Justin Haxton

Mars Sample Return Mission Mission Scope

Need: To understand the potential for life elsewhere in the universe, to characterize the present

and past climate and climate processes and to understand the geological processes

affecting Mars’s interior, crust, and surface (Planetary Decadal Survey - Chapter 6: Mars:

Evolution of an Earth-like World)

Goals: The highest priority science goal will be to address in detail the questions of habitability

and the potential origin and evolution of life on Mars.

1) Determine If Life Ever Arose on Mars

2) Understand the Processes and History of Climate

3) Determine the Evolution of the Surface and Interior.

Objectives:

Life:

• Assess the past and present habitability of Mars.

• Assess whether life is or was present on Mars in its geochemical context.

• Characterize carbon cycling and prebiotic chemistry

Climate:

• Characterize Mars’s atmosphere, present climate, and climate processes under both

current and different orbital configuration.

• Characterize Mars’s ancient climate and climate processes.

Geology:

• Characterize Mars’s atmosphere, present climate, and climate processes under both

current and different orbital configuration.

• Characterize Mars’s ancient climate and climate processes.

Primary Mission Description: A Mars Sample Return (MSR) mission would be a robotic spaceflight mission that would

collect atmospheric, rock and dust samples from Mars and return them to Earth for

analysis. Sample return is a very powerful type of exploration because instead of relying

on the limited sample analysis techniques that can be flow to the destination on-board a

robotic spacecraft, more sophisticated long-term analysis of returned samples can be

performed in laboratories on Earth.

(http://resources.saylor.org.s3.amazonaws.com/NASA/MSRMissonnew.html)

Constraints: Landing Area Several engineering constraints must be considered in order to prevent mission failure. These

constraints are listed and explained in the following paragraph.

Present targeting capabilities suggest a 20 km long landing ellipse. All elevations within the

landing ellipse just be below 2.5 km with respect to the 6.1 mbar geoid to allow the parachute

sufficient time to bring the spacecraft to terminal velocity before the retro-rockets fire. In any

case, landing sites would be selected from a 20° latitude window centered around the latitude

that optimizes mission lifetime (which is the 5°S latitude for the nominal design). Solar panels

sweep out an even larger area after they deploy so that the lander is susceptible to large slope

changes and high rocks on the surface. In addition, severe surface slopes could cause early or late

firing of the retro-rockets during terminal descent. The three-legged lander is stable on surfaces

with slopes up to 15°. Any tilt of the lander could adversely affect power generation on the

surface. Steep slopes are also a concern for rover power generation and trafficability. Rocks are

also a major concern. During landing large rocks could severely damage the underside of the

lander thermal enclosure, which is about 35 cm above the surface. In addition, each leg has two

stabilizers that extend from the lander feet to the base of the lander that could be damaged by

impact during landing. Rocks could also "catch" a lander foot during final landing resulting in

lander tip over if the retro-rockets do not zero out all horizontal velocity. The preliminary

engineering constraint is that the probability of landing on a rock >35 cm high should be less

than about 1%. Extremely rocky areas also slow or impede rover trafficability. (M. Golombek et

al., 2000)

Landing Environment Extremely dusty environments can negatively impact the mission. The surface must be radar

reflective for the lander to measure the closing velocity. Surfaces covered with extreme

thicknesses of dust may not be reflective and may not provide a load bearing surface needed for

safe landing and roving. Very dusty surfaces also could raise a plume of dust that could coat

instruments and rocks. Dust also could be deposited on solar cells thereby reducing power and/or

mission lifetime. (M. Golombek et al., 2000)

Lander Design To maximize the solar power, the lander must be near the subsolar latitude, which is ±25° from

the equator. The specific latitude results from the selected Earth-Mars transfer trajectory, which

effectively fixes the season (Ls) of arrival.(M. Golombek et al., 2000)

The location of the center of gravity is very constrained by the aerodynamic stability required

during the aerocapture (H. Price, 2000)

Rover Design To date Martian rovers are only capable of climbing dunes with slopes of ~50 degrees. A sample

return rover may need to climb slopes steeper than that. That is not to say, if the slopes were not

fine grained sediment the rover would be able to climb steeper slopes. Rover operation time is

also important; the rover will be able to complete the mission in a shorter time period if main

power is supplied via a radio isothermal generator as opposed to solar cells. The placement of the

sample storage box also plays a crucial role in the rover power supply. An RTG will allow the

box to be placed directly on top of the rover whereas that will prove to be difficult with solar

panels. Due to the Martian terrain and previous rover heritage, mobility should consist of a six

wheel rocker boagie design.

System Constraints

Cost, schedule and mass are predominant system constraints,. The launch window must be

sufficient both going to and returning from Mars. Mass and design constraints will greatly affect

overall mission cost. We would like to maintain an ideal cost to benefit ratio in order to maintain

mission success. In order to maintain that ratio we need to budget appropriately.

Return Constraints

The period of time necessary for the phase angle between Earth and Mars to repeat itself varies.

This variation is referred to as the Synodic Cycle. The Synodic Cycle, or mission repetition rate

for identical Earth-Mars phasing, and therefore launch opportunities for similar mission classes,

is on the order of every 26 months. The mission characteristics such as mission duration, trip

times, and propulsive requirements vary to due to the eccentricity of Mars’ orbit.

