Apollo 11 REDUX

RobertDyck · 2018-12-02 16:38:53

What do you want to achieve? This thread is "Apollo 11 REDUX", meaning Lunar surface. You'll need a lunar lander of some sort. But ignoring that...

Proton 8L82K/11S824 could launch 5,390kg into a trans-lunar trajectory. Proton 8K82K/11S824F could launch 6,220kg to a trans-Mars trajectory. The latter had an upper stage with 16,900kg gross mass, while the former had a 13,360kg upper stage. So the fact more mass to Mars is misleading. Falcon Heavy can lift 16,800kg to trans-Mars trajectory or 26,700kg to GTO. Proton does not have a spec for GTO, just circularized GSO which is quite different. So let's assume Falcon Heavy can lift the same mass to TLI as it can to TMI.

Falcon Heavy upper stage is capable of multiple engine restarts. If you want to use Dragon v2 as is, without modification, can it do an Apollo 8 mission? That would require the Falcon Heavy upper stage not only do the TLI burn, but also LOI, and TEI. Let's see...

Dragon v2 has a dry mass of 6,350kg. Cargo capacity 3,307kg or 7 astronauts. Cargo capacity includes astronaut body mass and spacesuit. For the Moon you would reduce crew to 4, remove the 3 lower seats and use that space for food and life support supplies (spare lithium hydroxide canisters). Apollo CM could install 2 seats in that lower (aft) space for the Skylab rescue ship, but for the Moon they used that space for food, life support supplies, and lunar samples. Dragon v2 is designed for 1 week free flight, or 2 years docked to ISS. That means it has enough life support (oxygen) for 1 week. Trip to the Moon takes 3 days each way, so that only gives you 1 day in Lunar orbit. You may want to reduce that to hours to provide a contingency. But even 8 hours in orbit staring at the Moon would be a lot. What do you do if you can't land? I don't have propellant mass for Dragon v2, but Dragon v1 carries 1,290kg propellant. However Dragon v2 has abort engines that Dragon v1 does not; I don't know how much propellant is needed for those. If we assume 360kg abort propellant, that works out to an even 8,000kg plus cargo and astronauts. Abort propellant is probably higher. This article from spaceflight now says the Dragon v2 abort test "consumed their nearly two-ton load of hydrazine and nitrogen tetroxide propellant in less than six seconds". It says "ton" not the metric term "tonne", so assuming that's US short tons, that's "nearly" 907.18474kg. For the same of simplicity, let's assume 900kg. That makes Dragon v2 8,540kg plus astronauts, spacesuits, and cargo including food and lithium hydroxide canisters.

Apollo era astronaut maximum body weight was 180 pounds (82kg). I don't have mass figures for the SpaceX spacesuit. I would like to use the orange ACES suit used on Space Shuttle from 1995 on, but don't have mass of that either. Shuttle LES suit was used on Space Shuttle after the Challenger disaster of January 1986 until the ACES suit was used in 1995. Total mass of the Shuttle LES suit was 11kg. So 4 astronauts with spacesuits would mass (82+11)*4=372kg.

Dragon doesn't use hydrogen fuel cells for power, so won't have a supply of water. It won't have a recycling life support like ISS either, just bottled O2 and lithium hydroxide like Apollo. That means whole food, not dehydrated. A military MRE masses 18 to 26 oz each, depending on menu. Let's use 22oz as an average. With one MRE per person per day, 4 astronauts over 7 days, that's 17.4633kg; round off to 17.5kg.

Apollo CM LiOH canisters massed 4kg, two used at a time, replaced alternately every 12 hours. That means one set of two canisters lasted 24 hours. They supplied 3 astronauts, so a Dragon with 4 astronauts would require 5.3kg canisters. Assuming LiOH and activated charcoal are the same. Frame could be plastic instead of aluminum alloy, but that won't save much mass. So a mission lasting 7 days would require 14 canisters. Apollo CM carried 30. So 14*5.3=74.2kg.

Total launch weight is now 8,540kg + 372kg + 17.5kg + 74.2kg = 9,161.2kg
Falcon Heavy can lift 16,800kg to TMI so it will have a lot of propellant left over after throwing this mass to TLI.

TEI requires that plus the Falcon Heavy upper stage plus propellant. Return from lunar orbit to trans-Earth trajectory requires 4,800 m/s delta-V. Lunar Orbit Insertion requires 700 m/s delta-V.

So let's assume the FH upper stage has 16,800kg - 9,161.2kg = 7,638.8kg of propellant remaining after TLI burn. The upper stage would have to be attached until end of TLI burn, so in this case just leave it attached. FH upper stage has a dry mass of 4,000kg, it's single Merlin-D vacuum engine has an Isp=348s. Total mass approaching the Moon will be 9,161.2kg + 4,000kg + 7,638.8kg = 20,800kg. Delta-V calculator says after LOI burn, total mass will be 16,940kg. You can do the math to see how much of that is propellant. Now we need the TEI burn. Total mass after TEI burn would have to be 4,150kg. However, Dragon mass is 9,161.2kg + FH upper stage dry mass is 4,000kg = 13,161.2kg. That means you just don't have enough propellant.

This is what staging is for. You need to eject the Falcon Heavy upper stage after LOI burn, use something smaller for TEI burn. That's why I said to convert the Dragon trunk into a service module with enough propellant for TEI. In fact my idea was to add one more stage, with 3 jobs: LOI, propellant transfer to LM, and crasher stage to de-orbit LM.

SpaceNut · 2018-12-02 18:21:30

It sort confirms that current Falcon will need refueling and more to make it possible to land on the moon and return.

Searched for the Altair or constellation lunar module and it still had the acronym LSAM or Lunar Surface Access Module

Altair - Lunar Lander (LSAM) - status

Reusable LSAM

https://en.wikipedia.org/wiki/Altair_(spacecraft)

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

RobertDyck · 2018-12-02 19:00:01

You could do a mission like EM-1. That is a free return around the Moon, not even entering Lunar orbit. Like Apollo 13. That's all.

