Reuseable Mars Lander, surface to orbit and back

SpaceNut · 2015-12-30 19:58:01

Since I was suggesting that the waste would be of benefit to the surface greenhouse soil construction and other uses the following topic is best seperated out as such...

SpaceNut wrote:

The manufacturing of soil is not all that hard we can recycle the journey's outward leg to mars waste stream for just that purpose and send it down in a seperate lander. Bring along a small sample bacteria and such containerized to keep then until needed on the surface.
In a controlled environment of warmth and moisture to allow for the process to work. Add in a bit of Co2 and we should be able to make the process start with no problems just like a methane digester....
If we need to pull out some of the waste to make room in the lander it will be in bags or containers in order to make it possible to be able to create that controlled environment inside the lander.

louis wrote:

Yes, a good point about the outward bound waste stream, SpaceNut...I would think that could be something like 600-700 Kgs for a six person mission. However, that is 600 Kgs plus that you have to land safely on the surface and that has its own costs in terms of fuel and storage!

GW Johnson wrote:

Your third biggest problem will be a big reusable lander that can ferry down the tons of sewage you created on the 6-to-9 month voyage to Mars.
Your fourth biggest problem will be creating local propellants fast enough to supply that reusable lander for those ferry trips.
GW

RobertDyck does in the foreseable future that a mars Mav would be replaced by some sort of "a reusable Mars shuttle; I had thought to base it on DC-XA, but now that SpaceX has a working reusable rocket, use their's."

Which is part of what Space x has demonstrated by the falcon but can it do the same on mars once we right size it to have the orbital connecting capability that we would need to act as a ferry for crews or just as I suggest as a cargo landing unit.....

louis · 2015-12-31 10:37:26

Responding to post #1 by SpaceNut:

Well the most obvious issue first - you couldn't land on something like the Falcon 9 first stage - because you would have no way of getting down without a reception tower...unless someone wishes to proposal some sort of disembarking system (I guess you might be able to create a zip wire system to get people to the ground, but it wouldn't be that easy!).

I presume the way the first settlers will get to Mars will be in the Red Dragon or a near equivalent...otherwise, what is the Red Dragon for?

http://www.space.com/24984-spacex-mars- … ragon.html

Could we use two Red Dragons? One for landing and one for ascent? I am wondering if a Red Dragon ascent vehicle (6 tonnes) could be landed by an even larger lander - which would in effect be the launch platform for the ascent?

Alternatively, can we use fuel either pre-landed or manufactured on the surface?

I guess we are back to mission architecture. I would favour pre-landing a surface hab, fuel, food, water and other supplies, PV panel power system, life support system and rover robots prior to the human landing. So, really, the lander would be essentially a shell to get the crew from orbit to the surface.

GW Johnson · 2015-12-31 11:21:07

Red Dragon is currently proposed as a one-way unmanned probe delivery system, not a manned lander. Any lander vehicle will resemble a capsule because of the hypersonic aero-deceleration necessary at Mars, and will little-resemble a Falcon-9 first stage. But it will be a lot larger than a Dragon.

Just trying to bound the one-way lander problem, lets make the assumption that landing gear equipment forces the inert mass fraction up to around 10% for a one-way/one-shot vehicle.

From LMO, the deorbit burn is relatively trivial, and most of the deceleration is hypersonic drag. You have around 2.0 km/s velocity to "kill" touching down in a vehicle most likely too large for any usefulness from chutes. So you do supersonic retropropulsion from end of hypersonics to touchdown. Using storable propellants, Isp is around 300 sec, for an exhaust velocity in the vicinity of 9650 ft/sec = 2.94 km/s. Req'd MR = 1.974, for a propellant mass fraction of right at 50%. That means your usable payload fraction is 40%

For a two-way/one-or-two-shots design, using the same propellants, LMO velocity+10% is 4 km sec, plus 2 for the landing. That's a total of 6 km/s velocity requirement, carrying the same payload both ways. MR = 7.7, for a propellant mass fraction of 87%. In that case, your usable payload fraction is 3%.

