Space Rovers
A rover (or sometimes planetary rover ) is a space
exploration vehicle designed to move across the
surface of a planet or other celestial body . Some
rovers have been designed to transport members
of a human spaceflight crew; others have been
partially or fully autonomous robots . Rovers
usually arrive at the planetary surface on a
lander -style spacecraft .[1]
Comparison with space probes of other types
Comparison of distances driven by various
wheeled vehicles on the surface of Earth's moon
and Mars ( NASA , 15 May 2013; updated version
of 03 Jan 2014).
landers : they examine more territory and they can
be directed to interesting features. If they are
solar powered, they can place themselves in
sunny positions to weather winter months. They
can also advance the knowledge of how to
perform very remote robotic vehicle control which
is necessarily semi-autonomous due to the finite
speed of light.
Their advantages over orbiting spacecraft are that
they can make observations to a microscopic level
and can conduct physical experimentation .
Disadvantages of rovers compared to orbiters are
the higher chance of failure, due to landing and
other risks, and that they are limited to a small
area around a landing site which itself is only
approximately anticipated.
Features
Rovers arrive on spacecraft and are used in
conditions very distinct from those on the Earth,
which makes some demands on their design.Such
as wheel motion and robotic parts
Reliability
Rovers have to withstand high levels of
acceleration, high and low temperatures, pressure ,
dust, corrosion, cosmic rays, remaining functional
without repair for a needed period of time.
Mars rover Sojourner in cruise configuration
Compactness
Rovers are usually packed for placing in a
spacecraft, because it has limited capacity, and
have to be deployed. They are also attached to a
spacecraft, so devices for removing these
connections are installed.
Autonomy
Rovers which land on celestial bodies far from the
Earth, such as the Mars Exploration Rovers ,
cannot be remotely controlled in real-time since
the speed at which radio signals travel is far too
slow for real time or near-real time
communication. For example, sending a signal
from Mars to Earth takes between 3 and 21
minutes. These rovers are thus capable of
operating autonomously with little assistance
from ground control as far as navigation and data
acquisition are concerned, although they still
require human input for identifying promising
targets in the distance to which to drive, and
determining how to position itself to maximize
solar energy. [2] Giving a rover some rudimentary
visual identification capabilities to make simple
distinctions can allow engineers to speed up the
reconnaissance. [2]
History
Landing sites of sample return and rover missions
Lunokhod 1A
The Soviet rover was intended to be the first
roving remote-controlled robot on the Moon , but
crashed during a failed start of the launcher 19
February 1969.
Lunokhod 1
Lunokhod 1
Main article: Lunokhod 1
The Lunokhod 1 rover landed on the Moon in
November 1970. [3] It was the first roving remote-
controlled robot to land on any celestial body. The
Soviet Union launched Lunokhod 1 aboard the
Luna 17 spacecraft on November 10, 1970, and it
entered lunar orbit on November 15. The
spacecraft soft-landed in the Sea of Rains region
on November 17. The lander had dual ramps from
which Lunokhod 1 could descend to the lunar
surface, which it did at 06:28 UT. From November
17, 1970 to November 22, 1970 the rover drove
197 m, and during 10 communication sessions
returned 14 close up pictures of the Moon and 12
panoramic views. It also analyzed the lunar soil.
The last successful communications session with
Lunokhod 1 was on September 14, 1971. Having
worked for 11 months, [4] Lunokhod 1 held the
durability record for space rovers for more than 30
years, until a new record was set by the Mars
Exploration Rovers .
