Interplanetary small-satellites list
Small-Satellites for interplanetary missions are
difficult to classify in terms of mass, as their propulsion requirements generally drive
the wet mass (i.e. fuelled spacecraft mass) of the spacecraft. Also the amount of fuel
carried depends on the launcher injection orbit and the complexity of the mission. For the
purposes of these pages, small interplanetary missions have been defined, as satellites
with a wet mass less than 500kg.
This list is restricted to those satellites that made it
onto the launcher, and is ordered in terms of launch date. For future interplanetary
satellite missions, refer to the future missions page.
More...[small satellite classification]
Mariner 1, 1962
- An interplanetary spacecraft launched on the 22nd July 1962 on an Atlas Agena B from
Cape Canaveral. Its aim was to perform a Venus flyby and gather information on the
Venusian atmosphere, its clouds and magnetic fields. Unfortunately the launcher had to be
destroyed as it veered from its course. The spacecraft weighs 202kg measuring 3.04m long
and 1.52m diameter, employing a tubular space structure with hexagonal base. A dish
antenna and solar panels are extended from this. The solar panels carry gas jets at the
ends for attitude control. A hydrazine engine was employed for manouevers. The structure
holds an octagonal magnesium central module which houses the equipment. A wide and narrow
field camera was flown and a cosmic ray telescope.
- Mariner 2, 1962
- A 202kg interplanetary spacecraft launched on the 27th August 1962 on an Atlas Agena B
from Cape Canaveral. It had the same mission as Mariner 1, and flew by Venus at a distance
of 34,830km, 109 days following trajectory injection from an Earth parking orbit. It
provided a total of 35 minutes of detail. This included measuring the surface temperature
to be higher than expected, at 428 degC, and concluded the atmosphere contained no water
content. No breaks were observed in the clouds which were found to be mainly carbon
dioxide. The magnetic field was found to be weak. Contact was finally lost on the 3rd
January 1963. The Spacecraft was designed and operated by NASA JPL in the US. More...
[Mariner at JPL]
- Picture (right) courtesy of NASA.
- Mariner 3, 1964
- A 261kg interplanetary spacecraft launched towards Mars on the 5th November 1964 on an
Atlas Agena D from Cape Canaveral. Its aim was to take 21 pictures of Mars from 14,840km
together with Mariner 4 , however the thermal protective shroud over the spacecraft and
solar panels could not be shed and so desired trajectory was not achieved and the
spacecraft missed Mars.
- Mariner 4, 1964
- The sister spacecraft of Mariner 3, a 261kg interplanetary spacecraft, was
launched on the 28th November 1964 on an Atlas Agena D from Cape Canaveral. Despite
the navigation system locking onto wrong stars, this problem was overcome soon along the
trajectory, and the spacecraft flew by Mars at a distance of 9,844km, 228 days after
leaving the Earth parking orbit. 21TV images were received, and a partial last 22nd image.
These were the first close-up images of Mars, and showed a cratered world, with a much
thinner atmosphere than predicted. It was largely concluded that Mars was geologically and
biologically dead. Subsequent missions were diverted to Venus. The spacecraft was still
shown to be operational 30 months later long after passing Mars.
- Lunar Orbiter, 1966/7
- A series of 5 lunar mapping missions launched on an Atlas Athena D between 1966 and
1967, following the successful Ranger series of spacecraft. The main purpose of the
missions was to select a suitable equatorial landing site for the Surveyer and Apollo
landers, but also to study the gravitational field, radiation and micrometeoroid
environment. The table below describes the main mission parameters. The 390kg spacecraft
employ a 1.6m high truncated cone, with four deployed panels measuring 5.6m span. Two
cameras were carried weighing 65.8kg, comprising a wide field (80mm) and narrow field
(610mm) lens. A mechanical shutter and quartz window was used, and 70mm film, which was
scanned on-board and transmitted on the downlink. The spacecraft were three axis
stabilised employing the sun and Canopus as a reference. Communications were via S-band
empluing an omni and directional antenna. Each spacecraft was crashed at the end of the
mission in order to asure a clean radio environment for subsequent orbiters.
||Lunar Orbiter 1
||Lunar Orbiter 2
||Lunar Orbiter 3
||Lunar Orbiter 4
||Lunar Orbiter 5
||7 N, 161
|-High resolution (qty)
|-Medium resolution (qty)
|Altitude range for
|-Periselene resolution (m)
|-Aposelene resolution (m)
|Hi-res framelet width at
|Med-res framelet width at
program at NSSDC including many of the data sets]
Photo and data (table) courtesy of NASA NSSDC.
