New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: As a reader of NewMars forum, we have opportunities for you to assist with technical discussions in several initiatives underway. NewMars needs volunteers with appropriate education, skills, talent, motivation and generosity of spirit as a highly valued member. Write to newmarsmember * gmail.com to tell us about your ability's to help contribute to NewMars and become a registered member.

#1 2015-11-06 20:59:06

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Servicing Earth Satelites

Initial post to start

Void wrote:

Barter, that's interesting.  It seems that before you can have a cash system, or if cash does not work, then you make deals.

I have been thinking of sources of starter cash for outer space.  Most or all are from other peoples ideas.

1) Servicing Earth Satellites.
2) Hosting Scientists sponsored by entities on Earth.  On Mars or the Moon, but most likely Mars.
3) Selling returned objects as gift items.
4) Providing transport for equipment and people.
5) https://en.wikipedia.org/wiki/Philanthropy
#5, why not.  it is a cause like save the whales or whatever, donations.
6) Getting material goods to Service Earth Satellites.  (Fuel).
7) Getting Metals down to Earth worth the bother.
8) Recreation for the wealthy, and interested types.
9) Land speculation/Lease speculation.

This is a deviation from Profits, but I think it has been established that the profit systems have to eventually tie to some cash linkages.

Any others?


I am thinking that the servicing includes item 6, 4 with salvage rights for 7 and 3 if owner releases them.

Online

#2 2015-11-06 21:25:08

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

We do have a basis on which to show a history as to the model...with the capability in the retired Space Shuttle...

Space Station Working to Solve the Puzzle of Orbiting Satellite Repair

The space industry grapples with satellite servicing

Goddard Satellite Servicing Capabilities Office (SSCO)

Of course that also includes space Tugs and other such methods

Online

#3 2015-11-07 10:02:51

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

History of service http://www.dept.aoe.vt.edu/~cdhall/cour … vicing.pdf

Some interesting slides for what could be... with lunar insitu resources such as water processing
Technology Applications that Support Space Exploration

We could say that this is a space spinoff http://spinoff.nasa.gov/index.html

But since the shuttle is no more the industry that was to be seems to have faded and from what I can see is non existant as the commecial industry does not seem to be caring about it.

Online

#4 2015-11-11 13:22:06

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Servicing Earth Satelites

Allright Mr. Spacenut:

Query phrase "SpaceX + Satellite"
Informative, but somewhat on the negitive side.
http://www.wired.com/2015/06/elon-musk- … -internet/
SpaceX moves:
http://qz.com/426158/the-details-behind … xperiment/
http://www.nbcnews.com/science/space/ho … 16-n370196
Even Elon Musk is tentative about this:
http://motherboard.vice.com/read/elon-m … end-spacex
Query phrase "Parts from asteroids for satelite repair"
Orbiting 'Rest Stops' to Repair Crumbling Satellites?
http://news.discovery.com/space/orbitin … 150618.htm
Query phrase "Asteroid Mining + Manufactured Parts"
http://www.wired.com/2013/01/deep-space … id-mining/

I fully understand that much of the above can disappear into vapors, but in general it points in a direction which could be like a place to put to root a growing outerspace industrial process capable of connecting cash finances on the surface of Earth to places beyond the atmosphere.  And that if it were to exist, might perhaps then be joined to multiple non-Earth profit structures.

During my searches, I observed references to the use of Drones and Balloons, which are potentially additional competitive technologies, I also think I observed reference to SpaceX considering Laser communications.  Laser because the bandwidth needed for regular transmissions is limited, and perhaps already owned.

Interesting then I can see that perhaps if you did have a ring of SpaceX/Other satellites in orbit, perhaps a Drone Airship method.
https://www.youtube.com/watch?v=4owUqfduT2c
The first video is of course on the topic, but if you let the next one play as well it is quite interesting.  More than quite interesting!

These would not necessarily be competitive, but symbiotic, as you could reduce the number of Satellites, to reduce cost, and could fly drone airships above the normal cloud layers, to allow them to receive and send laser transmissions from the satellite ring.  I would presume that then the airships would use bandwidth to retransmit to ground.