Apollo 15 Lunar Rover
Apollo Lunar Roving Vehicle
Main article: Apollo Lunar Roving Vehicle
NASA included Lunar Roving Vehicles in three
Apollo missions: Apollo 15 (which landed on the
Moon July 30, 1971), Apollo 16 (which landed
April 21, 1972) and Apollo 17 (which landed
December 11, 1972). [5]
Lunokhod 2
The Lunokhod 2 Lunar Rover
Main article: Lunokhod 2
The Lunokhod 2 was the second of two
unmanned lunar rovers landed on the Moon by
the Soviet Union as part of the Lunokhod
program. The rover became operational on the
Moon on 16 January 1973. [6] It was the second
roving remote-controlled robot to land on any
celestial body. The Soviet Union launched
Lunokhod 2 aboard the Luna 21 spacecraft on
January 8, 1973, and it entered lunar orbit on
January 12. The spacecraft soft-landed in the
eastern edge of the Mare Serenitatis region on
January 15. Lunokhod 2 descended from the
lander's dual ramps to the lunar surface at 01:14
UT on 16 January. Lunokhod 2 operated for about
4 months, covered 37 km (23 mi) of terrain,
including hilly upland areas and rilles , and sent
back 86 panoramic images and over 80,000 TV
pictures. [7][8][9] Based on wheel rotations
Lunokhod 2 was thought to have covered 37 km
but Russian scientists at the Moscow State
University of Geodesy and Cartography (MIIGAiK)
have revised that to an estimated distance of
about 42.1 to 42.2 km based on Lunar
Reconnaissance Orbiter ( LRO ) images of the lunar
surface. [10][11]
Prop-M Rover
Main articles: Mars 2 and Mars 3
The Soviet Mars 2 and Mars 3 landers had a
small 4.5 kg Mars rover on board, which would
have moved across the surface on skis while
connected to the lander with a 15-meter
umbilical. Two small metal rods were used for
autonomous obstacle avoidance, as radio signals
from Earth would have taken too long to drive the
rovers using remote control. The rover was
planned to be placed on the surface after landing
by a manipulator arm and to move in the field of
view of the television cameras and stop to make
measurements every 1.5 meters. The traces of
movement in the Martian soil would also have
been recorded to determine material properties.
Because of the demise of both the landers, the
rover was not deployed.
Lunokhod 3
The Soviet rover was intended to be the third
roving remote-controlled robot on the Moon in
1977. The mission was canceled due to lack of
launcher availability and funding, although the
rover was built.
Marsokhod
The Marsokhod was a heavy Soviet rover (hybrid,
with both controls telecommand and automatic)
aimed at Mars, part of the Mars 4NM and
scheduled to be released (after 1973 according to
the plans of 1970 ) launched by a N1 rocket that
never arrived to fly successfully. [12]
Sojourner on Mars
Sojourner
Main articles: Sojourner (rover) and Mars
Pathfinder
The Mars Pathfinder mission included Sojourner ,
the first rover to successfully reach another
planet. NASA , the space agency of the United
States , launched Mars Pathfinder on 1996-12-04;
it landed on Mars in a region called Chryse
Planitia on 1997-07-04. [13] From its landing until
the final data transmission on 1997-09-27, Mars
Pathfinder returned 16,500 images from the lander
and 550 images from Sojourner , as well as data
from more than 15 chemical analyses of rocks
and soil and extensive data on winds and other
weather factors. [13]
Beagle 2 Planetary Undersurface Tool
Beagle 2 was designed to explore Mars with a
small "mole" (Planetary Undersurface Tool, or
PLUTO), to be deployed by the arm. PLUTO had a
compressed spring mechanism designed to enable
it to move across the surface at a rate of 20 mm
per second and to burrow into the ground and
collect a subsurface sample in a cavity in its tip.
Beagle 2 failed while attempting to land on Mars
in 2003.
Mars Exploration Rover A Spirit
Main article: Spirit rover
Spirit is a robotic rover on Mars , active from 2004
to 2010. It was one of two rovers of NASA 's
ongoing Mars Exploration Rover Mission. It
landed successfully on Mars at 04:35 Ground UTC
on January 4, 2004, three weeks before its twin,
Opportunity (MER-B), landed on the other side of
the planet. Its name was chosen through a
NASA-sponsored student essay competition . The
rover became stuck in late 2009, and its last
communication with Earth was sent on March 22,
2010.
Active rover missions
Image map of Mars landings
The following imagemap of the planet Mars has
embedded links to geographical features in
addition to the noted Rover and Lander locations.
Click on the features and you will be taken to the
corresponding article pages. North is at the top;
Elevations: red (higher), yellow (zero), blue
(lower).
Spirit (2004) >
Opportunity (2004) >
< Pathfinder/Sojourner (1997)
Viking 1 (1976) >
Viking 2 (1976) >
< Phoenix (2008)
< Mars 3 (1971)
Curiosity (2012) >
Mars Exploration Rover
Mars Exploration Rover B Opportunity
Main article: Opportunity rover
Opportunity is a robotic rover on the planet Mars ,
active since 2004. It is the remaining rover in
NASA 's ongoing Mars Exploration Rover Mission .