If you want these vehicles to land, say, 10 tons of usable payload, then the one-way vehicle masses 25 tons as delivered to LMO. The two-way vehicle is much larger at 333 tons, as delivered to LMO. Now remember, that's carrying 10 tons back up to LMO in the two-way vehicle, such as return propellant for the orbit-to-orbit transport. Reducing the return payload makes only a small difference to achievable delta-vee, because the payload fraction is so small at 3%.

If you want to fly this vehicle many multiple times, you'd better make it stouter and stronger, which means its inert mass fraction increases, to perhaps 15% as a guess. To do that, you'd better use a more energetic propellant combination. LOX is relatively easy to do, and doesn't suffer too badly from evaporation losses, so assume kerosene-LOX at Isp in the vicinity of 320 sec. Exhaust velocity is near 3.14 km/s. Assuming 15% inert and a reduced 2% payload, propellant fraction is 83% for a mass ratio of 5.88, and a delta-vee capability (loaded both ways) of 5.56 km/s, which is not really enough. So there are real design limits to how long a reusability life we can expect out of such a vehicle, using current available propulsion technologies that might be in the least suitable at Mars.

In conclusion, existing storable propellant technologies (such as NTO-MMH) make possible a one-way delivery vehicle that delivers 10 tons onto Mars from LMO, which masses about 25 tons as delivered to LMO. So, how many of these do you need? Depends on your mission objectives.

Delivering only astronauts, assume half a ton per crewperson, for 6 crew max, 3 tons to ride as payload. At 3% payload and 10% inerts for the very-limited-life two-way vehicle, the crew lander then masses about 100 tons as delivered to LMO. Using this type of design precludes shipping mass quantities of ISRU-produced return propellant for the orbit-to-orbit return vehicle. It does use storable propellants.

The astronaut transfer vehicle is larger at 100 tons in LMO if you ship a crew of 6. It shrinks only a tad if one uses the not-storable more energetic kerolox propellants, and LOX-methane would do about the same job. Ship only 1 or 2 astronauts at a time, and your two-way vehicle falls in the 17-33 ton class, about the same size as the one-way vehicle. But you need more of them. How many astronauts on the surface, and how many trips do we make? Depends upon your mission objectives.

There, I sort-of bounded the lander problem for you.

GW

louis · 2015-12-31 17:42:22

In response to post #3 by GW:

As explained on another thread, I think we could use a smaller lander (something like the Red Dragon). I am basing that approach on pre-landing a lot of supplies over several years. We can use ballistic capture to send those, thus saving substantially on fuel (I read the saving is something like 25%).

"The two-way vehicle is much larger at 333 tons, as delivered to LMO." Well I guess that depends to the extent we manufacture rocket fuel on Mars and/or deliver it to the surface via robot loads.

SpaceNut · 2015-12-31 18:36:41

Thanks GW for some interesting numbers to think about....

What I was looking to do was to land the ship the first time with only the propellant to land but with the tank size to launch with and to be able to return once in orbit anytime. That would mean the higher mass fraction penalty but using lox-methane.

I was hoping to make this a single stage but its sort of looking like we need the have a falcon style design of a first stage to push the lander to orbit that can return to the launch site that could be made from recycled parts of other landers. While the lander comes back seperately once we are through on orbit.

If we wanted this could be the taxi to mars for each mission reducing the mass sent from earth and cost.

RobertDyck · 2015-12-31 19:38:29

Wikipedia: DC-X, short for Delta Clipper Experimental

This would be followed by the "DC-Y", Y referring to pre-run prototypes of otherwise service-ready aircraft. Finally the production version would be known as the "DC-1". The name "Delta Clipper" was chosen deliberately to result in the "DC" acronym, an homage to the famous Douglas DC-3 aircraft, which many credit for making passenger air travel affordable.
Built as a 1/3rd scale prototype, the DC-X was never designed to achieve orbital altitudes or velocity, but instead to demonstrate the concept of vertical take off and landing.
...
Several engineers who worked on the DC-X were hired by Blue Origin, and their Blue Origin New Shepard vehicle was based on the DC-X design. Blue Origin does not require the high cross range capabilities, and therefore uses a base-first re-entry profile. Also, the DC-X provided inspiration for many elements of Armadillo Aerospace's, Masten Space Systems's, and TGV Rockets's spacecraft designs.

