SLS and what asteriod will we go to

kbd512 · 2015-01-19 11:11:58

RobertDyck wrote:

Aerobraking requires a light heat shield. You call it heavy, but as you just pointed out, only GCNR has sufficient thrust and Isp to make propulsive capture lower propellant weight. And GCNR will take a lot of development. NASA is currently working on a carbon fibre parasol for aerocapture and aerobraking. So that technology is already in the works. Yes, I would like GCNR, but it doesn't look like it's happening.

I meant aerocapture into Mars orbit, an aerobraked descent to the surface is an architecture feature I assume will be implemented irrespective of how the cargo landers or crew transit vehicle are inserted into Mars orbit. If the parasol proves its feasibility, then there's no requirement for GCNR's, but GCNR's make propulsive capture possible using hardware that would or should exist if SLS development tracks the way it's supposed to, something that's also a big question. You have to pay for capture with mass. The only question is how much mass.

RobertDyck wrote:

In "updating Mars Direct", I came up with a list of equipment necessary to use Dragon as Earth Return Vehicle. Red Dragon is supposed to use its Draco thrusters to land on Mars. But the life support upgrades I list will also be necessary.

I'm assuming propulsive capture of the transit vehicle and return to Earth aboard the transit vehicle instead of further modifications to Red Dragon to enable it to do more than function as a crew transfer vehicle and lander. The crew can obviously withstand six to nine months of microgravity, but why subject them to that and confine them to a capsule for that length of time? I want them to be ambulatory for their ticker tape parade.

RobertDyck wrote:

Mars Direct requires 2 SLS Block 2 launches. Actually, 3 for the first mission, plus 2 per mission thereafter. That's because a second ERV sent behind the hab. And Mars Direct uses direct entry for the ERV, aerobraking for the hab. And includes artificial gravity for the transit to Mars, using a tether. But zero gravity for the return to Earth, in a capsule as small as Dragon. My discussion "updating Mars Direct" proposes actually using Dragon for that.

I'm trying to keep the number of SLS flights down to something NASA could afford over the course of the first mission.

RobertDyck wrote:

Then there's my alternate mission architecture. I call it "Mars orbit rendezvous". One person on this forum asked Robert Zubrin about it, and he reports that Robert Zubrin used the name "Hybrid Direct". That's because it takes elements from Mars Direct and NASA's DRM. It's flattering that Dr. Zubrin himself gave a name to my mission architecture. Mine uses a reusable craft to travel from ISS to Mars orbit and back. That reusable craft can be a lot more spacious, and dedicated for in-space operation. One option is artificial gravity, using the same system as Mars Direct. Updated launch requirements are here and here. I'll copy the list of launches for the first mission for one option:
- 1 SLS Block 2 for MAV (direct launch from KSC to Mars surface)
- 1 SLS Block 2 for lab & pressurized rover (direct launch)
- 1 Falcon Heavy for ITV
- 1 SLS Block 1 for TMI stage
- 1 Falcon 9 for lander & unpressurized rover
- 1 Falcon 9 for Dragon

I hadn't even considered the use of chemical propulsion because the penalty for using it is so high that I don't think there will ever be a Mars mission if that's all that's available. I don't have a problem with using chemical propulsion, but NASA wants magic pixie dust to reign down from the sky and miracle an efficient flight rated nuclear power and propulsion solution into existence. NASA is also insistent upon using massive cargo landers and transit vehicles and any proposal to use simple technology intelligently or smaller vehicles, like capsules on counterweighted tethers, seems to fall on deaf ears. NASA clearly wants to use nuclear power and propulsion but has no credible way of funding it. That is why I want Orion cancelled so badly. GCNR's are gateway technology. Orion is a supermassive black hole that is hungrily sucking away at all available funding that could be utilized for projects of broader application than propaganda campaigns.

Impaler · 2015-01-19 13:47:31

NASA hardly even mentions Nuclear propulsion even in passing anymore and only in the scope 'advanced propulsion' indicating they are not married to Nuclear, the trend is ALL towards SEP, a technology that NASA continues to invest in, use and improve upon. . Their is no long any mismatch between where the rhetoric and the development action is on the part of NASA. That mismatch existed in the 90's but it's gone now, people need to get with the times and look at what NASA is doing now, not what they remember from decades past.

kbd512 · 2015-01-19 16:03:56

Impaler wrote:

NASA hardly even mentions Nuclear propulsion even in passing anymore and only in the scope 'advanced propulsion' indicating they are not married to Nuclear, the trend is ALL towards SEP, a technology that NASA continues to invest in, use and improve upon. . Their is no long any mismatch between where the rhetoric and the development action is on the part of NASA. That mismatch existed in the 90's but it's gone now, people need to get with the times and look at what NASA is doing now, not what they remember from decades past.

