander is a retrofitted guts from space x dragon put inside a cygnus with legs to make it a lander less its orginal atk orbital attachment for cargo use.

Offline

#28 2017-02-14 23:42:25

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,741
Website

Re: Apollo 11 REDUX

Elon claimed the Dragon was designed to land on multiple bodies, including Mars and the Moon. However, I would not land that on the Moon. It's way too heavy. Any capsule with a heat shield, parachutes, and a hull capable of entering Earth's atmosphere is way too heavy for the Moon.

Offline

#29 2017-02-15 09:36:11

Tom Kalbfus
Banned
Registered: 2006-08-16
Posts: 4,401

Re: Apollo 11 REDUX

Then what is it for Mars? Anything on Mars weighs twice as much as it does on the Moon.

Offline

#30 2017-02-15 11:12:53

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,554
Website

Re: Apollo 11 REDUX

Dragon weighs twice as much on Mars as the moon.  So what?  Landing on a planetary body depends upon more than just its surface gravity!  Honestly,  I thought everybody corresponding on these forums knew that!

The figure of merit for this process is the body's escape velocity,  circular orbit speed being 71% of this figure.  It’s comparable to typical interplanetary speeds,  usually,  at least for Earth,  moon,  and Mars.  You must decelerate from interplanetary speeds to zero to land,  and reverse that to take off.  That can be direct from an interplanetary trajectory usually exceeding escape speed,  or it could be from orbit about the body,  if you already decelerated into orbit. 

For the airless moon,  you must do a fully propulsive landing.  The delta-vee for that is the same as the delta-vee for ascent.  Direct is right at lunar escape speed (nearly 2.4 km/s).  From lunar orbit (nearly 1.7 km/s),  it’s that 71% of lunar escape speed.  The numbers vary a little as the orbit altitude changes. 

For Mars,  even with its thin atmosphere,  you can use aerodynamic deceleration for most of the landing delta-vee.  Escape is 5 km/s,  with interplanetary direct entry speeds a bit higher at near 6 km/sec.  From orbit,  entry speed is near 3.6 km/s.  You come out of the hypersonics at local Mach 3 (about 0.7 km/s),  dangerously close to the surface if you weigh over a ton,  even at a very shallow entry angle.

So that's 0.7 theoretical km/s delta-vee you need for a "last-second" propulsive landing of a Dragon capsule on Mars.  That's a whole lot less than the theoretical 3.6 km/s from orbit or ~6 km/s from deep space!  Most of the deceleration is aerodynamic.  You come out closer to the surface on a direct entry than an orbital entry because of the higher speed,  but the exit speed from hypersonics is the same. 

Actuals are a tad higher,  but not a whole lot,  unless you intend to maneuver and hover the way Apollo-11 had to.  You’d better plan on that,  unless you have a prepared landing field that is actually quite large.  My figure of merit is 1 km/s delta-vee capability to land on an unprepared site Mars.  1.4-1.5 would be even safer for rough-site landings,  but is probably not really necessary. 

You do not get that benefit ascending from Mars!  It's propulsive all the way up.  Theoretically 3.6 km/s to achieve low orbit,  5 km/s to escape at all,  6+ km/s to achieve a return trajectory.  You'd better add about 2% to that for gravity and drag losses,  and about 3% more to cover fuel undrainable from the tanks. 

On Earth,  you come out of hypersonics way above 40,000 feet (12 km),  with air thick enough that terminal speed on a big chute is quite slow (20 mph ~ 30 km/h),  not near-sonic as it is on Mars.  Terminal speed falling without a chute is still only around half the speed of sound on Earth.  That’s why Dragon 2 can easily land propulsively on Earth without a chute (except as a backup):  the delta-vee is theoretically only ~200 m/s. 

If the Dragon2 capsule-without-a-trunk has ~ 0.7 km/s delta-vee capability theoretically,  then there is plenty to land,  plenty to direct the trajectory to make a precision landing (the real reason for doing this at all,  something impossible with chutes),  and plenty to hover and maneuver around any obstacles seen at touchdown. 

Dragon 2 and Red Dragon are the same basic capsule with landing legs.  They ripped out the life support,  seats and chutes,  and add back in equipment/cargo racks in Red Dragon.  They can also use a bit thinner heat shield for Red Dragon,  but that only saves something on the order of 50 kg inert.  PICA-X is not very dense.  It floats on water.

