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#1 2015-06-30 17:03:37

louis
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From: UK
Registered: 2008-03-24
Posts: 5,871

JPL Mars mission proposal


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#2 2015-06-30 17:18:02

RobS
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From: South Bend, IN
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Re: JPL Mars mission proposal

This is the newest proposal by NASA employees (this is not an official plan, though). I posted about it in late May when it was first described at a conference Humans 2 Mars. The slides there had the images the newspaper has. The idea is to develop the equipment incrementally over a long time in order to keep within NASA's current budget. This plan will take so long, better plans will be developed. Musk will probably get us there earlier.

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#3 2015-06-30 19:28:44

SpaceNut
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Re: JPL Mars mission proposal

I did post this in the another archetectural mission design topic

SpaceNut wrote:

Here is yet another architecture... A Scenario for a Human Mission to Mars Orbit in the 2030s
Its from Hoppy Price*, John Baker*, and Firouz Naderi* with thoughts Toward an Executable Program Fitting Together Puzzle Pieces & Building Blocks, A Future In-Space Operations (FISO) Telecon May 20, 2015 by *Jet Propulsion Laboratory California Institute of Technology.

It is suggested that splitting the efforts into a 2 step plan of first going to Mars orbit for a cycle duration and then a short stay on the surface in a later mission that returns to orbiting base as set by the first mission finally followed by a long term stay on the surface is to there liking. pg7/8

Using what we have currently but since we have no long term habitat other than the ISS or a lander we do not have all the pieces yet for this concept for it to work with keeping costs inline with current budgetting that Nasa has or of its future sand chart graphs....

By going to the Mars moons first we side step the issue of large mass landing for mars, a return mav from the surface using ISPP and it allows that time for design to catch up to what we do need for doing so. It starts a base to continue going to Mars if only be leaving the landers base behind as a building block for landing vehicles for Mars some far off future times once refueled.

So a re-designed for room lunar lander is more than capable to land on the moons of Mars and provide the stay that we would want.

The only item remaining on the fear page is exposure to radiation types that cause health issues.

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#4 2015-07-01 09:33:52

Terraformer
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Re: JPL Mars mission proposal

Perhaps the space colonisation community could help speed things along, by developing things such as life support - ideally involving the demonstration of a self-sustaining Antarctic base. After all, the stuff used on Mars *has* to be stuff they can fix (and later build) themselves, so it should be stuff that can be built in a well stocked home workshop. Perhaps other things, like rovers and space suits, could also be developed, leaving those with much more money and better equipment to focus on the challenges of getting there alive.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#5 2015-07-01 16:55:14

SpaceNut
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Re: JPL Mars mission proposal

We also have all the analog stations that Nasa and Mars Society run that could be gear a little better for answering the very question that we need hardware for when we do go to Mars....

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#6 2015-07-02 04:06:04

louis
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From: UK
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Posts: 5,871

Re: JPL Mars mission proposal

SpaceNut wrote:

We also have all the analog stations that Nasa and Mars Society run that could be gear a little better for answering the very question that we need hardware for when we do go to Mars....

Personally, I've always felt if you were doing a - let's say - $20 billion mission it would be worth creating a Mars Analog Base which would have a pressurised "atmosphere" (Mars "air" at low Mars pressure) large warehouse with Mars analog regolith, Mars sol cycle for night and day, PV cells, Mars-style wind effects, and a separate section for an analog exploration (like a flight simulator with the Mars Rover on rollers). It might cost $100 million but it would be worth it in terms of training. It could take a couple of years to build, but you would then have a fantastic training facility.  That could be followed up by analog missions to the Moon testing the crew ability to set up base after a long 6-8 months flight. A 10 year mission programme would allow for this.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#7 2015-07-02 18:02:38

SpaceNut
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Re: JPL Mars mission proposal

Sure we could design a Mars biosphere/dome experiment but we are not able to change gavity and that is one of the main issues for a Mars mission.

I hope we can focus on a first phase mission design elements for landing on the moons of Mars and try to make it with something less than 2 SLS launchers.

