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Prospector-1: The First Commercial Small Spacecraft Mission to an Asteroid

  • Deep Space Industries
  • Orbit Fab, Inc.

Abstract and Figures

Deep Space Industries (DSI) is developing a microspacecraft asteroid exploration mission named Prospector-1. The goal of this mission is prospecting for resources, particularly water, extractable from the surface of a volatiles-rich target asteroid. This mission objective implies not just surveying the water content of the surface, but penetrating to subsurface depths as well. In addition to water reconnaissance, Prospector-1 will also investigate the mineralogy and geotechnical characteristics of the asteroid using a proprietary instrument suite that is intended to be used on the asteroid surface. In addition to representing what will potentially be the first private interplanetary mission yet undertaken, it is also expected that Prospector-1 will be the smallest and least expensive asteroid mission to date. The mission involves dispatching a small microspacecraft using all-chemical propulsion to an asteroid, followed by the use of water electrothermal propulsion for cruise, rendezvous, and proximity operations. A multi-week remote sensing campaign will map the surface and subsurface in visible and mid-wave infrared bands, in parallel with the generation of a water map of the asteroid at near-subsurface levels. Finally, the spacecraft will attempt to land on the asteroid surface to assess geotechnical characteristics of potential resource extraction sites, as well as to assert a presence and establish the first commercial base on a space object. This mission is being developed with an aggressive cost-cap in the tens of millions of USD and a schedule in single-digit years.
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Prospector-1: The First Commercial Small Spacecraft Mission to an Asteroid
Grant Bonin, Craig Foulds, Scott Armitage, and Daniel Faber
Deep Space Industries, Inc.
NASA Ames Research Park, Building 156, Moffett Field, CA 94035
+1 (650) 772 1105
Deep Space Industries (DSI) is developing a microspacecraft asteroid exploration mission named Prospector-1. The
goal of this mission is prospecting for resources, particularly water, extractable from the surface of a volatiles-rich
target asteroid. This mission objective implies not just surveying the water content of the surface, but penetrating to
subsurface depths as well. In addition to water reconnaissance, Prospector-1 will also investigate the mineralogy and
geotechnical characteristics of the asteroid using a proprietary instrument suite that is intended to be used on the
asteroid surface.
In addition to representing what will potentially be the first private interplanetary mission yet undertaken, it is also
expected that Prospector-1 will be the smallest and least expensive asteroid mission to date. The mission involves
dispatching a small microspacecraft using all-chemical propulsion to an asteroid, followed by the use of water
electrothermal propulsion for cruise, rendezvous, and proximity operations. A multi-week remote sensing campaign
will map the surface and subsurface in visible and mid-wave infrared bands, in parallel with the generation of a
water map of the asteroid at near-subsurface levels. Finally, the spacecraft will attempt to land on the asteroid
surface to assess geotechnical characteristics of potential resource extraction sites, as well as to assert a presence and
establish the first commercial base on a space object. This mission is being developed with an aggressive cost-cap in
the tens of millions of USD and a schedule in single-digit years.
Deep Space Industries (DSI) is a space resource and
technology company with the ultimate goal of
harvesting asteroids to industrialize the frontier. In the
not too distant future, the abundance of raw materials in
near-Earth asteroids will allow the production of salable
products in spacesuch as fuel, air, water, and large
structuresin quantities that are simply impractical to
launch from the surface of the Earth, but which will
nevertheless enable space development in a way that
has not yet been possible.
While the company vision is long-term, its near-term
roadmap and strategy begin small: leveraging the
increasing capabilities of nano- and microspacecraft to
undertake simple, cost-effective, and aggressively-
scheduled asteroid exploration missions.
DSI’s value chain and product line comprise the
missing technologies needed to enable interplanetary
small spacecraft missionsin particular, high-
performance propulsion systems; reliable deep space
communication systems; novel absolute and relative
navigation technologies; and robust, radiation-tolerant
avionics. While DSI considers these to be exploration-
enablers for its own missions, the company business
model is also predicated on monetizing such
technologies in the existing small satellite market,
selling them into other customer programs to enhance
activities in Earth orbit and beyond. Ultimately, DSI
aims to satisfy a customer base today with products that
can be serviced using in-space resources in the future.
1.1 Mission Context, Objectives and Constraints
As with any mining project, the first stage in the
harvesting of space resources is prospecting. As early
as the end of this decade, Deep Space Industries intends
to launch Prospector-1: a microspacecraft that has the
promise of being the first private mission to an asteroid,
for the purpose of assessing the abundance of
extractable resourcesin particular, water and carbon
dioxideas well as performing geotechnical
reconnaissance of the asteroid in order to understand its
overall mineability. This mission intends to combine
the best of flight-proven microsatellite systems with the
cornerstone technologies being developed by DSI in
order to accomplish space exploration at significantly
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lower-cost than would have been achievable as recently
as five years ago.
Selected fundamental objectives of the Prospector-1
mission include:
undertaking the first private missions to a candidate
asteroid for future mining operations;
verification of commercially-viable returnable
quantities of resourcesin particular, water and
carbon dioxidefrom the candidate asteroid; and
exploration of the geotechnical characteristics and
mechanical properties of the target asteroid’s
regolithessentially, the asteroid’s “diggability”
to inform the design of extraction and processing
equipment on subsequent missions.
Selected fundamental constraints of the Prospector-1
mission include:
the mission must be developed to flight-readiness
within three years;
the target cost must be in the low tens of millions
USD, the actual figure being confidential;
the mission must be launch vehicle agnostic to the
extent practical and able to be launched as a
secondary payload; and
the target asteroid visited by Prospector-1 must be
the intended mining target for follow-on missions.