Whether NASA talks about nuclear thermal rockets or not is irrelevant to its suitability for use as a propulsion technology that dramatically reduces propellant requirements. SEP isn't going to appreciably lower the mass of the types of interplanetary transit vehicles NASA has proposed in the near term. I realize advancements have been steadily made in solar panel power density, durability, and electric propulsion hardware and I think NASA should continue its work on SEP. It will work quite well for LEO space tugs to get rid of space junk/debris and small interplanetary probes that don't transit very far beyond Mars. It's ultimate suitability for propulsion of manned spacecraft is limited in ways that nuclear propulsion is not.

SpaceNut · 2015-02-23 20:50:08

I have said this before in another mission topic in that we talked about whats wrong with it, so lets see if we could fix it.
Let’s Fix the Asteroid Redirect Mission

Congress is about to begin consideration of NASA’s fiscal 2016 budget request, which includes $220 million for the controversial Asteroid Redirect Mission (ARM). Two years after it was proposed by the Obama Administration, ARM still has few supporters. Why, and what can be done to change the equation?
Fundamentally, ARM is two good ideas kluged together into one bewildering idea that NASA itself seems unable to explain effectively.

duh...

ARM involves developing high-power solar electric propulsion (SEP). Good idea.
ARM involves sending astronauts to cis-lunar space (between the Earth and the Moon) for up to three weeks at a time. Good idea.

So good that Nasa says that it does not have the budget to do it:

NASA determined that sending astronauts on a multi-month trip to an asteroid in its native orbit was not feasible now. Among other things, it requires a habitation module in addition to the Orion spacecraft and Space Launch System. There is no room in NASA’s budget for such a module.

Now who's being duh...

To get to Mars we need long term habitation modules regardless of it being the tuna can style or inflateables....

kbd512 · 2015-02-23 23:49:16

For the asteroid mission to be anything other than a colossal waste of time and money, NASA would need to do three things:

1. Develop a habitat module suitable for deep space transit.

2. Develop a space propulsion system capable of transferring the habitat module in a simple and timely manner.

3. Develop a rocket capable of economically lifting the habitat module and tug to LEO.

Naturally, there's no funding for any of this and no rocket to launch the hardware with. It no longer matters because the money and time have already been wasted.

Here's what "doing it right" involves:

1. Develop a launch system that is actually capable of launching payloads with the mass required for manned deep space exploration, not something that might one day be capable of launching the payloads after many more years of development and billions expended.

2. Develop a space propulsion system capable of taking the crew to the intended target in a reasonable amount of time with minimal operational complexity.

3. Develop a habitat that is durable and fault tolerant enough for long duration missions.

This means that expensive STS hardware designed for refurbishment and reuse, an expensive new capsule system incapable of carrying the supplies required for the transit, and propulsion methods that require months for orbital transfer are unsuitable technologies for meeting these requirements.

The development of a small space capsule system incapable of landing anywhere but a terrestrial ocean was and is completely useless for deep space exploration. Orion has no reason to exist and it never really did. Even its intended use for lunar missions did not require it. There was never any real reason to retire the Space Shuttle. Someone managed to convince NASA management that STS was "unsafe" (as if the entirely fictional human brain construct called "safety" ever existed to begin with).

The criticisms regarding the sustainability of the Apollo and Saturn programs seem to apply to an even greater degree to the Orion and SLS programs. There is simply no way to make the current RS-25's and SRM's economical to use. Using two very different propulsion technologies for the launch vehicle's first stage was, is, and always will be more expensive and more difficult than using a single propulsion technology.

I'm not a fan of the STS program, but it was and is real flight hardware that does not require further development for use. I think its familiarity bred contempt for it, but its replacement is "something new" as opposed to "something required".

There is no way to "fix" the asteroid mission, apart from making it an actual deep space exploration mission that we can't do because we're still not developing the hardware required for the task.

Sometimes you have to admit that you made a mistake. Orion was a mistake in no uncertain terms. SLS was a mistake (the implementation, not the concept of a HLV). These mistakes don't have to consume any more time and money than they already have, but there's no way for anyone in the government to admit to making a mistake without forfeiting their job.