However, again I point out a simple means to return to the Lunar surface. 2 launches: first delivers a reusable LM to Lunar orbit without crew, second delivers Dragon with crew.

modify Dragon v2 capsule to abort without trunk (nothing more)
add propellant tanks and engine to trunk for TEI. I recommend Dragon v1 trunk with carbon fibre composite tanks, and LOX/LCH4. No thruster quads required, the thrusters on the Dragon capsule are all you need.
an additional stage on top of existing FH upper stage. The new stage would use carbon fibre composite tanks, and LOX/LCH4.
develop a new LM. I recommend an aluminum alloy isogrid hull like Dragon rather than the flimsy hull of Apollo LM. The Apollo LM could only withstand 5 pressure cycles, but we want a reusable LM so it'll have to be more robust.

Once Dragon docks with LM in Lunar orbit, the crasher stage will have to detach, move around to the back of LM, and attach. This is a significant manoeuvre, but Dragon v1 currently rendezvous with ISS autonomously. Yes, this does mean LOX and LCH4 propellant transfer in Lunar orbit from crasher stage to LM. It will also require transfer of helium pressurant, and O2 for breathing. LiOH canisters can be transferred by hand from Dragon to LM. This will demonstrate carbon fibre composite tanks, LOX/LCH4 in space, and in-space propellant transfer. All necessary technologies for BFR/BFS or whatever it's called now.

Last edited by RobertDyck (2018-12-02 19:00:56)

kbd512 · 2018-12-02 19:14:43

SpaceNut,

I've been working on trying to determine the required stage propellant masses for a split-mission plan that optionally uses NASA's lunar orbital space station. I think Robert's ideas are generally along the lines of what we must do to prep for Mars, but the first missions should probably use propulsion systems with flight heritage that require minimal technology development.

What does minimal technology development entail?:
* man-rate Falcon Heavy (optional with on-orbit refueling of the Falcon 9 / Falcon 9 Heavy upper stage since Falcon 9 can still orbit Dragon 2)
* test Falcon Heavy upper stage on-orbit propellant transfer (initial missions if Falcon Heavy is not man-rated or later missions if Falcon Heavy is man-rated)
* lunar space station, if built, is just a fuel and consumables replenishment depot for the reusable LEM (later missions with cryogenic propulsion can go directly to their surface targets and return directly to Earth, but the plan must still work without the lunar space station at the expense of reusability)
* last but certainly not least, development of a LEM service module with sufficient dV to get to and from LLO

What can't be a requirement for the initial missions?:
* advanced cryogenic propulsion (later missions can use LOX/LCH4 or LOX/LH2 for the LEM and TEI maneuvers, but this requires a redesign of existing vehicle upper stages and a more capable rocket than what we have to work with)

Here's what NASA was working on a decade ago to enable nearly complete surface access and anytime departure:

Lunar Orbit Insertion Targeting and Associated Outbound Mission Design for Lunar Sortie Missions

CEV TRAJECTORY DESIGN CONSIDERATIONS FOR LUNAR MISSIONS

* worst case LOI for polar orbit is 850m/s, but 1,250m/s covers other types of insertions combining plane changes
* worst case TEI is 1,476m/s, but will range between 900m/s and 1,150m/s
* Dragon 2's dV capability is about 800m/s, which is not sufficient for LOI without modifications and certainly not enough for TEI

Robert,

I propose using Bigelow Aerospace's BEAM for the LEM's habitable section with an airlock attached through the center of the service module for docking with Dragon 2 and the lunar space station. The service module will employ Draco for RCS and Super Draco thrusters for primary ascent / descent propulsion. The dry mass of the entire vehicle would approximate the dry mass of the ascent stage of the Apollo era LEM. Later flights in the program may employ LOX/LCH4 or LOX/LH2, as lunar resources and technological readiness levels dictate.

* Apollo's LEM provided 235ft^3 of habitable space for 2 crew, but BEAM provides 565ft^3 of habitable space for 4 crew
* dry mass of the entire vehicle is essentially the same as the dry mass of the Apollo LEM's ascent stage
* primary power provided by deployable Orbital ATK solar arrays with Lithium-ion batteries for storage
* contingency power provided by an onboard NTO/MMH micro APU (IVF-type capability)
* airlock from BEAM to the lunar surface will be surrounded by the LEM's service module containing the NTO/MMH for Draco and Super Draco
* astronauts enter the LEM from below the service module to preclude the requirement for all crew to wear suits during EVA's
* bulk cargo such as surface transportation vehicles or science experiments delivered separately by ESA lunar landers
* science cargo is delivered first, then the LEM homes in on the cargo lander's radio beacon to assure precision landing capability and to confirm that the landing site is free of obstructions using the cargo lander's onboard cameras
* airlock reconfigured to a radiation shelter for protection from CME's / SPE's using remaining ascent fuel and CTB's filled with water and food, but primary use is space suit storage
* BEAM can be launched fully inflated inside the payload shroud of a Falcon 9 Heavy or Atlas V rocket
* Falcon Heavy can supposedly TLI about 21,000kg in fully expendable mode and LOI about 15,200kg (the LEM is reusable, so this should be a one-time launch cost)
* crew transfer from Dragon 2 to LEM at LLO, either directly or from LOP-G; LEM remains docked to LOP-G when not in use

LOP-G configuration and usage:
* station consists of the unused ISS Node 4 module, a MPLM module, and an Orion-derived service module
* each station component fits within Falcon Heavy payload shroud and is near or under the 15,200kg LOI capability of the upper stage
* all modules mated in LLO
* Node 4 module contains the station's avionics, life support, and communal facilities such as toilet and galley
* life support equipment derived from Orion
* Orion variant propulsion module stores NTO/MMH for the reusable LEM
* capability to transfer propellants for both the RCS and primary propulsion to alter the station's orbit to support landers
* visiting Centaur or ACES upper stages will replenish propellant and crew consumables

Why would we do it this way?:
* uses avionics, life support, space station modules, and propulsion systems with flight heritage
* only the LEM service module and its airlock must be designed from scratch, but using existing propulsion hardware
* everything fits in the payload shroud of Falcon Heavy and is within the upper stage's maximum LOI capability of about 15,200kg
* new propulsion technologies can still be incorporated whenever they're ready for prime time

SpaceNut · 2018-12-02 19:35:05

Since the Falcon 9 block 5 is being used for the crewed launch the heavy should be approved as well for use.