So the question is first the design for the moons lander size that would make it possible. A key element is the volume of habital space, power source, Volume for all consumables and waste recovery which then would be followed by what is the science mission that we would want to make happen.

This leads to what is going to be a base for the next question. How much time we will spend to make it possible and what would we need to send in addition to make it possible to follow the plan.

Phobos is 27 km long in its longest dimension and Deimos is 15 km long in its longest dimension.

Phobos is only about 3000 miles above the Martian surface and orbits in a little over 7 hours (thus it makes more than 3 orbits in a single Martian day).

Deimos orbits distance of 23,460 km Deimos is a little further out and orbits in about 30 hours.

Phobos has only 1/1000th as much gravitational pull as Earth. A 150-pound (68 kg) person would weigh two ounces (68 grams) there.


Mars Surface gravity 3.711 m/s² or 0.376 g

Mars Escape velocity 5.027 km/s

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#8 2015-07-02 20:04:13

kbd512
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Re: JPL Mars mission proposal

SpaceNut wrote:

Sure we could design a Mars biosphere/dome experiment but we are not able to change gavity and that is one of the main issues for a Mars mission.

Landing a habitat module on the moon would be a far better test for going to Mars and would give Orion "something to do", if there's some sort of congressional mandate for it to "do something".

SpaceNut wrote:

I hope we can focus on a first phase mission design elements for landing on the moons of Mars and try to make it with something less than 2 SLS launchers.

With a minor increase in the payload fairing diameter (MPLM) or length (Destiny) of Falcon Heavy, ISS modules would easily fit inside.

With perhaps four Falcon Heavy flights, a MTV (habitat, mini-mag, SEP module, and kick module) could be assembled at ISS.  A further one or two FH flights would transfer a kick stage to Mars using SEP tug.  That gets our explorers to Mars and back.  I don't know what the mini-mag would cost, but it's a safe bet that it's at least three billion dollars worth of mission hardware and half billion dollars worth of launch hardware.  That's well within the realm of NASA's manned space program budget.

The first flight would be unmanned, but if the MTV survives we should build a second MTV and send both MTV's, crewed, to a Martian moon.  If that mission is also successful, there's nothing left to do except land and plant the flag.

SpaceNut wrote:

So the question is first the design for the moons lander size that would make it possible. A key element is the volume of habital space, power source, Volume for all consumables and waste recovery which then would be followed by what is the science mission that we would want to make happen.

We can concern ourselves with the type/size/cost of the lander once we can prove that we can get to/from Mars without killing anyone.  Once that hurdle has been cleared, it's only a matter of making steady progress towards the landing.

SpaceNut wrote:

This leads to what is going to be a base for the next question. How much time we will spend to make it possible and what would we need to send in addition to make it possible to follow the plan.

The aforementioned proposal is easily achievable in the next ten years, does not require a single SLS or Orion flight, and is far less complicated and risky than any proposal mandating a landing on the first mission, even if unlimited funding was available.

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#9 2015-07-02 21:40:56

SpaceNut
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Re: JPL Mars mission proposal

I have boiled down the slides:

Phobos Landing Concept Architecture was analyzed for a crew of 4

It would require 4 SLS launches to Pre-position assets in Mars system with SEP tugs prior to crew arrival at Mars Orbit Insertion (MOI)

SEP tugs ARM or TDM
Block 1 50 kWe, 8 t Xenon 4-Hall Thrusters
Block 1a 100 kWe, 16 t Xenon 8-Hall Thrusters

The first launch is for a 100 kWe SEP Tug the SEP Payload Two in-space chemical stages:Trans-Earth Injection (TEI) Stage + Phobos Transfer Stage (PTS) a chemical propulsion stage of possibly Hydrazine/NTO bi-propellant stage with ~500 kN thrust pump-fed engine; similar in size to the Titan II second stage or Proton 3rd stage and Dnepr 2nd stage.

