THE DESIGN OF SURFACE TRANSPORT SYSTEMS FOR A
MARS POLAR STATION
Bob Parkinson & Malcolm Smith
Abstract
The Mars Polar Expedition will require two sorts of vehicle – a long-range, pressurized Rover for
major expeditions, and a short-range, unpressurized Utility Vehicle for EVA operations around the
Station and elsewhere. Operating in pairs for safety, the long-range Rover will require a range of
about 1600 km to reach the edge of the polar cap and return, carrying two astronauts for up to 24 sols,
or four astronauts in an emergency return to Base. Power for the Rover will come from an oxygenmethane turbo-generator power system. The Rover will be delivered in a fully fuelled state to aid in the
initial “setting up” operations, and has a delivery mass of 7.1 tonnes plus 1.9 tonnes of support mass.
The utility vehicle has an estimated delivered mass of 252 kg.
1.
INTRODUCTION
To justify the use of human explorers to
explore Mars, the astronauts will need to range
much further from the landing site than the 7.5
km “walk back” range allowed during the
Apollo programme. In the case of the Mars
North Polar Station there is a desire to conduct
traverses from the pole to the edge of the
permanent ice cap.
requirements are set by the need to conduct a
traverse to the edge of the ice cap and return.
An integrated system model has been used to
assess trade-offs and produce an initial design
of a Mars Polar Rover.
2.
REQUIREMENTS
2.1. Mission Definition
Initial discussions considered a variety of
transportation means across the polar ice cap,
including aircraft, airships and “skidoos”. One
promising idea – that of “polar kiting”,
successfully demonstrated in the Antarctic [1]
– turns out to be unsuitable for the Martian
environment due to the low density of the
Martian atmosphere.
In addition, deeper
investigation of the environment [2] indicates
that skiing in the sense familiar to Antarctic
operations may not be possible on Mars due to
the high friction factors of the low-temperature
ice/dust mix. The ultimate conclusion was that
to fulfil the operational requirements of the
Polar Station, a long range pressurized Rover
serving as a mobile “camper” would be
required. In addition, a small, unpressurized
“utility vehicle” would be required for EVA
operations around the Station itself.
The primary requirement for the Polar Rover is
to conduct a survey from the Polar Base to the
edge of the polar ice cap. Fig. 1 shows three
possible routes. The most direct route is about
400 km in length. However, a more interesting
route (marked Route C in Fig. 1) to the
Chasma Boreale must take a curved route 650
km in length due to the spiral topography of
the ice cap. If a 20% allowance is included for
off-track travel, a visit to the edge of the ice
cap from the pole and return requires about
1560 km. For design purposes this was
rounded to 1600 km.
Various designs of rover vehicles have been
produced both for the Moon and Mars in
different contexts [Ref. 3]. Vehicle design is
however dependent upon the requirements the
environment in which the vehicle must
operate. In the case of a Mars Polar Station the
environment is significantly different even
from elsewhere on Mars, and the mission
Maximum travel speed not only depends on
terrain roughness and the quality of the vehicle
suspension, but also on the local gravity. On
the Moon the Lunar Rover managed a top
speed of 17 km/hr, but for comfortable
extended driving managed about 8 km/hr.
Martian gravity is twice that of the Moon, and
the polar ice cap is expected to be reasonably
The north pole of Mars is also about 3000 m
higher than the plain surrounding the polar
cap, and the Rover will need to descend this
distance on the outward journey and climb it
again on the return.
smooth, so an average travel speed of about 15
km/hr should be achievable. With 6 hours
driving per day (or more accurately per sol) the
Rover should be able to achieve 90 km/sol.
In addition to having an emergency rescue
capability, Rovers will be designed on a “failoperational, fail-safe” basis, and each Rover
will be equipped with a winch with which to
rescue the twin Rover from soft terrain or
“snowdrifts.” During EVAs it is expected that
both crewmembers will be outside to support
one another. As a consequence it will be
necessary to enable the Rover to be controlled
externally, either by the EVA party or by a link
to the companion vehicle.