GW Johnson · 2015-02-24 09:19:07

The real problem with the ARM ("asteroid redirect mission") is that it's not an asteroid mission, it's a lunar mission. The plan (such as it is) is to use a small unmanned vehicle to go out and grab an NEO (not a main belt object) and bring it back to the vicinity of the moon. They think they can do this with something resembling the few probes sent out there, but they're wrong about that, and such vehicles are NOT being developed.

Once the NEO is near the moon, then a moon rocket with a reprise of Apollo's capsule is adequate to go and look at it. The mission is only a week or two long, you can do it with nothing but a moon rocket and capsule, and you don't need a lander to visit an NEO. SLS is what a Saturn 5 looks like if built from shuttle-era technology in the congressional districts where shuttle stuff was built. Orion is quite literally Apollo-on-steroids, an Apollo design scaled up for crews from 4 to 7.

I disagree that shuttle could have continued as a still-safe vehicle. Shuttle was never safe, it was always an accident-waiting-to-happen, driven there by arbitrary budget constraints. Every time they fixed something, they made it worse (SRB joints case in point: you NEVER EVER use multiple O-rings in a solid motor; if it leak checks OK at 5 psi, it'll hold at 5000 psi). Plus, the airframes were reaching fatigue end-of-life sooner than expected. Plus the avionics were so obsolete they were reduced to obtaining spares off Ebay.

You can easily recognize when an outfit is serious about manned travel in deep space from the crewed habitation design approach. It will have artificial gravity-by-spin, it will have a solar flare shelter (and they won't use cosmic ray exposure as an excuse not to go), and it will have plenty of properly-arranged space in which to stay sane. The ISS fails to fill the bill researching these issues, on all three counts. It comes the closest on space-to-stay-sane, but Skylab was the real "standard".

And no, you don't need a giant rocket to launch all this stuff at once. We have already learned how to assemble things on-orbit from docked modules. That's how we built ISS. The difference is, we can now launch those modules for $2000-3000/pound instead of the $30,000/pound we were paying with shuttle.

GW

Last edited by GW Johnson (2015-02-24 09:22:00)

kbd512 · 2015-02-24 11:31:11

GW,

So, if the multiple O-ring design was an issue with the STS SRM's, have the SLS SRM's switched to using a single O-ring design? If not, then there's no change between STS and SLS, so that's not a valid argument for why STS was "unsafe" (bearing in mind that there's no such thing as "safety" that exists anywhere except between someone's ears).

Regarding avionics upgrades, would it be easier to develop new avionics for an existing vehicle for which there was lots of experience from actual operations or a completely new vehicle with unproven flight characteristics?

I agree that a giant rocket isn't necessary, but it does make some aspects of operations simpler. It made no sense whatsoever to build an expendable launch vehicle using the most expensive reusable hardware ever devised. NASA should have simply declined that Congressional mandate. If Congress wanted to shut down the manned space program, it could have. However, if everyone at NASA stood firm on that position, Congress would also have suffered the backlash from their corporate owners and public opinion. It's just a jobs program at this point. We can sugar coat it any way we like, but it is what it is.

At this juncture, we're going to get a giant rocket whether it's needed or not. Given the length of time SLS has already been in development and the length of time it will be in development before its first flight, I don't think there's any way that it could have been more expensive to simply re-create Saturn V. If we'd done that, we'd have a 130t class rocket as a starting point.

GW Johnson · 2015-02-24 15:40:02

Has NASA learned how to do a SRM joint right yet? NO. The solid manufacturers back then knew (the one left today does still know, I hope) how to do this right, but dince the beginning contractors get threatened with loss of contract if they disagree with arrogant-but-ignorant NASA "experts" (same goes for all the government labs, not just NASA). Nobody at NASA since its inception in 1958 ever built a solid propellant anything. All that stuff was bought from contractors.

Sometimes it's easier, cheaper, and/or safer to just fly-with-what-you-got, even avionics. The B-1B is a case in point, and its deciding factor was cost. 2/3 of its price is avionics, and even today you cannot turn on all 3 critical systems simultaneously. That's why they NEVER flew it in combat in any high-density SAM environment, not since it entered service. And they still won't, today. Because it cannot survive in that environment without all 3 critical systems. That was a USAF mistake, claiming the systems integration job when they should have paid Rockwell to do it. Rockwell actually knew how, USAF did (and still does) not.

GW

SpaceNut · 2015-02-24 19:04:02

IIRC the SRB for Ares I was to change the joint in the segments but with the cancellation of that program its doubtful that it was carried forward into the SLS.