Encyclopedia Astronautica: DC-Y

LEO Payload: 4,500 kg (9,900 lb) to a 300 km orbit at 90.00 degrees. Payload: 9,000 kg (19,800 lb) to a LEO 28 deg. Launch Price $: 350.000 million in 1991 dollars.

This rocket was designed as a cone, not a cylinder. That makes landing easier, if it's a slight angle when legs touch down then weight will right it. And the wider bottom can be covered with a heat shield for re-entry from orbital speed. Falcon uses legs that spread out to give it the wide landing stance, yet narrow stage core for reduce aerodynamic drag during supersonic and hypersonic flight. One guy on the Mars Society DC email list questioned whether Falcon is still within the sensible atmosphere when hypersonic, I don't have its flight profile so I can't confirm that. But the cone shape of DC-Y in particular permits a heat shield. Something like this for Mars?

SpaceNut · 2015-12-31 20:21:57

Falcon Hypersonis flight path from http://spaceflightnow.com/2015/12/22/ro … successes/

After the Falcon 9’s fiery liftoff from Cape Canaveral’s Complex 40 launch pad at 8:29 p.m. EST Monday (0129 GMT Tuesday), the rocket steered on a trajectory northeast from the launch base, accelerating to nearly 4,000 mph and 50 miles altitude in two-and-a-half minutes.
Then the first stage detached from the Falcon 9’s upper stage, with a nudge from a new pusher separation device flying for the first time on Monday’s launch.

http://spaceflightnow.com/2015/04/10/fa … -timeline/

Moments after two of the Falcon 9’s first stage engines shut down, the remaining seven Merlin engines cut off at an altitude of 80 kilometers, or about 50 miles, and a velocity of Mach 10.
T+0:02:41: Stage 1 Separation

Void · 2016-01-01 10:42:52

I understand that SpaceX is not interested at this time in recovering the 2nd stage. It is probably not economic, or if it will be, it is not a thing to do until recovery of the 1st stage and reuse is preformed with proficiency.

So, correct me if I am wrong, but as I understand it, the 2nd stage is disposed of in two manners.
Case 1: If it is a low orbit delivery, the 2nd stage is left in a low enough orbit that eventually say about 6 months atmospheric drag will bring it down, to burn up (Hopefully).
Case 2: If it is to deliver to geosynchronous orbit, then I presume it becomes an orbital object permanently.

Case A: When you say reusable Mars lander, I presume you are thinking of a perfected effective device that would have value for long term re-use with maintenance.

CASE B: This would be different than an expedition device which might be reused 2, 3, or 4 times. In that situation you will not have local resources to refurbish a strongly degraded device.

So, I am going to presume that you are expecting that in case A. This device must be created as a creation beyond expedition efforts.

So I suggest that as in the 1st Stage method a process of evolution, that is revise, rebuild, and test in cycles will be appropriate. Of course I am wondering how the 2nd Stage reuse evolution might lead finally to your Reusable Mars Lander.

For Case 1: I suggest consideration of this:
http://www.space.com/23834-photos-x-37b … ssion.html
x37b-space-plane-landing-oct17-2014-closeup.jpg?1413608404

I don't know the dimensions of the spaceplane compartment relative to the 2nd stage. It doesn't matter. I am sure they are a mismatch.
As for the spaceplane, then a new version required, stripped of anything not involving the quick retrieval of a 2nd stage in a decaying orbit.
Robitic, it would itself not have to achieve a very good orbit, so that reduces the rigor on it. The 2nd stage would have to play nice, perhaps and not tumble about, keep itself oriented in a good way during the scooping operation in the decaying orbit.

The spaceplane would also be lighter because it would be stripped of the other capabilities that the existing space plane has.

Then the question of cost comes up. Well, if the 2nd stage booster is not worth it, then of course it would not be done. But I understand that the machines casually dispensed with are vastly the cost of space flight. If you could reliably go up and retrieve the 2nd stage booster, and bring down the two devices for a reasonable cost that would make business sense.