2.3. Environment
Fig. 1: Possible routes to the edge of the
Martian North Polar Cap
Allowance must also be made for stops and
EVAs to deploy scientific instruments and
permit local exploration. With pre- and postEVA activities, EVAs will occupy most of the
day (sol) in which they occur. An EVA has
been scheduled for every fourth sol of the
mission, with no travel on that day. As a
consequence, the complete traverse to the edge
of the polar cap and return will take 23.8 sol
with six EVAs. There is adequate margin built
into this model, with the possibility of driving
further on particular days with good driving
conditions, or some travel during EVA days.
2.2. Safety
Safety is a prime concern for any extended
mission distant from the permanent base. In
the event of a Rover breakdown it must be
possible to recover the crew back to the Polar
Station either by external support or by design
of the expedition. It is proposed that any
expedition consists of two Rovers, each with a
nominal crew of two but with life support
capable of supporting four people on an
emergency return to the pole.
While it takes ~ 12 sols on the outbound leg to
reach the maximum distance, eliminating stops
for EVAs and driving 8 hours/sol on the return
reduces the return home time to 6.7 sols. For a
nominal mission some 47.6 man-sols of
consumables are required. The worst-case
emergency raises this requirement by only 3.8
man-sols to 51.4 man-sols.
The summer polar environment of Mars is
relatively benign. Temperatures at the pole
can climb to 205 K and the surface is frozen
(water) ice with between 10 and 40% of dust
[4]. This provides a surface harder than
concrete [5] with a friction angle of about 27.
There is no significant evidence of cratering,
and analogy with Antarctic conditions suggests
a surface rippled to a height of a few
centimetres. At the edges of the ice cap
gradients may be between 10 and 15.
The polar winter provides more adverse
conditions.
Atmospheric condensation
deposits 1 - 2 metres of carbon dioxide “snow”
onto the surface. The trafficability properties
of this CO2 “snow” are not known but possibly
lie at the higher end of those encountered in
terrestrial snowfields, with a density of ~ 920
kg/m3. Long-range traverses may not be
possible in the Martian winter, but the Rover
has been designed to be able to drive across the
expected “snowfield”.
The principal environmental problems the
Rover design will face are the low
temperatures and the dust in the atmosphere.
Ambient temperatures may be less of a
problem than first appears - convection is not a
major heat transfer mode in the thin Martian
atmosphere, but items of the Rover will require
continuous thermal control and special
measures may be required to prevent wheels
“freezing” when the vehicle is immobile [6].
Dust suspended in the atmosphere with particle
sizes of a few micrometres may be more of a
problem - infiltrating rotating machinery and
requiring special precautions for drive and
generating equipment.
2.4. Science Payload
The science requirements for a long-range
traverse will be dealt with in a companion
paper [7]. However, some assumptions have
to be made of the payloads to be carried on
board the Rover. These are listed below in
Table 1.
RMS Effector Package
6 kg
Deployable Surface Experiment
138 kg
Packages (5)
SEP Storage Rack
14 kg
On-Board Analysis Equipment
18 kg
Portable Drilling Package
179 kg
Table 1: Assumed Science Payload (each
vehicle)
Deployable packages will be placed at
intervals along the traverse and will transmit
telemetry back to Mission Control via the
communications network.
Deployment
progressively reduces the mass carried by the
Rover, but at the same time the Rover can be
expected to acquire samples (principally local
drill cores) so the effect on performance has
been neglected.
2.5. Communications
Away from the fixed Polar Station the Rover
will be unable to use line-of-sight
communications. In the polar region it will
also be unable to see any network of
aerosynchronous communications satellites
above the Martian equator. Since continuous
or near-continuous communications between
the Rover and the Base and/or Earth are
required, the options are for the Rover to
deploy a series of repeaters along its journey,
or to use a Molniya-type relay satellite in an
inclined, elliptical orbit [8]. Surface relays
would have to be numerous – a 100 m high
mast would only have a range of 26 km – and
so a satellite solution is preferred.
The Rover will also need to serve as a
communications relay for EVA activities and
also for Rover-to-Rover communications.
3.