Budget:

NASA’s FY2014 budget totals to $17.64 billion. Of this budget, $1,918 million is for Space

Launch System (SLS) of which $1,600 million is for launch vehicle development and $318

million is for exploration ground systems,$302 million is for exploration research and

development, $5,151 million for science, of which $80 million is for pre-formulation or

formulation activities for a Europa mission, and the James Webb Space Telescope's development

costs remain capped at $8 billion,$576 million for space technology,$566 million for

aeronautics,$3,778 million for space operations, $515 million for Construction and

Environmental Compliance and Restoration,$37.5 million for Inspector General (www.nasa.gov)

The total budget of the Mars Science Laboratory mission is $2.3 billion. That is spread out over

nine years and includes all the stages -- development, assembly, testing, launch and two Earth

years of operating the rover and analyzing the science results. (http://beamartian.jpl.nasa.gov/)

Based on these numbers and the fact that most, if not all of the proposed instruments and

mechanisms on the MSR rover and lander are all heritage, the only relatively costly aspects will

be integrating instruments, arms, scoop and sample box grabbing mechanism. We believe it

would be safe to allocate $1 billion for all integration and $2-$3 billion for developing the ascent

stage of the return capsule. This would bring the total mission budget to ~$6 billion ± $1 billion

contingency. This budget leaves roughly $10.64 billion of the original budget.

Schedule:

Pre-Launch Activities

Landing Site Selection 2020-2024

Assembly & Testing (JPL) Feb – Sep (2024)

Assembly & Testing (KSC) March-September (2024)

Shipping Spacecraft to Cape October 2024 (2 months)

Launch

Mission Lift Off November 2024 (T+4 min)

Mission Reaches Earth Orbit Nov. 2024 (T+14-30 mins)

First Contact Nov. 2024 (T+20-50mins)

Mission Health Check Nov. 2024 (T+60 mins)

Cruise

Health Check & Maintenance November 2024

Spacecraft & Subsystem Monitoring & Calibration November 2024

Attitude Correction Nov. 2024, Feb, Apr, May,

Jul, Aug 2045

Nav. activities (trajectory correction), nav training Jan-July 2045

Prep for entry, descent, landing & surface ops

(comm. tests during entry, descent, landing)

August 2045

Approach

final trajectory correction maneuvers, attitude

pointing updates, "Delta DOR" measurements, start

of the entry, descent, and landing behavior software,

entry, descent, and landing parameter updates,

spacecraft activities leading up to the final turn to the

entry, loading of surface sequences and

communication windows needed for the first several

sols

July-August 2025

Entry, Decent and

Landing

Guided Entry August 2025 (43 sec)

Parachute Descent August 2025 (42 sec)

Powered Descent August 2025 (13 sec)

Sky Crane August 2025 (45 sec)

First Drive Systems, Mobility & Instrument Check August 2025 (4 hours)

Surface Operations Sample Categorization & Acquisition August 2025 – July 2027

Launch

Mission Lift Off

July 2027 Mission Reaches Martian Orbit

First Contact

Mission Health Check

Cruise

Health Check & Maintenance July 2027

Spacecraft & Subsystem Monitoring & Calibration July 2027

Attitude Correction Jul. 2027, Sep, Nov, Jan, Mar,

May 2028

Nav. activities (trajectory correction), nav training Feb.-Apr. 2028

Prep for entry, descent, landing & surface ops

(comm. tests during entry, descent, landing) April 2028

Approach

final trajectory correction maneuvers, attitude

pointing updates, "Delta DOR" measurements, start

of the entry, descent, and landing behavior software,

entry, descent, and landing parameter updates,

spacecraft activities leading up to the final turn to the

entry

April 2028

Entry, Decent and

Landing

Guided Entry April 2028 (3-5min)

Rendezvous With ISS April 2028

Parachute Descent May 2028 (5-10 minutes)

Lab Operations Final Lab Set Up & Sample Testing May 2028

Authority & Responsibility:

Rover and lander will be built by sub-contractors including but not limited to Lockheed Martin

Space Systems, Ball Aerospace, the Jet Propulsion Lab, SEAKR Engineering and Raytheon.

Delta IV Heavy launch vehicle developed by United Launch Alliance.

Since the proposed rover will utilize heritage instruments that have already been built, there will

be no need to re-build the instruments with the exception of the lander’s grabbing arm, and the

rover’s hybrid scoop and integrated instrument suite which will be developed by a well-known

robotics company such as Honey Bee Robotics. Final assembly and test will take place at the Jet

Propulsion Lab. Funding will come out of NASA’s FY2014 budget appointed by Congress.

Space craft operations will be overseen by NASA’s Johnson Space Center and science

instruments and hand lens imagery will be overseen by the research university responsible for the

instrument. Systems engineers at Johnson and Goddard Space centers will oversee the project.

Assumptions:

Given what we know about the Martian surface we assume that traces of life may be found

utilizing instruments that will find traces of life based on water. We can also assume that the

likelihood of mission success from a scientific, mobility and operation point of view is high due

to the numerous previous Mars missions. Other assumptions include a much greater

understanding of the geological and biological evolution of Mars based on the returned samples.

We must also adhere to all planetary protection laws and do our very best to keep all samples

contained and clean.

Concept of Operations

System Architecture

Product & Work Breakdown Structures

Science Traceability Matrix

Lifecycle Schedule

Trade Studies

Power Trade Study (Lincoln, Patel, Knaus 2013)

Communications

Trade Study

(Zaw, Smith,

Bridgeman 2013)