Prospector-1 can be viewed as the precursor mission for
sub-scale and full-scale resource harvesting missions,
which DSI refers to as its Harvestor program. In our
proposed mission sequence, a given asteroid would first
be prospected using one or more small Prospector
microspacecraft, after which a much larger Harvestor
spacecraft would be dispatched to extract and process
its resources. The low-cost Prospector missions are
used to de-risk each mining targetif the particular
asteroid is deemed to not be prospective for mining, the
much larger capital investment to harvest it would not
occur, and the company would move on to a different
target. In this architecture, a fully-mature asteroid
mining capability involves prospecting and harvesting
multiple asteroids in parallel to achieve a high cadence
of returned resources, with a Prospector dispatched to a
new potential target in parallel with a Harvestor sent to
the previously scouted one.
Of course, the matter of asteroid selection is central to
the mission architecture and mission cadence described
above, but discussion of target identification and down-
selection is beyond the scope of this paperand
particularly represents a key proprietary aspect of DSI’s
work. Intermediate steps depicted below are described
in subsequent sections.
Figure 1: Deep Space Industries Mission Roadmap Prospector-X (launching in 2017) will be the first
precursor risk-reduction mission flown by DSI.
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The Prospector-1 spacecraft concept is depicted in
Figure 2 and Figure 3, with a summary of key
characteristics and specifications presented in Table 1.
Prospector-1 combines the best of high-heritage nano-
and microsatellite technologies with cornerstone DSI
technologies to enable an extremely low-cost, yet
highly capable small spacecraft exploration platform.
While DSI is developing this spacecraft for asteroid
prospecting, the intent is also to offer the platform
commercially for other customer missions, which may
range from high-performance Earth-orbit missions to
low-cost exploration missions to the Moon or Mars.
2.1 Spacecraft Platform
Prospector-1 is an approximately 30 kg dry mass, 50 kg
wet mass spacecraft that employs an approximately
50 cm tall hexagonal platform, with a single primary
load path through its central axis for launch and
interplanetary injection. The structure is simple, with
avionics in discrete enclosures mounted peripherally
around a central propellant tank and harnessed
circumferentially, with body panels serving as
secondary structure to house solar panels, as well as
externally-mounted instruments and thrusters.
The spacecraft uses three sets of four thrusters arranged
in quad-pack configurations, which serve the combined
purpose of reaction control system (RCS) and
interplanetary maneuvering system (IMS). These
thrusterspart of the DSI-developed Comet design
familyuse water as propellant, which is intrinsically
inexpensive, inert, launch-safe, and, most significantly,
uses the most abundant and key resource that can be
derived from in-situ asteroid materials. Each Comet
thruster uses a simple design that expels superheated
water vapor at close to 1000 °C to produce thrust,
achieving approximately 200 s specific impulse.
Whereas commercial DSI missions employ single
thruster configurations, Prospector-1 thrusters each use
a manifold to feed individual thruster heads. Each
thruster in a given quad is throttlable, and each also
offers extremely fine impulse resolution and control.
DSI has invested in water propulsion in recognition of
the future importance of having propulsion systems that
can be serviced using propellant derived from space
Prospector-1 uses a distributed network device
architecture based around a single CAN bus. The
system employs functional redundancy rather than
actual redundancy, with the role of the flight computer
reduced as compared to more common central
computer, or star, architectures. The Prospector-1 flight
computer is being custom-developed for deep space
missions in concert with its power system, under a
partnership that is expected to be announced by the
time of this paper’s presentation.
Figure 2: Prospector-1 Spacecraft Depicting
primary optical aperture, neutron spectrometer,
star trackers, proximity operations cameras, and
injection stage adapter.
Figure 3: Prospector-1 Spacecraft Depicting main
solar panels, scanning antenna array, reaction
control thrusters, and landing penetrator legs
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Table 1: Prospector-1 Overview
Specification / Description
Spacecraft mass (post injection)
29 kg dry mass
49 kg wet mass
Spacecraft Size
Hexagonal form factor
54 cm x 47 cm x 50 cm (27 cm wide faces)
Cruise Propulsion
Water electrothermal propulsion (DSI Comet thrusters)
200 s specific impulse
1000 m/s delta-V on-board
Power generation
Three deployed and three body-mounted solar arrays
120 W nominal (main solar panels at 1AU solar distance)
Tracking, telemetry and command
Scanning X-band antenna system
DSN-compatible ranging transponder
Minimum 3.1 dB link margin at worst-case range / orientation
Minimum 1 kbps at worst case range / orientation
Attitude determination and control
Dual star tracker configuration
Three reaction wheels
RCS propulsion shared with primary propulsion
Arcminute-level attitude control
Guidance and navigation
Ranging transponder for absolute navigation
Optical (IR) navigation for relative navigation
Stereo optical navigation for proximity operations
Command and data handling
Distributed network CAN architecture
Single computer and high-speed data recorder
VIS/MWIR Camera (0.5 m spatial resolution @ 10 km range)
Neutron spectrometer
Instrumented landing legs, magnetometer, gravimeter
The Prospector-1 design uses three deployed and three
body-mounted solar arrays using triple-junction cells
for power generation. The spacecraft is able to produce
keep-alive power in any attitude, and uses an
approximately 24 V to 28 V 7s3p internally-redundant
battery pack for energy storage and load-levelling. The
spacecraft power system uses a battery bus with series
peak-power tracking (PPT) at the individual panel level
to maximize power production from each array across a
range of temperatures, while also decoupling the array
and battery voltages. Each array is operated at its
optimum voltage for power production, and stepped
down to the battery (bus) voltage. Peak power trackers
are synchronized to operate in polyphase to reduce bus
voltage ripple and conducted electromagnetic
interference. The spacecraft power management system
protects all spacecraft loads from overcurrent events
such as single event latchup (SEL) with resettable solid-
state switches.
Prospector-1 uses a DSN-compatible ranging
transponder for tracking, telemetry, and command
(TT&C) in X-bandnominally 7.2 GHz uplink,
8.4 GHz downlinkcombined with a scanning antenna
that offers nearly full hemispherical coverage with
high-gain upon acquisition of signal from Earth. This
combined system permits a robust communications and
navigation solution with a single beam-steering antenna
system. The Prospector-1 transponder also supports
hardware-decoded commands which enable system
reset (“firecode”) functionality, and a DSI-developed
interface node which allows all subsystems on the
satellite platform to be commanded directly over the
command link, removing the need for a dedicated
computer to intermediate device-level communications.