The 100 kWe SEP Tug with TEI Stage + Phobos Transfer Stage (PTS) a chemical propulsion stage will take ~3.8 years to reach High Mars Orbit (HMO) where it will be staged for 75 days until the crew arrives later in the Deep Space Hab


The second 100 kWe SEP Tug the SEP Payload:Phobos Habitat taking ~3.5 years until it lands to be part of the Phobos Base.

The third launches the Deep Space Hab (DSH) Supports a crew of 4 for 500 days (transit to Mars and back) Mass is approximately 30 t + MOI Stage a chemical propulsion stage and forth sls launches Orion + EUS which dock together for Trans Mars Injection (TMI) to bring the crew to Mars 200 - 250 days with the spent EUS being dumped after its used up. The Deep Space Hab + TEI a chemical propulsion stage is left in MOI to await when it will be used to return home. The Orion is Docked with the Phobos Transfer Stage to land at the Phobos Base and will be used to get the crew back to HMO.

Round trip crew mission ~2 ½ years; ~300 days at Phobos

Not sure where the Docking node and airlock are in the payload scheme that are required for Orion to go to Phobos base site to mate upwith the already landed moon lander....

With a followup mission for a two man crew that would then spend a month on the surface of Mars, followed by four astronaut crew to spend a year on the surface but each of these followup mission need 6 SLS launches to make each possible...

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#10 2015-07-03 08:31:01

GW Johnson
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From: McGregor, Texas USA
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Re: JPL Mars mission proposal

What the proposal Louis linked to really means,  is this: 

(1) NASA wants 13 years to develop and prove out a habitat and life support system capable of supporting a small crew for 2.5 years.  That gets us from now to 2033 for a trip to Phobos at a few $B. 

(2) NASA wants another 6 years to prove out a lander capable of landing a small crew on Mars.  There might be some sort of separate hab,  or the crew might just camp out in the lander as they did in Apollo (I'm betting on the Apollo model,  since this is NASA we're talking about).  This is not to be done in parallel,  but in series behind,  task (1),  which is why the first manned landing is 2039.  They're not planning on supporting the astronauts with any sort of ISRU on the surface,  which is why the landing is only one month long.

(3) NASA wants another 4 years to work out,  and prove out,  a larger surface hab with some sort of ISRU to help support astronauts on the surface.  This is also a serial,  not parallel development,  which is why the year-long stay is for 2043,  on the third trip. 

The constraints here are driven by minimizing launched mass,  and by limiting budget in every year.  This is what you get when politicians and accountants overrule engineers on technologically-demanding projects.  We've seen this before with the shuttle.  And the F-35.  And the TFX decades ago that became the F-111.

The fly in the ointment is that Congress will never,  ever authorize 3 sequential manned trips to Mars at taxpayer's expense.  They might (I emphasize "might") authorize one.  If you believe in a 3-trip plan like this,  I have a bridge in Brooklyn I'd like to sell you.  At the first trip,  the public will ask "why no landing?",  and that might even kill it. 

The same set of developments could be had for that landing in one single trip,  resulting in a landing and several-months stay,  sometime about 2035 (if NASA does it).  BUT ONLY if the budget constraint is relaxed for parallel developments,  and MOST LIKELY also the minimum-mass constraint,  so you can ship more supplies and propellants all the way to the surface. 

I'm pinning more hopes on the likes of a Spacex,  because NASA is caught up in a Catch-22 of essentially its own making.  NASA is too risk-averse,  and too bureaucratized,  to take on this kind of exploration anymore.  Especially when Congress quite demonstrably doesn't care a whit about exploration,  only pork-barrel support for NASA contractors in their districts. 

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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#11 2015-07-03 18:00:31

SpaceNut
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From: New Hampshire
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Posts: 19,729

Re: JPL Mars mission proposal

Speaking of COTS as to keeping costs low that said comercially off the shelf with regards to the first item that is needed, SEP is so far a one off designed for a specific mission to utilize and that means developement money for each unit as it is not a standard unit that is in production for others to make use of.