Airships being that high up, perhaps they could then "See" more of the satellites.

And of course we could expect our evil enemies then to say why not just the drones?  Well, the reason being that with a ring of satellites, laser communications could work all the way to the ground, if the weather permitted.  As for the drone airships, you would only have them over populated areas such as cities.

Where are all you minions Spacenut?

Anyway for such a topic, I did not think I might have much to add.  But it is an interesting topic.

So, various entities propose to:
Manufacture parts from Asteroid materials, perhaps for satellites.
Obtain Fuel from Asteroids for satellites perhaps.
Place a ring of internet satellites in low Earth Orbit.  Low enough were eventually perhaps even humans might be involved in some of the servicing.

And of course I feel the Moon should have a review, as it could in fact supply materials, both for parts and propulsion.

It is possible that a cash coupling to outerspace could be engineered.  It is not beyond hope.

Last edited by Void (2015-11-11 13:39:03)


Done.

Offline

#5 2015-11-11 18:00:26

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

No minions just a nut about Space, Science and Technology .... as for all that you bring up its all possible with the right business model and cash funding.

Problems for the model starts with the decision of robotic versus manned mission for the rescue of the satelite in question. Then we must remember that the satelite was most like assembled by man and not robotics here on Earth so the chances are that its a choice for the higher cost manned mission or letting it die as it plumets from orbit or giving it a boost to a higher orbit until the funds are available.

For manned missions we need a manned launch provider and with the Cots program, we are about to have a capsule of short term useages shortly via Space x Dragon V? and Boeings CST100 aka Starliner. But without an orbital platform to attach the satelite to it may be to risky for a manned mission to occur. That said we have identified another need to make manned rescues possible. To make it less costly for the next rescue we should make that platform reuseable so now it needs station keeping capabilities.

Robotics use the same launch vehicle for a satelite rescue mission with each robotic piece of equipment needing to be custom made for each satelites repair as its not likely to be the same for any. This makes robotics quite costly as well when we consider the price if the satelite is not repaired.

Online

#6 2015-11-11 21:49:33

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Servicing Earth Satelites

Ya, I was reluctant to dip into this one.  It requires the work of the truly gifted.  Lets hope they will be involved.


Done.

Offline

#7 2015-11-11 22:24:25

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

I am not a gifted, just an average joe.... but would hope that others might contribute there comments.

I would start with something simular to the cygnus like cargo container making some modifications to the unit, such as creating cargo bay doors simular in function to the shuttle bay and have an arm for latching onto the satelite within it.

The docked Dragon or CST-100 capsule would allow the crew to exit into the repair bay allowing a platform for the astronauts to preform the repairs as a catch and release. If the repair bay were made large enough one might be able to make it a shirt sleeve environment to work within rather than the bulky space suits.

Online

#8 2015-11-12 10:08:07

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: Servicing Earth Satelites

Well,  how about leaving what amounts to a shuttle bay and arm on orbit without the shuttle?  That's pretty similar to what Spacenut just said in the previous post.  Add an operator’s cabin and some on-orbit propulsion to go to the job site.  You just send a crew up with supplies and propellants when you have a job to do,  launching a few tons at a time,  instead of 100 tons of spaceplane every time. 

Maybe there ought to be 3 of these,  one in the usual eastward orbit,  one near the ISS,  and one polar.  Who knows?  You can always add extra features to it over time.

I first proposed this idea on my blog site 4 years ago.  And I updated it to a more capable assembly facility last year.  Go to http://exrocketman.blogspot.com.  Navigate down to 2 August 2011 to “End of an Era Need Not Be End of a Capability”,  written in response to the announcement of the retirement of the space shuttle. 