GW

Last edited by GW Johnson (2017-02-15 11:13:39)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#31 2017-02-15 15:26:53

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,741
Website

Re: Apollo 11 REDUX

Dragon has the ability to land, but not lift off again. Dragon can land (one way) on Earth, Moon, or Mars. I don't know about you, but I would like to return home alive. NASA tried to design Apollo to land the CSM on the Moon, and return to Earth. That was called "Direct Launch", mass was so high that even a Saturn V couldn't launch it. An engineer for the manufacturer of the Lunar Module showed NASA the engineering math. Using the same Command Module but a much smaller Service Module, plus their Lunar Module, total mass was small enough to fit on a Saturn V. They even had a little launch mass left over. They used that for Apollo 15-17 to carry a lunar rover, and a little more life support for extended surface stay.

My argument is you can't launch both a Dragon spacecraft to lunar orbit, and a lunar module as heavy as Dragon. The lunar module must be light-weight. Especially if it will both land and ascend back to lunar orbit.

Offline

#32 2017-02-15 16:38:24

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,639

Re: Apollo 11 REDUX

Take a look at my post #56 on the SpaceX, NASA, and the New Administration thread; the utilization and/or modification of existing or already proposed hardware should be combinable into a Moon vehicle system.

Proposed architecture: Dragon 2 capsule initially modified for an Apollo 8 redux with increased food and consumables simply by lengthening the capsule. Convert the trunk segment into a booster stage with enough fuel to undertake Moon orbit insertion and orbital departure on a return trajectory. Have an in-orbit assembly of an Earth orbit to lunar trajectory throwaway booster. Could in principle, become a technology demonstrator for the tether system of artificial gravity production? This system could utilize the surplus crew capacity of 7, scaled back to 2-3-4 astronauts in order to conserve oxygen and consumables.

For the Apollo 11 redux, lengthen the trunk stage(s) to include a lunar landing motor, fuel supply for landing in a separable stage that could be left behind with landing legs, etc. The other trunk stage would contain a motor and fuel for lunar departure. The Dragon capsule would have the 8 small Raptor engines and MMH/NTO fuel for an Earth landing. This whole system is again, built at the ISS, thereby making the boys at NASA's eyes cross with ecstasy. This only tasks SpaceX with building the intermediate stages modified from the currently unpressurized cargo trunk.This whole system isn't some multi-billion dollar wet dream. Just a rationalization of existing capabilities.

Offline

#33 2017-02-15 23:14:29

Tom Kalbfus
Banned
Registered: 2006-08-16
Posts: 4,401

Re: Apollo 11 REDUX

RobertDyck wrote:

Dragon has the ability to land, but not lift off again. Dragon can land (one way) on Earth, Moon, or Mars. I don't know about you, but I would like to return home alive. NASA tried to design Apollo to land the CSM on the Moon, and return to Earth. That was called "Direct Launch", mass was so high that even a Saturn V couldn't launch it. An engineer for the manufacturer of the Lunar Module showed NASA the engineering math. Using the same Command Module but a much smaller Service Module, plus their Lunar Module, total mass was small enough to fit on a Saturn V. They even had a little launch mass left over. They used that for Apollo 15-17 to carry a lunar rover, and a little more life support for extended surface stay.

My argument is you can't launch both a Dragon spacecraft to lunar orbit, and a lunar module as heavy as Dragon. The lunar module must be light-weight. Especially if it will both land and ascend back to lunar orbit.

It just needs to be refueled on the Moon, that's all, the acceleration to get off the Moon is the same as the deceleration to land on its surface. What you need to do is have twice as much hydrogen as you need to land on the Moon's surface, then you manufacture oxygen and liquefy it for the ascent back to orbit.

Offline

#34 2017-02-16 00:12:21

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,741
Website

Re: Apollo 11 REDUX

Tom Kalbfus wrote:

It just needs to be refueled on the Moon, that's all, the acceleration to get off the Moon is the same as the deceleration to land on its surface. What you need to do is have twice as much hydrogen as you need to land on the Moon's surface, then you manufacture oxygen and liquefy it for the ascent back to orbit.