While its ranging transponder provides absolute
navigation, an infrared camera sharing optics with the
primary spacecraft science imager provides a longer-
range navigation solution in the far infrared for target
localizationin order to remain independent of
approach angle with respect to a dark target asteroid
while a smaller stereo navigation camera set provides
close-range proximity operations navigation, and, most
significantly, serves as the terminal guidance approach
for landing.
Attitude determination and control is enabled using
Sinclair Interplanetary star trackers and reaction
wheels, with the Comet propulsion system providing
the dual role of maneuvering and wheel desaturation. In
the event of wheel failure, the propulsion system can
serve as the primary attitude control system. Two star
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trackers are employed to ensure availability and provide
improved roll accuracy. Arcminute-level attitude
control has been demonstrated on multiple missions
with this hardware suite.
2.2 Spacecraft Instruments
Prospector-1 carries several different payloads. First, a
set of three cameras sharing common optics are used
for (1) imaging in visible (VIS) bands (red/green/blue)
using a Bayer-filtered CCD detector; (2) a mid-wave
infrared (MWIR) high spectral resolution instrument for
imaging the 3.1 µm water absorption band; and (3) a
far-infrared (FIR) detector that is used for longer-range
navigation purposes.
Figure 4: Prospector-1 Spectral bands of interest,
overlaid on blackbody-calculated (170 K) asteroid
radiance. Visible, mid-wave IR (water absorption
band), and far-IR (for navigation) of particular
The spacecraft also carries a highly-compact neutron
spectrometer, which can be used at relatively long-
range as well as near the surface to detect the presence
of hydrogenand, by inference, waterat the asteroid.
This spectrometer will map the depth and distribution
of water on the target asteroid, and the data will be co-
registered with imagery from the VIS/MWIR
instrument to create a comprehensive water map of the
target asteroid.
Lastly, the spacecraft carries a set of instrumented
landing legs, with accelerometers and thermocouples,
as well as a three-axis magnetometer for geotechnical
reconnaissance at the surface. At the end of its remote
sensing survey, Prospector-1 will attempt to land at a
prospective water-rich site on the asteroid, at a
relatively low rate of centimeters-per-second, using its
thrusters to apply downforce and using its landing
penetrators to measure the compression and shear
strength of the local asteroid regolith. Once settled on
the surfaceand with the ability to provide down-force
via thrust, since asteroid “landing” is more akin to
“rendezvous”temperature and local magnetic field
measurements will be recorded. Landing will be
attempted in sunlight and in-pass. This final sequence
of measurements is expected to be end-of-life activities,
as the spacecraft is not expected to survive long once on
the surface. However, with that said, the intent is to
have the spacecraft beacon key health telemetry
whenever its panels are illuminated once on the surface
if it remains able to do so.
Instrument development partnerships for Prospector-1
are expected to be announced by time of this paper’s
Whereas previous sections described the Prospector-1
spacecraft and instruments, in this section we describe
the overall concept of operations. Prospector-1 is
currently being built between DSI’s offices in
California and Luxembourg City. The intent is to
achieve flight-readiness within three years.
3.1 Near-Earth Asteroids
Asteroids are primitive inner solar system bodies that
are the primary source of meteors. In popular culture,
they are monolithic silicate rocks in the asteroid belt,
but in reality, asteroids are extremely diverse. Many are
darker than charcoal, some are completely desiccated
and are held together by Van der Waals forces, and
others have surfaces that are the same density and
hardness as a dust-bunny [1]. The asteroids of greatest
interest to asteroid miners contain water and other
volatileslow temperature sublimating compounds
that promise to dramatically change space infrastructure
as we know it.
C-Cadre, primarily C-, D-, and P-type, asteroids contain
carbonaceous materials and water. Some C-type
asteroids on the outer edge of the main belt have been
detected completely covered in ice [2]. The surfaces of
these asteroids are cold enough for ice to exist on the
surface, even in vacuum, and some microgravity
geology can act as a concentrating mechanism. C-cadre
asteroids that are closer to the sun are compositionally
the same as these main-belt objects, but the surfaces are
too warm for ice to ever exist [3]. Surface minerals can
still be aqueousmolecularly bound within silicates
and ices can exist beneath a thermally insulating layer
of regolith [4].
Asteroids are a complex geochemical and geotechnical
environment for Prospector to explore. The science
campaign begins as soon as Prospector can identify the
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target against the background stars, which is anticipated
to be 10 km from the target.
3.2 Target Selection
One of the perceived challenges with asteroid mining is
associated with target selection. However, with more
than 14,000 near-Earth asteroids discovered to date, and
with discovery rates only increasing, DSI has already
identified several highly attractive targets for its first
prospecting mission. In fact, DSI has identified enough
targets so as to enable more flexibility regarding launch
and Earth departure than typical for any interplanetary
DSI has developed an extensive target selection and
evaluation process that considers, among other aspects,
the outbound and return opportunities and velocity
change requirements for each target, the maximum
Earth-asteroid and Sun-asteroid ranges for power
generation and communication purposes, the orbit
condition code of each target, whether the target has
been spectrally characterized or offers an opportunity
for spectral characterization, whether the target is
volatile rich, i.e. a carbonaceous chondrite or generally
C-cadre, and whether the target is sufficiently large that
an industrial quantity of material, particularly water,
has high odds of being recoverable from the object. DSI
has actively worked with commercial and government
customers for future resoruces to establish a viable
product which must be proven to exist and be
recoverable from a target.