The same on-orbit facility can be expanded for assembly of things too large to fit in launch shrouds.  The most effective form requires a far more supple space suit.  It requires a light framework covered in space blankets to create a lighting-powered radiation reverberation space so that all workpieces equilibriate near room temperature,  and without obscuring shadows.  This is also located on http://exrocketman.blogspot.com,  navigate down to 11 February 2014,  for “On-Orbit Repair and Assembly Facility”. 

This sort of thing does not need an SLS to launch.  The existing rockets could do it in dockable modules,  certainly Falcon-Heavy could put the bulk of one up in one throw.  The COTS spacecraft would be just fine as the crew taxis.  You're looking at (order of magnitude) $100M per launch,  not $1.5 B the way it was with shuttle,  or the $0.5B to $1.0B projected for SLS,  depending upon who you choose to believe. 

Just something to think about.  A major improvement in capability,  for a price that won’t break the bank.  We haven’t been able to fix satellites on orbit since the shuttle retired.  Why not restore that capability and take it a step forward,  for a lower price than shuttle ever was?

GW


GW Johnson
McGregor,  Texas

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

Offline

#9 2015-11-12 19:55:46

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

I agree that just a little R&D money would be needed to make a prototype of what we have described and to place it on any of the current launchers that have the ability to loft it into a station keeping orbit for later use. In fact this is a good way to prove out space tugs, a more powerful ION engine for getting a crew out to the region where the satelites are and so much more. Much of the real design work is just implementation of parts and pieces to make it happen.
The canadians would love to be making more arms and Italy (I think thats where the cygnus is made) would definitely welcome more business with the MPL platform and intergration of it into a new casing for use simular to that of a shuttle. with the capability to have items dock to either end for use on such a rescue mission.

Online

#10 2015-11-13 14:47:53

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: Servicing Earth Satelites

Somebody better than me at orbital mechanics could probably address this issue of getting the on-orbit repair facility to the job site.  This relocation may not need a crew;  send them straight to the job site.  As long as there is no plane change involved,  I would think a facility could be boosted into an long elliptical orbit,  from which only the timing of the perigee burn is involved to rendezvous with whatever needs servicing. 

That's why I was thinking place one in LEO at 23.5 degrees inclination,  one at the ISS inclination (near 60 degrees isn't it?),  and one for the polar stuff.  It's plane changes that really eat up the delta-vee.  The one at ISS inclination likely ought to be flying formation near ISS anyway. 

My proposed concept does require that US and ESA astronauts and agencies learn how to do the same kind of on-orbit refueling that the Russians have been doing.  Nothing wrong with the same storable hydrazine blends and NTO,  either.  We've a history that goes back all the way to Gemini-Agena that says those propellants are the right thing to do,  for long periods in space. 

Can you imagine being able to repair Hubble a few more times?  Safely,  with a real capture facility?  And a simple bailout capsule any of those rare times it is actually called for?  Or fixing some of those other failed satellites? 

GW


GW Johnson
McGregor,  Texas

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

Offline

#11 2015-11-13 20:40:01

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

Nasa is looking to build a deep space habitat and why not give them a hint as to what can be used that already has plans all done to make it easy. This same structure can also be used for the servicing space for a crew to spend time in as they go towards there new rescue location.

1. crew taxi could be either Dragon v... or the CST-100
2. crew supplies and cargo for the repair can go up in a Dragon Truck or cygnus
3. use a module simular to the Tranquility (Node 3) complete with Cupola for the habitat with the crew taxi and cargo truck to dock with
4. dock the shuttle style bay and mplm with canadian arm at the end of tranquility
5. dock propusion module to the very end of this long train of pieces, fuel could be delivered to the propellant tanks via the truck and arm useage

Online

#12 2015-11-14 09:57:32

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: Servicing Earth Satelites

Actually,  when you think about it,  some version of this same repair/assembly facility ought to be a part of any manned mission anywhere beyond cislunar space.  (Wouldn't hurt to be this well equipped,  just going back to the moon.)  That's because of the necessity of self rescue when (not if) things go wrong.  So,  NASA had better be thinking about such designs,  for Mars or just about anything else. 

