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#26 2016-04-05 11:46:25

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,813
Website

Re: Saturn V to Mars

Bill and his VP also tried to build VentureStar. Let's try to keep partisan politics out of this thread.

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#27 2016-04-05 13:26:14

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,464
Website

Re: Saturn V to Mars

None of the candidates and politicians have been interested in space for many years now.  Part of NASA's problem derives from that.  That’s problem I.

A major chunk of NASA's problems is congressional mismanagement/micromanagement.  That’s problem II.  There were no special interests and established constituencies going to the moon.  There have been ever since,  which is why NASA keeps going back to the same favorite contractors for the same kind of tinkertoys they provided before.  That's in turn why SLS is Saturn 5 redone with shuttle technology,  and Orion is Apollo-on-steroids,  and yet the old Saturn 5 and Apollo were actually more capable. 

That crap has been going on since the end of Apollo,  and is the majority reason why men have not flown beyond earth orbit since 1972.  That was 44 years ago,  which is ludicrous.  Those sources now need produce nothing that actually works,  they just need to have the "credential" of a prior history with NASA (and that is by definition "corporate welfare").  To do that,  they just need to keep buying politicians in whose constituencies they are located.  Why would they ever recommend doing anything new or different?  No profit there.

Another significant chunk of NASA's problem is overblown risk aversion.  That is problem III.  This is the knee-jerk reaction to losing two shuttle crews,  both traceable to criminal-class management stupidity,  both times revealed to the public,  with an attempted cover-up on the first one.  The risk aversion behavior hadn't set in until well after the Apollo-1 fire.  That risk aversion behavior stinks to high heaven of “we’re sorry we got caught” instead of “we’re sorry we screwed up”,  too. 

Sending men to Mars (or anywhere outside cislunar space) is inherently risky precisely because of (1) microgravity diseases,  and (2) solar flare events of lethal radiological impact.  (The galactic cosmic radiation excuse is but a canard.)  We could have sent men to Mars in 1983 with Saturn/Apollo technology,  given solutions to only those two critical problems,  which they really didn't have back then. 

You'll notice there has been no serious effort ever since toward (1) artificial gravity or (2) a radiation shelter.  That's prima facie evidence that NASA does not intend to go,  until someone in a position of power orders it,  and furthermore backs that order up with gobs of money.  Ain’t gonna happen,  because congress doesn’t work that way anymore!

The final chunk of NASA's problem is having to be everything to everybody,  instead focusing upon accomplishing a limited set of goals for a limited number of "customers".  That’s because it no longer has a front-burner mission,  and hasn’t had one since Apollo.  That is problem IV.  It's a scope problem,  leading directly to a bloated organization chart,  top-heavy with management,   and consisting mostly of support functions. 

The most successful remaining piece of NASA is JPL,  which has managed to avoid most of the bloat.  That’s why the planetary probes,  and the Mars landers,  orbiters,  and rovers,  have been as successful as they have been.  If NASA ever successfully remakes JPL in its own image,  that success will cease. 

Because I see no candidates or politicians interested in space, I see no possibility of change coming to NASA to overcome these four fatal problems.  As long as that situation persists,  no Americans will ever go to Mars in a government mission. 

You will have to look to that rarest of entities,  visionary private concerns,  to get around that impasse,  because government as it exists today is not going to do its part.  It’s chicken-and-egg,  because there is no financial reason up front to go,  in the shorter term,  just like with the voyages of exploration 500 years ago.  The possibility of profit came later.  It took government exploration,  followed by public-private cooperative settlements and resource development,  finally followed by private sector colonization,  to settle the Americas from Europe.  That pattern is broken today. 

I'm sorry,  but that's a fairly well-supported opinion.  Look around you.  Look hard at NASA.  I dare you to show me a different picture.

GW


GW Johnson
McGregor,  Texas

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

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#28 2016-04-05 14:20:42

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,813
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Re: Saturn V to Mars

There are practical reasons to support NASA. Tax revenue from the space industry is greater than NASA's budget, so it's positive net revenue. After NASA was neglected for so many years, ESA and Russia had gained most of the commercial launch industry, compromising that net revenue. Congress realized they have to invest in NASA, which leads the American space industry. So they developed EELVs: Atlas V and Delta IV. But after contractors were through with them, they weren't as affordable as hoped, so didn't recapture the launch industry. Some in Congress are able to see that revenue calculation, other see all those jobs for NASA employees and their contractors. Keeping voters employed and happy is good for votes. But none of this addresses actually doing anything productive.

There are spin-off technologies, which are quite real but hard to track. And NASA inspires young people to study Science Technology Engineering and Math (STEM); fields that drive the modern economy. Some in Congress want to continue that inspiration, but again don't understand how that could be improved by actually accomplishing something.