How this could relate to a Reusable Mars Lander. It is just another proposal, but for Mars, instead of a spaceplane, a vertical take off and vertical landing "Clam Shell" robotic rocket.

So the "Clam Shell" mates with the analog for the 2nd stage booster, in orbit, and brings it down. The "Clam Shell" has a heat shield.

For reorbit, perhaps the 2st Stage Analog, is simply a payload delivery device to orbit. It would not be human rated. It could therefore have acceleration methods that are hostile to humans, but efficient for delivery.

The Clam Shell Robot would have a heat shield and landing engines, but would first serve as the launch pad for the 2nd Stage Analog.

After launch of the payload, the "Clam Shell Robot" would be evaluated, clam shell shut, and the launch to orbit to retrieve the 2nd Stage Analog. Of the two devices, I would think that the Clam Shell would be the one I would want to use to deliver humans to and from orbit. It would have a heat shield and landing engines.

During launch to orbit with humans on board, if a problem showed up, the device would be under loaded, and would have fair chances to abort to ground or to orbit and keep the humans alive.

Perhaps it would never do both, get the 2nd stage analog and bring it down, and also land humans to the surface.

For:
Case 2: If it is to deliver to geosynchronous orbit, then I presume it becomes an orbital object permanently.
I suggest the idea that these devices be fetched by an electric rocket and moved to a Lunar associated position "L#" location perhaps, and be reusable for landing and launching from the Moons surface. This from a Mars selfish perspective would give an opportunity to evaluate the reusability of the 2nd stage for Mars.

Of course when I say 2nd stage, I am talking about heritage of the 2nd Stage. Not as it is now.

The 1st stage was just rebuilt, so that it can come down and land. It had extra power and fuel added I believe, so it is not strictly speaking the same device that was being used to attempt landing testing at first. So I consider it reasonable to give allowances for the 2nd stage device to evolve.

Done.

Last edited by Void (2016-01-01 11:18:29)

SpaceNut · 2016-01-01 21:16:53

Some things to think on in your post void about what we can and cannot do.

The glide/lifting body design would require a wings span that is greater by a factor of 4 as the atmosphere is to thin to provide much lift.

I am thinking that this is a near term within the first decade transportational need to reduce mission costs from earth. Its just me but I do not see where we will building many runways for a landing to happen but its food for thought still the same. As we will need to build a flight control location first for such mission useages.

Void · 2016-01-01 23:38:48

I said vertical for Mars so;

I am sorry people, but this has gone on long enough. Replies that I get back indicate that you either do not receive what I send or don't bother to read them. This has been going on for years.

I'm done.

SpaceNut · 2016-01-02 20:36:33

Yes vertical launch is all you have, the clam shell is called a shroud to protect the object with in them in this case the plane that you indicated by the image, and its the return that is a glide path void with the plane......

GW Johnson · 2016-01-03 10:42:23

Mars is an oddity: too little air to do much with, yet too much to ignore.

A conical shape for a two-way lander makes good sense, pointy-end forward for a lower-drag ascent, blunt end forward with a heat shield for aero deceleration on descent. The air is thin enough you can use a short, squat cone, as you leave any sensible air at rather low velocities on ascent. Short and squat is far more stable when landing on rough ground. That's a good thing.

For a one-way lander, cylindrical is OK, as you just need a blunt end with heat shield for entry aero-deceleration. Keep it short and squat for landing stability.

The heat shield need not be as capable as those we use returning to Earth, because entry speeds and peak heating are lower, plus you need shallow entry angles at Mars to keep from smacking the surface during the hypersonics. Shallow angles reduce entry gees and peak heating. The problem gets to be very easy if you enter from LMO: speed at entry is only about 3.6 km/s vs the 8 km/s here. Peak heating varies crudely as speed cubed, all else being equal.

I like the idea of a propulsion core surrounded by an annular cargo or habitat space, for easy entry with fold-down hull panels that become entry ramps. On a two-way design, that propulsion core can be tipped with an ascent stage, and/or an abort bail-out capsule.