GW


GW Johnson
McGregor,  Texas

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

Offline

#13 2015-11-15 11:30:20

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

I do agree that this gives us an orbital platform to complete any assembly of large missions from smaller building blocks with current launch vehicles.

What we have talked about is creating a commonality of elements that we need to make a mission happen. I made note of that in the JPL Mars phobo mission topic the slides talk about commonality with in it and how it can reduce costs. This also means recurring missions with Delta developement of improvements to allow for greater mass, longer stay times ect...

http://spirit.as.utexas.edu/~fiso/telec … -29-15.pdf

On slide 18 the Chariot and Athelte are still being shown from the Lunar programs developement which is sort of on hold to cancelled unless we go and continue to stay going. As it appears today Nasa is not even landing on the moon and is only using the cislunar mission as a stunt.

Nasa is indicating that a Discovery program is to have a – $425 million cost cap and 3 year development period such as a sample return.

Delta V map from Earth
thecaseforam.png

Online

#14 2016-05-09 20:13:55

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

well it would seem that they are reading our topics.....
NASA Plans Satellite-servicing Spinoff To Industry

Subscription required for full article.....has anybody else found anything else....

Online

#15 2016-06-08 17:13:49

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

Appears that someone must think that this is a good idea.... Public private model would make DARPA's on-orbit service capability a reality

darpa-robotic-servicing-geosynchronous-satellites-rsgs-program-lg.jpg

Online

#16 2016-06-09 02:44:23

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,782
Website

Re: Servicing Earth Satelites

Wow!

The concept of servicing satellites in space has been studied and talked about for decades. The up-front investment in developing such a technology has been a barrier to commercial industry getting into the business of servicing and refueling GEO spacecraft. But now with government funding, the concept is moving closer to reality, with DARPA combining input from industry, government, and academia in its RSGS program. Here's a Defense News interview with more information.

Once launched, RSGS would offer means for lengthening the life of a satellite by refueling or repairing it and installing technological updates while the satellite is in orbit - even removing defunct satellites by guiding them to graveyard orbit beyond the GEO arc that would forestall adding debris to the space environment.

So a commercial fuel depot would get a lot of work. The service satellite would require fuel to haul repair and upgrade parts around, as well as fuel for satellites serviced.

To me this raises the issue of harvesting fuel from asteroids.

Offline

#17 2016-06-09 13:53:06

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: Servicing Earth Satelites

Some of the things I read say that the little ones under 100 m in size are pretty dry,  and very loosely bound.  They are essentially dry rubble piles,  and a lot of them with significant spin show an equatorial ridge of loose material not quite flung off into space. 

I have no idea what kind of material a "carbonaceous chondrite" really is,  but it would seem that this unconsolidated small body stuff is mostly some kind of minerals.  I'm not at all sure what you could mine such a thing for,  especially as propellant manufacture would seem to require volatiles like water,  CO2 and CO. 

That stuff seems to be inside some of the larger bodies,  especially the outer regions of the main asteroid belt,  and in the still-active comets (much harder to reach).  In fact,  I don't see any real distinction between "asteroid" and "comet" except maybe remaining volatile content.  There's water,  CO2,  and CO inside one of these bigger things,  so if you could put it in a giant baggie and shine a very bright light on its surface,  you might be able to cook the volatiles out,  and capture them. 

They should be easier to accumulate if you just let them re-freeze on the inside surface of the baggie and the outer surface of the asteroid.  Should be much easier than trying to compress the vapors from near-vacuum pressure.  Those three volatiles have the carbon,  hydrogen,  and oxygen atoms that you need.  It will take considerable expenditure of energy and effort to convert them to practical propellants like methane and oxygen,  though. 

As I said,  it looks like bodies bigger than 100 m are the ones with volatiles in them.  This is going to require a really big baggie. 

If you had a robot "factory" ship that you could take to the outer asteroid belt and leave there moored to a suitable asteroid,  you could maybe produce mass quantities of propellants out there.  Solar power is a bit weak at that distance,  we might need nuclear electric power.  But some sort of electric propulsion could "slowboat" the product back to earth orbit or cis-lunar space.  Delta vee is not much more than from Mars,  really. 