As for artificial gravity: I already proposed on this forum, many times, a very simple and inexpensive experiment. Connect a crew capsule to a cargo ship with a tether. Rotate for artificial gravity. Most importantly, change orbit while rotating. How orbit changes doesn't matter, all that matters is it's controlled. You could use Dragon V2 attached to Dragon CRS, or CST-100 Starliner attached to Cygnus, or Soyuz attached to Progress. The point is to prove technology. That can be used for mid-course corrections enroute to Mars.

Would be nice if the Centrifuge Accommodation Module was installed on ISS, but that would be a big job. The above experiment uses equipment already available, or soon will be.

Robert Zubrin and his partner included a radiation shelter in Mars Direct. So it's been there at least since June 1990. If you want another design, I see funding opportunities for those wanting "random house parts" as Dr. Zubrin put it. Mini-Magnetosphere radiation protection, not for propulsion. There is current research into alternate materials: they discovered polyethylene! Yup, lots of money spent studying polyethylene and polypropylene. How long have they existed? But using stored food and water for life support as radiation shield? Brilliant! Do we really need to reinvent the wheel?

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#29 2016-04-05 18:15:01

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Re: Saturn V to Mars

Sorry for the political sensoring......

We keep meantioning artificial gravity via tethering spin as one option....

Crew Tether Spin - With Final Stage - On Routine Mission To ISS - First Human Test Of Artificial Gravity?

Momentum Exchange Space Tethers

Tip Velocity and Material Strength

The maximum tip speed of all these systems is a function of the "launcher to payload mass ratio" of the tether system and the "characteristic velocity" of the material used. The characteristic velocity of the material in a tether is given by the square root of the ratio of the design tensile strength T of the tether to the density D of the tether material. u = (T_d/D)^1/2. In practice, the design tensile strength is usually chosen to be 50% of the measured strength for metals and 25% of the measured short-term individual fiber strength for other materials. Thus, using imperfect materials with reasonable safety margins, the characteristic velocity of most metals and fibers is around 1 km/s, with optimistic predictions for graphite and improved polymers reaching 3 km/s. With the development of a design for a high strength-to-weight tapered Hoytether, the design tensile strength can be safely chosen to be 60% of the measured strength of the individual fibers, allowing commercially available fibers to have characteristic velocities up to 4 km/s.

CISLUNAR TETHER TRANSPORT SYSTEM

https://engineering.purdue.edu/AAE450s/ … sec3_2.doc

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#30 2016-04-05 19:57:27

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,813
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Re: Saturn V to Mars

Interesting. From your link...

You may remember, a while back I talked about Joe Carroll's ingenious idea to do our first ever true experiment in a gravity tether during a routine Soyuz crew transfer to the ISS, His idea is to use the third stage -which goes into orbit anyway, as the counterweight. Remarkably, the whole thing, even including the spin up to create artificial gravity, uses almost no extra fuel over a normal mission to the ISS. This could help with numerous health issues of zero g.

Something like this: 600m tether 1 rpm - Crew In Artificial Gravity Tether Spin
...
The dot a quarter of the way along the tether which you might just make out when you show it full screen isn't a feature of the experiment, but just a symbol to show the position of the center of gravity.
...
The idea is to use a pre-attached tether which unfurls as the spacecraft separate - a method tested in many missions now - though only twice before used to generate artificial gravity, microgravity only - in the Gemini missions.

The simulation shows Soyuz rotating with the aft end toward centre of rotation. That means astronauts would "hang" from their seat belts. Wouldn't it work better the other way around? So artificial gravity pushes astronauts into their seats?

My idea was to use Progress as the counterweight. This idea is to use the upper stage. Ok, that works too. Requires a longer tether. I read that 2 rpm is tolerable without dizziness. Using a counterweight with equal mass cuts tether length, increasing rpm cuts it again. So 163m length should produce Mars level acceleration at Soyuz seats. Assume tether connects to top (docking hatch), add length of orbital module (3m), and distance from top of descent module to seat. Descent module is 2.3m tall, so assume seat is 1.3m from top. Mass of Soyuz TMA is 7,250kg, Progress M is 7,450kg.

Last edited by RobertDyck (2016-04-05 22:20:20)

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#31 2016-04-06 21:46:57

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,813
Website

Re: Saturn V to Mars

One interesting point from the NERVA video. It was produced in 1968, and mentions a human mission to Mars in 1978. That's 10 years later. It took Apollo 9 years. I count Apollo from initial NASA proposals dated 1960, not JFK's public speech. GW Johnson says he remembers NASA promising a human mission to Mars in 1983. That promise was after Apollo 11. This NERVA video is even earlier. Can we go already?