POWER OPTIONS
3.1. Housekeeping Power Demands
Besides providing power for mobility, the
Rover will need to provide housekeeping
power for such functions as life support and
communications. Housekeeping power is a
constant factor, but demands change as
different activities are carried out. Table 2 lists
the modes have been assessed in an initial
housekeeping power budget:


The vehicle static, crew active
The vehicle moving


The vehicle static, crew asleep
The vehicle static, crew performing
an EVA
Static Mobile Sleeping
Expected
total 232
107
190
duration
Life Support
1811
1811
1811
Crew
520
146
32
Accommodations
Avionics
& 212
251
166
Communications
Thermal
30
30
24
Miscellaneous
111
275
0
Switching
& 72
67
54
control
Total 2766
2581
2087
Table 2: Housekeeping Power Requirements
The biggest variation in housekeeping power
comes during EVAs, when not only are
internal systems shut down, but the absence of
the crew themselves removes additional
thermal input. Adding a balancing heat input
of 1.2 kW during these periods actually reduce
the overall mass of the system.
3.2. Power Sources
A surface vehicle typically requires about 0.1
w-hr/kg/km travelled [9]. With an all-up mass
of ~7.5 tonnes, this implies a total energy
requirement
of
about
1200
kW-hr.
Housekeeping power will add about 2300 kWhr to this. Hydrogen-oxygen fuel cells would
give the highest energy per unit mass of fuel,
but (liquid) hydrogen demands storage at very
low temperatures (~20 K) and has a low
density. In addition, fuel cells are relatively
heavy in terms of mass per kW generated. Gas
turbine engines are much lighter for similar
power output.
At the Martian pole, with carbon dioxide and
water
(ice)
available
in
abundance,
manufacture of methane and liquid oxygen is
relatively simple using the exothermic Sabatier
reaction:
CO2 + 4H2  CH4 + 2H2O
The hydrogen is generated
electrolysis:
2H2O  2H2 + O2
by
water
While both methane and oxygen need storing
at cryogenic temperatures, they can both be
stored at a common temperature (~100 K), and
used to drive a turbine-generator system to
provide electricity.
EVA
42
hr
611
105
w
w
198
w
1200
529
71
w
w
w
2713
w
Allen and Zubrin [10] have suggested that it is
not much more difficult to manufacture
ethylene to provide an even higher density and
more readily storable hydrocarbon. Zubrin [11]
has also suggested that a carbon
monoxide/oxygen propellant combination,
with the carbon monoxide generated by a
reverse water gas reaction or electrolytic
means [12], might be more suited to
production on Mars, and ESA have sponsored
work on developing a fuel cell for this
combination [13]. A comparison was therefore
made of the total system mass of oxygenhydrogen fuel cells with methane-oxygen,
ethylene-oxygen and carbon monoxide-oxygen
turbo-generator systems.
The results are
shown in Table 3. (Note that these results are
for the final computed mobility power
requirements, not the approximation in the first
paragraph above.)
O2 /
H2
1.26
CH4 /
O2
1.05
C2H4
/ O2
0.91
CO/
O2
0.68
Electrical
output
Reactants*
1758
2055
2342
3117
Storage
860
132
146
217
tanks
Generating
293
32
32
32
equipt.
Total Mass 2911
2219
2520
3366
 Figures include allowance for mass
loss due to CO2 venting
Table 3: Comparison of Competing Power
Sources
While H2/O2 has the highest output per
kilogram of propellants, the associated mass of
generating equipment and storage tanks more
than offsets the gain in propellant mass over
methane-oxygen. At the other extreme, while
CO/O2 takes less power to generate from local
resources (the Martian atmosphere), the
resultant power density leads to a significantly
larger total mass, and hence a larger Rover.
Table 3 suggests that, due to the difference in
the mass of the associated equipment, a dual
CH4/O2 turbo-generator system is the
preferred power source.
3.3. Mobility Analysis
Fuel requirements for the Rover are a
significant part of the total mass of the vehicle,
with a substantial contribution coming from
mobility requirements. Estimating mobility
power requirements is therefore important in
sizing the Rover system.
Following the
example of Wallace & Rao [14] methods
proposed by Bekker [15] have been used to get
an initial estimate, even if these will need to be
replaced by more accurate methods for further
design.