The Red Dragon design is a one-way delivery to the surface of 1 to no more than 2 tons. I don't know whether that is from LMO or a direct entry from an interplanetary trajectory, but the tonnage is too low for it to act as a crew landing vehicle, I suspect. It makes a dandy abort capsule on a larger lander, though.

GW

louis · 2016-01-03 18:11:57

The Dragon is reported (Wikipedia) to have a Dry mass of 4,200 kg and can deliver a payload to the ISS of 3,310 kg. It can return to Earth 3,310 kg , which can be all unpressurized disposal mass or up to 2,500 kg of return pressurized cargo.

Not quite sure why you think it could only deliver 1-2 tonnes to the Mars surface. Are you factoring in life support or something else?

GW Johnson wrote:

Mars is an oddity: too little air to do much with, yet too much to ignore.
A conical shape for a two-way lander makes good sense, pointy-end forward for a lower-drag ascent, blunt end forward with a heat shield for aero deceleration on descent. The air is thin enough you can use a short, squat cone, as you leave any sensible air at rather low velocities on ascent. Short and squat is far more stable when landing on rough ground. That's a good thing.
For a one-way lander, cylindrical is OK, as you just need a blunt end with heat shield for entry aero-deceleration. Keep it short and squat for landing stability.
The heat shield need not be as capable as those we use returning to Earth, because entry speeds and peak heating are lower, plus you need shallow entry angles at Mars to keep from smacking the surface during the hypersonics. Shallow angles reduce entry gees and peak heating. The problem gets to be very easy if you enter from LMO: speed at entry is only about 3.6 km/s vs the 8 km/s here. Peak heating varies crudely as speed cubed, all else being equal.
I like the idea of a propulsion core surrounded by an annular cargo or habitat space, for easy entry with fold-down hull panels that become entry ramps. On a two-way design, that propulsion core can be tipped with an ascent stage, and/or an abort bail-out capsule.
The Red Dragon design is a one-way delivery to the surface of 1 to no more than 2 tons. I don't know whether that is from LMO or a direct entry from an interplanetary trajectory, but the tonnage is too low for it to act as a crew landing vehicle, I suspect. It makes a dandy abort capsule on a larger lander, though.
GW

SpaceNut · 2016-01-03 21:36:36

RobertDyck thanks for the DC-y post as its got my mind thinking of another older topic that I started...will post the link in later once I find it....

The wider base as GW says makes it ideal for Mars and we could alter it by using the flat bottom which is sort of square made out of segmented pica-x heat shield materials. Sustituting the Red dragon design for the top of the craft for the purpose of bailout if the ship did not make orbit once we launch it from the mars surface for rendivous in orbit.

Making sort of a new combination ship just for Mars. So how do we launch it from earth to Mars is the question that would requires the use of a new inter stage coupler and booster to get it on its way.

SpaceNut · 2016-01-03 22:00:00

Here is the old The viability of the DC-Y topic...

Will fix it so that it can be read without the shifting or artifacts....

I still remember another and will post it when found....

RobertDyck · 2016-01-03 22:03:52

SpaceNut wrote:

So how do we launch it from earth to Mars is the question that would requires the use of a new inter stage coupler and booster to get it on its way.

It's a rocket. It's intended to enter Mars atmosphere from Mars orbit, and land. All it requires is a big rocket to launch from Earth. The heat shield will probably be optimized for Low Mars Orbit, not interplanetary speed. So add ADEPT, the same umbrella style deployable heat shield that Robert Zubrin included with Mars Direct. In this case the heat shield would be used for aerocapture, and perhaps aerobraking into LMO. The heat shield on the bottom of the Mars shuttle (DC-Y) should be able to aerobrake, but I doubt it would catch enough atmosphere for sufficient braking for aerocapture. If you launch with the Mars shuttle propellant tanks full, then it can land itself.

You could use SLS block 2B, it can throw 44 tonnes into trans-Mars trajectory. The chart that SpaceNut gave us says that with liquid boosters with a pair of F-1B engines each, it will throw 44.0 metric tonnes to TMI. With 6 AR-1 engines per booster, it could throw 44.2 tonnes to TMI. How heavy will this Mars shuttle be?