Next up is the in-space chemical stages choices for boosters in the Titan II second stage, Proton 3rd stage, Dnepr 2nd stage to make use of and when I look at what is still in production we only see the Russian units which make for a problem at this stage of the game. So this is an Item that must be developed.

Facts about Proton 3rd stage; single RD-0212 engine http://russianspaceweb.com/proton_stage3.html or https://en.wikipedia.org/wiki/Proton-K

Technical specifications of the third stage of the original Proton-K rocket: Diameter 4.15 metres (13.6 ft) Length 6.5 metres (21 ft)

  • Dry mass          4,570 kilograms
    Fueled mass    68,660 kilograms
    Liftoff mass     68,650 kilograms
    Oxidizer mass   32,800 kilograms
    Fuel mass        12,940 kilograms 
    The end mass   23,500 kilograms
    Liftoff to end mass ratio 2.92
    Propulsion system thrust to liftoff mass ratio 0.90
    Specific impulse 325 sec
    Burn time 238 seconds

    Fuel N2O4/UDMH

As others have noted items we do not have are the moon Phobos Habitat lander, the Deep Space Hab (DSH) and if the SLS does not develope the EUS we have no means to get to Mars.....

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#12 2015-07-03 18:50:49

kbd512
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Re: JPL Mars mission proposal

SpaceNut,

I can simplify the presentation even further:

JPL has a grossly unrealistic operational plan, never mind the development plan, that would require a considerable budget increase that NASA won't receive.  In other words, their "plan" is a fiscal policy fiction article designed to "capture the imagination" of ADD nation…  For an entire two seconds.

Does NASA have a team devoted to coming up with plans that won't work?  Sometimes it seems that way.

SLS was deliberately designed to be impossibly expensive to actually use and the combination of the SLS and Orion development programs were clearly designed to shut down the manned space exploration program.  Maybe that was the objective; give NASA an impossible development task, blame them for the inevitable failure resulting from the policy edicts handed down by Congress, and then Congress has an excuse to shut down the manned space flight program and can point to SLS and Orion as proof of NASA's funding mismanagement.

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#13 2015-07-03 19:07:44

SpaceNut
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Re: JPL Mars mission proposal

So but lets continue to poke holes or flesh out the paramters that the vaporware is thinking might work:

Here is the Dnepr 2nd stage: http://www.spaceflight101.com/dnepr-lau … ation.html

  • Second Stage
         
    Type R-36M      2nd Stage 
    Inert Mass        4,260kg 
    Launch Mass    41,100kg 
    Diameter           3.0m 
    Length              5.7m 
    Fuel              Unsymmetrical Dimethylhydrazine 
    Oxidizer         Nitrogen Tetroxide 
    Propellant Mass   36,740kg 
    Propulsion RD-0255 (RD-0256 + RD-0257) 
    Thrust (Vacuum)    755kN 
    Impulse (Vac)        340sec 
    Main Engine       1 Chamber, fixed 
    Vernier Engine    4 Chambers   
    Burn Time         190sec   
    Attitude Control Gimbaling Vernier Jets

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#14 2015-07-03 20:10:36

SpaceNut
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Re: JPL Mars mission proposal

The in-space chemical propulsion stage is a hydrogel fuel that is long term storeable and avoids the boil off issue that cyrogenic fuels have.

The rockets that America still launches with this are few, only one so far comes to mind.
https://en.wikipedia.org/wiki/Delta_II

second stage of Delta II is the Delta-K, powered by a restartable Aerojet AJ10-118K engine burning hypergolic Aerozine-50 and N2O4. These propellants are highly toxic and corrosive, and once loaded the launch must occur within approximately 37 days or the stage will have to be refurbished or replaced. This stage also contains a combined inertial platform and guidance system that controls all flight events. The Delta-K stage is 6 meters long and 2.4 meters wide, contains up to 6 t of propellant, and burns for up to 430 seconds.