Tom, we've been over this. Effectively there is no water on the Moon. LCROSS did find water, but it was such low concentration that it would take about 100 metric tonnes of equipment to produce 1 metric tonne of propellant (fuel and oxidizer). That isn't worth it. Besides, water on the Moon is so scarce that it would be a crime to waste it as fuel. What tiny bit of water that does exist must be reserved for life support, recycled and preserved indefinitely. And LCROSS impacted the most concentrated spot on the Moon, as identified by Lunar Prospector. There is no spot that concentrated. And that spot isn't concentrated any more, LCROSS blew it up, distributed it over a vast area.

Problems with the Moon: no water, no hydrogen, no carbon, no nitrogen. The only oxygen is tied up as metal oxide ore. The Moon makes a great "tree house" but not a place to build a colony. No resources to live.

I posted several times the work by John Wickman to produce Lunar Soil Propellant. That uses powdered aluminum and liquid oxygen. That's the only practical lunar propellant. If you aren't willing to use that, then there is no ISPP on the Moon.

Offline

#35 2017-02-16 07:34:32

RGClark
Member
From: Philadelphia, PA
Registered: 2006-07-05
Posts: 501
Website

Re: Apollo 11 REDUX

http://exoscientist.blogspot.com/2012/0 … -cost.html

SpaceX has said two Falcon Heavy launches would be required to carry a manned Dragon to a lunar landing. However, the 53 metric ton payload capacity of a single Falcon Heavy would be sufficient to carry the 40 mT (Earth departure stage + lunar lander) system described below. This would require 30 mT and 10 mT gross mass Centaur-style upper stages. This page gives the cost of a ca. 20 mT Centaur upper stage as $30 million:

Those calculations were based on the first, cargo version of the Dragon, at ca. 4,000 kg dry mass. I need to redo that for the upgraded manned version Dragon V2 at ca. 6,000 kg dry mass.

But the Falcon Heavy will also have upgraded payload ability with the Falcon 9 v1.2 upgrade, to perhaps ca. 65 metric ton payload. Note also though you probably would want to use the more reliable F9 to loft the crew to orbit. So the total payload capability will then be ca. 85 to 95 metric tons to LEO. Quite likely this will be enough to do a manned lunar landing and return.

According to reports the new administration wants to return to the Moon:

Trump's Advisers Want to Return Humans to the Moon in Three Years.
The plan could dramatically shift the mission of the space agency, prioritizing low-Earth orbit activity over distant exploration.
MARINA KOREN  FEB 9, 2017  SCIENCE
https://www.theatlantic.com/science/arc … pe/516123/

By the quoted prices for the Falcon Heavy and Falcon 9 this might be doable for ca. $300 million per launch.

Bob Clark


Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:
Nanotech: from air to space.
https://www.indiegogo.com/projects/nano … 13319568#/

Offline

#36 2017-02-16 08:55:32

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,639

Re: Apollo 11 REDUX

So...for maybe $300 Million, we get the "return to the Moon" out of the way? Then, with some tested technology firmly in hand--SpaceX's hand, we can finally get on the road to Mars?

Offline

#37 2017-02-16 08:57:49

Tom Kalbfus
Banned
Registered: 2006-08-16
Posts: 4,401

Re: Apollo 11 REDUX

RobertDyck wrote:
Tom Kalbfus wrote:

It just needs to be refueled on the Moon, that's all, the acceleration to get off the Moon is the same as the deceleration to land on its surface. What you need to do is have twice as much hydrogen as you need to land on the Moon's surface, then you manufacture oxygen and liquefy it for the ascent back to orbit.

Tom, we've been over this. Effectively there is no water on the Moon. LCROSS did find water, but it was such low concentration that it would take about 100 metric tonnes of equipment to produce 1 metric tonne of propellant (fuel and oxidizer). That isn't worth it. Besides, water on the Moon is so scarce that it would be a crime to waste it as fuel. What tiny bit of water that does exist must be reserved for life support, recycled and preserved indefinitely. And LCROSS impacted the most concentrated spot on the Moon, as identified by Lunar Prospector. There is no spot that concentrated. And that spot isn't concentrated any more, LCROSS blew it up, distributed it over a vast area.

Problems with the Moon: no water, no hydrogen, no carbon, no nitrogen. The only oxygen is tied up as metal oxide ore. The Moon makes a great "tree house" but not a place to build a colony. No resources to live.