3.3 Launch, Commissioning, Earth Departure, and
Prospector-1 has been designed to be launched as a
secondary payload and injected to its target asteroid
directly from low-Earth orbit. While there are any
number of intermediate parking orbits that would be
preferable for interplanetary injection, not the least of
which is a hyperbolic trajectory outbound using direct
throw of the launch vehicle, in order to manage costs
and maximize launch opportunity, it was considered an
unacceptable risk to assume the mission would be able
to start anywhere else than low-Earth orbit. However, a
LEO initial orbit offers the advantage of allowing
spacecraft commissioning prior to injection at relatively
close range using commercial ground stations.
Prospector-1 and its injection stage would be delivered
to LEO as secondary payloads. No dedicated small
launch vehicle is assumed, though it is also not
precluded by DSI’s mission architecture, and a
dedicated small launch would be extremely attractive if
any of the emerging providers are flying in the near-
future. The spacecraft would be commissioned in LEO
months prior to injection to ensure that the spacecraft is
fully functional prior to Earth departure. Prospector-1 is
depicted with its injection stage in Figure 5.
Figure 5: Prospector-1 with injection stage and
stowed panels
A high-energy, dedicated chemical injection stage is
used for Earth departure. This avoids the expensive,
high-power, and high operations tempo otherwise
associated with an electric propulsion spiral injection
particularly from LEO or GTO, which adds the
additional challenge of frequent passage through the
Van Allen radiation belts. However, while designed to
use impulsive chemical injection, Prospector-1 is also
designed to be largely decoupled from its Earth
departure propulsion so as not to preclude any number
of optionse.g. a dedicated solar electric stage
dispatched from GEO, a larger carrier spacecraft
transporting Prospector as a subspacecraft or hosted
payload, or direct throw from a dedicated smallsat
launcher. This is also done in the interest of offering
Prospector as a platform to other commercial or
government customers wishing to procure a high-
performance exploration platform without precluding a
different launch or Earth departure arrangement.
Following Earth departure, the spacecraft cruises to the
asteroid with its main panels on the sun. After an initial
drift period post-injection, Prospector-1 will perform a
series of course corrections using its Comet water
thrusters. As both the Sun and Earth remain in the same
hemisphere during cruise, Prospector’s scanning
antenna is used to acquire Earth while its main solar
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panels remain trained on the sun. The X-band
transponder on Prospector-1 also permits high-accuracy
absolute range and range-rate information during
3.4 Rendezvous and Stationkeeping
The Prospector-1 mission plan involves the spacecraft
being able to localize its target asteroid in interplanetary
space using its far infrared camera. Even with an orbit
condition code of zero, position uncertainty of the
asteroid requires acquisition at long-range by the
spacecraft, though with close operator-in-the-loop
supervision. In general, target asteroids are chosen to
maximize position and acquisition certainty, with DSI’s
evaluation cost function favoring asteroids that remain
near Earth during Prospector-1’s mission duration to
maximize operator-in-the-loop capability and minimize
required spacecraft autonomy.
From a propulsive standpoint, rendezvous is a relatively
benign maneuverin fact, a series of small
maneuverswhich in most cases are smaller than mid-
course adjustments needed by the spacecraft. Target
asteroids are so small that it is more useful to imagine
Prospector-1 co-orbiting the sun nearby the asteroid,
rather than capturing into orbit. While maintaining a
sunlit position with respect to the asteroid, Prospector-1
is considered to have arrived at its target when a stable
stationkeeping range of approximately 10 km is
achieved. Again, it is important to note that 10 km is
long-range relative to an asteroid with mean dimensions
in the tens to hundreds of meters.
3.5 Science Campaign
A high-level illustration of Prospector-1’s acquisition
and science (water-mapping) campaign is presented in
Figure 6. During this remote sensing phase, a
combination of sub-resolution visual imagery, mid-
wave IR imagery around the 3.1 µm water absorption
band, and neutron spectroscopy will combine to create
an extremely high-resolution volatile map of the target
The broad sequence from target acquisition, to the
creation of a complete hydrogen (water) map, to
descent and landing, is summarized as follows:
1. Identification/of/asteroid/against/background/stars./
2. Proximity/course/corrections,/acquisition/of/long-
3. Early-stage/asteroid/images/returned,/major/
4. Thermal/neutron/counter/receives/confirmation/of/
5. Reduction/of/stationkeeping/range/with/continued/
6. Position/hold/at/medium-range/(~1/km)/from/
7. High/resolution/imaging./
8. Begin/north-south/drift/maneuver/for/hydrogen/
9. Creation/of/hydrogen/map/from/differential/
10. Initial/landing/site/selected;/begin/descent/at/sub-
11. Continue/high/resolution/imaging/on/approach./
12. Constant-velocity/touchdown,/in-pass,/in-sunlight;/
Figure 6: High-level sequence of Prospector-1 hydrogen mapping campaign
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3.6 Remote Sensing and Neutron Survey
The Prospector-1 approach to neutron spectroscopy is
sufficiently different from prior art that it bears further
elaboration. Neutron spectrometry for the Moon, or for
large asteroids such as Vesta and Ceres, has been
historically done by performing hundreds of low-
altitude mapping orbits. Asteroid neutron counting
requires a different approach, where the asteroid rotates
“beneath” the spacecraft, and the neutron count rate
differs as new regolith is revealed on the dawn horizon
while old material is hidden at asteroid-dusk. This
method of horizon edge-mapping is expected to create a
very high resolution map of hydrogen abundance,
which is the marker for water, when co-registered with
visible and mid-wave infrared imagery.
Figure 8: Example hydrogen map created from
thermal neutron counting by the Dawn spacecraft
on Vesta. A difference in count-rate of thermal and
epithermal neutrons determines the moderator-
quality of the regolith, which is indicative of
hydrogen percentage [5].
3.7 Descent, Landing, and Geotechnical
Prospector-1’s propulsion system has been sized to
enable three months of proximity operations assuming a
worst-case target asteroid size and range. There is
expected to be ample time to perform the remote
sensing survey described above. However, at end of
mission, ostensibly the riskiest part will be attempted:
trying to land the microspacecraft on the surface of the
asteroid. There are two objectives to attempting to put
down on the surfacethe non-technical objective is to
assert a presence and secure tenure at the asteroid for
future mining; the technical purpose is to perform
geotechnical reconnaissance.