The small chunk approach does waste up mass for each segment (air locks and docking assemblies) to make the unit hole and does create a weak point in the design just waiting for disaster to happen. I would favor a Skylab style design. So with a Falcon 9 heavy 53t, would such a lab be within the launchers capability, if not its back to SLS.

The way to look at the lunar missions is to just go, prove out the systems and processes for some insitu utilization and make it so that we survive in a better condition than we do onboard the ISS. Then leverage anything that we used for the moon towards going to mars that is possible.

kbd512 · 2015-02-25 00:21:20

The more and more I think about, the worse the idea of sending people to Mars in a tiny tin can seems.

As someone who has spent time in small spaces with lots of different people, I can attest that not everyone takes confinement all that well.

Something even bigger than Skylab may be required to keep everyone sane.

That Skylab II concept NASA is floating is looking better every day.

RobertDyck · 2015-02-25 07:55:44

kbd512 wrote:

The criticisms regarding the sustainability of the Apollo and Saturn programs...

There was no issue of "sustainability" of Apollo or Saturn. The problem was Nixon. During that election, he was the 3rd presidential candidate. He didn't have the Republican nomination. He wasn't the Republican candidate, nor Democrat, he ran on his own. He campaigned that he had a "secret" plan to end the Vietnam War early. Voters at the time were so desperate to end that war, that they elected him. Once elected, we saw what his "secret" plan actually was. He raided NASA's budget, and gave the money to the military. He claimed giving that money to the Vietnam War would end it. That didn't work at all. He was an idiot, and NASA still hasn't recovered. NASA's budget is almost as large as it was before Nixon, after adjusting for inflation, but NASA lost a lot of capabilities that it has never regained.

So I'm going to blame you, the voters. If you are so stupid that you elect a candidate who claims he has a "secret" plan to do anything, then you deserve whatever destruction he brings. Repeat: Any politician who claims he has a "secret" plan will destroy America. If you elect him, you deserve that destruction.

Last edited by RobertDyck (2015-06-24 19:39:46)

SpaceNut · 2015-03-29 09:37:32

NASA's Asteroid Redirect Mission Gets Wimpier

"NASA Wednesday announced more details in its plan for its Asteroid Redirect Mission (ARM), which in the mid-2020s will test a number of new capabilities needed for future human expeditions to deep space, including to Mars. NASA also announced it has increased the detection of near-Earth Asteroids by 65 percent since launching its asteroid initiative three years ago. For ARM, a robotic spacecraft will capture a boulder from the surface of a near-Earth asteroid and move it into a stable orbit around the moon for exploration by astronauts, all in support of advancing the nation's journey to Mars."

NASA Chooses Asteroid Mission Plan

Keith's note: The original idea would have had astronauts actually go into deep space and visit an asteroid as part of a plan for longer duration spaceflight from Earth. There are some real operational applications to a mission like that. Then the policy wonks got involved and NASA started to lower expectations because they could not figure out how to do the engineering behind the press release images. NASA has now wimped out completely and decided to only grab a small boulder from an asteroid that a robot has already brought to lunar orbit as part of a pale Apollo reboot. Why even use humans at all for this? If NASA wants the boulder that bad why not just bring it back to Earth orbit where it would be much easier to access and study?
NASA wants everyone to think that this is actually part of the things they need to do to send humans to Mars.

How does robotic mission to move a bolder to lunar orbit get us to mars?

The robotic missions costs for the probe are likely to balloon into the billions.

Nasa announces next steps on journey to Mars progress on Asteriod Initiative

Yet there is no budget identified for any of this. Congress is formally against it. The planetary science community is either against it or has been blackmailed into tepid support. And the White House wonks who pushed this idea on NASA will be gone very soon - and with them goes their support. NASA doesn't ever address any of that, do they?
If NASA wants to send humans on a "journey" to Mars then it needs to aim at Mars - not at the lowest hanging fruit on their capability matrix - fruit that they keep lowering.

kbd512 · 2015-03-29 20:45:52

The ARM is a total waste of time and money and I think NASA is paying lip service to the idea with the knowledge that this nonsense mission will be cancelled when Obama leaves office.