I posted several times the work by John Wickman to produce Lunar Soil Propellant. That uses powdered aluminum and liquid oxygen. That's the only practical lunar propellant. If you aren't willing to use that, then there is no ISPP on the Moon.

You could simply land an oxygen tank in a shadowed crater. Without an ascent stage, you can devote the extra mass to bringing more oxygen, then land another lander with empty tanks nearby, and extend a hose from the fuel tank to the lunar lander with empty fuel tanks. Unlike astronauts, a tank of liquid oxygen doesn't need life support or food, it just sits there. In a cold permanently shadowed crater, the liquid oxygen tank can be prevented from boiling off quite easily, liquid hydrogen would be more difficult. for long term storage methane would probably be better.

Offline

#38 2017-02-16 10:23:26

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,791

Re: Apollo 11 REDUX

Tom there will be no reuse or mining or any far off future wish list. The first decade of going back will be just getting back and staying going.

The propellant to land is greater as you are carrying the ascent mass of fuels and cabin which is all that goes back up.

Apollo 17 Lunar Module Ascent Simulation

https://www.hq.nasa.gov/alsj/a11/A11_PressKit.pdf

The topic is a narrow scope can we do it mission with hardware that we have and what can be adapted to make it possible.

Offline

#39 2017-02-16 11:32:27

Tom Kalbfus
Banned
Registered: 2006-08-16
Posts: 4,401

Re: Apollo 11 REDUX

In the shadow of a crater, we could store fuel for ascent for a long time, also a lander would require less fuel for descent if it also didn' have to carry its ascent fuel. It could use precisely the same amount of fuel it used for descent as it would need for ascent if it could refuel on the Moon. The extra payload capacity could be used to haul up more Lunar rocks, or the same descent rockets could be used for ascent. I think establishing a base for fuel production would be a good idea after the first few missions.

Offline

#40 2017-02-16 12:36:03

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,554
Website

Re: Apollo 11 REDUX

Quote from above:  "Dragon has the ability to land, but not lift off again. Dragon can land (one way) on Earth, Moon, or Mars. "

True except not the moon.  Even just from lunar orbit,  the delta-vee to land is approximately 1.7 km/s.  Dragonv2 or Red Dragon (doesn't matter much which) only has about 0.7 km/s delta-vee if carrying only about 1-2 ton payload.  I get that with 6200 kg dry unladen mass plus 1500 kg payload plus 1900 kg propellant,  and Isp = 335 sec.  MR = 1.246,  delta-vee = 0.724 km/sec.  Rough numbers,  as none are very traceable. 

One of the serious issues with them is the 6200 kg dry unladen mass.  I think that includes the empty trunk.  Things would be a skosh better if we knew and could subtract trunk empty weight from that figure.  Trade trunk inert for more payload. 

It is because of the atmospheres on Earth (plenty) and Mars (barely),  that Dragon can land 1-way on those two places with only 0.7 km/s capability.  It would need a stage capable of more than 1 km/s additional delta-vee just to land one way on the moon,  and trying to stage during descent would be very risky regarding collision with the stage you just shed. 

Escape velocities for Europa,  Callisto,  and Io all fall between 2 and 2.4 km/s.  Ganymede is 0.9.  Titan is 0.8 km/s (and has a dense atmosphere).  The largest asteroid Ceres is under 0.5.  Based on that list,  Red Dragon as proposed for Mars cannot land on any of them except the asteroids,  Titan,  and maybe just possibly Ganymede if carrying almost nothing. 

Based on Musk's comments about some version of Dragon being a one-way "truck" to reach any of those destinations,  I think his people must already be looking at a service module stage to replace the trunk,  that has a delta-vee capability of around 2.5 km/s or more.  That also is just enough for a direct landing on the moon.  This would be an item not yet revealed,  since it is not needed for Mars.  And with all the troubles,  it's probably been a back-burner item to boot. 

A two-way lander on the moon,  departing from and returning to lunar orbit,  needs about 3.4 km/sec capability for the round trip as a single stage.  At 335 sec Isp, that's a mass ratio requirement of about 2.82,  which means the vehicle ignition mass is about 55%.  The Isp is a "good vacuum design" with NTO-MMH storable propellants.