The objective of the geotechnical reconnaissance is
fundamentally to assess “diggability”. It is of limited
value to know bulk volatile composition without
understanding the mechanical and mineralogical
characteristics of it, since it is the mechanical and other
properties of the regolith that will inform the design of
mining equipment. Put a different way: Prospector-1’s
remote sensing will prove that the resources of interest
are there, while touching down will tell us how difficult
those resources will be to interact with and extract.
During the descent, the neutron counter should
experience a change in relative signal strength
indicative of water percentage heterogeneity of the
regolith. The hydrogen map generated in Phase 9 will
give an expected regional hydrogen percentage to the
mapping resolution. If that expected signal strength
differs relative to range during the descent, then
Prospector-1 will have determined whether or not water
is distributed relatively homogenously or in
concentrated pockets in the near subsurface.
Figure 9: Hover perspective hydrogen map (left) vs
north-south transition map. The initial hydrogen map
will only have longitudinal resolution. As Prospector
drifts north-south in the asteroid’s inertial reference
frame, the map takes on a vertical component.
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At a controlled centimetre-per-second level velocity,
Prospector-1 will attempt to put down. Accelerometers
will measure the failure force of the regolith, after
which shear and friction forces dominate and will also
be measured. Once the spacecraft has come to a rest on
the surfaceassuming it doestemperature and
magnetic measurements will be performed and
beaconed, along with imagery, while the spacecraft is
still able. It is expected this is where Prospector-1 will
remain: as the first permanent commercial station on an
Development of Prospector-1 is already underway at
Deep Space Industries. However, there are several key
partnerships and essential, cornerstone technologies that
remain to be proven. DSI has planned a series of
technology demonstration activities, through R&D
activities and commercial activities, to reduce risk for
4.1 Precursor Missions: Prospector-X
Before undertaking Prospector-1, DSI is currently
developing a precursor mission for low-Earth orbit with
the intent of flight-demonstrating several key
Prospector-1 technologies. This mission, referred to as
Prospector-X (the “X” denoting “experimental”),
funded by the government of Luxembourg as part of
their initiative, will demonstrate
several key subsystems of Prospector-1, notably
including its power system, command and data
handling system, tracking, telemetry and command
system, optical navigation, water-based propulsion
system, and (TBC as of this writing) one of its key
science payloads.
The Prospector-X nanosatellite (Figure 10) is a CubeSat
scheduled for launch in Q3 2017. The mission will be
assembled and tested in DSI’s European office, located
in Luxembourg City.
Figure 10: The Prospector-X Pathfinder
Figure 11: The Prospector-X nanosatellite, funded by the Government of Luxembourg
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4.2 Precursor Missions: HawkEye 360
Recently, Deep Space Industries was awarded the
mission prime contract on the HawkEye 360 Pathfinder
mission. HawkEye 360 is developing a constellation of
formation-flying micro-satellites in low Earth orbit
(LEO) to execute a unique radio frequency (RF)
spectrum monitoring and geolocation capability. The
company’s analytics engine generates reports on signals
that can be used to track and monitor global
transportation networks, detect distress alerts, assist
with emergencies and much more. By implementing
this exciting new concept, HawkEye 360 will provide
highly accurate maritime domain awareness, establish a
spectrum inventory, and develop insight into how
signals are being used globally. Preparing for its
product launch, HawkEye 360 is poised to address
pressing needs of commercial and government
customers worldwide.
Deep Space Industrieswho is leading the mission
with its manufacturing partner, the UTIAS Space Flight
Laboratoryis notably contributing the same Comet
water-based propulsion systems to each of the
HawkEye satellites as it will be flying on Prospector-X,
Prospector-1, and other commercial missions. Taken
together with the deep expertise within DSI on small
spacecraft formation flight, Deep Space Industries was
awarded the HE360 contract in a competitive bid and is
currently building the first three satellites of their
constellation. The targeted launch is Q3 2017, similar to
Prospector-X. A single HawkEye 360 microsatellite is
shown in Figure 12, with a cutaway showing DSI’s
Comet-1 thruster in Figure 13.
Figure 12: HawkEye 360 Satellite Concepteach
spacecraft is a small approximately 10 kg
microsatellite, with roughly 40 x 30 x 20 cm
Figure 13: HawkEye 360 Spacecraft Cutaway with
Extended DSI Comet-1 Thruster (Purple)
4.3 DSI Comet Thruster Line
The common, cornerstone technology shared across all
DSI missionsfrom its ambitious Prospector-1
asteroid mission, to its risk-reduction Prospector-X
precursor, to the first three HawkEye 360
microsatellites launching in 2017, is the DSI-developed
Comet-1 water electrothermal thruster.
Comet-1 is an electrothermal thruster that uses an
extremely high-temperature chamber to heat and
exhaust superheated water vapor to produce thrust. The
thruster is intrinsically simple and robust, and most
significantly, uses the most inexpensive and ubiquitous
propellant available on Earth and elsewhere in the solar
system: water. This thruster is depicted in Figure 14,
with a functional block diagram of the thruster
presented in Figure 15.
Figure 14: 1U Water Electrothermal Thruster
While Comet-1 is ultimately intended for a small
microsatellite developed by DSI, the base unit being
employed by HawkEye 360 and Prospector-X is
CubeSat-compatible, in response to the ever-growing
number of users and customers in the CubeSat space.
Bonin et al 11 30th Annual AIAA/USU
Conference on Small Satellites
Figure 15: Comet-1 Simplified Functional Block
Diagram for Prospector-1
Additionally, while the Prospector-1 implementation
employs a bladder tank and pressurant to feed water
into each thruster manifold, the smaller thrusters flying
on DSI’s missions next year employ a proprietary feed
system that entirely avoids high-pressure components
on launch. This enables, among other benefits, a
propulsion system that is completely safe for delivery,
deployment, and even fueling on board the International
Space Station.