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#32 2016-04-07 07:28:15

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

Re: Saturn V to Mars

You want alternate history, What if NASA did with Saturn V stages what SpaceX is doing with Falcon stages?
Diagram_of_Saturn_V_Launch_Vehicle.jpg
What if we could reuse all of these stages, for instance, lets say we covered them with shuttle tiles so they could reenter the Earth's atmosphere without burning up, then we were able to land each one of these stages intact, and then with a little refurbish men, used them over again, and suppose we did this in the 1970s and 1980s? After all, we could land the Lunar Module on the Moon's surface, you think it might of occurred to some NASA engineers that if some of the fuel in each stage could be saved, then each one could be landed.

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#33 2016-04-07 10:40:36

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,813
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Re: Saturn V to Mars

This isn't about "alternate history", the point is to demonstrate NASA could go a long time ago. In 1968 NASA had grand plans, including a manned mission to Mars in 1978. After Apollo 11, they said the mission to Mars would be 1983. Then it got delayed further. Now NASA is saying its multiple decades away!

NASA didn't have precise computer control required for automated recovery. During the Apollo program, they bragged that computers had shrunk down to the point it was now only the size of a small room, about the size of a shed. Your smart phone has more computing power than all the computers on Saturn V and Apollo combined. There was one comedian who claimed his Vic-20 computer had as much memory as the Apollo LM, but that wasn't quite true. The LM had 75 kilobytes (KB) of memory. Processors today have more than than in on-chip cache.

But if you did want to do that, then the first and second stages did not require a heat shield. They didn't travel fast enough to require it. Falcon 9 does not have a heat shield. SpaceX had plans for a heat shield on their upper stage, as well as landing legs and retractable rocket engine. According to their YouTube video. That didn't happen. If you wanted Saturn V to recover it's S-IVB stage, it would require the same thing. But S-IVB was used for TLI, so it either crashed into the Moon or entered orbit around the Sun.

If you want 1960s plans for recoverable launch systems, they did have some. Original requirements for Shuttle that NASA gave contractors was fully reusable Two-Stage-To-Orbit, with lifting body orbiter and piloted fly-back booster. It would launch 50 times per year, and everything reused. Lockheed (before it merged with Martin-Marietta) submitted a bid, together with NASA's Marshall Space Flight Centre, lifting body based on X-24B...
sts70lc.jpg
McDonnell Douglas also submitted a bid, lifting body based on HL-10...
stslbmd7.jpg

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#34 2016-04-08 08:57:30

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

Re: Saturn V to Mars

Von Braun has some rockets designed to be recoverable.
th?id=OIP.M56b06d8eb18b6165cc8ebb879feb137eo0&w=238&h=188&c=7&rs=1&qlt=90&o=4&pid=1.1
th?&id=OIP.M2b61bd0272c66794a4613b7c7b845361o0&w=299&h=202&c=0&pid=1.9&rs=0&p=0&r=0
th?&id=OIP.M177d4c3a95eb4955aab9f45cc2248816o0&w=300&h=300&c=0&pid=1.9&rs=0&p=0&r=0
Each one of these stages was designed to be reusable, but that all fell by the wayside in the rush to get to the Moon before the Russians.

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#35 2016-04-08 09:14:43

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,813
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Re: Saturn V to Mars

You don't get the point. You realize NASA does read this forum. The point is Mars is not multiple decades away. We were able to go to Mars a long time ago. Going now is just a matter of deciding to do it.

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#36 2016-04-08 17:04:35

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,464
Website

Re: Saturn V to Mars

I agree with RobertDyck.  We could have done this trip to Mars long ago.  About 1990 we knew enough to get the crew home alive and in reasonably-good health.  That was over a quarter of a century ago. 

Back about 1980-1988,  I think we would have most likely killed them.  We still just didn't know enough back then. 

The bugaboos that were fatal were microgravity diseases and solar flare events.  Still true today,  although today we know how to deal with them quite effectively.  The other bugaboos are all tolerable or treatable in one way or another,  with what we know today.  And they have been for a long time now.  Since about 1990,  in fact,  if not before,  for some of them. 

What's holding us back is the party-independent political will do it.  All are at fault. 

That's what got x'd-out of my post #27 above,  in spite of the fact that I tried desperately not to let specific party politics be mentioned. 

Sorry,  I did not mean to offend,  or to bump into very-wise discussion restrictions.  It's just that the truth that sets you free often hurts.  I take no "sides" in this.   

As for the mid-1950's von Braun stuff,  as envisioned then,  we know today those specific ideas won't work.  Uncooled metal skin is infeasible,  as we know today.  Especially for nosetips and leading edges.  Variations on those same ideas became the shuttle and the X-37B.  There are still other variations we still haven't tried yet. 

Not shown was the von Braun spinning wheel space station for artificial gravity.  That idea would work,  but there's no need to do that expensive form today.  The spinning baton does the same job a lot cheaper,  and without all the failure modes of a tether-connected design.