Or do you want to speculate about Falcon X Heavy, or Falcon XX?

Last edited by RobertDyck (2016-01-04 02:23:20)

SpaceNut · 2016-01-03 23:14:54

Thanks so we can create a single stage to orbit for mars lander mars use vehicle which could be sent on its way to mars on a ship that Nasa is working on......

Found these links while exploring....

http://www.lpi.usra.edu/meetings/marsco … f/4353.pdf
NOFBX™ MARS ASCENT VEHICLE: A SINGLE STAGE TO ORBIT APPROACH

http://www.lpi.usra.edu/publications/re … /Rowan.pdf
A Comparison of Preliminary Design Concepts for Liquid, Solid and
Hybrid Propelled Mars Ascent Vehicles Using In-Situ Propellants

GW Johnson · 2016-01-03 23:24:46

To answer Louis's question in post 13 above, I went and looked up "Red Dragon" on Wikipedia, and two Space.com articles. The Red Dragon project never left concept stage nor was a proposal actually submitted for a NASA Discovery class mission. But enough work was done to determine that a Falcon-Heavy could send a Red Dragon to Mars for direct entry from interplanetary transfer. I believe I read the empty-but-fueled capsule was 6 tons, so that's 7 tons at entry.

This is a one-way trip to the surface. The payload was definitely listed as 1 metric ton, that being as heavy as the capsule could be and still land on its Super Draco thrusters. Entry would be at shallow angle so as to come out of hypersonics without smacking the ground. No parachutes, just direct hypersonic/supersonic/subsonic retropropulsion to touchdown.

The one ton was to include core drilling and sample recovery gear, plus an ascent vehicle to Mars orbit, and from there an Earth return vehicle to high Earth orbit, for retrieval later by some other craft. The retropropulsion landing without chutes was also to test for the first time the sort of thing that men are going to have to use anyway, because nothing over about 1 ton at entry will be able to use a supersonic ringsail chute. The ballistic coefficient brings you out of hypersonics too close to the ground at such sizes. It's just physics.

The other thing about chuteless retropropulsion touchdowns is this technique will work at higher elevations where the local air is far too thin for any sort of chute.

As for landers in general, you want the span between the landing pads larger than the height to the center of gravity, and you want a lot of stroke to the landing legs, without bringing your engine bell too close to the surface if all legs fully stroke. That's just required to land on rough ground without a human at the controls real-time, up-close, and personal.

GW

Last edited by GW Johnson (2016-01-03 23:28:00)

SpaceNut · 2016-01-04 20:49:19

With Mars cargo landers being a use once most likely, we can look at how to modify them once empty for creating such a vehicle on Mars to make it possible to lessen further mission costs.
Or Nasa can spend the up front bucks to make it happen from the first mission onward sending 1 for this purpose.

kbd512 · 2016-01-05 14:24:39

Why are people so obsessed with large and complicated Mars landing systems, let alone reusable Mars landing systems? Money isn't going to magically appear in NASA's coffers for their development. If you give up trying to land multiple people in a properly tested multi-person capsule system with a bunch of consumables, your reentry solution becomes much lighter and far less costly to properly test.

Land cargo separately. If more complicated methods for landing heavier payloads are required, so be it. Don't apply the same technology to landing humans if it isn't necessary.

Land each astronaut individually in unpressurized micro capsules with minimal consumables. HIAD works on Earth. It'll work on Mars, too. There's only one problem to solve with the micro capsule design- inflation of a deployment bladder on a large ringsail using a CO2 cartridge to force the parachute open. If you can make the parachute large enough and still deploy it successfully, propulsive landings are unnecessary. With something as complicated as reentry and soft landing on another planet, simpler is always better.

It does not matter whether or not you land your astronauts in one large, heavy, and complicated multi-person capsule or in individual capsules. If something goes wrong during reentry, they die. If the astronauts land too far from their habitat or rover, they die. The only difference between those two solutions is that with the multi-person capsule, if something goes wrong during reentry, you lose everyone at the same time. Assuming the astronauts landed successfully, but landed significantly off target, the only difference between the multi-person capsule and micro capsule solutions is the elapsed time between landing and loss of crew/mission. Either way, the results are the same.