Comet-1 is so-named as the first in a line of Comet
thrusters for a reason. Additional propulsion
technologies on DSI’s roadmap include both solar
thermal and helicon electric water thrusters, all fed by a
common propellant management approach. As stated
early in the paper: DSI is endeavoring to create an
ecosystem of products today that can be supplied by
space resources in the future. And the future of space
resources is water.
Deep Space Industries was founded with a bold
ambition to industrialize the frontier by harvesting
space resources: derived from space, for use in space,
for the betterment of humankind and the expansion of
life in general. The vision is large, but the
implementation begins small: with extremely low-cost,
small spacecraft to prove that asteroid resources are
indeed prospective. At the same time, DSI is generating
both key technologies and a spacecraft platform that
others can use for a wide variety of Earth orbit satellite
applications and low-cost space exploration missions.
From the small beginning of Prospector-1, DSI will
attempt to set the stage for the exploration of space
using small spacecraft in general. It is among our
foundational beliefs that we are living at the most
exciting time for space exploration: in which a larger
number of smaller, lower-cost missions will enable a
new understanding of the solar system, and usher in a
new era of space exploration that is more open to a
larger number of commercial and government actors.
In short, Deep Space Industries is attempting to stand
on the shoulders of what the small satellite community
has accomplished to date and take the next obvious step
for this community: beyond Earth.
1. “Mining the Sky”; J. S. Lewis; Basic Books, New
York, NY: (1997)
2. Water ice and organics on the surface of the
asteroid 24 ThemisCampins, Humberto; Hargrove, K;
Pinilla-Alonso, N; Howell, ES; Kelley, MS; Licandro,
J; Mothé-Diniz, T; Fernández, Y; Ziffer, (2010)
3. Hydrated Minerals on Asteroids: The Astronomical
Record”; A. S. Riven, E. S. Howell, E. Vilas, L. A.
Lebofsky; (2002)
4. Formation of the “ponds” on asteroid (433) Eros by
fluidization D.W.G. Sears, L.L. Tornabene, G.R.
Osinski, S.S. Hughes, J.L. Heldmann; (2015)
5. Elemental Mapping by Dawn Reveals Exogenic H
in Vesta's Regolith” T. H. Prettyman et al. (2012)
The authors would like to acknowledge the government
of Luxembourg, particularly its Ministry of the
Economy, Luxinnovation, and for
their continuing support of the Prospector program. As
well, we would like to acknowledge customers and
partners, HawkEye 360, the UTIAS Space Flight
Laboratory, Sinclair Interplanetary, the NASA Ames
Research Center, Jet Propulsion Laboratory, and
PhaseFour for their continued collaboration and
At an individual level, the authors also wish to thank
the DSI science team, led by Chief Scientist John
Lewis, for decades of work aimed at bringing asteroid
resource utilization to reality, and to truly opening
space to humankind. As well, we would like to thank
Meagan Crawford, Jeff Valentine and Bryan Versteeg
for their exceptional contribution on promotional
materials and artwork.
... If the study of asteroids is demonstrated to be possible using autonomous 3U CubeSats, these could provide a low-cost solution to determine initial stages of solar system formation through asteroid exploration (or the primordial sources of organic matter if used for cometary exploration) (National Research Council, 2013), they could be used to identify potential targets for future missions, to complement the scientific objectives of larger missions, or to support the emerging asteroid mining industry (Calla et al., 2017), etc. Noteworthy small-satellite missions proposed by commercial asteroid mining companies include, for instance, Deep Space Industries' 50-kg microsatellite mission to land on an asteroid (Bonin et al., 2016), and Planetary Resources' already-in-orbit 6U CubeSat mission to demonstrate asteroid prospecting technologies (Planetary Resources, 2018). ...
... Deep Space Industries, for instance, offers 1.5U and 2.5U water-based thrusters providing 440 N s and 1300 N s of total impulse, with respective minimum impulse bits of 25 mN s and 50 mN s (Deep Space Industries, 2016). Their thrusters will be flight-tested in the 2018 Prospector-X and HawkEye 360's Pathfinder missions (Bonin et al., 2016). VACCO Industries also developed a 2U cold gas propulsion system for the 2018 MarCO mission (25-mN nominal thrust, 755-N•s total impulse) (VACCO Industries, 2015), and now also offers a variety of cold and warm gas propulsion modules for CubeSats. ...
CubeSat technology has recently attracted great interest from the scientific community, industry and space agencies, and represents today an exciting movement towards a more affordable and accessible space industry. In view of potential applications of CubeSat technology to small-body planetary exploration, this paper studies the feasibility of using autonomous CubeSats to flyby near-Earth asteroids. This work provides an overview of the current state of CubeSat technology and proposes a 3U CubeSat mission using primarily off-the-shelf components. The proposed mission considers a CubeSat is deployed by a larger spacecraft in a periodic orbit around the first (L1) or the second (L2) Sun-Earth Lagrange points (common destinations to observe the Sun and outer space), from where fuel-optimal impulsive trajectories are designed to flyby asteroids between 2019 and 2025. Navigation support and ground operations costs still represent a major challenge for interplanetary CubeSats. As such, Monte Carlo simulations are performed to determine the flyby accuracies that can be accomplished by a 3U CubeSat flying autonomously (i.e., using observations of the Sun during cruise and observations of the asteroid before the flyby to estimate its own trajectory, instead of using ground stations for navigation support). Asteroid flyby opportunities for an autonomous 3U CubeSat are identified between years 2019 and 2025. Flyby altitudes below 500 km are found possible with currently-available CubeSat components. Possible science payloads are also overviewed, and the potential scientific return of such a low-cost mission is discussed.
... Also the organic and hydrated materials could be detected [2]. Bonin et al. [23] proposed a viable mid-infrared camera with 0.5 m spatial resolution at 10 km range and spectrometer in order to identify the asteroid characteristics for the DSI Prospector-1 spacecraft. Given this system's ability to characterize asteroid surface features and identify potential landing locations, it will be included in this project. ...