Would that fill the bill?  Production facilities in the outer belt,  propellant depots scattered in various Earth and cis lunar-space orbits? 

GW


GW Johnson
McGregor,  Texas

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

Offline

#18 2016-06-09 14:49:15

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,782
Website

Re: Servicing Earth Satelites

I was thinking of a drill. Land an unmanned vehicle on the asteroid, use spikes with solid rockets embedded in them to spike the lander's feet down. Drill down into the asteroid. Then heat the drill head to melt ice. Water will become liquid at only 6.12 millibars, so it only requires very little pressure, say 10 mbar, to produce warm water. It would be muddy, require filtration. But filter the water, then use electrolysis to split into H2 and O2. Refrigerate to LH2/LOX.

I'm told carbonaceous chondrite is pebbles of rock embedded in soft material. That soft material is clay, gypsum, other hydrated minerals, as well as tar, ice, and dry ice. Objects that wander too close to the Sun have boiled off their ice and dry ice long ago. One astronomer claims asteroids have to orbit as far as Mars or father to retain their ice. That's an educated guess. This made me think of another Mars Society members suggestion of mining the moons of Mars. Based on the spectrum of light reflected from their surface to telescopes, they are carbonaceous chondrite asteroids captured into Mars orbit. Mining them would allow using Mars atmosphere for aerocapture. Bring that fuel back to fill a depot in Earth orbit.

But there is one potential asteroid already discovered. News from 2013...
Surprise! Near-Earth Asteroid Is Actually 'Sopping Wet' Comet

Scientists spotted a faint atmosphere called a coma around 3552 Don Quixote, an object classified as a near-Earth asteroid. The space rock was thought by some to be a "dead comet" — one that had shed its carbon dioxide and possible water ices long ago, after the ices were evaporated by the sun.

Wikipedia: 3552 Don Quixote

3552 Don Quixote, provisionally designated 1983 SA, is a near-Earth asteroid (NEA), also classified as Amor, Mars-crossing, and Jupiter-crossing asteroid. It has a highly inclined comet-like orbit of 31 degrees that leads to frequent perturbations by Jupiter. Don Quixote measures 18.4 kilometres in diameter and has a rotation period of 7.7 hours.

Last edited by RobertDyck (2016-06-09 14:51:43)

Offline

#19 2016-06-09 15:05:01

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: Servicing Earth Satelites

I don't know that stakes are going to work.  They didn't for the Philae lander.  I think Hayabusa had one too (although I could be mistaken).   Both landers had real troubles. 

On an unconsolidated one,  there's almost zero normal gravitational pressure.  So by the friction laws,  there's almost zero friction force on a stake.  I don't know whether that is the effect that caused the lander problems,  or that the hard space-weathering crust was the problem.  Or maybe both.  Or maybe something we haven't even imagined yet. 

As for Don Quixote,  at 18 km,  it's certainly big enough to contain volatiles,  even if it doesn't show a tail anymore at perihelion.  That just means the remaining volatiles are deeper inside. 

If stakes fail to work,  how are we going to apply the normal force and the torque required to run a conventional drill?  Interesting question,  that one,  no?

GW


GW Johnson
McGregor,  Texas

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

Offline

#20 2016-06-09 15:52:23

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,782
Website

Re: Servicing Earth Satelites

GW Johnson wrote:

I don't know that stakes are going to work.  They didn't for the Philae lander.  I think Hayabusa had one too (although I could be mistaken).   Both landers had real troubles.
...
If stakes fail to work,  how are we going to apply the normal force and the torque required to run a conventional drill?  Interesting question,  that one,  no?

Uh...

Offline

#21 2016-06-09 17:13:34

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: Servicing Earth Satelites

Don't feel bad.  No one knows the answers to such questions yet.  If they say they do,  they are lying.  You can bet on that!

