“Mars To Go” Based Missions Donovan Chipman David Allred, Ph.D

Past Mars Missions Ideas Von Braun – Apollo Follow-on – Space Exploration Initiative – Mars Direct and Variations – Constellation Program and NASA DRM 5.0. (Image from NASA) (Image from Mark Wade’s Encyclopedia Astronautica) (Image from the Mars Society)

What, in Essence, is Mars To Go? Mars To Go is an answer to the question: “How can I land someone on Mars and return him/her to Earth without having to create new technology that the other plans require?” This will require: 1. Rocket. 2. Tug (sometimes). 3. Capsule. 4. Habitat 5. Mars Entry, Descent, and Landing (EDL) 6. Landing Vehicle. 7. Ascent Vehicle. 8. Return Propulsion.

Three Variations on the Concept 1.1. Mars to Go Classic 2.2. Basic Mars 3.3. Mars to Go Lite

The Idea Use what we have The Mars Science Laboratory entry descent and landing system (EDL). Middle sized military and commercial rockets – not huge government moon rockets like the Saturn V that aren’t in production anymore. (Delta IV, Falcon IX, maybe NASA’s SLS) Keep in space Systems light Use Small Earth launch and re-entry capsule and/or a small habitat. Minimize the amount of mass that needs to be placed on the planet’s surface. Land only one person at a time. Minimize surface stays (a few days perhaps). Make ascent vehicle as spartan as possible. Keep it simple No nuclear power, exotic propulsion, aerocapture, “Moon rockets”, or huge landing vehicles. Possibly no In-Situ resource utilization either. Judiciously maximize system commonality.

To Get To Mars, One First Needs Rockets (To get from the ground into orbit, of course) Falcon Heavy: mt LEO.Proposed SLS Core (J-130): 77.8 tonnes LEO (Image from SpaceX) (Image from directlauncher.com) Delta IV Heavy: 7.7 mt TMI (Image from the Orlando Sentinel)

Earth Departure Stage Propulsion (EDS. This is what we use to get out of Earth’s orbit) Delta-IV Medium Upper Stage (Images from Wikipedia) Delta-IV Heavy Upper Stage (Images from Wikipedia) Centaur Upper Stage (Images from Wikipedia)

Outbound Propulsion Requirements Earth C3 Escape: 3.2 km/s Trans-Mars Injection: 0.44 km/s Mars Capture: 0.9 km/s Low Mars Orbit: 1.4 km/s Mars Surface: 3.5 km/s From NASA MSFC Interplanetary Mission Design Handbook (1998)

Inbound Propulsion Requirements Mars Ascent: 4.1 km/s Trans-Earth Injection: 1.3 km/s To Earth Surface: 6.0 km/s From NASA MSFC Interplanetary Mission Design Handbook (1998)

Space Tug (Like boats, these are used to push other space vehicles around) The tug module is the Soyuz/Progress spacecraft service module. It weighs 2,950 kg fueled and about 2,000 kg dry. This is used to attach some payloads to their EDS. (Image from Wikipedia)

Manned Earth Launch and Re-entry Systems (Like launch, coming back to the ground is rather… flamey) The Dragon Capsule of SpaceX (left) is an American resupply spacecraft currently in advanced stages of development. Designed for a crew of seven, the spacecraft mass minus payload and propellant is about 4.1 tonnes. It is large enough to serve as a long term habitat for one person if you have no other choice. (Image from SpaceX) Smaller capsules, such as the shuttle escape capsule concept shown at right, offer a lighter weight option if a separate habitat (wait a couple of slides) is available. These could weigh as little as 200 kg, though a more sane one selected (again at right) is closer to 700 kg. (Image from astronautix.com)

In-Space Habitat (Where you live while being bored in Interplanetary Space) The Galaxy module from Bigelow Aerospace. The partially completed, and thus unflown, article has twice the volume of earlier Genesis I and II orbital space station prototypes. Design already includes life support systems. Empty, it weighs about 3,000 kg, while stocked it could weigh between two and three times that much. (Image from Bigelow Aerospace)

Radiation Protection (The ozone layer doesn’t extend out this far.) All radiation protection is passive. The walls of the habitat use hydrogen-rich foam. Food and water can be place around the outer walls. The task is simplified in comparison to earlier mission concepts by the smaller volume of the capsule and inflatable habitat as compared to a larger spacecraft.

Mars Atmospheric Entry System (Landing on Mars is harder than it sounds.) The Mars Science Laboratory rover aeroshell will be the largest ablative heat shield system ever flown (even larger than the Apollo command module.) It can soft land approximately 900 kg on the Martian surface with the skycrane, or nearly 1,600 kg if landing stage mass is included with a traditional landing system. This is about the largest vehicle mankind can land on Mars without needing to qualify new technology. (Image from Lockheed Martin.)

MTG Classic MAV The MAV is composed of two identical methane/carbon monoxide and LOX stage units. It has an ISRU propellant production kit and enough hydrogen feedstock to produce more than 3 metric tonnes of ascent propellant. The hydrogen is converted into methane and oxygen. However, hydrogen takes more volume than the methane it creates, so we can take extra space and use it to store carbon monoxide fuel made from the Martian atmosphere.