... For the spacecraft side, the Prospector-1 mission from DSI (Deep Space Industries) proposes the use of X-band communication. In their studies, they also define some link budget characteristics such as the transponders power, to ensure continuous communication [23]. Considering data volume, the prospection phase is the system driver, however, no real time communication is needed. ...
Full-text available
Asteroid mining offers the possibility to revolutionize supply and availability of many resources vital for human civilization. Analysis suggests that Near-Earth Asteroids (NEA) contain enough volatile and high value minerals to make the mining process economically feasible. Considering possible applications, specifically the mining of water in space has become a major focus for near-term options. Most proposed projects for asteroid mining, however, involve spacecraft based on traditional designs resulting in large, monolithic and expensive systems. An alternative approach is presented in this paper, basing the asteroid mining process on multiple small spacecraft, i.e. a decentralized architecture. To the best knowledge of the authors, limited thorough analysis of the asteroid mining capability of small spacecraft has been conducted. This paper explores the lower limit of spacecraft size for asteroid mining operations. After defining a feasible miniaturized spacecraft design, capable of extracting water from asteroids and transporting it to an appropriate orbit, a high-level economic analysis is performed. This analysis reveals several key constraints in making near-term asteroid mining financially sustainable under the assumptions given in this study.
... Bonin et al, [11] proposed a visible and midinfrared camera with 0.5 m spatial resolution at 10 km range and spectrometer in order to identify the asteroid characteristics for the DSI Prospector-1 spacecraft. This approach is also considered in this project as it is able to identify the resources and characterize the landing spot. ...
... The considered approach uses X band antennas for the entire system. Prospector-1 mission from DSI (Deep space industries) proposes the use of X band communication and some basic requirements for prospection activities regarding the link budget [11]. The ESA Marcopolo mission considered the use of three antennas for communications: a high gain antenna, a medium gain antenna and 2 low gain antennas, basing the design on the Bepi Colombo and the Solar Orbiter mission. ...
Conference Paper
Full-text available
Recent studies suggest that Near-Earth Asteroids (NEA) supposedly contain enough volatile and high value minerals to make the mining process economically feasible. Considering future applications, the importance of mining water in space has become a major focus. Most proposed projects for asteroid mining, however, involve single spacecraft that are traditionally large and expensive. Recent examples of such concepts, which rely on the capturing capacity of the spacecraft are the Asteroid Retrieval Mission (ARM) and the Asteroid Provided in-situ Supplies (APIS) project. As an alternative approach, asteroid mining could be based on multiple small spacecraft, another emerging trend in the space sector, which could enable a higher degree in reliability and a potentially lower cost of operation and a smaller chance of single point failures. Nonetheless, limited analysis on the asteroid mining capability of small spacecraft was conducted so far. The project explored the possibility to perform asteroid mining operation with small spacecraft. An overview of the different approaches is provided, analyzing the current architectures and technologies. This analysis provides the foundation to establish a feasible design for a spacecraft capable of extracting water from asteroids and transport it to an appropriate orbit for further processing.
... This opens the door to a wide range of cost effective alternative propellants, including molecular gases like CO 2 , O 2 , and H 2 O. 5 Water has the added benefit of not requiring highly pressurized storage, making it particularly well suited for ride-share launches. Currently available water operated small sat thrusters relying on electrothermal and electrolysis technologies 6,7 are limited to I SP values on order of 180 to 310 seconds. In theory, an appreciably higher ISP, over 1000 seconds, can be attained with an ECR device operating on water. ...
Conference Paper
Full-text available
Electrodeless plasma thrusters, and in particular Electron Cyclotron Resonance (ECR) thrusters, are attracting an increasing amount of commercial and academic interest by virtue of their ability to function without a neutralizer. This opens the door to operation with a wide range of alternative propellants all the while ensuring mitigation of some of the major life limiting erosion issues plaguing established technologies like Grid-ded Ion Engines and Hall Effect Thrusters. Building on the success of the proof-of-concept ECR thruster AQUAJET, the AQUAJET|NJET|XJET consortium, comprised of AVS UK Ltd., the University of Surrey, STFC ISIS, Viper RF, and Surrey Satellite Technology Ltd., have undertaken a follow on project to design, build, and test an improved thruster model capable of operating on water, xenon, and ammonia propellants. In the context of this project, analytical plasma modelling of water and ammonia discharges was undertaken. In the case of water discharge, these analyses revealed that at low electron temperatures (less than 6 eV) a significant fraction of energy is being dissipated to molecular dissociation. These analyses also allowed us to conclude that ammonia discharge can be expected to be slightly better than water in terms of power efficiency. Feasibility of ammonia operation was thus confirmed. We also describe the design upgrade of the AQUAJET breadboard, namely the improvements made to its microwave line, and to several of its key components.
Full-text available
Interest in the new space industry is growing in Korea due to the lifting of the US–Korea missile guidelines and the development of the Nuri launch vehicle. This paper reviews the space industry and the technology for asteroid mining. The definition and classification system of asteroids are explained, and first-generation companies in the asteroid mining industry and start-ups established after 2010 are introduced. The countries of the relevant companies are becoming more diversified, and the business areas are expanding to include not only space telescopes and space launch vehicles but also robotic mining equipment, space manufacturing and mineral processing, and the construction of space gas stations. The trends of exploration, transportation, and the energy and mining technologies necessary for asteroid mining are summarized, and issues related to international laws and economic feasibility are presented. Continuous investment and efforts are required to develop technologies and improve international laws for asteroid mining.
Conference Paper
Full-text available
Asteroid mining offers the possibility of revolution supply and availability of many sources vital for human sources, also there are private companies that support asteroid mining for recognition precious metals. Hence, the new missions are defining beyond LEO, so light-time communication delay issues, such as time lag and low bandwidth, will prohibit this type of operation because of huge data and limitation at windows to DSN. Hence, several solutions have been considered such as use higher frequency bands direct to ground, spacecraft autonomy system, swarm small satellites asteroids prospector etc. by this way the communication is the most important subsystem for this issue, based on the previous researches for prospecting of asteroids, Ka or X band is used for direct communication to ground and S or UHF band is used for constellation. In this proposal a communication subsystem for a small-satellite (1U, 2U…) by direct communication to ground and constellation by mother ship and mining robot is investigated.