RobertDyck · 2016-01-05 15:37:03

Separating cargo from crew is a good idea. Keeping the crew lander small and simple is also good. However, I don't think you know what that means. Landing crew alive is not that simple. One reason for separating cargo is that you can take risks with cargo that you can't take with crew. If a cargo lander fails, destroying the vehicle and payload, then it's expensive but it's just money. If a crew lander fails, people die.

This is what an individual capsule actually looks like:

YouTube video. I downloaded this as an .mp4 file, and tried to convert to an animated .gif, but the result had 1 frame per 2 seconds.
Landing
Ascent

kbd512 · 2016-01-05 16:34:54

Rob,

That's what an individual capsule looks like when you include more consumables than are required for immediate survival and active propulsion. It was also intended for lunar landings. Our target has an atmosphere.

The Mars reentry capsule has two primary functions:

1. Survive entry into Mars atmosphere from LMO.

2. Soft land the person inside.

Anything more sophisticated than a capsule that performs those two tasks is expensive and complicated extravagance.

The micro capsule I have in mind is a two piece unpressurized aeroshell so small and light that the astronaut inside can open it by hand after he or she has landed. The top shell contains a parachute and perhaps a backup parachute. The bottom shell contains HIAD. While still in orbit, a small service module provides propellant and thrusters for attitude control and deceleration used for reentry.

The astronaut inside wears a MCP suit, he or she sits on a fabric seat suspended by bungees inside the shell. The avionics are incorporated into the astronaut's suit and instrumentation readouts are projected onto the astronaut's visor. The only flight controls are a pull handle to release the parachute and a hand controller to orient the capsule for reentry.

It's a real capsule versus a suit designed for a Red Bull style stunt, but it's a minimalist design that performs two functions and only two functions. It doesn't do anything else because it doesn't need to do anything else.

Everyone here and at NASA keeps trying to "what-if" all the possible contingency scenarios ad nauseam rather than accept that certain landing scenarios are not survivable, short of simply landing the crew in a fully functional surface habitat module.

As you stated, if the cargo that makes this mission possible doesn't land successfully, then all we've lost is some expensive hardware. The reentry system should be stupidly simple, lightweight, and inexpensive. Complication cravings should be satisfied elsewhere.

What's more complicated and expensive to design and test?

A: Multi-person pressurized capsule propulsively landed and refueled for return to the MTV (or Earth, as some here would like to do) on another planet

B: Single-person unpressurized capsule parachute landed and thrown away

Edit:

The entire point of landing the habitat modules and other equipment first is to have everything required for surface survival in place before the astronauts arrive. I think it's a really good idea, but that solution also requires a separate crew landing. There's no reason to replicate a miniature version of the surface habitat vis-a-vis a multi-person capsule system. It only ensures that funding for such an endeavor is years or even decades away.

A micro capsule is something that NASA can develop in the interim that doesn't cost so much that absolutely no development of human landing technology occurs in the interim, which is exactly what we have now.

Land the humans in the surface habitat or land the humans in a capsule that only lands them, rather than attempts to replicate what the habitat provides. Pick one, not both.

Last edited by kbd512 (2016-01-05 16:53:38)

RobertDyck · 2016-01-05 17:35:08

And some people think my idea is too spartan. And some think Mars Direct is too spartan. Your idea is way beyond that.

I said to land in a capsule. Just a capsule. Just a seat for each astronaut, heat shield, parachute, landing rockets, and landing legs with shock absorbers. Nothing fancy. You could think of an air bag to cushion the astronauts for final touch-down, but you can't delete the landing rockets, just-bounce-and-roll like Pathfinder/Spirit/Opportunity. That produced up to 35g acceleration, which isn't survivable for humans. And my idea includes an inflatable habitat and open rover. The reason is to ensure all that stuff is immediately available. Some people don't like the idea of an all-inflatable habitat, no hard walls at all. But this idea was to fit a Mars mission on the Russian Energia, devised when Boris Yeltsin was still president of Russia. Today, well, SLS block 2B has more lift capacity.

