mars sample return mission - saylor academy · mars sample return mission ... not be reflective and...
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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)