MTG Classic MAV: Stage 1 Propellant Production Liquid Hydrogen Sabatier/ RWGS Liquid Methane Water Liquid Oxygen CO2 Electrolysis Waste CO

MTG Classic MAV: Stage 2 Propellant Production Liquid Hydrogen RWGS Water Liquid Oxygen CO2 Electrolysis Liquid Carbon Monoxide LH2

MTG Lite: MAV BasicMars includes two Mars Ascent Vehicles per mission. The MAV, based heavily on the Langley Lightest moon vehicle, enters the atmosphere in an MSL aeroshell (no astronaut) and lands as a complete unit with propellant already onboard. Each MAV takes one astronaut from the surface to LMO. ( Image from astronautix.com)

MAV Lite Mass Breakdown Rocket Engines: 160 kg Tanks: 150 kg Structure: 90 kg Propellant: 1250 kg Descent: 250 kg Ascent: 1000 kg Batteries: 30 kg (3.0 kW*hrs total storage) Solar Panels: 10 kg (650 W production) Electronics: 15 kg Total Dry: 460 kg Total Landed: 1460 kg Total: 1710 kg

MLV Rover The Mars Landing Vehicle/Rover is basically a small electric car that uses methanol/oxygen fuel cells for power. The rover is pressurized to 2 psi. In Mars To Go Classic, the MLV is battery powered with solar power supplementation. The rover has a mass of approximately 900 kg.

Propulsion Modules: near Mars maneuvers The propulsion modules for MTG Classic and Basic Mars weigh between 4.2 and 8.4 tonnes, depending on the use. Each one is composed of a rocket stage with optional forward docking equipment and solar panels. The tug for Mars to Go Lite has both a chemical (methane/oxygen) engine, as well as an electric VASIMR engine. The two 75 kW Ultra-Flex solar panels each have a diameter of 16 meters.

Mars To Go Classic

Mission Architecture 1 Year 1: A single Delta-IV Heavy lifts two MAVs directly onto a trans-Mars injection trajectory.

Mission Architecture 2 Year 3: A Falcon 9 Heavy carries two propulsion modules and a Centaur Upper Stage into LEO. The Centaur delivers the TMI burn for the two Propulsion Modules.

Mission Architecture 3 Year 3: A Delta IV Heavy places the SAVe aeroshell and one propulsion module directly into TMI.

Mission Architecture 4 – One month later, a Falcon 9 Heavy carries a Centaur Upper Stage, One Propulsion Module, and the manned Space Capsule into LEO. The Centaur Delivers the TMI Burn for the stack.

Mars to Go – Chemical. EELVs. 1 Crew. ISRU Required.

Basic Mars

Mission Architecture 1 Month 1: An SLS core vehicle lifts two MAVs, a PM, and two Delta-IV Heavy upper stages to LEO. (76.8 mT)

Mission Architecture 2 Year 3: An SLS core carries a Delta-IV Heavy Upper Stage, three PMs, a tug, and two MLVs into LEO. (64.75 mT)

Mission Architecture 3 Year 3: An SLS core places a Delta IV Medium Upper Stage, a Delta IV Heavy Upper Stage, a PM, and the Galaxy habitat into LEO. (76.8 mT)

Mission Architecture 4 – A Falcon 9 Heavy carries a tug, a PM, and the manned space Capsule into LEO. (13.28 mT)

Basic Mars – Chemical. HLVs. 2 Crew. Modification for Artificial Gravity.

Mars to Go Lite (Just one launch, made possible this last Tuesday)

Mission Architecture 1 A Falcon Heavy carries a Delta IV Heavy Upper Stage, the MAV, the MLV, the Earth Entry Capsule, the habitat, and a propulsion tug to GTO.

Mission Architecture 2 The Delta IV Heavy Upper Stage places the Mars vehicle stack into C3 Earth escape trajectory.

Mission Architecture 3 Solar panels deploy. VASIMR engines are activated to gradually propel Mars vehicles through TMI. (MLV stack shown).

Mission Architecture 4 Propulsion tug fires chemical engine for MOI into an elliptical orbit.

Mission Architecture 5 Following MOI, the vehicle stack aerobrakes into LMO over the course of several months.

Mission Architecture 6 Once in the proper orbit, the astronaut transfers to the MLV. The MLV, MAV and tug separate from the habitat.

Mission Architecture 7 The MAV and MLV separate from the tug and land on Mars

Mission Architecture 8 Rover cabin is deployed. Astronaut roves surface for a day or so before reaching the MAV.

Mission Architecture 9 MLV rover rendezvous with MAV. Astronaut walks to MAV.

Mission Architecture 10 MAV with astronaut on board ascend to LMO.

Mission Architecture 11 MAV docks with habitat in LMO. Astronaut transfers to habitat.

Mission Architecture 12 MAV vehicle is jettisoned. Tug redocks with habitat.

Mission Architecture 13 Return tug electrically propels remaining spacecraft to a high Mars Orbit. A final short chemical burn carries the vehicle to Mars escape velocity.

Mission Architecture 14 VASIMR engines are activated to gradually propel combined vehicles through TEI.

Mission Architecture 15 Capsule separates from habitat and re-enters Earth’s atmosphere prior to ocean splashdown.

QUESTIONS?