SLS Forward Missions to Mars

Dook · 2016-11-03 19:12:57

Forward Work Mars Landing, a crewed mission, with four to six astronauts, to a semi-permanent habitat for at least 540 days on the surface of the red planet in 2033 or 2045.

The mission would include in-orbit assembly, with the launch of seven SLS Block 2 heavy-lift vehicles (HLVs). The seven HLV payloads, three of which would contain nuclear propulsion modules, would be assembled in LEO into three separate vehicles for the journey to Mars; one cargo In-Situ Resource Utilization Mars Lander Vehicle (MLV) created from two HLV payloads, one Habitat MLV created from two HLV payloads and a crewed Mars Transfer Vehicle (MTV), known as "Copernicus", assembled from three HLV payloads launched a number of months later.

In-orbit assembly? Do the modules self fly to one another and self dock?

So, 7 launches, 3 are propulsion modules, so three propulsion modules for three vehicles and four cargo modules so one of the propulsion modules powers two cargo modules.

1 cargo ISRU Mars Lander created from two launches, so, once again, in-orbit assembly.

1 habitat created from two launches.

The Mars Transfer Vehicle is three launches.

So, that's a total of 14 launches of the SLS and 4 cargo modules to Mars, 1 ISRU, 1 habitat, and a Mars Transfer Vehicle that stays in orbit over Mars.

What are the first cargo modules full of? Food, water, solar panels, open rovers, inflatable greenhouses...

RobS · 2016-11-03 19:33:28

Sounds interesting. But each SLS launch probably costs $1 billion each and they say NASA's budget won't allow more than 2 per year, so you just exhausted 3.5 years of NASA budget on those 7 launches. And the nuclear propulsion modules will probably cost $5-10 billion to develop if you can get it through Congress. No estimate of the cost to keep the protestors away from Cape Canaveral every time you launch one.

SpaceNut · 2016-11-04 19:17:57

Sounds to me like you are talking about Design Reference Mission 5.0 but with SLS rather than the Ares V which is being indicated in its documentation.

Dook · 2016-11-04 19:27:36

That's from the SLS Wikipedia page. I guess that's what NASA plans to do.

SpaceNut · 2016-11-05 21:31:14

Like you indicated in the first post there are lots of questions from the original reference mission.

Then there is the entire list of items once we have the heavy lift rocket which are needed to make the trip possible just to mars orbit and back to which the list gets even bigger with the items that we need for landing plus staying on the mars surface that we do not have....
Sure we have lots of different tech in developement but these are not even in the prototype stage yet.

Dook · 2016-11-06 17:02:42

What's the formula for figuring out how much payload a rocket can send to Mars?

The SLS block l can put about 70 tons into LEO and the block ll is supposed to be able to put about 130 tons into LEO, so how much can they get to Mars?

kbd512 · 2016-11-06 17:35:13

Dook,

Have a look at this web page from NASA first:

Ideal Rocket Equation

Then take a look at this web page from NASA:

The Tyranny of the Rocket Equation

To directly answer your question, SLS Block II can send 31.7t to a Trans-Mars-Injection (TMI) trajectory. Then you need more propellant to actually brake into Mars orbit. Then you need even more propellant to actually land on Mars.

To actually get back to Earth, you need propellant to get from the surface of Mars back to into Mars orbit. Then you need more propellant for a Trans-Earth-Injection (TEI) trajectory. Then you need even more propellant to actually brake into Earth orbit.

There are ways to reduce the propellant requirements. You can aerobrake into Mars orbit and Earth orbit using the atmosphere of both planets. However, you need heavy heat shields to do that. ADEPT is a fabric deployable umbrella that weighs less than traditional heat shields and is what JPL and NASA are working on to brake spacecraft at Mars.

Last edited by kbd512 (2016-11-06 17:46:18)

Dook · 2016-11-06 17:57:08

What if someone here gives me an educated guess? We know what rockets have already put things on Mars so we can probably come up with an idea? If it's off by a couple tons, big deal, we're not working for NASA.

Zubrin's Ares V was really big. I saw a chart that said his Ares V would launch 188 tons to LEO, and the tuna can to Mars was 28 tons. So, a bit more than 1/6th of your LEO payload can get to Mars.

So, if the SLS can put 130 tons into LEO then about 1/6th of that is a bit over 21 tons.

I know it's not perfectly exact but it doesn't have to be. We're all just pretending to be NASA engineers here anyway.

SpaceNut · 2016-11-06 18:01:04

Here is what I am able to locate....most of this is in the SLS topics....