http://www.spaceflight101.com/delta-ii-7920h-10.html

Delta_II_second_stage.jpg

Second Stage
     
Type Delta K
Diameter 2.40m
Length 2.40m
Inert Mass 6,953kg (15,331 lbs)
Propellant Aerozine
Oxidizer Dinitrogen Tetroxide
Fuel&Oxidizer Mass 6,004kg (13,236lbs)
Guidance Inertial
Propulsion 1 AJ-10-118K
Thrust 43.4kN (9,753lbf)
Engine Length 2.68m
Engine Diameter 1.53m
Engine Dry Weight 275lbs
Burn Time Variable
Engine Start Restartable
Attitude control Redundant Attitude Control System    Roll, Pitch, Yaw Control
Propellant Hydrazine

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#15 2015-07-04 13:56:49

GW Johnson
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Re: JPL Mars mission proposal

That "37 days to do something or else replace or refurbish" points out the corrosive nature of that storable propellant system.   I think Aerozine-50 is a hydrazine variant,  which would be rather caustic basic,  like ammonia.  N2O4 is a rather corrosive oxidizer.  I know less about its properties,  but I suspect it may be acidic. 

Materials like that will require a more sophisticated tank liner to be truly long-term storable,  on a time scale appropriate to a 2.5-year Mars mission.  That will add to the stage inert weight fractions,  no way to avoid that necessity. 

So,  there's "storable" and then there's "long-term storable".  Just something to think about. 

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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#16 2015-07-04 16:30:33

SpaceNut
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Re: JPL Mars mission proposal

While searching just found that the J2-X engines for the SLS are out and that NASA is going withNASA confirms EUS for SLS Block IB design and EM-2 flight
June 6, 2014 by Chris Gebhardt

The desire to use an ICPS for SLS Block I instead of developing the actual upper stage to be used for full-up SLS missions stems primarily from a Congressional mandate regarding SLS development and system implementation.
SLS Advanced Development Office has officially put forth a recommended Point of Departure (POD) for the Exploration Upper Stage (EUS) based on “guidance for the Block 1B vehicle (EM-2). It now has the Exploration Upper Stage.”

Under this EUS POD, the new upper stage for SLS Block IB will be a four (4) RL-10-C1 engine stage (a switch away from the J-2X engines) with a maximum propellant load of 285,000 lbm.

The EUS will carry a length NTE (Not To Exceed) 60 ft, an LH2 tank diameter of 8.4 m, and a LOX tank diameter of 5.5 m

https://en.wikipedia.org/wiki/Exploration_Upper_Stage

The Exploration Upper Stage (EUS) is being developed as a large second stage for Block 1B and Block 2 of the Space Launch System (SLS), replacing Block 1's Interim Cryogenic Propulsion Stage. It will be powered by four RL10 engines burning LOX/LH2 to produce a total of 440 kN (99,000 lbf) thrust.

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#17 2015-07-04 19:41:30

RobertDyck
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Re: JPL Mars mission proposal

GW Johnson wrote:

I think Aerozine-50 is a hydrazine variant,  which would be rather caustic basic,  like ammonia.

Wikipedia

Aerozine 50 is a 50/50 mix by weight of hydrazine and unsymmetrical dimethylhydrazine (UDMH). ... Aerozine 50 is more stable than hydrazine alone, and has a higher density and boiling point than UDMH alone.

By cutting straight hydrazine, hydrazine's inconveniently high freezing point of 2°C is lowered through freezing point depression. In addition, UDMH is a more stable molecule; this reduces the chances of straight hydrazine decomposing unexpectedly, increasing safety and allowing the blend to be used as a coolant in regeneratively cooled engines.

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#18 2015-07-08 19:21:14

SpaceNut
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Re: JPL Mars mission proposal

Filling in some more of the blanks...

Next Steps for SLS: Europe’s Vinci is a contender for Exploration Upper-Stage Engine

By David Todd on 7 November, 2014 in NASA, SLS

Here is a table of all the engine to block information.


SLSenginetradeoff.jpg

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#19 2015-07-08 19:41:57

SpaceNut
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Posts: 19,729

Re: JPL Mars mission proposal

Trying to nail down the SEP tugs ARM or TDM...