The following mobility requirements need to
be taken into consideration:





Level travel across hard ice/dust surfaces
(the principal long-range mode)
Descent of up to 3000 m down slopes of
10 - 15 on hard ice/dust
Ascent of up to 3000 m up slopes of 10 15 on hard ice/dust
A capability to move across CO2 “snow”
surfaces with two wheels inoperative
Travel across North Polar Erg permafrost
surfaces, characterized by the “crusty-tocloddy” material identified by Arvidson
et.al. [16]
Wheel and tyre dimensions are sized by the
kW-needs to travel over soft, CO2 “snow” surface
hr/kg
without getting buried. In this case a vehicle
kg with six wheels of 1.25 m diameter and 0.35 m
kg tyre width was used, giving a maximum
sinkage of 0.156 m with the assumed load
kg carrying properties.
kg Resistance to travel comes from the following
sources:




Rolling resistance, due to energy losses
due to flexure of the wheel and calculated
from empirical data from terrestrial tyres
[17]
Bulldozing resistance due to accumulation
of surface material in front of the wheel
Compaction resistance of the surface
material
Resistance due to grades. In the case of
downhill grades it is assumed that
regenerative braking will be applied,
recovering 80% of the available energy.
The capability of the drive system is defined in
terms of “drawbar pull” – measuring the
difference between the tractive force applied
and the resistance to travel. The power
requirement is the product of resistance and
speed of travel. For high resistance modes
such as the maximum uphill grade or travel in
CO2 “snow” reducing the travel speed reduces
the power required. Total mobility energy
requirements are calculated by assigning travel
durations to each mode.
The results of the mobility analysis are shown
in Table 4.
Total
resistance
Drawbar
pull
Travel
speed
Travel
duration
Total drive
power
Hard
ice
1.2
U/hill
Grades
6.0
D/hill
Grade
- 3.6
CO2
Snow
8.5
Permafrost
2.2
17.4
12.6
22.1
4.1
28.8
4.2
2.7
4.2
2.0
4.2
88.2
2.6
1.2
4.0
10.7
6.0
22.7
-10.1
13.3
10.7
Table 4: Results of Mobility Analysis
For short durations, excess power (e.g. to
extract the vehicle from a “snowdrift”) can be
supplied from the batteries (see § 3.5), but a
long duration continuous ascent will require
higher powers than provided by a single turbogenerator and which would drain the batteries.
The options for an extended climb are to use
both turbo-generators or, as a fall back
position, to halve the rate of travel.
Each wheel of the Rover will be driven
independently by an electric motor with an
output torque of about 14 N-m driving through
a harmonic drive reduction gearbox
with a ratio of about 100:1.
Independent suspension is provided for
each wheel in the form of a
MacPherson strut – or rather the
Chapman version, since the steering
function can be carried out through
differential driving of each wheel.
temperature. Maximum (rocket) performance
occurs at an O/F ratio of about 3.25, but this
would reduce the overall density of the
propellant mixture and was not considered
worthwhile.
The basic stochiometric
k
combustion
flame
will need to be “watered
N
down”
using
recycled
steam to give a turbine
k
Nentry temperature ~ 1700 K. A schematic of
mthe power system is outlined (without showing
/s
the parallel redundancy) in Fig.2.
h
r
k
W
3.5. Energy Storage
An auxiliary energy storage capability
(secondary battery) is included in the overall
power system. Battery sizing must fulfil the
following conditions:




Provide energy storage for peak demands
over the nominal generating capacity of
the turbo-generators
Provide additional energy for long
continuous ascents
Provide energy storage for regenerative
braking on extended descents
Provide independent power for start-up
and for up to four hours operation without
support from the power trailer.
3.4. Power System Design
The Rover power system consists of
two parallel turbo-generators driven by
methane-oxygen combustion, with
auxiliary battery energy storage. The
power system (excluding the batteries) and
propellant storage tanks are housed in an
articulated “power trailer”. Water in the
exhaust will be condensed out and supplied to
the Rover life support system. Uncondensed
CO2 will be vented to the Martian atmosphere.
Using dual redundant turbo-generators
(together with having two vehicles supporting
one another on an expedition) means that the
expedition is not dependent upon maintenance
during the mission [Ref. 18], avoiding the need
for including it within the pressurized envelope
of the Rover.