- Pioneer 6, 7, 8, 9
and E, 1965-69
- A series of interplanetary small satellites built by TRW for NASA Ames Research Center
in order to measure large scale magnetic phenomena and particle fields in interplanetary
space. All were launched on a THOR DELTA into a 0.8x 1.2 AU solar orbit, and were designed
for 0.5 year life. The satellites structure was cylindrical Aluminium measuring 812mm long
and 940mm in diameter, with three 1.8m magnetometer booms, also containing nutation
dampers and orientation nozzles. A 1.32m mast on the cylinder end holds high and low gain
antenna. The other end carries a dual frequency antenna, used in radio propagation
experiments. The satellites were spin stabilised, and weighed 63.6kg. 79W of power was
generated from the solar panels. The satellites were described as extremely simple, and
formed the first space based solar weather network.
Pioneer E suffered a launch failure.
This series of spacecraft discovered the Earth's magnetic field tail away from the Sun.
Simultaneous measurements from Pioneer 6 and 8 when they were 161 million km apart allowed
the most accurate determination of the solar wind density to be made up to that point. In
September 1972, Pioneer 7 was reactivated after being blocked by the Sun 312million km
- [Ref TRW spacecraft guide].
||16 Oct 1965
||THOR DELTA (DSV-3E)
||17 Aug 1966
||13 Oct 1967
||THOR DELTA (DSV-3E)
||8 Nov 1968
||THOR DELTA (DSV-3E)
||27 Aug 1969
- Mariner 5, 1967
- A 425kg interplanetary spacecraft launched on the 14th June 1967 on an Atlas Agena D
from Cape Canaveral. Originally intended as the back-up spacecraft for Mariner 4, it
was altered to fly by the Sun and Venus. The spacecraft solar panels were reversed and
reduced in size. A thermal shield was also added. The spacecraft flew by Venus at a
distance. distance of 3990km on the 19th October 1967. The surface temperature was now
measured to be 267deg C, magnetic fields were measured to be only 1/3% of that of the
Earth, and a weak ionosphere was detected above the atmosphere.
- Mariner 6, 1969
- A 413kg interplanetary spacecraft launched on the 24th January 1969 on an Atlas Centaur
D from Cape Canaveral, with the mission to study Mars. The JPL NASA mission resulted
in 201 images in combination with Mariner 7, when passing to within 3412km after 156 days.
- Mariner 7, 1969
- A 413kg interplanetary spacecraft launched on the 27th March 1969 on an Atlas Centaur
from Cape Canaveral, to join Mariner 6 in its mission. It passed to within 3524km
after 130 days. A few days before arrival antennas had to be switched, possibly due to a
- Explorer 43,
- Explorer-43 was launched on the 13th March 1971. The second generation Interplanetary
Monitoring Platform aimed to investigate the ralationship between Earth's and the Moon.
The spacecraft weighed 288kg.
- A Particles and Fields experimetal scientific microsatellite weighing 36kg, was launched
from the Apollo 15 spacecraft into lunar orbit on the 4th August 1971. The spacecraft
measured the mass of the moon, and its gravitational field, the radiation environment, and
the interaction of the Earth and moon's magnetic fields. The payload included a 1W S-band
transponder, 48k bytes of magetic core memory, 25W solar panels, and transmitted data at
128bps. The satellite was hexagonal in shape with dimensions 355mm diameter x 787mm
height. The satellite crashed into the moon after 6 months.
- Particles and Fields experimetal scientific microsatellite weighing 36kg, was launched
from the Apollo 16 spacecraft into lunar orbit on the 23rd April 1972 into an unintended
plane. The spacecraft measured the mass of the moon, and its gravitational field, the
radiation environment, and the interaction of the Earth and moon's magnetic fields. The
payload included a 1W S-band transponder, 48k bytes of magetic core memory, 25W solar
panels, and transmitted data at 128bps. The satellite was hexagonal in shape with
dimensions 355mm diameter x 787mm height. The satellite crashed into mountains on the far
side of the moon after 425 orbits on the 29th May 1972.
- Explorer 47
- A 375.9kg mini-satellite launched on the 22nd September 1972. The Interplanetary
Monitoring Platform measured interplanetary radiation, solar wind and energetic particles.
[IMP-8 at GSPC]
- Explorer 50,
- Explorer-50 was launched on the 25th October 1973. An interplanetary explorer to
investigate the Earth's radiation environment. The satellite weighed 397.2kg.
- Ulysses, 1990.
- The 367kg Ulysses minisatellite was launched on the 6th October 1990 on the STS-41
mission with an inertial upper stage. It was placed into an interplanetary trajectory that
would take it on a February 1992 flyby of Jupiter to place it into a 5.4x1.3AU
Modern Small Interplanetary Missions
- Muses-A (Hiten),
- A 185kg satellite launched on the 24th January 1990 from Kagoshima on an M3S2 launcher.
The spacecraft released the Hagoromo sub-satellite in lunar orbit.
- A 12kg lunar sub-satellite on Muses A (Hiten), but contact was lost after its release on the
19th March 1990, possibly due to a tranmistter failure before its planned
lunar swingby. The spacecraft was built by NEC for ISAS, and was launched on
top of the 185kg Hiten spacecraft on an M3 launcher.