SpaceNut · 2015-03-29 22:13:50

Plan B... Nasa Selects Option B

Option B is estimated at costing $100 million more than Option A, but Lightfoot points out that, excluding the launch vehicle, Option B is still less than $1.25 million for the robotic part of ARM.
In addition to retrieving asteroidal samples, the crewed mission will test the procedures required for a mission to Mars, including the docking mechanism that will connect the Orion with the robotic spacecraft carrying the boulder.
The astronauts will conduct extravehicular activity using new space suits designed for use in deep space, and the retrieval of samples will provide data on how best to collect samples from Mars.
The material from the asteroid might provide information to scientific research firms or corporations that might be interested in asteroid mining in the future.

It will take six years for the ARM spacecraft to tow the boulder into lunar orbit using Solar Electric Propulsion (SEP) system, which collects sunlight through solar arrays and converts it to electricity. Sure it will be slower than a conventional rocket, but cheaper and require fewer launches and no men.

GW Johnson · 2015-03-30 08:38:34

NASA's real problem is not having a mandated front-burner mission (reason-to-be) since Apollo ended. All they have had is a series of money-pit giant projects foisted upon them by a series of presidents and congresses. These giant money-pit projects were more about corporate welfare and political hay than anything to do with real space exploration.

That's not to say we didn't learn good things from them, because we did. But you all have also noticed that men have not left LEO since 1972. If you don't have a reason-to-be, then being-all-things-to-everybody-who-who-walks-up is the way to get funding, but it also dilutes your resources to the point where you actually accomplish very little. The JPL planetary probe guys are the most notable exception to this general observation.

GW

Last edited by GW Johnson (2015-03-30 08:39:22)

SpaceNut · 2016-01-29 22:30:24

NASA Stays on Course for Asteroid Redirect Target

NASA still plans to pluck a boulder off the surface of asteroid 2008 EV5, bring it to lunar orbit and send a crew of astronauts for a visit in about ten years.

The ridge-bisected, 400-kilometer-wide asteroid is the "reference target" for the robotic portion of the agency's Asteroid Redirect Mission, ARM, and will likely become the actual destination unless a better candidate is found. The asteroid's orbit is roughly the same as Earth's, orbiting the sun every 343 days.
EV5 last passed Earth in 2008 and won't return until 2023 or 2024. That means launching the retrieval mission in 2020 could get the spacecraft into lunar orbit for an astronaut visit by late 2025. The mission timeline dictates the size and mass of the boulder that will be returned.
"In the timeframe we're talking about, launching the robotic mission and then the follow-on crewed mission, we're probably looking at a two-to-three-meter object that we can return," said Dan Mazanek, a senior space systems engineer at NASA’s Langley Research Center. "And our requirement is a 20-ton boulder to be able to bring back from the surface."

I still do not understand why do this mission this way as we can pluck a boulder off the moon and study it at the ISS for all the study of a boulder will do.....

As far as developing a more powerful ION engine thats got to be done any way to get cargo to mars....

SpaceNut · 2016-02-05 22:22:50

Congress Scolds NASA, Underscoring How Far We Are From Mars

The main issue is that NASA doesn't have a solid, detailed plan for how it's going to get to the Red Planet, according to Tom Young, the former director of NASA's Goddard Space Flight Center. "We do not have a planned strategy or architecture with sufficient detail," Young told the committee.

In December Congress voted to give NASA a budget of $19.3 billion for 2016, an increase from 2015 of more than $1 billion, and $750 million more than President Obama had even requested. Of course, this largesse came with some strings attached, as we've previously noted — Congress gave NASA a brisk timetable of about 700 days to get a deep space habitat prototype built, for example.

kbd512 · 2016-02-06 09:16:49

NASA has just three technologies it must develop to go to Mars and come back:

1. SEP Cargo Transfer Vehicle (SEP-CTV) - 30t to 50t class

2. Storable chemical propellant kick stages - This is very old and well understood technology that requires minimal additional technology development

3. Deep Space Habitat (DSH) - 40t class 500 day mission duration ISS-derived module(s)

Once we have that hardware set, we can reasonably take astronauts to and retrieve them from Mars and Venus. SLS and Orion are not required for inner solar system exploration and thus far have consumed all available funding for what's minimally required for manned exploration of the inner solar system.

Whether physicists understand it or not, NASA needs to determine whether or not the so-called EM-Drive or Q-thruster actually works by building a test setup that has a power input level in the range that the SEP-CTV will operate at. If it actually works, then it produces thrust levels in the range of existing ion engines and requires no propellant. We only need to determine thruster life and incorporate appropriate power conversion hardware for the new Q-thrusters. If it doesn't work, then continue on with traditional SEP.