So we are now up to 3 falcon 9 heavy of which; one is for refueling, one for Crew TEI,TLI and one for Lunar module of a sort.

gateway items ISS Modules with airlock

https://en.wikipedia.org/wiki/Internati … ce_Station

https://en.wikipedia.org/wiki/Columbus_(ISS_module)
https://en.wikipedia.org/wiki/Harmony_(ISS_module)
https://en.wikipedia.org/wiki/Quest_Joint_Airlock
https://en.wikipedia.org/wiki/Unity_(ISS_module)

https://en.wikipedia.org/wiki/Zvezda_(ISS_module)
https://en.wikipedia.org/wiki/Zarya

RobertDyck · 2018-12-03 01:33:12

kbd512 wrote:

* Falcon Heavy can supposedly TLI about 21,000kg in fully expendable mode and LOI about 15,200kg (the LEM is reusable, so this should be a one-time launch cost)

Ok. However...

kbd512 wrote:

* lunar space station

<screem> *NO* First realize Apollo 11 landed on the Moon with 1969 technology, and didn't need any space station. Why the hell would we need one now? Second, a Lunar space station will require years to build and billions of dollars. All that money will suck funds from anything else, so no money for Mars, or a Lunar surface station, or manned expeditions anywhere, or anything else. The station will suck all the time and money, accomplish nothing, then a change in President will cancel everything. That's what has happened every time since Nixon, it'll happen again. The only way to get anything to happen is to accomplish something. A Lunar space station will result in a Lunar space station. Nothing else. No manned mission to the surface of the Moon, no humans to Mars, nothing.
------------

Specific problems:
N2O4 (known in the 1960s as NTO) is highly toxic. When Apollo-Soyuz mission completed, the Apollo command module had some loud noise. When it was time to deploy parachutes, the commander ordered one of the other astronauts to flick the switch turning off automatic stabilization by thrusters. But the noise was so loud neither of the other astronauts heard him. Automated system tried to continue to stabilize the CM even after the main 'chute deployed. When the CM entered air thick enough to breathe, a valve automatically opened to allow air in. This started to re-pressurized the CM. However, thruster exhaust was sucked in through the intake, causing N2O4 to enter the cabin. The air became foggy with thruster exhaust, and astronauts breathed N2O4. That caused chemical burns to their lungs; all 3 astronauts.

LOX and methane are far safer to handle. And specific impulse is higher. A major reason Lockheed-Martin's Orion won the CEV contract over Boeing's CST-100 was use of LOX/LCH4 for the service module. I criticize them strongly for abandoning that. Orion is a heavier capsule, heavy is bad. Both were originally designed to carry 4 astronauts to Lunar orbit. Lockheed-Martin paid 2 subcontractors to develop RCS thrusters that use LOX/LCH4. Both completed the contract, thrusters were ready. Both said their thruster could be easily scaled up to SM main engine, but hadn't received funding for that. We need to get the job done!

Russia has performed on-orbit propellant transfer with N2O4 and UDMH since the first Progress resupplied Salyut 6 in 1978. When Europe built their ATV spacecraft, it used N2O4/MMH for it's own thrusters, but delivered N2O4/UDMH to the station using Russian docking ports. This is not a new technology.

I have to emphasize, if you're afraid of any new technological development, then you're in the wrong business. This is space. NASA went from Explorer I (technically launched before NASA) to Apollo 11 in 11 years. NASA was an out-growth of NACA, which was established because commercial companies were afraid to invest money to develop new aircraft technology. NASA's mandate is to develop high-risk/high-payoff technology. And LOX/LCH4 isn't even high risk! As I said, RCS thrusters have already been developed.

Soft LM crew cabin? Problem with that is docking. What happens when Dragon tries to dock with a soft squishy LM? Will the soft cabin just move out of the way, preventing hard dock? You need hard dock for pressure seal. Manufacturing an isogrid cabin using the same technology as Dragon is not a risk at all; it's established technology.

A separate air lock on LM is unnecessary. I envision the LM being little more than crew taxi to deliver crew from Dragon in Lunar orbit to a Mars Direct habitat on the Lunar surface. Robert Zubrin proposed using Mars Direct on the Moon to demonstrate technology before proceeding on to the Moon. And if you want a permanent Lunar base, the easiest way is drop a Mars Direct hab. That's an instant base.

I proposed a reusable LM. It can be parked in Lunar orbit between missions. Apollo was able to rendezvous and dock the CSM with LM, no station needed. We can certainly do the same with 21st century technology. But a reusable LM raises another issue: how do you deliver science instruments? Apollo LM had storage compartments around the outside of the descent module. But with a reusable LM, that would require a space walk to move equipment from a non-pressurized storage compartment in Dragon's trunk or LOI stage to outside storage compartments of LM. Not at all practical. That's why I suggested the Mars Direct hab would carry its usual rover. And the hab would have surface science instruments. The LM would only carry science instruments within the pressurized crew cabin. The reason is transfer would be from the pressurized Dragon capsule to LM cabin; easy and safe.

You suggested heavy things to the Moon delivered by recently announced commercial carriers. Ok.

Radiation shelter. Again, I suggest the LM just be a taxi. Mars Direct habitat would have sand bags filled with Lunar regolith as radiation shielding. If a solar event happens, get in the base.

If LM is parked in polar orbit, this means a mission to access any of the Lunar surface. The mission wouldn't be able to go from the base to Lunar surface, but a mission from Earth could go to any location, then back to Earth. Limitation is propellant to refuel the LM. This would restrict missions far from the permanent base to instruments that could be carried within the crew cabin. Heavy stuff could be pre-positioned via commercial carrier, provided they can land accurately enough.