For in‐situ resource utilization (ISRU), the cost‐mass conundrum needs to be solved, before any other formidable challenges may be tackled. Technologies may need to be conceptualised from first principals, rather than taking the most advanced technology of today. Using this approach, this paper seeks to provide a think tank about how chemical process intensification can help with technology and business case disruption of ISRU matters, how this might influence Space‐industry start‐ups, and first of all even Earth‐industry transformations. The disruptive technology considered is continuous micro‐flow solvent extraction and, as another disruptive element therein, the use of ionic liquids (instead of conventional organic solvents). The Space business considered is Asteroid mining, as it is probably the most challenging resource site, and the focus is on its last step: the purification of adjacent metals (cobalt versus nickel). The key economic barrier is defined as the reduction of the amount of process water used in the Asteroid mining process. This paper suggests a pathway toward water savings by orders of magnitude, up to the technological limit of best Earth‐process intensification and their physical limits (e.g. of solubility). This is believed to provide a solution to a major economic bottleneck, whilst leaving many technology developments to be achieved before a holistic system and business picture can be given.
Conference Paper
Full-text available
We report on recent efforts to advance water-propellant-based microsatellite electric propulsion using the Microwave Electrothermal Thruster (MET). This thruster uses microwave power at 17.8 GHz for plasma production within a resonant cavity. Water is utilized as the propellant, unlike previous MET models that have used helium, ammonia, and hydrazine decomposition products. Prior miniaturization efforts have resulted in a CuMET version that can be integrated into a 3U CubeSat bus. An overview of a proposed implementation is presented. Redesign of the CuMET allows for implementation of the thruster block into the "tuna can" volume available in the CubeSat standard, increasing either propellant or secondary payload space onboard. The theoretical underpinnings of water as a propellant in an MET are also detailed, including challenges faced in testing and discovered through analysis of the MET flow and heating system. Continuing work involves the development of viable spacecraft microwave signal sources and an adequate heater configuration for water vapor production aboard a spacecraft.
Full-text available
Vesta to the Core Vesta is one of the largest bodies in the main asteroid belt. Unlike most other asteroids, which are fragments of once larger bodies, Vesta is thought to have survived as a protoplanet since its formation at the beginning of the solar system (see the Perspective by Binzel , published online 20 September). Based on data obtained with the Gamma Ray and Neutron Detector aboard the Dawn spacecraft, Prettyman et al. (p. 242 , published online 20 September) show that Vesta's reputed volatile-poor regolith contains substantial amounts of hydrogen delivered by carbonaceous chondrite impactors. Observations of pitted terrain on Vesta obtained by Dawn's Framing Camera and analyzed by Denevi et al. (p. 246 , published online 20 September), provide evidence for degassing of volatiles and hence the presence of hydrated materials. Finally, paleomagnetic studies by Fu et al. (p. 238 ) on a meteorite originating from Vesta suggest that magnetic fields existed on the surface of the asteroid 3.7 billion years ago, supporting the past existence of a magnetic core dynamo.
Full-text available
Knowledge of the hydrated mineral inventory on the asteroids is important for deducing the origin of Earth's water, interpreting the meteorite record, and unraveling the processes occurring during the earliest times in solar system history. Reflectance spectroscopy shows absorption features in both the 0.6-0.8 and 2.5-3.5-micron regions, which are diagnostic of or associated with hydrated minerals. Observations in those regions show that hydrated minerals are common in the mid-asteroid belt, and can be found in unexpected spectral groupings as well. Asteroid groups formerly associated with mineralogies assumed to have high-temperature formation, such as M- and E-class steroids, have been observed to have hydration features in their reflectance spectra. Some asteroids have apparently been heated to several hundred degrees Celsius, enough to destroy some fraction of their phyllosilicates. Others have rotational variation suggesting that heating was uneven. We summarize this work, and present the astronomical evidence for water- and Hydroxl-bearing minerals on asteroids.
The “ponds” on asteroid (433) Eros are fine-grained deposits approximating flat ( quasi-equipotential) surfaces with respect to local topographic depressions (e.g., craters) in spacecraft images. These ponds are discussed in the context of laboratory simulation experiments, crater-related ponded and pitted deposits observed on Mars and Vesta, terrestrial phreatic craters, and degassing features associated with eroded impact craters on Earth. While the details of formation of these features on Mars, Vesta and the Earth are thought to be different, they all include mechanisms that requires the interactions between surface materials and volatiles (e.g., water vapor). Indeed, analogous features similar to the Eros ponds can be reproduced in the laboratory by the release of vapor (ice sublimation, water evaporation, or N2) through an unconsolidated regolith (independent of regolith composition). Eros is widely thought to be dry, but the discovery of exogenic water on Vesta, and recent arguments that subsurface water might be present in the inner asteroid belt, suggests that endogenic water might also be present and serve as a source of the gases producing the ponds. The amount of water required is comparable to the amount of water observed in little-metamorphosed ordinary chondrites (a few wt %). The primary morphologic characteristics of the Eros ponds can be explained this model. The heat source for degassing could have been solar heating following transfer from a main belt orbit to a near Earth orbit. Although other hypotheses (e.g., electrostatic levitation, seismic shaking, and comminution of boulders) can account for most of the features of the ponds recent observations regarding the role of volatiles on planetary surfaces, our laboratory experiments, and fluidization deposits on active comets, suggests that degassing is a reasonable hypothesis to be considered and further tested for explaining the Eros ponds, and similar features on other bodies.
Mining the Sky Basic Books
  • J S Lewis
" Mining the Sky " ; J. S. Lewis; Basic Books, New York, NY: (1997)