And some think my idea of a Mars Assent vehicle is too spartan. I said just a seat for each astronaut, place to strap down sample containers, and a fairing for high-speed assent through Mars atmosphere. No pressurized hull at all, astronauts would ride in their spacesuits. The MAV would have extra large propellant tanks, because the entire MAV would dock to the Interplanetary Transit Vehicle, acting as the TEI stage.

Your micro capsule sounds like MOOSE: Man Out Of Space Easiest

SpaceNut · 2016-01-05 18:25:09

kbd512 we have had the 248Smallest Human Ascent or Descent Lander for Mars Or Earth topic or have all forgotten about it.....

So do it there.....

louis · 2016-01-05 18:31:49

I like the "Keep it simple" approach. I too advocate pre-landing of habs and supplies.

However, I am not entirely convinced of landing individuals in solo pods. Personally I feel we need to be assured the crew can rest upon arrival rather than immediately find themselves in an EVA situation. It would be better in my view if they have a couple of days' supplies with them on landing. Then one or two people, after say six hours of health and equipment checks following landing, can leave the lander and test the hab. If there is a problem with the hab (unlikely but cannot be ruled out), then the whole crew move to a pre-landed ascent vehicle and exit the scene.

Basically I think the lander needs to be "as small as possible".

There might be an argument for single person lander/ascent craft. So, if - say - this was a 6 person mission, you would ferry people down one at a time. The advantage then would be that the craft could be kept as small as possible. Each time the craft returned to the orbiting transit craft, it would be refuelled. It might tkae several sols to land everybody. But it might make the whole mission a lot easier to mount.

Question: How small could a single person lander and ascent craft be and how much fuel would be required for landing and ascent?

kbd512 wrote:

Rob,
That's what an individual capsule looks like when you include more consumables than are required for immediate survival and active propulsion. It was also intended for lunar landings. Our target has an atmosphere.
The Mars reentry capsule has two primary functions:
1. Survive entry into Mars atmosphere from LMO.
2. Soft land the person inside.
Anything more sophisticated than a capsule that performs those two tasks is expensive and complicated extravagance.
The micro capsule I have in mind is a two piece unpressurized aeroshell so small and light that the astronaut inside can open it by hand after he or she has landed. The top shell contains a parachute and perhaps a backup parachute. The bottom shell contains HIAD. While still in orbit, a small service module provides propellant and thrusters for attitude control and deceleration used for reentry.
The astronaut inside wears a MCP suit, he or she sits on a fabric seat suspended by bungees inside the shell. The avionics are incorporated into the astronaut's suit and instrumentation readouts are projected onto the astronaut's visor. The only flight controls are a pull handle to release the parachute and a hand controller to orient the capsule for reentry.
It's a real capsule versus a suit designed for a Red Bull style stunt, but it's a minimalist design that performs two functions and only two functions. It doesn't do anything else because it doesn't need to do anything else.
Everyone here and at NASA keeps trying to "what-if" all the possible contingency scenarios ad nauseam rather than accept that certain landing scenarios are not survivable, short of simply landing the crew in a fully functional surface habitat module.
As you stated, if the cargo that makes this mission possible doesn't land successfully, then all we've lost is some expensive hardware. The reentry system should be stupidly simple, lightweight, and inexpensive. Complication cravings should be satisfied elsewhere.
What's more complicated and expensive to design and test?
A: Multi-person pressurized capsule propulsively landed and refueled for return to the MTV (or Earth, as some here would like to do) on another planet
B: Single-person unpressurized capsule parachute landed and thrown away
Edit:
The entire point of landing the habitat modules and other equipment first is to have everything required for surface survival in place before the astronauts arrive. I think it's a really good idea, but that solution also requires a separate crew landing. There's no reason to replicate a miniature version of the surface habitat vis-a-vis a multi-person capsule system. It only ensures that funding for such an endeavor is years or even decades away.
A micro capsule is something that NASA can develop in the interim that doesn't cost so much that absolutely no development of human landing technology occurs in the interim, which is exactly what we have now.
Land the humans in the surface habitat or land the humans in a capsule that only lands them, rather than attempts to replicate what the habitat provides. Pick one, not both.

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