Last edited by RobertDyck (2018-12-03 09:16:36)

kbd512 · 2018-12-03 12:58:48

Robert,

LEM Design Criteria

The LEM design I proposed would be single stage and reusable, but reuse requires on-orbit refueling to return to the lunar surface. It need not make it all the way back to Earth since it's only intended for use on the moon. The lunar space station would create a habitable propellant depot in LLO. It need not be absurdly expensive if it's delivered by Falcon Heavy and uses existing ISS and propulsion systems hardware.

NTO/MMH vs LOX/LCH4

The mission and the crew are important. En-vogue propulsion systems aren't important. I specifically stated that whenever better propulsion systems are flight qualified they'll automatically become the new baseline, but not a moment before then. If NASA, USAF, or private corporations pony up the cash to develop and flight qualify new propulsion systems, then that's great and we'll use them wherever they're appropriate.

Since the moon has no easily extractable CO2 to make LCH4, there is zero practical benefit to mandating the use of LOX/LCH4 for lunar operations when everyone knows there's no practical way to make more of it on the surface of the moon. I proposed using LOX/LH2 in previous discussions because H2O is available every place a human could possibly live. As a result of my suggestion, the SpaceX groupies had their usual religious experience and wanted me ex-communicated from the forums on claims that I was an ULA employee or bashing SpaceX. I merely pointed out what's so blatantly obvious, which is that you need significantly less tonnage of propellant for equivalent upper stage performance since the specific impulse of LOX/LH2 is so high relative to other current-use propellant combinations. If resources and usable power are at a premium, as they always are in space, then less consumption is better.

STS used NTO/MMH for decades and both Dragon variants also use NTO/MMH. Any design that permits oxidizer or fuel to enter the cabin through a ventilation system is a bad design. More recent designs don't seem to have that problem. As far as specific impulse is concerned, AJ10-118K is 319s and AJ10-190 is 316s. There are still no LOX/LCH4 engines that have flown in space and if it's really such a swell idea, then I'm starting to wonder why no space agencies use them for anything and the only two companies doing serious work on the engines haven't flown them, either. We can wait indefinitely for the propulsion systems we'd like to have or use what we do have.

The extra 19s of maximum theoretical specific impulse, if both NTO/MMH and LOX/LCH4 operate at the same chamber pressure, are offset by substantial tankage mass increases and thermal management issues. My LEM concept is about producing something that's flyable within 5 years. SpaceX and Blue Origin have already spent more than 5 years messing with LOX/LCH4 and nothing has flown, unless you count the pieces of the engine that flew off Blue Origin's test stand as flight qualification. The only thing I'm afraid of is twiddling our thumbs for another 5 years due to an insistence on using engines that aren't ready with a propellant combination that provides no substantial Isp advantage, a substantial increase in tankage volume / mass, thermal management issues, and is still every bit as dangerous as any other propellant combination. Call me crazy, but I want a flight program that involves actually flying hardware rather than endless propulsion systems development on the mere promise that someday something will fly.

Last but not least, if we're so hard-up about using cryogenic propulsion systems, then combining LOX with a Hydrazine of some variety would provide the same or nearly the same specific impulse as LOX/LCH4, but at least the fuel wouldn't require lots of extra insulation for thermal stabilization and the impulse density would fall somewhere between NTO/MMH and LOX/LCH4. However, you must also incorporate an ignition system at that point since the propellants are no longer hypergolic. All in all, there's just not a lot of logic behind the decision to switch to cryogenics unless you get a substantial specific impulse increase and significant wet mass decrease. The bigger you go, the more sense it makes, but Falcon Heavy and the success of on-orbit refueling is what dictates the mass of the mission architecture components that can be sent to the moon using rockets we do have (Falcon Heavy and Atlas V), rather than rockets we'd like to have (BFR, SLS, New Glenn, Vulcan).

The propulsion systems rant is now complete.

Inflatables for Habitation, Docking, and Airlocks

The soft squishy part of BEAM is as fluffy as concrete, but it's also attached to an aluminum alloy docking ring. I believe that's the same material you proposed using and there were no issues with docking BEAM to ISS, so I fail to understand your concern about docking issues. At any rate, Dragon and BEAM are much more solidly built than Apollo era pressure vessels. The airlock for the LEM that I proposed is also rigid and would serve as the transfer tunnel between the Dragon and LEM or the lunar surface. The airlock negates the requirement for all crew members to wear suits when only a pair of the crew members will perform an EVA. Whether there is a lunar surface base in the immediate vicinity or not, it's useful functionality to have.

SPE and CME Mitigation

Regarding radiation, I suggest that SPE's / CME's don't just happen when it's convenient to your plans about when it should happen. In decades past, we just launched and hoped for the best. We have better materials technology than what was available decades ago, so I consider available and practical protection measures another useful feature to have. You're worried about better propulsion, as if somehow the mission can't possibly work without it, but a solar flare will kill a $40M crew and a $200M mission in minutes to hours. One dead crew and squandered mission later, FAA will pull the plug on the entire program.

Orbital Mechanics and Lunar Bases

The inclusion of the lunar orbital station provides a convenient place to store fuel on orbit. The lunar base can be built using the same ISS hardware or the newer inflatables. Neither precludes building the other. That is the same logical fallacy applied to the Space Shuttle. If only we were willing to kill the STS program, then rockets and spacecraft capable of lunar or Mars missions would magically appear. We all know how that turned out.

SpaceNut · 2018-12-03 19:24:31

Bigelows inflatables all have the issue of to few docking ports and that makes them not all that usable. I do agree that advance materials need to be used for the SPE and CME particles that could exceed limits safe for man.

I am kind of with Robert Dyck on the lunar orbital station as we need that later on for a means to continue going as its only a small safe haven for some issues that might prevent you from coming home. But I do agree that cheap launchers to get fuel and other goods to such a location is a must.