We know that the block 1 is 70 mt and srb with ssme but the table says it not....

Block 1 50 kWe, 8 t Xenon 4-Hall Thrusters

The SLS Block 1A configuration with the proposed Liquid Advanced Booster provides payload capability from 103 mT (F-1 derated to 85 percent) to 120 mT (100 percent F-1 power level). and this one is not in the table at all.....

Block 1a 100 kWe, 16 t Xenon 8-Hall Thrusters

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#20 2015-08-20 18:15:54

SpaceNut
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From: New Hampshire
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Posts: 19,729

Re: JPL Mars mission proposal

Green Propellant Propulsion Subsystem to Fly in 2015 Demonstration

A green propellant propulsion subsystem was recently delivered to Ball Aerospace for integration into the Green Propellant Infusion Mission spacecraft. The subsystem will be one of three experimental payloads on the spacecraft.

GPIM a $45 million project aims to introduce AF-M315E is hydroxylammonium nitrate (NH3OHNO3) fuel/oxidizer blend as a green alternative to hydrazine. Hydrazine requires careful measures in transportation, storage, and handling. It poses health hazards including irritation in the throat and eyes, and skin rash if exposed to the liquid or its vapour. Long term exposure can cause serious illness and can even lead to death.

353793.jpg?lastModified=08%2F19%2F2015%2018%3A33%3A17&size=2

Currently, the most common fuel used in satellite and spacecraft thrusters is toxic and not very safe. A joint US government and industry team will be testing a safer propellant, called AF-M315E, for use in future missions. “We think the payoff for this is going to be really huge if we can take the first step in getting rid of toxic propellant,”


gpim-earth-flyover.jpg


AF-M315E is comparatively safer and easier to transport, store, and hande. The propellant also has higher density and higher specific impulse compared to hydrazine, and is expected to improve overall performance efficiency of the spacecraft. One shortcoming of AF-M315E is that it requires a higher temperature for combustion compared to hydrazine. Therefore the ignition system and engine housing would need to be designed to bear the high temperature.

Although there would be costs associated with transitioning existing vehicles from hydrazine to AF-M315E, the enhanced efficiency of the new propellant is expected to offset such costs.

https://en.wikipedia.org/wiki/Green_Pro … on_Mission

The Green Propellant Infusion Mission is scheduled to launch aboard a SpaceX Falcon Heavy rocket in 2016, on a test mission called Space Test Program 2 (STP-2).

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#21 2015-09-26 21:48:30

SpaceNut
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Re: JPL Mars mission proposal

2A1DC3F900000578-0-The_new_proposals_to_sending_astronauts_to_Mars_proposes_a_stepw-a-23_1435685621948.jpg

Nasa could land humans on Mars by 2039: New 'minimal' plans will send astronauts to Phobos then build a base on red planet•The new mission to Mars would not require any increase in Nasa's budget
•The plans were drawn up by scientists at Nasa's Jet Propulsion Laboratory
•They propose sending astronauts to orbit Mars and land on Phobos in 2033
•They say humans be sent for a month on Mars in 2039 and a year in 2043

SLS manifest options aim for Phobos prior to 2039 Mars landing

Current planning documents have, for years, baselined SLS’s first mission, the uncrewed EM-1 flight, for 2017/2018, with EM-2, the first human mission of SLS and Orion, not occurring until at least 2021.

EM-3 had subsequently been mentioned as a notional mission occurring sometime thereafter, potentially not until 2023.

However, these concerns could prove to be for naught as NASA’s near-term Cis-lunar operations begin to take shape and long-range planning for human missions to the Martian system solidify – with current projections shown in the Evolvable Mars Campaign: Status Update to SLS Evolvability TIM presentation showing a total of 41 SLS flights from 2018 through 2046 to build-up to and support human Phobos and Mars surface missions.