Say 4 astronauts riding in the open in suits plus no cabin,  that's ~200 kg per person = 800 kg payload.  Add a 1 ton rover car,  and another ton of supplies and equipment.  Simply assume the total inert fraction to be a very generous 20%.  55+20 = 75,  leaving 25% to be the 2.8 tons of payload.  You are looking at crudely a 11.2 ton = 11,200 kg lander.  Not far from the mass of a loaded Dragon plus trunk,  but sharing no components in common.  From-scratch design.  6160 kg propellants on board.

Notice that I made it single stage.  That means you refuel it,  load up more equipment and supplies as needed,  and fly it again,  from a supply dump of propellants and cargo in lunar orbit.  On the Earth,  that 11,200 kg machine weighs about 110 kN.  On the moon that is only about 18 KN = ~4100 lbth.  That would be more than enough thrust to land.  You do need deep throttle capability.

Anybody know of an existing stage of about that thrust level using storables?  Maybe a version of what could serve as the service module to put a Dragon in lunar orbit?  Same stage re-rigged does both jobs,  perhaps?

What I have really done here and earlier is show that two Falcon Heavy launches to lunar orbit could put there a Dragon/service module combo (from one) and a fueled lander (from the other).  A third could easily fling 13+ tons of propellant to lunar orbit to support 2 more landings.  3 launches at ~$100M each. 

There,  I did the engineering feasibility!  At launch cost = 20% of program cost,  you could visit 3 sites on the moon for ROM $1.5B.  And variants of the same propulsion stage could be the lander,  the powered Dragon v2 service module,  and the service module needed for one-way probe Dragons to almost anywhere in the solar system.

Looks like I might have reverse engineered what Musk's people probably already have in mind but have not yet revealed.  Just my best guess,  but it does seem likely to me.

So why has this moon landing thing been so hard ever since the old Constellation program?  (Ans. -- because pork barrel politics in congress trumps all logic and common sense,  regardless of party-in-power,  if you'll forgive my choice of that word "trump".)

GW

Last edited by GW Johnson (2017-02-16 16:17:35)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#41 2017-02-16 13:02:10

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,741
Website

Re: Apollo 11 REDUX

GW: You are arguing in favour of my point. I should accept that. However, could Dragon do a one-way mission with a separate de-orbit stage? Using the same mission architecture as the Soviet LK? This would still be one-way, but could be done. Would it work?
lkprof.gif

Numbers: orbit has 2.2 km/s delta-V to shed. The de-orbit stage sheds 2.1 km/s delta-V, dropping down to only 0.1 km/s. De-orbit stage separates, gains some speed due to lunar gravity, crashing at 0.115 km/s. Lunar Kraft (Russian word for "craft" starts with "K") descends to the surface, and slows the remaining 0.1 km/s.

Offline

#42 2017-02-16 16:13:36

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,554
Website

Re: Apollo 11 REDUX

Hi RobertDyck:

I think you answered before I was done editing.  Take another look.  The answer to your question is yes. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#43 2017-02-17 11:30:06

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,639

Re: Apollo 11 REDUX

IMHO, we've equipment-wise progressed beyond the "minimalist approach' taken by the 1960s NASA design teams, and thus, should be utilizing some of the more sophisticated hardware becoming available. I'd be all for reverse engineering the landing, and subsequent Earth return of a Red Dragon vehicle from the lunar surface. It would require orbital assembly techniques unavailable to the Apollo mission designers. Working backwards, we need a lunar departure booster based on the current Dragon trunk unit, powered by MMH/NTO unit capable of getting the necessary delta-V for lunar departure and trans-Earth trajectory. The Red Dragon capsule should be slightly uprated w/r fuel on board to permit midcourse corrections and Earth touchdown requirements. Call that portion 8 metric tons. The trunk departure stage would be scaled to doing the boost into ERT, leaving on the lunar surface the landing stage with legs, descent engines, etc. The lunar landing stage should be scaled to complete insertion into lunar orbit, and a subsequent landing. Prior to that, there will be another stage constructed to accomplish the trans lunar trajectory, which COULD accompany the Dragon, retaining enough fuel for  final destructive boost into a solar trajectory, but also capable of becoming the experimental tether system counterweight; thereby allowing artificial gravity experiments to be conducted for say 3 days? All these various booster stages could be chunks of appropriately engined hardware based on expansion of the Dragon cargo trunk currently used as an unpressurized cargo up to the ISS.