So as far as a possible service module we might look at the European Service Module (ESM) that is being built for the compatible Orion as they could be reworked to adapt to any capsule that we would wish to use. If nothing else it gives rock solid numbers for its abilities that we will need of one. This is derived from the ATV which was able to dock with the ISS.

http://www.esa.int/Our_Activities/Human … ice_Module
https://en.wikipedia.org/wiki/Orion_Service_Module

Dimensions 4 m long
diameter of 4.1 m excluding solar panels, 5.2 m diameter stowed 19 m with wings unfurled
Primary engine 1 Space Shuttle Orbital Maneuvering System providing 26.6 kN
Secondary engine 8 490 N Aerojet R-4D-11 Auxiliary Thrusters providing 3.92 kN
Maneuvering thrusters 24 220 N Airbus Reaction Control System Engines in six pods of four
Fuel capacity 9,000 kg in four 2000 l propellant tanks, 2 mixed oxides of nitrogen (MON) and 2 monomethyl hydrazine (MMH)
Power generation 11.2 kW from 4 x 7.375 m wings each containing 3 solar panels
Consumables 240 kg of water in four tanks, 90 kg of oxygen in three tanks, 30 kg of nitrogen in one tank

kbd512 · 2018-12-03 21:37:46

SpaceNut,

I'm talking about using BEAM as the primary habitable portion of the LEM, not as part of LOP-G or a lunar surface base. While it's true that the Apollo era LEM had both a docking port and an ingress/egress hatch for EVA's on the lunar surface, since the crew left their PLSS on the moon to economize on ascent mass, I'm not sure how well an emergency escape through the secondary hatch would've worked. In order for this mission architecture to work with rockets we have, rather than rockets we wish we had, we need to think about how each kilogram of mass adds to or subtracts from the feasibility of the mission. The mass margins are tight, but it looks doable. BEAM was a compromise for the lander that combines flight heritage habitation technology with reasonable volume and low mass. It's not what I want, given my druthers, but we can actually do a mission with one because it will survive the environment. The same applies to all current propulsion systems.

I don't think LOP-G is absolutely necessary, either, but it's hard to argue that a real space station capable of storing propellant and consumables isn't a useful tool to have if it's not inordinately costly to launch and maintain. I look at Mars Base Camp the same way. A Mars orbital station isn't absolutely necessary, either, but it would be useful if we had one.

If SpaceX is serious about going to Mars or the moon, the fastest way they could enable that is with a Falcon Super Heavy with 5 booster cores instead of 3 and perfecting on-orbit refueling. Even with just those contributions, they'd be light years ahead of everyone else, even before BFR is fully operational. That'd equate to a lift capability slightly exceeding Saturn V, at a fraction of the cost, or TMI capability at least matching Falcon Heavy with booster reusability. Their commodity rockets are affordable for initial Mars base setup and exploration. BFR would be even better, but anyone who doesn't think that won't take at least as long as Falcon Heavy's development is ignoring history. I could always be wrong, but I'll believe the timeline when I see it fly for the first time.

RobertDyck · 2018-12-03 22:07:35

kbd512 wrote:

lunar space station ... need not be absurdly expensive if it's delivered by Falcon Heavy

It won't be. That's the point. NASA already raised the issue that SLS does not have manifest. It doesn't have a reason for being. They need something for SLS to do. This was announced at a meeting in the VAB at KSC. So they concocted Lunar Space Station to do that. This means the very definition of what Lunar Space Station is for is to justify SLS. It will be built with SLS, and traditional NASA contractors including Boeing and Lockheed-Martin. The same guys who drastically increased cost of Shuttle causing cancellation of Shuttle.

kbd512 wrote:

Since the moon has no easily extractable CO2 to make LCH4, there is zero practical benefit to mandating the use of LOX/LCH4 for lunar operations

There's also no easily extractable water. Some in NASA keep claiming there is, but results from Lunar Prospector said the only ice is the bottom of craters at the poles, with a concentration of a cup over an area the size of a football field. LCROSS was sent to the highest concentration on the Moon, and whacked into it, distributing that ice over a larger area. It *HAD* a higher concentration, but no longer. Besides, how does that justify N2O4/MMH?

kbd512 wrote:

There are still no LOX/LCH4 engines that have flown in space and if it's really such a swell idea, then I'm starting to wonder why no space agencies use them for anything and the only two companies doing serious work on the engines haven't flown them, either. We can wait indefinitely for the propulsion systems we'd like to have or use what we do have.

It isn't a matter of "waiting". It's a matter of doing. Research doesn't do itself. Someone has to spend the time and effort to do it. NASA has been "infected" by views of corporations that claim "someone else" has to do the research. Corporations want to reap the rewards, but don't want to invest the money or effort to do the work. This is why NACA was created in 1915. NACA is a major reason why aircraft underwent rapid technological development. The other reason is war; aircraft were used in World War 1 and 2, going from wood and canvas biplanes before World War 1 to the B-29 Superfortress used to bomb Japan at the end of World War 2. That was developed into B-47 Stratojet in 1947. Technology for that was used to develop a commercial passenger jet prototype called Boeing 367-80, first flown in July 1954. That was the prototype, the commercial production version was Boeing 707, first flown in December 1957. Jumbo Jets have had minor tweaks since then, nothing revolutionary.

kbd512 wrote:

Call me crazy, but I want a flight program that involves actually flying hardware rather than endless propulsion systems development on the mere promise that someday something will fly.

Ok, you're crazy. This isn't like other radical technologies. This is a minor tweak over existing technology, and basic research has already been done. Electric propulsion has already shown it has a major problem with power. Power requires a reactor so heavy that it defeats any benefits. NERVA was an NTR with dramatic performance, but major problem with engine mass due to reactor mass. There has been Timberwind, which promised dramatic reduction in reactor mass, but that requires a lot of further work. LOX/LCH4 has already been demonstrated in the lab, it works with trivial development. So do it!

kbd512 wrote:

you must also incorporate an ignition system at that point since the propellants are no longer hypergolic.

kbd512 wrote:

The soft squishy part of BEAM is as fluffy as concrete, but it's also attached to an aluminum alloy docking ring.