At a stochiometric mixture ratio (O/F = 4), the
combustion temperature of methane and
oxygen (3053 K) is too high as a turbine entry
Fig.2: Schematic of power generation system
The last of these cases sizes the battery at 22
kW-hr. Since implementation design is still
some distance in the future, lithium-polymer
batteries have been assumed [19] rather than
the current lithium-ion cells that might have
been assumed. However, this is not a critical
technology area. The design includes the
battery within the main Rover inventory rather
than as part of the power trailer, so that the two
components can be separated for specific
operations at the home Station.
3.6. Support Requirements
Using CH4/O2 propellants, the Rover will
require a support system at the Polar Station to
generate and refuel it. As indicated in §3.2, this
will be generated from the atmosphere and
polar ice using a Sabatier reactor and water
electrolysis, together with a plant for
liquefying and storing the propellants. An
compartment. The volume estimates are not
inconsistent with Mars Society experience
[Ref. 22] although those tests were not done
with long-term occupancy as a major
consideration.
initial estimate has been made of the size of
this support plant.
The size and power
requirements are approximately inversely
proportional to the time required to generate a
full fuel load for the Rover. For a 40-sol
recharging time (i.e. taking 80 sols to
completely refuel a two-vehicle expedition) the
support equipment has a mass of about 1.9
tonnes and uses 14.5 kW of power.
Fig. 3: Layout of Pressurized section of Rover
In the design shown there is room for life
support equipment (and in particular water and
air tanks) below the floor, and accessible
storage beneath the bunks. The airlock is
offset to one side of the rear bulkhead, which
allows for an external platform with an isogrid
floor to clean off suits after an EVA.
4.2. Environmental Systems
4.
LIFE SUPPORT SYSTEMS
4.1. Volume Requirements
The volume requirements for short to medium
duration missions in space are reasonably well
established [20,21].
Because the volume
requirement increases with mission duration, it
the internal volume is set by the nominal crew
living in the Rover for 24 sol rather than the
emergency carriage of 4 for a significantly
shorter return to base.
However, these
requirements are for zero gravity enclosures,
and the presence of the Martian gravity
provides an emphasis on floor area as well.
Fig. 3 shows a possible layout for the Rover.
The zero gravity requirement suggests a
volume of 22.6 m3, but with a diameter of 2.75
m (set by the need to provide adequate
headroom) the plan area is insufficient to
accommodate sleeping bunks, hygiene, food
accommodations and storage and recharging
provisions for EVA suits. As a consequence it
was necessary to add 0.3 m to the length of the
cylindrical section of the pressurized
The initial assumption for environmental life
support was to recover the CO2 from the
atmosphere and reduce it back to provide
breathable oxygen via a Sabatier reactor and
water electrolysis system.
However, this
oxygen production process is essentially that
used for producing propellant for the Rover. If
there is no forward contamination constraint,
the recovered CO2 can be vented into the
Martian atmosphere, and oxygen supplied
directly as liquid oxygen without requiring
further energy input.
The system still requires CO2 recovery, but
eliminating the Sabatier reactor (a mass of 304
kg) reduces the overall mass of the Rover by
465 kg. Removing the water electrolysis unit
(mass 161 kg) and replacing it with a liquid
oxygen dewar reduces the mass of the Rover
by a further 951 kg by eliminating the 1200
watt power requirement associated with this
unit.
Drinking water is loaded aboard the Rover at
the start of the mission, but all remaining water
requirements use the condensate from the
turbo-generator power system.
The Rover is equipped with a toilet but no
shower – the crew will have to be content with
sponge baths for the duration of their mission.
Food is stored in a freezer and heated in a
microwave oven.
4.3. Consumables
Table 5 shows the estimated consumables
required for a 24-sol mission. A 5-day
contingency
provision
is
made
for
emergencies, with the oxygen kept as bottled
gas rather than liquid.
The “other inorganic material” in Table 5
includes 35 kg of lithium hydroxide canisters
for use during the EVAs, plus a limited amount
of spares and consumables for the crew
accommodations.
Emergency (bottled) oxygen
26 kg
Liquid oxygen
138 kg
Nitrogen
16 kg
Potable water
74 kg
Dry food
40 kg
Packaging
19 kg
Other inorganic material
82 kg
Total
560 kg
Table 5: Consumables for 24-sol mission
4.4. Thermal Control
Thermal control of the habitation volume is
complicated by the variation of internal heat
generation with activity.