Maybe GW could do these back calculations; it's been too long since I did this sort of stuff as an aerospace undergrad some 55 years ago. But--this would get us away from the "flimsy landers" with limited accommodations for the crew. Yeah, we can bring back more rocks....if only for evidence that we've returned to the moon. In and of itself, the lunar return is nothing more than an exercise demonstrating that we still are capable of leading the way to the stars. It can also serve as a technology demonstration for the Red Dragon capsule and also demonstrate the tether for artificial gravity production. The moon rocks are just more dead weight on the return.

Last edited by Oldfart1939 (2017-02-17 11:33:08)

Offline

#44 2017-02-17 11:34:57

elderflower
Member
Registered: 2016-06-19
Posts: 1,091

Re: Apollo 11 REDUX

If all you are going to do is make a loud statement and bring back some rocks, is this a mission worth doing, considering the cost and risks?

Offline

#45 2017-02-17 13:21:51

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,639

Re: Apollo 11 REDUX

I'd view it as a, possibly necessary politically, detour from the ultimate goal of colonizing Mars. It would serve as a technology demonstrator of orbital assembly, artificial gravity production, use of more sophisticated "any planet possible" landers, improved life support systems over more than just a few days/hours in a space vehicle, etc. I'd support it as just another step forward than as a step sideways. Call it a small scale Mars expedition rehearsal.

Offline

#46 2017-02-17 15:05:23

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,741
Website

Re: Apollo 11 REDUX

In the other thread, Moon mission today - Dragon & Mars hab, I proposed a very light lunar lander. Even lighter than the Apollo LM. But that would accompany a Mars Direct hab on the Moon. So it demonstrates Mars hardware. Or you could say "Mars expedition rehearsal". Really Robert Zubrin's idea, but addressing some concerns NASA raised. You could do a lot with Mars Direct hab on the Moon, with life support and food for more than a year.

Offline

#47 2017-02-17 16:25:58

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,639

Re: Apollo 11 REDUX

One would really need it due to the 14 day diurnal cycle, during the "dark phase." Staying on the Moon for  long period of darkness is one of the reasons for NOT going there. "A neat place to visit, but I wouldn't want to live there."

Offline

#48 2017-02-17 16:34:03

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,639

Re: Apollo 11 REDUX

RobertDyck-

We now have sufficient heavy lift capacity available, making development of another piece of expensive THROWAWAY  hardware unnecessary. My concept was utilization of existing hardware, and development of new hardware which, with suitable alteration/expansion, could be used on a Mars mission. I'm using the tinkertoy method of construction; mix and match, so to speak.

Offline

#49 2017-02-17 17:04:01

elderflower
Member
Registered: 2016-06-19
Posts: 1,091

Re: Apollo 11 REDUX

The moon is more difficult than Mars except in the matters of time to get there and back, and ease of communication. It doesn't have an atmosphere for aero braking, it doesn't have significant resources for the manufacture of return fuels or life support, it is dark for 2 weeks at a time and it doesn't have much gravity. I'm sorry to say this, but I think it would be a side show, and a distraction for the time being.

Last edited by elderflower (2017-02-17 17:05:05)

Offline

#50 2017-02-17 17:11:09

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,741
Website

Re: Apollo 11 REDUX

I did not propose THROWAWAY. I said we could use a Mars Direct habitat, delivered to the Moon on a single SLS block 2B, as a permanent lunar base. With multiple trips to that base using light-weight throwaway lunar landers. And keep recurring mission cost to a minimum by designing it for SLS block 1. Not block 1B, I said block 1. Constellation would require 2 launches per throwaway mission: Ares V and Ares I. SLS was intended to replace both: block 2 would replace Ares V, and block 1 - Aries I. NASA now intends to build block 2B instead of block 2. So what I proposed is the first mission to the Moon would require a single block 1, and a single block 2B. But two great advantages: the surface habitat can be used many times. Subsequent missions only require a single SLS block 1. And the surface habitat is the Mars habitat, so that prepares for Mars. And the Dragon capsule is re-usable.

Offline

Board footer

Powered by FluxBB