I have worked with pressurized balloons with some sort of attachment. The metal attachment moves out of the way when trying to connect it. The aluminum alloy ring may be rigid, but the inflatable it is connected to is not. BEAM was connected to ISS before it was inflated. How well will it connect when inflated? That hasn't been tested. Will the aluminum alloy ring move out of the way due to the soft squishy fabric it's attached to? Rather than connecting?

kbd512 wrote:

You're worried about better propulsion, as if somehow the mission can't possibly work without it

It's not just improved propulsion, it's ISPP. A mission to Mars is really dependent on ISPP. We just can't do ISPP on the Moon, but Mars needs it.

kbd512 wrote:

a solar flare will kill a $40M crew and a $200M mission in minutes to hours

A Mars Direct habitat deployed on the Moon as a permanent Moon base provides all the protection you need.

kbd512 wrote:

The inclusion of the lunar orbital station provides a convenient place to store fuel on orbit.

Robert Zubrin already calculated that if Lunar oxygen were free, it still wouldn't make any sense. The only way lunar propellant is useful at all is if you can make fuel. You can make oxygen by smelting metal ores on the Moon, but the only fuel requires lunar water. But water is extremely scarce, not likely to be usable. And even if there were usable quantities, it's far better to position a fuel depot in Earth orbit. There's no use at all for anything in Lunar orbit.

kbd512 wrote:

That is the same logical fallacy applied to the Space Shuttle. If only we were willing to kill the STS program, then rockets and spacecraft capable of lunar or Mars missions would magically appear. We all know how that turned out.

The problem is Congressmen wanted to protect jobs, without understanding what they were doing. They created SLS and Orion to protect jobs for Shuttle personnel (engineers and technicians). However, Orion has flown once unmanned on Delta IV Heavy, and SLS has never flown at all. That money would have been far better spent on getting astronauts somewhere.

Current plants are completely different. There is no Lunar Gateway, or Lunar Space Station, or whatever you call it. The money hasn't been spent yet. That money is far better spent building hardware for Mars. Deploy prototypes of that hardware on the Moon. Again, hardware designed solely for the Moon cannot be used anywhere else, it's useless. Hardware designed for Mars can be used on the Moon or an asteroid. The reason is Mars is hard. The Moon isn't easy, but Mars is far more difficult than the Moon. If you design equipment for the more difficult destination and use it on the less difficult one, it works. If you design equipment for the easy destination, it doesn't work anywhere else.

Last edited by RobertDyck (2018-12-04 07:39:54)

kbd512 · 2018-12-03 23:37:56

Robert,

If LOP-G is just something for SLS to do, then yes, I would oppose it. I'm not proposing using SLS. As far as I'm concerned, until a rocket flies it's a concept that looks great on paper. The devil is always in the details.

NTO/MMH is about going to the moon with what we have right freaking now! It's not my first choice, it's my only choice if I want engineers to put hand to keyboard and start designing real flight hardware. The only thing they have to design is the LEM service module. If they can't get that right, then we can't go anywhere at all. I'm totally unopposed to using LOX/LCH4 or even LOX/LH2, but flight qualify and fly the system first, then it can be incorporated into the design. SpaceX and Blue Origin are trying to do it, but they still haven't done it. After working on it for the last half decade, it's still not done. If magic piles of cash could solve the problem, then Elon or Jeff would've solved it by now. I'm not concerned about lunar ISPP because I already know that's not going to happen. Apart from ISRU, there are a slew of other technologies required for Mars that can be tested on the moon, most being related to construction activities and maintenance.

BEAM would be pre-inflated in the launch shroud of Falcon Heavy (because it still fits when inflated) and connected to a RIGID AIRLOCK that serves as the docking port for Dragon. BEAM is permanently attached to the other end of the rigid airlock. There is no docking directly to BEAM because it's an integral part of the LEM. How can I possibly make that any clearer?

* <- pretend the asterisk is a solar array and Draco RCS quad, even though they're in different locations around the SM
|[LANDING GEAR]
[NTO/MMH]-[S. DRACO]
[BEAM][LEM SM AIRLOCK]<DRAGON 2][SM] <- astronauts only enter and exit through this airlock, which faces the lunar surface on the moon
[NTO/MMH]-[S. DRACO]
|[LANDING GEAR]
* <- pretend the asterisk is a solar array and Draco RCS quad, even though they're in different locations around the SM

There is use for things in lunar orbit because the LEM only has to make it to LLO for refueling, but I'm not opposed to refueling in LEO. Once again, the architecture is about rockets with payload capability we have, not what I would like to have. This seems to be some sort of ideological point for you. For me, it's "Do we want to go to the moon or do we want to go to the moon?" If yes, then we have a rocket with a 15.2t LOI capability. Anything heavier requires on-orbit refueling of a Falcon Upper Stage. That's just more technology we don't have that I'm totally unopposed to using whenever we get it.

Regarding the solar radiation issue, which is quite real and lethal, the lunar base will provide all the protection required as soon as you're in it. If you're on your way to or from it, then what? If your only answer to that question is a painful death, then you're wrong.

Stop flogging the dead SLS horse already. Everyone but Congress already knows it's dead and NASA's own administrator isn't even shy about saying he'll put NASA's resources behind any commercial option the minute after their rocket actually flies for the first time.

RobertDyck · 2018-12-04 08:00:14

I'm surprised the current NASA administrator is so willing to abandon SLS. Congress invested literally billions in it. When Obama cancelled Constellation and Ares V, Congress insisted on reviving it. That's what SLS is, Ares V with mistakes corrected. I argue for something that can be done now, but fear Congress and those who lobby Congress will want SLS. Notice my plan includes one and only one launch of SLS. Just to deliver the Mars Direct Hab. We could do it with a couple Falcon Heavy launches: one to deliver Hab to LEO, second to deliver TLI stage. The first could even recover all 3 core stages. But is Congress willing to abandon SLS without a single useful mission?

kbd512 · 2018-12-04 09:48:00

Robert,

NASA's administrator knows that Boeing is years behind schedule and has consistently and badly underestimated the level of effort required to move SLS through the development process. I honestly believe that if there was any realistic alternative available that could TLI the Orion capsule that SLS would be DOA. Apart from the redesign of the pressure vessel and the constant plague of software development, which seems to be a weakness for Lockheed-Martin, Orion's development has been comparatively smooth and has demonstrated learning and correction of mistakes. Learning and correction of mistakes is what I most admire about SpaceX since they also immediately apply lessons learned without prompting, just as if they were one of NASA's traditional contractors.