The
external
surface
temperature changes from
205 K in the summer to
less than 148 K in the
winter, but this is of
secondary
importance
because the principle
mode of heat loss from the
outer surface of the
vehicle is radiation –
convection to the thin
Martian atmosphere is
typically less than 5% of
the total.
There is a substantial heat
loss through the 0.75 m2
of
window.
The
remainder of the cabin is
insulated with 5 cm of
Rohacell-50 foam insulation, providing a
balanced heat loss (i.e. constant internal
temperature) during the minimum EVA mode.
An active heat rejection system (thermal loop)
is then added to control temperatures during
activity modes with higher internal heat
generation. Some balance can be achieved by
using electrical heaters to compensate for the
lower internal activity levels during EVAs, but
an additional 400-watt active heat rejection is
required to balance all modes. An internal
water-cooling loop is also useful to cool local
hot spots such as avionic equipment. 1.26 m2
of external radiator area will be required for
active heat rejection, using a heat pipe system
that will not freeze up at Mars polar
temperatures when not in use.
5.
VEHICLE CONFIGURATION
The pressurized Rover is a six-wheeled vehicle
in two sections – a four wheeled tractor section
carrying the pressurized habitation unit and an
articulated trailer that carries the propellant
and power generating equipment. The front of
the tractor section carries a strong beam on
which are mounted the remote manipulator
arm, a winch, and an external driving position
so that the vehicle can be moved by the crew
during EVAs. The overall configuration is
shown in Fig. 4.
One feature that needs to be incorporated into
the design is the need for the Rover to dock
with the Station. When attached to the Base
the crew will need to have frequent access to
the vehicle for the purpose of maintenance and
replenishment, and the need to mount an EVA
for each access to the vehicle is not acceptable.
Fig. 4: Perspective View of Mars Polar
Rover
Docking on a planetary surface gives some
additional problems over docking in zero
gravity since the vehicle lacks all the needed
degrees of freedom. Two possibilities exist – a
front end docking port, or an access point on
the roof of the vehicle. The latter option is
illustrated in Fig.4, allowing better access to
the vehicle and less interference with the
frontdriving position. The docking access
hatch also provides the second exit route from
the pressurized compartment in the event of
emergency.
The remote manipulator arm is located at the
forward corner of the vehicle. It has the
possibility of placing equipment up to 3.5 m
from the vehicle, and it also has the capability
of reaching round to the side of the vehicle to
pick up scientific equipment from an
unpressurized external rack.
A mass breakdown for the pressurized Rover is
summarized in Table 6. The mass estimate has
been assembled at equipment level, with
margins applied dependent upon the degree of
confidence ranging from 5% to 20%.
With articulation between the tractor and
trailer, the Rover is capable of transitioning
between slopes of 20º and 10º in opposite
senses, has a ground clearance of 0.55 m and
can cope with individual blocks of 0.42 m
height. The turning circle will have a radius of
about 5 m.
Crew & EMUs
Science Payload
Crew Accom.
Life Support
Basic
Mass
(kg)
327
328
220
819
Margin
5%
8%
20%
20%
System
Mass
(kg)
344
354
264
982
Avionics
140
16%
162
Power (tractor
161
5%
169
Harness
75
20%
90
Mechanisms,
241
17%
282
wheels etc.
Structure incl.
1065
20%
1275
suspension
Thermal
192
13%
216
systems
Consumables
395
Tractor
4664
(loaded)
Power Trailer
674
17%
790
(dry)
Propellants &
2125
Residuals
Trailer (wet)
2915
Fully Loaded
7451
Delivered Mass
7130
Table 6: Mass Breakdown for Pressurized
Rover
6.
CONCLUSIONS
An initial design concept has shown that it is
possible to provide a pressurized Rover
capable of supporting a traverse of the Martian
North Pole from a base at the pole to the edge
of the permanent ice cap. The mission would
consist of two identical Rovers carrying a total
of four astronauts, and would take an estimated
24 sol to complete, including stops for EVAs.