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

ReachMars 2024 A Candidate Large-Scale Technology Demonstration Mission as a Precursor to Human Mars Exploration

A High-Heritage Blunt-Body Entry, Descent, and Landing Concept for Human Mars Exploration

Assumed Lander Capability
The lander concept for this study was designed to have the following key features and capabilities:
 A 10 m diameter blunt-body entry vehicle that would launch in a slight hammer-head configuration on the
SLS
 75 t entry mass, which is based on the performance capability for two SLS launches to inject a payload to
Mars on a conjunction-class trajectory
 An ogive-shaped lander backshell that would have a dual use as the launch fairing on the SLS
 The lander would use aerocapture to enter High Mars Orbit (HMO) where it would loiter for an extended
time awaiting the arrival of the crew in a separate vehicle
 Able to support a crew of 2 for 24 days, a crew of 3 for 16 days, or a crew of 4 for 12 days in the MAV

https://www.nasaspaceflight.com/2013/11 … n-options/

kbd512 · 2016-11-06 18:45:22

My SWAG is that 20t (44,000lbs) is probably what one SLS rocket could actually deliver to the surface of Mars using an aerobraking reentry from interplanetary space and every trick in the book to decelerate the payload from 5.7km/s to 0km/s. There are orbital mechanics "tricks" that could improve that figure. If ion engines were used to go from LEO to TMI, to a halo orbit, to the surface of Mars, the actual delivered tonnage would be a lot higher than that. However, that depends greatly on how fast you want the payload to get there.

SpaceNut · 2016-11-06 21:18:25

But for Man to the surface there is just the one method as there is no slow ION drive engines to get the larger mass to mars orbit just sub assembly in LEO of large pieces which are mostly fuel to get us to mars with as much as possible.
The rovers were about 1 mT and the on orbit delivered is about 15 mT using parachutes to help in reaching the surface and with man needing to land in a much larger vehicle and with cargo to survive we will need to get rid of the parachutes and go for a retro rocket landing instead.

kbd512 · 2016-11-07 01:16:40

SpaceNut,

Humans can reach the surface in something as small as Red Dragon. Neither Red Dragon nor Orion are physically voluminous enough to store the food and water required for a 180 day transit to Mars using a chemical rocket. However, Red Dragon can actually land on Mars using its SuperDraco rocket engines whereas Orion can only land in an ocean here on Earth because it was originally designed to take astronauts to the moon in conjunction with a lunar lander.

Red Dragon has a wet mass of 6.4t (14,080lbs) and a payload mass (delivered to the surface of Mars) of 1t (2,200lbs). Red Dragon performs propulsive landings, so it can fly to a specific target on the surface of Mars. Between pre-positioned Mars Surface Habitat (MSH) and Mars Ascent Vehicle (MAV) delivered using SEP (solar electric propulsion or ion engines) tugs with SLS and orbital assembly of the Mars Transfer Vehicle (MTV), we should be able to get away with a mission architecture of 4 SLS launches and 1 Falcon 9 launch.

Launch Opportunity #1:
1 SLS for the pre-positioned MSH (inflatable or ISS-derived aluminum lab hab module)
1 SLS for the pre-positioned MAV (storable chemical propellants; unpressurized, just like Red Dragon, but no abort capability - if you abort, you're still dead)

Launch Opportunity #2:
2 SLS for the MTV (1 for the habitat module, 1 for the propulsion module - chemical kick stages for TMI / TEI and SEP for orbital insertion)
1 F9 for the Red Dragon (to deliver the crew to the MTV and to the surface of Mars)

There are no backups for the mission architecture I proposed above. If any component fails, the mission and/or crew are lost. However, 4 SLS launches and 1 F9 launch are within NASA's current and projected budgets for human space flight. The only technologies at work involve existing or to-be flight hardware that has been funded by Congress. The mission is decidedly no-frills with very limited surface transport capability, but requires no special technology development apart from what we're already doing.

kbd512 · 2016-11-08 18:11:44

Dook,

Here's where I'm getting my numbers from for how much SLS can TMI:

SLS upper stage proposals reveal increasing payload-to-destination options

Right now, it looks like the upper stage for SLS will use 4 RL-10 engines. That provides the most payload to LEO and payload to TMI of all the studies NASA has conducted. The LOX/LH2 RL-10's have the most flight heritage of any US upper stage engine flying. RL-10's are very light, very compact, very reliable, and have the highest Isp of any current production engine. The engines were never man-rated, but it looks like NASA intends to do that.

Here's where I'm getting my down mass numbers for what a storable chemical propellant retro-propulsive delivery system could actually deliver to the surface of Mars:

NASA considers SLS launch sequence for human Mars missions in the 2030s

The 20t figure I quoted is the final mass of the delivered Mars Surface Habitat (MSH) module and propulsion hardware. The reason I think we can "improve" on the delivered tonnage figure a little bit over what NASA quoted it could deliver, which is 18t with a 40t wet (fully fueled mass), is that better orbital mechanics can be utilized (the halo orbits I mentioned) and the mass of the structural mass associated with the habitat and lander could be substantially lowered using the sky crane configuration with the fuel and engines on top. NASA is trying to co-opt AJ-10-190 technology (Space Shuttle OMS engines). I would use SuperDraco.