What it says is that we have to visit places like that and run the experiments.  Eventually,  this requires men on-site in the asteroid belt.  There are no robots "intelligent" enough to do that job.  What could possibly be a better argument for a manned spaceflight program?  Other than a killer asteroid defense?

That robot intelligence limitation is inherent with the von Neumann architecture for the data processing in all computers as we know them at this time in history.  Regardless of what you see some others say on these forums,  von Neumann architecture is nothing but a fast-arithmetic adding machine.  That what it was originally designed to do,  and that's all it will ever do. 

GW

Last edited by GW Johnson (2016-06-09 18:28:12)


GW Johnson
McGregor,  Texas

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

Offline

#22 2016-06-09 20:31:50

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,782
Website

Re: Servicing Earth Satelites

My university education is Computer Science. I studied computer hardware, then took computer science in university. I'm a software developer. Von Neumann architecture is the basis for all modern processors. If you have a Pentium 1 or later then your desktop PC or laptop is way beyond Von Neumann.

I have argued for automated asteroid mining mechanisms, but they have to be designed by someone. And commercial operations will require someone to go out and fix it once in a while. Quantum entanglement communication would *REALLY* speed up the cycle: try something, test, redesign, send a replacement. Unless someone gets that to work, we may have to send humans out before we can design the first automated drill rig.

Ps. I was aware of the drill force and torque issues. I was just counting on rocket propelled stakes to work.

Offline

#23 2016-06-10 09:30:03

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: Servicing Earth Satelites

I don't know about rocket-propelled stakes,  either.  That's just part of the experimenting that needs to be done. 

I was worried about them pulling out too easily, once embedded.  Getting them embedded in the first place seems to be where Philae failed.   But,  one screwy idea would be to inject water around the stake and let it freeze in the regolith,  making a sort of concrete.  If the stake has a rough surface,  that should hold fairly well.  The bigger the frozen glob,  the better it should hold.  But it'll never be strong on a small body,  simply because the gravitational binding is so pitifully weak. 

A lot of this experimentation can be done robotically,  and it can contribute toward some sort of mining or drilling machine's design.  Whether that design can be done before men go is unknown.  But sooner or later,  they must go,  to deal with the unexpected.  I don't think I'd count real heavy on the very first mining or drilling machine actually working right.  It may take 2-3 tries before we find out what really works. 

Most of the NEO's and even the main asteroid belt can be reached with the same sort of spacecraft that can take men to Mars orbit.  That's part of why I picked the Mars mission architecture that I did (orbit-to-orbit transport with separate landers),  and insist on recovering the spacecraft in LEO for reuse.  The very same craft could visit asteroids.  The travel requirements and times are similar. 

GW


GW Johnson
McGregor,  Texas

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

Offline

#24 2016-06-10 17:45:09

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Servicing Earth Satelites

I agree we need demonstrator missions and experimentation but not at flagship mission funding levels which Nasa is famous for......

Online

#25 2016-06-11 12:53:43

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: Servicing Earth Satelites

Well,  I came up with a different Mars mission than most propose today,  including Zubrin. 

When I ROM'd the costs I got only $50 billion to send a crew of 6 to the surface of Mars,  at up to 8 different sites in the one mission.  I used LH2-LOX only for LEO departure.  The rest is NTO-MMH storables,  including the one-stage reusable landers.  I send assets ahead by electric propulsion to await the men.  Those assets are the landers and their propellant,  plus return propellant for the men.  Full one gee gravity and solar flare shielding the whole way.  And,  I recover and reuse the manned vehicle in LEO. 

That same transport could take men to the main asteroid belt (or Venus or Mercury),  and no lander is needed,  only return propellant.  The velocity requirements and travel times are similar to going to Mars orbit.  Without landers,  my Mars mission was under $20 billion.

All of that was with existing launchers operated expendably.  Not SLS.  Not even Falcon-Heavy. 

GW

Last edited by GW Johnson (2016-06-11 12:54:30)


GW Johnson
McGregor,  Texas

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

Offline

Board footer

Powered by FluxBB