Last edited by kbd512 (2016-02-06 09:39:44)

SpaceNut · 2016-02-06 10:35:45

kbd512 wrote:

NASA has just three technologies it must develop to go to Mars and come back:

Thats a good question as to what is R&D versus bloated cost plus construction....

kbd512 wrote:

1. SEP Cargo Transfer Vehicle (SEP-CTV) - 30t to 50t class

Solar panels with higher efficiency, ion thrusters with higher levels of push both come to mind.

kbd512 wrote:

2. Storable chemical propellant kick stages - This is very old and well understood technology that requires minimal additional technology development

This one while its straight forward is dependant on the final mass of what they will push versus what we can then launch it on that changes its shape and need for orbital assembly versus changing to a large launcher.

kbd512 wrote:

3. Deep Space Habitat (DSH) - 40t class 500 day mission duration ISS-derived module(s)

article

The main one is that NASA needs to spend $55 million of its budget to start building a deep space habitat that will house astronauts during the actual missions to Mars. And Congress isn't fooling around: NASA has to get to work on this thing now and must have a prototype to show Congress by 2018, just about 730 days from now, so NASA scientists have to move this thing along as quickly as they can.

How the shape will determine how many pieces of what we will design if ISS derived, power source mass (solar panels & batteries) versus nuclear, artifical gravity will change the shape and design as well as the piece and launch count to build. Making the 700 days questionable.....

As for new engine types until we build it and put it in the environemt of use we just have experiments and paper.

kbd512 · 2016-02-06 12:33:34

SpaceNut wrote:

Thats a good question as to what is R&D versus bloated cost plus construction....

We don't need to R&D anything. We need to start building hardware. That's what Congress has directed NASA to do.

SpaceNut wrote:

Solar panels with higher efficiency, ion thrusters with higher levels of push both come to mind.

We already have ion engines and solar panels that produce the required output. No more development. Let's start building and testing flight hardware. Whether we could have squeezed a few more kWe out of better panels or not or used more efficient engines is irrelevant. Engines that have the required output and solar panels that provide the required input have already been ground tested. Let's stop wasting time and money screwing around and just decide to start building flight hardware.

SpaceNut wrote:

This one while its straight forward is dependant on the final mass of what they will push versus what we can then launch it on that changes its shape and need for orbital assembly versus changing to a large launcher.

If you push everything to Mars from L1, you get more than enough dV capability from a storable chemical propellant kick stage than is required to push the mass class payloads we need to push using just one standard Falcon Heavy rocket.

FH 1 - Storable Chemical Propellant Kick Stage mated to SEP-CTV

SEP-CTV departs from LEO for L1.

FH 2 - DSH Module 1, SEP-CTV

Payload sent to ISS.

FH 3 - DSH Module 2, Airlock

Payload sent to ISS. DSH assembled at ISS. DSH departs ISS for L1 using SEP-CTV.

FH 4 - Dragon 2

Sent directly to L1. FH can send 13t to TMI, so it can easily send slightly more than half that mass to L1.

No super heavy lift rockets are necessary because SEP-CTV's eat through high dV maneuvering requirements (going from LEO to a higher orbit).

SpaceNut wrote:

The main one is that NASA needs to spend $55 million of its budget to start building a deep space habitat that will house astronauts during the actual missions to Mars. And Congress isn't fooling around: NASA has to get to work on this thing now and must have a prototype to show Congress by 2018, just about 730 days from now, so NASA scientists have to move this thing along as quickly as they can.

NASA needs to build a DSH that fits on either SLS or Falcon Heavy. Give SpaceX money to design and build a lengthened payload shroud. Increasing the width of the payload shroud is not required, so this should not be a major problem.

SpaceNut wrote:

How the shape will determine how many pieces of what we will design if ISS derived, power source mass (solar panels & batteries) versus nuclear, artifical gravity will change the shape and design as well as the piece and launch count to build. Making the 700 days questionable.....

The requirement is 500 days and we can figure out how well that works in the interim by flying an astronaut for 500 days on ISS. The MTV doesn't need a nuclear energy source. No technology development. Build it, fly it, and discuss how much better it could be after we've done a manned Mars fly-by.

SpaceNut wrote:

As for new engine types until we build it and put it in the environemt of use we just have experiments and paper.

New engines are not required. New solar panels and other energy sources are not required. No new nothing. Build it and fly it.

Edit:

Fly DSH-1 in LEO in late 2017.

Fly DSH-2 at L1 in late 2018.

No more super heavy lift rockets. No more super heavy capsules. Go to Mars with what we have. Forget about what we could have and focus on what we do have.