Also not shown was the von Braun team-developed idea of the ion-drive Mars mission,  launched and recovered in LEO,  based in LMO,  and equipped with multiple landers.  That basic concept would still work today,  whether you choose ion engines or something else.  It offers the most return in one mission,  hands-down.  Bang for the buck is the measure,  not just bucks.

GW

Last edited by GW Johnson (2016-04-08 17:24:23)


GW Johnson
McGregor,  Texas

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

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#37 2016-04-08 17:53:31

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Re: Saturn V to Mars

Considering the COT's providers and SLS there is just a few pieces that we still need to get back to the Apollo LM era...In fact the moon should be all COT's provided via a Nasa Space funding to provide the equipment just as its done for the ISS cargo and soon manned flight. Have Nasa continue to fund for a base build up by lowering the finds to ISS to give the amount needed for such a base to begin commercial control from a subsudized model....

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#38 2016-04-09 07:21:08

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

Re: Saturn V to Mars

RobertDyck wrote:

You don't get the point. You realize NASA does read this forum. The point is Mars is not multiple decades away. We were able to go to Mars a long time ago. Going now is just a matter of deciding to do it.

I think SpaceX is better on track for it than is NASA, because SpaceX is reducing costs, NASA is in the process of spending billions. The problem is that when NASA spends billions of dollars, it doesn't try to reduce costs, it has it in its mind that a trip to Mars will cost hundreds of billions of dollars, and it can think of many other things it would rather spend hundreds of billions of dollars on, to it puts manned Mars exploration decades in the future, when it thinks it can come up with the hundreds of billions of dollars necessary to go to Mars, it can only think in those terms, it does not try to reduce the cost of getting there, the largest component of that cause is simply launching things to low Earth orbit! SpaceX is investing its money on reducing the cost of getting into space, once that cost is reduced far enough, then people will spend their own money to go into space, SpaceX will make a profit selling trips into space, and will recoup their investments in cheap space travel. For NASA, spending billions of dollars is all about jobs, (temporary jobs), if they cut corners, that means fewer jobs, they are not eager to do that, they like to keep their contractors busy building rocket stages for each launch, those contractors rewards the politicians who appropriate the funds, and so the cycle goes on and on, until the government decides on a better way to spend those billions and reward other people, and space travel gets left in a lurch. Our best bet is to spend money on reducing costs to get to space! The Space Shuttle was a feeble attempt to do so, and it got turned into a government jobs program instead!

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#39 2016-04-09 07:26:04

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

Re: Saturn V to Mars

GW Johnson wrote:

I agree with RobertDyck.  We could have done this trip to Mars long ago.  About 1990 we knew enough to get the crew home alive and in reasonably-good health.  That was over a quarter of a century ago. 

Back about 1980-1988,  I think we would have most likely killed them.  We still just didn't know enough back then. 

The bugaboos that were fatal were microgravity diseases and solar flare events.  Still true today,  although today we know how to deal with them quite effectively.  The other bugaboos are all tolerable or treatable in one way or another,  with what we know today.  And they have been for a long time now.  Since about 1990,  in fact,  if not before,  for some of them. 

What's holding us back is the party-independent political will do it.  All are at fault. 

That's what got x'd-out of my post #27 above,  in spite of the fact that I tried desperately not to let specific party politics be mentioned. 

Sorry,  I did not mean to offend,  or to bump into very-wise discussion restrictions.  It's just that the truth that sets you free often hurts.  I take no "sides" in this.   

As for the mid-1950's von Braun stuff,  as envisioned then,  we know today those specific ideas won't work.  Uncooled metal skin is infeasible,  as we know today.  Especially for nosetips and leading edges.  Variations on those same ideas became the shuttle and the X-37B.  There are still other variations we still haven't tried yet. 

Not shown was the von Braun spinning wheel space station for artificial gravity.  That idea would work,  but there's no need to do that expensive form today.  The spinning baton does the same job a lot cheaper,  and without all the failure modes of a tether-connected design.

Also not shown was the von Braun team-developed idea of the ion-drive Mars mission,  launched and recovered in LEO,  based in LMO,  and equipped with multiple landers.  That basic concept would still work today,  whether you choose ion engines or something else.  It offers the most return in one mission,  hands-down.  Bang for the buck is the measure,  not just bucks.

GW

Actually the lower stage wouldn't need heat shields A wheel provides more floor space under full gravity than a baton would for a given volume. The main thing is reducing costs to space, if you can do that, then the wheeled space station and the ion drive would follow.

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#40 2024-01-03 20:37:21

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 9,320

Re: Saturn V to Mars

Are modular space stations cost effective?

https://caseyhandmer.wordpress.com/2019 … effective/

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