- The Clementine minisatellite was launched on the 25th January 1994, with a mission to
map the moon to much greater detail than ever achieved before, and to subsequently perform
an astroid fly-by. The satellite was built at Naval Reseacrh Laboratories, and payloads
integrated at the Air Force Phillips Laboratories. The mission proved extremely succesful
in the lunar mapping phase, but the astroid fly-by had to be abandoned on its outbound
journey due to failure of the propulsion system resulting in uncontrolled spin. It was
concluded that fuel might have migrated back past valves.
Prospector, 1998-001A (25131)
- A Lockheed Martin built lunar mission for NASA under the Discovery program, was launched on the
5th January 1998 from Spaceport Florida on the first flight of the Athena-2 launch
vehicle. The flight time to the moon was 105 hours, and it was placed into a 100km
circular orbit. The 290kg (65kg dry?) satellite is cylindrical in shape and It is
cylindrical in shape and measures 1.37m high and 1.22m in diameter, with three 2.4m booms.
Its mission is to map the lunar surface composition, measure its gravity and magnetic
fields, and to investigate the Clementine measurements seeming to indicate the existance
of trapped ice on the lunar southern pole. For this reason the spacecraft carries a gamma
ray spectrometer, magnetometer, electron reflectometer, a neutron spectrometer, and an
alpha particle spectrometer.The spacecraft is spin stabilised, and carries no on-board
computer. Instead, an hour delay line permits hour old telemetry to be interspersed with
current telemetry, for when the spacecraft is out of view of the Earth. The satellite
employed the LM100 bus and was built in 17 months, and the total mission cost is expected
to be US$63m including launch and operations.
- On the 5th March 1998, it was reported that the prospector had shown there to be water
in ice form at both poles.
The polar lunar orbit was lowered on Dec 19 from 77 x 122 km to 25 x 55 km. Inclination
remained at 90 degrees, and the updated lunar gravity model appears to remain accurate in
this orbit. The orbit was then reduced to only 25 x 35 km on the 29th January 1999.
Finally on the 31st July 1999 the spacecraft was deliberately crashed into a South Pole
crater at 42.1E, 87.7S with the remainder of fuel, in an attempt to throw up a dust cloud
which could have been observed by ground based observatories and might show up water
vapour. No positive findings have been reported. The final orbit had the apogee raised to
More:[NASA NSSDC, NASA AMES, Lockheed Martin, NASA HQ, LANL][Masts at AEC-ABLE]
- Cool: [Watch the telemetry
Pictures courtesy of LM
- Deep Space-1,
- Developed by the prime contractor Spectrum Astro with JPL, under a US$139.5m (1996)
contract within the NASA New Millenium project, in order to develop and test advanced
technologies for interplanetary missions. It was launched on a DELTA 7326 into a 0.99x
1.32AU solar orbit inclined at 0.4 degrees on the 24th October 1998 with SedSat-1 as a
piggyback payload. It employs the SA-200HP platform and will employ 12 new technologies
including solar electric propulsion, carrying 81.5kg of Xe on the 486.3kg spacecraft, to
perform a 5km fly-by of the near-Earth astroid McAuliffe in 1999 and comet
West-Kohoutek-Ikemura in 2000, using a Mars gravity assist maneouver. It also carries
31.1kg of hydrazine. Amongst the other new technologies carried are solar array lens
concentrators on 11.5m long arrays, delivering a total of 2600W. The concentraters employ
cylindrical lenses to intensify the light levels onto the 3600 solar cells. A 3D computer
intended for this spacecraft was delayed until a future mission. It is slated for launch
on a DELTA-2-7326 (the first DELTA med-lite) in July 1998. The spacecraft will weigh
365kg. Other spacecraft in the Deep-Space series are being considered. Originally,
problems were encountered with the ion thruster, but these were later overcome.
- The spacecraft made its flyby of the astroid Braille on the 29th July 1999 at a distance
of 15-25km, but failed to target its camera at time of closest approach, although IR
imagery was returned. A later flyby of Borrely returned spectacular views.
On the 18th December 2001 the spacecraft was retired. Its ion engine has
been selected for the NASA Dawn mission.
- [artist impression][DS-1
at NASA][DS-1 at Spectrum Astro]
Pictures courtesy of Spectrum Astro
- Stardust, 1999-003A
- A 350kg spacecraft in the Deep Space series being developed for NASA, launched on a 7
year trip towards the edge of the solar system and back, on a DELTA-2-7325 on the 7th
February 1999. The spacecraft employs an Aerogel to capture and measure particles of space
dust, from the 4km diameter comet Wild-2, astroids, and other objects. The capsule
containing this will be recovered in 2006 for detailed chemical and isotopic analysis. The
estimated project cost is $34m (1996). More...
- [Stardust at JPL][Stardust at GSFC]