Last edited by kbd512 (2016-02-06 12:39:16)

SpaceNut · 2016-02-19 22:21:26

Build it fly it is just a way to wring out the bugs as you have no set plans to build it from so you are doing R & D to develope the testing article for setting the steady state plans into motion to which you build the final manufactured item to.
The current level of ION thrusters are wimpy go look at my post in the SEP topic....for what we need versus what we have....

NASA Issues Asteroid Redirect Mission Report provides input to important areas of robotic mission requirements development to explore the science benefits and to what potential knowledge we will gain from the agency's Asteroid Redirect Mission (ARM).

Formulation Assessment and Support Team (FAST) report which has been generated by selected 18 engineers and scientists out of 100 applicants from academia / industry to work with three NASA leaders.

http://www.nasa.gov/sites/default/files … ts-508.pdf

kbd512 · 2016-02-19 23:49:47

SpaceNut wrote:

Build it fly it is just a way to wring out the bugs as you have no set plans to build it from so you are doing R & D to develope the testing article for setting the steady state plans into motion to which you build the final manufactured item to.
The current level of ION thrusters are wimpy go look at my post in the SEP topic....for what we need versus what we have....

The only thing we need to do a Mars mission is a SEP-CTV and moderately sized chemical kick stages attached to SEP-CTV's. If you accept the fact that not all missions have start in LEO, then you can do lots of exploration without enormous rockets. LEO imposes a huge dV penalty that even the most evolved variant of SLS won't overcome. The most powerful upper stage planned can throw just over 41t to TMI. A $500M to $700M rocket is required just to throw 41t to TMI using chemical propellants.

If the SEP-CTV costs less than $250M, there's no economics argument on launch costs alone. If SpaceX and ULA can reuse a booster just once and the price drops to $50M to $75M per launch, there's really no economics argument to be made.

If you mate a 30t-50t payload to a 30t-50t SEP-CTV using two Falcon Heavy or Vulcan rockets, you can throw the same payload for a fraction of the cost. If you use commodity rockets from SpaceX and ULA, there's no $3B a year fixed program costs for NASA to pay to operate SLS and therefore plenty of money to purchase hardware and propellants for SEP-CTV's.

The SLS upper stage is a paper concept at this point. Let's cut our losses and return to using moderately sized launch vehicles that have moderate operational costs so there's funding for payload development. Now that SpaceX and ULA are competitors, both can bid on NASA contracts. Both have the hardware and expertise to deliver payloads to LEO or GEO and that's all we really need them to do.

SpaceNut · 2016-02-20 20:57:00

The paper upper stage is being pushed down Nasa's throat by congress as a do it or else. Nasa is almost at that point now with not having a manned flight as it is by the date congress set but they have given Nasa some wiggle room....look to have the funding start to drop if they do not suceed and soon.....

kbd512 · 2016-02-21 04:08:12

SpaceNut,

If NASA properly funds the commercial spacecraft development programs they've already spent billions of our tax dollars on, the agency would have several different vehicles to choose from (CST-100, Dragon, and Dream Chaser), each offering unique capabilities for different purposes. The Orion capsule is not required nor even feasible for any space exploration mission other than lunar exploration. For lunar missions, Orion was only marginally feasible. Use of Orion as originally intended required not one but two launch vehicle programs.

If the Orion, Altair, Ares I, and Ares V programs were implemented as originally intended, the combination of the those programs would make STS and SLS look affordable.

NASA had one shot at development of an affordable super heavy lift rocket and that was basically a rehash of Saturn V through development of the F-1B and J-2X engines. NASA has squandered the opportunity to develop or retain a super heavy lift rocket multiple times and there's no need for a repeat performance with SLS. No matter how simple or smooth SLS development has supposedly been, it's taken far too long, cost far too much, and if the program survives the next political administration it will be every bit as unaffordable as STS was. Consequently, no payloads that require such a massive rocket will ever be developed in the next decade from the absence of funding that comes from such an expensive launch vehicle development program.

Chemical rockets are all that's currently available for delivering payloads to orbit. That's highly unlikely to change within our lifetimes. However, there are a variety of in-space propulsion technologies that dramatically improve delivered payload mass. The most advanced technology available for that purpose is solar electric propulsion. Electric propulsions systems were flown in space before the first Saturn V ever left the ground.

Even if NASA had a flight rated solid core NTR and super heavy lift rocket, most of what you're delivering to orbit is still propellant and structural mass. There's no way around that with chemical propulsion or inefficient nuclear propulsion. Efficient in-space propulsion is the longest-lived stumbling block for human exploration missions and more of the same is definitely not the solution to the problem.