Apart from that, NASA never wanted SLS because they knew that they needed something with the lift capability of Ares V (150t to 200t) all along. Well, BFR would be a reusable Ares. If one of their contractors (SpaceX or Blue Origin) showed up with a reusable rocket with the lift capability of Ares V, they'd be all over it.

RobertDyck · 2018-12-04 11:19:13

SLS block 2 was supposed to lift 130t to LEO. Last couple years they've talked about block 2B which is supposed to lift more to TLI or TMI, and uses the same core stage as blocks 1 and 1B. Why would they need 200t capability?

Ps. You are expressing a lot of insight into internal thinking of NASA. Where are you getting this? Or are you just guessing?

Last edited by RobertDyck (2018-12-05 00:57:17)

SpaceNut · 2018-12-04 18:51:10

I think 3 SLS could do a huge jump start for lunar colony and for reuse.

mission 1 sending a storable fuel depot to lunar orbit via SEP as this makes a reusuable moon lander possible.
mission 2 send a lunar lander for reuse and a lunar habitat that will start the base also by SEP parked and waiting on lunar orbit.
Mission 3 is to send the crew to lunar orbit with a bigelow inflateable or a multi port tin can for lunar orbiting station creation.

Other launch vehicles would be slightly smaller but still do able with on orbit assembly for each mission time line

Oldfart1939 · 2018-12-04 21:02:35

I would not be at all surprised to see the SLS cancelled after the new Congress is seated. It can be effectively killed by lack of appropriations originating in the House, where Democrats have control for the next 2 years. I suspect the NASA budget to get pared a lot, so other "more deserving programs" can advance. The Senate can bitch an moan on behalf of the "favored contractors," and SpaceX will simply go chugging along unhindered. SLS/Orion was a giant workfare program for LockMart and Boeing.

Terraformer · 2018-12-05 09:42:15

How do the Dems feel about Elon Musk? I wouldn't put it past them to try and hobble SpaceX because of a dislike of it's founder.

JoshNH4H · 2018-12-05 10:31:09

I would say the Democratic party is generally favorable towards him, seeing as he's the electric car/solar power billionaire. The Democratic Party is distinct from the entire universe of left-of-center Americans, of course. My understanding is that the farthest leftward people (perhaps 1% of the actual population or less although disproportionately loud online) dislike him. I would expect continuing support from elected dems unless spaceflight becomes a polarized political issue.

SpaceNut · 2018-12-05 10:44:47

Terraformer, Some democrats are not so far from center as will be some republicans and its rhetorical to make each the extreme as they are not.

For Space x concentrate on sustainability and not all out change to what you do and make. We should have learned that from Nasa's storied past and when we went from capsules to Shuttle and now going back when all that was needed was to continue and grow in a parallel path all the time moving forward. Had we done that Shuttle would have been the mass passenger carrier to orbit while the Saturn V would have been the heavy lift for the building blocks to go further. But instead both are now dead and almost forgotten.

We can do better than that...but we must start by reigning in the costs plus contracting, billion dollar gravy trains and start doing business in space smarter.

kbd512 · 2018-12-06 08:32:51

Robert,

Part of it is based on guesswork and part of it based on statements directly from NASA's #1 and #2, along with analyzing what NASA came up with during the Ares program. Ares V was designed the way it was for a reason. In order to implement NASA's DRA 5.0 vision, that kind of lift capability was what they needed. BFR would provide that kind of capability. It's obvious now that little serious work is being done to revive the NERVA program, but BWXT is still working on the design of a nuclear thermal rocket engine on a shoestring budget, just like KiloPower. To me, it looks like reliving the past. The world moved on in the interim. It seems like NASA is worried about being left with no capability at all, but I sincerely doubt the people at SpaceX and Blue Origin would ever permit that to happen. They're not about to let go of their dreams.

SpaceX currently has no technology and thus no practical capability to return their BFS back to Earth. If anyone did have a LOX/LCH4 plant in a shipping container, then I think that'd quickly sway opinion at NASA in favor of a fully reusable and therefore affordable (for exploration purposes) chemical solution. Even so, the tonnage requirements for all-chemical solution are entirely impractical for sustainable operations. Shipping propellant costs the same amount of money as shipping payload. Any serious colonization efforts or lengthy exploration campaigns mandate electric solutions for in-space propulsion.

As it stands, SpaceX would need a multi-megawatt solar array to provide enough power to make enough propellant to return BFS in 26 months or less. It's a not-so-miniature generating station that has to be constructed entirely of extraordinarily lightweight materials and small individual components that are integrated or actually fabricated in-situ into a system that's deployable and maintainable by a handful of humans and robotic helpers. That's asking quite a lot and NASA is having a hard time seeing that as a practical plan for exploration, let alone colonization. That doesn't mean it won't work, but opinions have to be changed through meaningful demonstrations and PowerPoint doesn't count for much when lives are at stake.

My personal opinion on this matter is that anything sent to the surface of Mars must stay there on the surface or in orbit around Mars because repeatedly subjecting a lightweight composite spacecraft to orbital debris and interplanetary reentry velocities is asking too much from a rocket's upper stage, which must be as light as possible to be of optimal utility as an upper stage. Basically, I agree with Dr. Zubrin about the best way to maximize the utility of the BFR/BFS, except that I would forward deploy a small fleet of BFS to Mars to serve as ferries. The more often you fly it, the faster you achieve return on investment and the better your people become at maintaining the rocket.