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#22 2015-09-27 11:09:59

GW Johnson
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From: McGregor, Texas USA
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Posts: 4,078
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Re: JPL Mars mission proposal

Hmmmm.  When this SLS/Orion thing started as the Ares thing,  we were supposedly going to Mars along about 2033.  Then by the time it became SLS,  that was 2035 or so.  Now it's 2039 at the earliest,  and only if you believe there will be no more delays.  (If you believe that,  I have some beachfront property in Atlantis to sell....)

Does anybody else see the trend here? 

If you stretch it out long enough,  you never have to actually go.  The whole shmear just devolves into giant-corporate welfare for "big space",  and you let non-"big space" private enterprise take on all the risks and shoulder all the costs. 

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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#23 2015-09-27 15:54:08

SpaceNut
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Re: JPL Mars mission proposal

That is just one of the reasons why I was calling crap on the launch build rate for the SLS and missions when we could do so much more with the capacity that Nasa has with the current contractors which seem to be in the R&D contract plus mode for everyhting that they do. Its time to have the build for useage done by some other companies that can build the product and be cost concious about it.

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#24 2015-09-27 19:23:50

SpaceNut
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Re: JPL Mars mission proposal

Here is the post by

RobS wrote:

By the way, NASA engineers are now designing two plans to get people to Mars in the 2033-43 time frame. You may want to take a look:

http://www.nasaspaceflight.com/2015/09/ … ons-2030s/

It relies of the largest SLS design AND solar electric propulsion, which is used to get all hardware and payload to cislunar space where it is parked until the crew arrives. They are looking at 600+ tonnes in cislunar space for the first manned landing on Mars and about the same for the earlier mission to Phobos. They are figuring 10-14 SLS launches for each flight, spread out over 4 years (they can't get them all launched in time to go every 2 years). How much will an SLS launch cost, though? I doubt we have a real number, but I gather they are so expensive we can't do more than a few every year. that's the big problem with the use of SLS. The link also has lots of really interesting graphics and information about the Mars landers (they are considering 3 different sizes).

I have move this copy here as this is a Nasa concept and not the one put forth by RobertDyck in the other topic.

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#25 2015-10-13 19:35:53

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 19,729

Re: JPL Mars mission proposal

Here is a slide that contains SEP http://spirit.as.utexas.edu/~fiso/telec … -13-13.pdf slide 17 in the Prepositioning Cargo Freighters

300kW Cargo Tug
• First flight: 2017
• Dimensions (stowed): 5m dia., 8m overall length (OAL)
• Mass: 36t wet, 6t dry
• Propellants: Xenon or Krypton (30t)
• Propulsion: 3 x 150kW modules @ 3000s
– Leverages NASA 457M development
– Carries one spare 150kW module
• Utility: High ΔV maneuvers on long duration cargo missions with 35t class payloads
• Technology: Implements high efficiency radiation hardened solar arrays, 150kW Hall thruster propulsion systems, light weight inert gas propellant tanks

600kW Cargo Tug
• First flight: 2020
• Dimensions(stowed): 5m dia., 10m OAL
• Mass: 76t wet (via 70t ORU), 8t dry
• Propellants: Xenon or Krypton (65t)
• Propulsion: 5 x 150kW modules @ 3000s
– Leverages 300kW Cargo Tug propulsion
– Carries one spare150kw module
• Utility: High ΔV maneuvers on long duration cargo missions with 70t class payloads
• Technology: Implements high efficiency radiation hardened solar arrays, 150kW Hall thruster propulsion systems, light weight inert gas propellant tanks

There is also more tug design details on page 26

Slide 18 goes onto the crews chemical stages that get us there faster.... read on for the information....

Slide 19 goes onto Mars details of insitu fueling and consumables

The Mars Ascent Vehicle Propellant is planned to be manufactured on Mars
– CH4 - 5500 kg (12100 lbs)
– LOX- 16500 kg (36400 lbs)
• For crew consumables for the 540 day stay on Mars are planned to manufactured on Mars.
– Breathable O2 - 2000 kg (4400 lbs)
– Drinkable H2O - 10,000 kg (22000 lbs)

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