I don't see any space exploration program sending humans anywhere but LEO until we're able to efficiently deliver payloads to higher orbits. The most important technological advancements to make for human space exploration are development of affordable reusable lift vehicles and more efficient in-space propulsion. I don't believe super heavy lift rockets or super heavy capsules do anything to lower the insane cost of delivering a payload to orbit or doing anything useful with it after it has been orbited.

louis · 2016-02-21 08:40:29

KIND OF OFF TOPIC:

Just to let you know kbd12 that I incorporated your mission outline in the Mars Missions comparison doc:

https://www.docdroid.net/vCwcfFY/mars-m … .docx.html

kbd512 wrote:

SpaceNut wrote:
Build it fly it is just a way to wring out the bugs as you have no set plans to build it from so you are doing R & D to develope the testing article for setting the steady state plans into motion to which you build the final manufactured item to.
The current level of ION thrusters are wimpy go look at my post in the SEP topic....for what we need versus what we have....
The only thing we need to do a Mars mission is a SEP-CTV and moderately sized chemical kick stages attached to SEP-CTV's. If you accept the fact that not all missions have start in LEO, then you can do lots of exploration without enormous rockets. LEO imposes a huge dV penalty that even the most evolved variant of SLS won't overcome. The most powerful upper stage planned can throw just over 41t to TMI. A $500M to $700M rocket is required just to throw 41t to TMI using chemical propellants.
If the SEP-CTV costs less than $250M, there's no economics argument on launch costs alone. If SpaceX and ULA can reuse a booster just once and the price drops to $50M to $75M per launch, there's really no economics argument to be made.
If you mate a 30t-50t payload to a 30t-50t SEP-CTV using two Falcon Heavy or Vulcan rockets, you can throw the same payload for a fraction of the cost. If you use commodity rockets from SpaceX and ULA, there's no $3B a year fixed program costs for NASA to pay to operate SLS and therefore plenty of money to purchase hardware and propellants for SEP-CTV's.
The SLS upper stage is a paper concept at this point. Let's cut our losses and return to using moderately sized launch vehicles that have moderate operational costs so there's funding for payload development. Now that SpaceX and ULA are competitors, both can bid on NASA contracts. Both have the hardware and expertise to deliver payloads to LEO or GEO and that's all we really need them to do.

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#51 2015-01-19 11:11:58

Re: SLS and what asteriod will we go to

#52 2015-01-19 13:47:31

Re: SLS and what asteriod will we go to

#53 2015-01-19 16:03:56

Re: SLS and what asteriod will we go to

#54 2015-02-23 20:50:08

Re: SLS and what asteriod will we go to

#55 2015-02-23 23:49:16

Re: SLS and what asteriod will we go to

#56 2015-02-24 09:19:07

Re: SLS and what asteriod will we go to

#57 2015-02-24 11:31:11

Re: SLS and what asteriod will we go to

#58 2015-02-24 15:40:02

Re: SLS and what asteriod will we go to

#59 2015-02-24 19:04:02

Re: SLS and what asteriod will we go to

#60 2015-02-25 00:21:20

Re: SLS and what asteriod will we go to

#61 2015-02-25 07:55:44

Re: SLS and what asteriod will we go to

#62 2015-03-29 09:37:32

Re: SLS and what asteriod will we go to

#63 2015-03-29 20:45:52

Re: SLS and what asteriod will we go to

#64 2015-03-29 22:13:50

Re: SLS and what asteriod will we go to

#65 2015-03-30 08:38:34

Re: SLS and what asteriod will we go to

#66 2016-01-29 22:30:24

Re: SLS and what asteriod will we go to

#67 2016-02-05 22:22:50

Re: SLS and what asteriod will we go to

#68 2016-02-06 09:16:49

Re: SLS and what asteriod will we go to

#69 2016-02-06 10:35:45

Re: SLS and what asteriod will we go to

#70 2016-02-06 12:33:34

Re: SLS and what asteriod will we go to

#71 2016-02-19 22:21:26

Re: SLS and what asteriod will we go to

#72 2016-02-19 23:49:47

Re: SLS and what asteriod will we go to

#73 2016-02-20 20:57:00

Re: SLS and what asteriod will we go to

#74 2016-02-21 04:08:12

Re: SLS and what asteriod will we go to

#75 2016-02-21 08:40:29

Re: SLS and what asteriod will we go to

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