If BWXT and NASA actually manage to flight test and qualify a NTR, which is a dubious prospect at this point, then the ability to use pure CO2 as the propellant, as in Dr. Zubrin's world-famous NIMF, would greatly reduce electrical power demands associated with chemical propellant production and permit routine flights to orbit to retrieve new arrivals coming in on NTR-powered BA-2100's launched by BFR whilst BFS remains in the vicinity of Earth for immediate reuse to maximize profits from its use. Meanwhile, SEP-powered and Argon-fueled cargo transports deployed by BFR would provide exceptional economy for that purpose.

I could be completely wrong about all of this, but this is what I see as the most technologically and economically feasible way forward that leverages all the strengths of available and near-term developmental technologies required for truly sustainable operations into the foreseeable future. It also happens to be in keeping with what NASA is presently investing development funds into.

SpaceNut · 2018-12-27 21:13:03

Nasa you missed the Apollo 8 flyby and now its seems like that going to happen again...
Spoiler alert: Apollo 8 was a spectacular success, and one of the key milestones along the long road to landing Apollo 11 on the moon on July 20, 1969.

SpaceNut · 2018-12-27 22:09:54

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

On January 10, 1962, NASA announced plans to build the C-5. The three-stage rocket would consist of: the S-IC first stage, with five F-1 engines; the S-II second stage, with five J-2 engines; and the S-IVB third stage, with a single J-2 engine.[13] The C-5 was designed for a 90,000-pound (41,000 kg) payload capacity to the Moon.[13]
The S-IVB was built by the Douglas Aircraft Company at Huntington Beach, California. It had one J-2 engine and used the same fuel as the S-II. The S-IVB used a common bulkhead to separate the two tanks. It was 58.6 feet (17.86 m) tall with a diameter of 21.7 feet (6.604 m) and was also designed with high mass efficiency, though not quite as aggressively as the S-II. The S-IVB had a dry weight of about 23,000 pounds (10,000 kg) and, fully fueled, weighed about 262,000 pounds (119,000 kg).[25]
The S-IVB-500 model used on the Saturn V differed from the S-IVB-200 used as the second stage of the Saturn IB, in that the engine was restartable once per mission. This was necessary as the stage would be used twice during a lunar mission: first in a 2.5 min burn for the orbit insertion after second stage cutoff, and later for the trans-lunar injection (TLI) burn, lasting about 6 min.

SpaceNut · 2018-12-27 22:17:34

The J-2 engine was reignited to propel the spacecraft into translunar trajectory at a speed of 39,430 kilometres (24,500 miles) per hour.

https://en.wikipedia.org/wiki/Apollo_co … ice_module
Launch mass
32,390 pounds (14,690 kg) Earth orbit
63,500 pounds (28,800 kg) Lunar
Dry mass 26,300 pounds (11,900 kg)
Payload capacity 2,320 pounds (1,050 kg)

https://en.wikipedia.org/wiki/Apollo_Lunar_Module
Launch mass
33,500 pounds (15,200 kg) std
36,200 pounds (16,400 kg) Extended
Dry mass 9,430 pounds (4,280 kg) std
10,850 pounds (4,920 kg) Extended

SpaceNut · 2018-12-28 12:48:17

Just a reference for SLS thou its not going at this point

SpaceNut wrote:

As I indicated in the ares 1 topic I could have thought that we have a more collective topic for the sls but it seems quite spread out...
Ares I (CLV) - Upper stage status evolved into the SLS upper stage
Automated Transfer Vehicle (ATV) - ESA ISS cargo carrier this has eveloved into the srvice module for Orion
Orion (CEV / SM) - status mating has been done for EM1 test flight
Ares V (CaLV) - status this was the base line once forced to reuse existing labor and construction components to make the SLS
Current status of a moon lander is dormant and are critical for a lunar landing to celebrate the 50 anniversary of Apollo 11:
Northrop Grumman Lunar Lander Challenge
Altair - Lunar Lander (LSAM) - status
The system still is lacking the ability to land on the moon and while Nasa has chosen to go with a mini space station for moon observation is seen as a distraction. It is also seen the same for going to mars as well.

SpaceNut · 2018-12-28 19:14:07

I keep running up against english and metric measurements when trying to come up with numbers for figuring out what can we do with the on orbit 131 mT of sls or the 63 mT of Falcon 9...

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#251 2018-12-02 16:38:53

Re: Apollo 11 REDUX

#252 2018-12-02 18:21:30

Re: Apollo 11 REDUX

#253 2018-12-02 19:00:01

Re: Apollo 11 REDUX

#254 2018-12-02 19:14:43

Re: Apollo 11 REDUX

#255 2018-12-02 19:35:05

Re: Apollo 11 REDUX

#256 2018-12-03 01:33:12

Re: Apollo 11 REDUX

#257 2018-12-03 12:58:48

Re: Apollo 11 REDUX

#258 2018-12-03 19:24:31

Re: Apollo 11 REDUX

#259 2018-12-03 21:37:46

Re: Apollo 11 REDUX

#260 2018-12-03 22:07:35

Re: Apollo 11 REDUX

#261 2018-12-03 23:37:56

Re: Apollo 11 REDUX

#262 2018-12-04 08:00:14

Re: Apollo 11 REDUX

#263 2018-12-04 09:48:00

Re: Apollo 11 REDUX

#264 2018-12-04 11:19:13

Re: Apollo 11 REDUX

#265 2018-12-04 18:51:10

Re: Apollo 11 REDUX

#266 2018-12-04 21:02:35

Re: Apollo 11 REDUX

#267 2018-12-05 09:42:15

Re: Apollo 11 REDUX

#268 2018-12-05 10:31:09

Re: Apollo 11 REDUX

#269 2018-12-05 10:44:47

Re: Apollo 11 REDUX

#270 2018-12-06 08:32:51

Re: Apollo 11 REDUX

#271 2018-12-27 21:13:03

Re: Apollo 11 REDUX

#272 2018-12-27 22:09:54

Re: Apollo 11 REDUX

#273 2018-12-27 22:17:34

Re: Apollo 11 REDUX

#274 2018-12-28 12:48:17

Re: Apollo 11 REDUX

#275 2018-12-28 19:14:07

Re: Apollo 11 REDUX

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