NASA's configuration is similar to the LEM configuration, but that configuration is not optimal for heavier structures. The configuration I advocate for would have the habitat on the bottom instead of 15 feet in the air, doing away with the support structure. The rocket engines are now on all four sides of the payload instead of directly underneath it, which also provides more directional control during descent. The tankage and support structure only has to hold its own weight instead of the weight of the habitat. The habitat itself is substantially stronger than is necessary to support its own weight because it has to contain the force of 14.7psi. As long as you don't land the habitat on a massive rock, you're good to go. Landing on rock would tip the habitat, but the same thing would happen from a landing pad landing on a rock.

The advantage to my solution, apart from the significant reduction in structural support mass, is that the astronauts don't have to climb down a ladder to the surface and therefore can't fall off of the lander. When the Eagle lands, it should be a very small step for a man or woman or even a child.

SpaceNut · 2017-01-22 20:12:42

Like the MCT the SLS is a BFR....
The first of the three SLS rockets is projected to cost $7.021 billion, and the entire project around $12 billion.

So for the 5 Billion for the reamining portion of the project just how many rockets are we getting?

SpaceNut · 2022-11-20 17:40:57

The tides of change keep making it harder to plan for mars initially and for the future but NASA’s 30-day mission to Mars

https://www.nasa.gov/sites/default/file … tives-.pdf

Mars_B4_Moon · 2023-03-02 15:11:20

Questions
https://twitter.com/NASA_SLS/status/1630285140403404800
The Artemis missions will return humanity to the lunar surface where astronauts will research and study the Moon's South Pole

Mars_B4_Moon · 2023-03-19 07:59:48

The big reveal: What's ahead in returning samples from Mars?
https://www.space.com/mars-sample-return-whats-ahead

Lunar and Martian Lava Tube Exploration as Part of an Overall Scientific Survey
https://solarsystem.nasa.gov/studies/4/ … ic-survey/

Starship Demo mission coming, Next Mars Orbiter NeMO a proposed NASA Mars communications satellite with high-resolution imaging payload and two solar-electric ion thrusters, Jet Propulsion Laboratory awarded five $400,000 sub-contracts to conduct concept studies. The five engineering companies are Boeing, Lockheed Martin Space Systems, Northrop Grumman Aerospace Systems, Orbital ATK, and Space Systems/Loral.[Mars Sample Return but how big government and old generation of builder contracting is working? The costs, Space Launch System (SLS) used by NASA is an expensive stepping stone to Mars.

Musk is not interested in hype for the new Heavy Lift Rocket yet

Elon Musk says SpaceX’s Starship rocket only has 50% chance of reaching orbit
https://nypost.com/2023/03/14/elon-musk … d-explode/

even if it fails the overall journey is a winner, it has made others come along and created a commercial space flight revolution

The world's first 3D printed rocket is preparing to launch. Here's how it could beat Elon Musk's SpaceX to Mars.
https://www.businessinsider.com/relativ … nch-2023-3

New Mars Forums

Announcement

#1 2016-11-03 19:12:57

SLS Forward Missions to Mars

#2 2016-11-03 19:33:28

Re: SLS Forward Missions to Mars

#3 2016-11-04 19:17:57

Re: SLS Forward Missions to Mars

#4 2016-11-04 19:27:36

Re: SLS Forward Missions to Mars

#5 2016-11-05 21:31:14

Re: SLS Forward Missions to Mars

#6 2016-11-06 17:02:42

Re: SLS Forward Missions to Mars

#7 2016-11-06 17:35:13

Re: SLS Forward Missions to Mars

#8 2016-11-06 17:57:08

Re: SLS Forward Missions to Mars

#9 2016-11-06 18:01:04

Re: SLS Forward Missions to Mars

#10 2016-11-06 18:45:22

Re: SLS Forward Missions to Mars

#11 2016-11-06 21:18:25

Re: SLS Forward Missions to Mars

#12 2016-11-07 01:16:40

Re: SLS Forward Missions to Mars

#13 2016-11-08 18:11:44

Re: SLS Forward Missions to Mars

#14 2017-01-22 20:12:42

Re: SLS Forward Missions to Mars

#15 2022-11-20 17:40:57

Re: SLS Forward Missions to Mars

#16 2023-03-02 15:11:20

Re: SLS Forward Missions to Mars

#17 2023-03-19 07:59:48

Re: SLS Forward Missions to Mars

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