The mission would take place during the polar
summer, and is made possible by the fact that
the permanent ice cap presents a hard surface
relatively free of mobility difficulties. The
total mass requirement that must be delivered
to Mars, including support equipment for
refuelling, amounts to 16.1 tonnes.
References
1
P. Woodhead “Misadventures in a White Desert”. Sceptre Books, London 2003. ISBN 0-340-82810-2
Bob Parkinson “The Environment of the North Polar Cap of Mars” JBIS Special Issue[Reference to
come]
2
J.J.Zakrajsek et.al., “Exploration Rover Concepts and Development Challenges”, NASA TM-213555
(March 2005), Delivered as AIAA Paper 2005-2525 at 1st Space Exploration Conference, Orlando,
Florida, Jan.30 – Feb.1, 2005
3
A.W.Nolin “Mapping the Martian polar ice caps: Applications of terrestrial optical remote sensing
methods.” J.Geophys.Res., 103, pp. 25851 – 25864 (1998)
4
B.A.Ivanov “Martian Upper Crust Strength Estimates”, Institutes for Dynamics of Geospheres,
Russian Ascademy of Science, www.geokhi.ru/~planetology/theses/31_ivanov_n_a.pdf
5
6
C.S.Cockell “Field Innovations in Support of Martian Polar Expeditions”, JBIS, 57, pp. 92-98 (2004)
7
S.Baxter JBIS Special Issue [Reference to come]
8
J.Pahl “Communications and Navigation Services” JBIS Special Issue [Reference to come]
W.J.Larsen & L.K.Pranka (Eds), “Human Spaceflight: Mission Analysis and Design”, Chapter 14:
R.Arno, “Planetary Surface Vehicles” (McGraw Hill, New York, 2000)
9
W.J.Larsen & L.K.Pranka (Eds), “Human Spaceflight: Mission Analysis and Design”, Chapter 15:
C.C.Allen & R.Zubrin, “In-situ Resources” (McGraw Hill, New York, 2000)
10
R.Zubrin “Methods for Achieving Long-Range Mobility on Mars” 28th AIAA/SAE/ASME/ASEE
Joint Propulsion Conference, Nashville TN, July 6-8 1992
http://Zubrin.marsstuff.com/docs/mobility.pdf
11
D.M.Deffenbaugh, M.A.Miller & S.T.Green “Mars In Situ Oxygen Production, 1809065”
Southwest Research Institute IR&D
http://www.sri.edu/3pubs/IRD1999/18906599.htm
12
“Development of a CO/O2 fuel cell system for power generation on Mars”
http://www.esa.int/esaMI/Aurora/SEMUS6A5QCE_2.html
13
B.E.Wallace & N.S.Rao, “Engineering Elements for Transportation on the Lunar Surface”,
Appl.Mech.Rev., 46, p.301 (1993)
14
15
M.G.Bekker “Introduction to Terrain-Vehicle Systems” (Univ. Michigan Press, 1970)
R.E.Arvidson et.al., “Physical Properties and Localization Investigations associated with the 2003
Mars Exploration Rovers”, J.Geophys.Res., 108 (E12), p. 8070 (2003)
16
A.A.Popov, D.J.Cole, D.Cebon & C.B.Winkler, “Laboratory Measurement of Rolling Resistance in
Truck Tyres under Dynamic Vertical Load”, Cambridge Vehicle Dynamics Consortium, University of
Cambridge (Nov. 27, 2002)
http://www.cvdc.org/recent papers/PopovColeCebonWinkler.pdf
17
C.S.Cockell “The Trans-Mars Expedition – a Long-Distance, Long-Duration, Scientific EVA.”
JBIS, 55, pp.291-306 (2002)
18
19
Sanyo, “Next Generation Lithium Power”, http://www.Sanyo.com/batteries/lithpol.cfm
“Man-Systems Integration Standards”, NASA-STD-3000, NASA Johnson Space Center, Houston,
TX
20
Silvia Bayon, “Model for the Habitation Module of the Transfer Vehicle,” Working Document for
the ESA Aurora Study Team, 12 Sept., 2003
21
G.A.Mann et.al. “Comparative Field Tests of Pressurised Rover Prototypes”, JBIS, 57, pp 135-143
(2004)
22