Launched from Earth on July 7, 2003, it landed on
the Martian Meridiani Planum on 25 January 2004
at 05:05 Ground UTC (about 13:15 local time ),
three weeks after its twin Spirit (MER-A) touched
down on the other side of the planet.
Mars Science Laboratory Rover "Curiosity"
Main article: Curiosity (rover)
Mars Science Laboratory
On 26 November 2011, NASA's Mars Science
Laboratory mission was successfully launched for
Mars. The mission successfully landed the robotic
"Curiosity" rover on the surface of Mars in August
2012, whereupon the rover is currently helping to
determine whether Mars could ever have
supported life, and search for evidence of past or
present life on Mars . [14][15]
Chang'e 3
Main article: Chang'e 3
Chang'e 3 is a Chinese Moon mission that
includes a robotic lunar rover . Launched in 2013,
it is China's first lunar rover, part of the second
phase of the Chinese Lunar Exploration Program
undertaken by China National Space
Administration (CNSA).
Planned rover missions
Chandrayaan 2
Main article: Chandrayaan-2
The Chandrayaan-II mission is a joint venture
between India and Russia, consisting of a lunar
orbiter and a lunar lander. An opportunity was
given to students to design this rover. 150
students gave their designs but only 6 were
selected. They gave a demonstration in NRSA and
are going to ISRO.The Russian designed rover
weighs 50 kg, will have six wheels and will run on
solar power. It will land near one of the poles and
will operate for a year, roving up to 150 km at a
maximum speed of 360 m/h. The proposed launch
date is 2015.
ExoMars Rover
Main article: ExoMars rover
The European Space Agency (ESA) is currently
designing and carrying out early prototyping and
testing of the ExoMars rover which is scheduled
for launch in 2018. [16]
Mars 2020 rover mission
Main article: Mars 2020 rover mission
The Mars 2020 rover mission is a Mars planetary
rovermission concept under study by NASA with a
possible launch in 2020. It is intended to
investigate an astrobiologically relevant ancient
environment on Mars, investigate its surface
geological processes and history, including the
assessment of its past habitability and potential
for preservation of biosignatures within accessible
geological materials.[17]
Future lunar missions
As of 2009, NASA had developed a series of plans
for future moon missions which called for rovers
that have a far longer range [ clarification needed ]
than the Apollo rovers. [18] [dated info]
See also
Google Lunar X Prize
Lander (spacecraft)
LORAX (robot)
Lunar rover
Mars rover ( Manned )
References
1. ^ "Exploring The Planets - Tools of
Exploration - Rovers"
. Air and Space Museum . 2002. Retrieved 3
January 2013.
2. ^ a b "Rovers of the future may make
decisions on their own"
. Astrobiology Magazine (Mother Nature
Network). 8 July 2012. Retrieved
2012-07-10.
3. ^ "Lunar Lost & Found: The Search for Old
Spacecraft"
. www.space.com. Retrieved 2009-03-18.
4. ^ "Luna 17 and Lunokhod 1" .
www.zarya.info. Retrieved 2009-08-23.
5. ^ "Experiment: Lunar Rover Vehicle" .
Ares.jsc.nasa.gov. Retrieved 2009-03-18.
6. ^ "Luna 21 and Lunokhod 2" .
www.zarya.info. Retrieved 2009-08-23.
7. ^ Andrew Chaikin (March 1, 2004). "The
Other Moon Landings" . Air & Space/
Smithsonian . Retrieved May 25, 2013.
8. ^ Lewis Page (March 16, 2012). "New NASA
snap of game developer's electric cart
FOUND ON MOON: Probe in low pass over
Garriott's radioactive tub-rover"
. The Register. Retrieved May 25, 2013.
9. ^ "Lunokhod 2 Revisited" . NASA. March 13,
2012. Retrieved May 25, 2013.
10. ^ Lakdawalla, Emily (June 21, 2013). "Is
Opportunity near Lunokhod's distance
record? Not as close as we used to think!"
. The Planetary Society. Retrieved June 26,
2013.
11. ^ Witze, Alexandra (June 19, 2013). "Space
rovers in record race" . Nature News.
Retrieved June 26, 2013.
12. ^ Советский грунт с Марса {{Country data
{{{1}}} | flaglink/core | variant = | size = |
name = | altlink = national rugby union team
| altvar = rugby union }} [dead link ]
13. ^ a b "Mars Pathfinder" . NASA. Retrieved
2009-03-18.
14. ^ NASA Staff (26 November 2011). "Mars
Science Laboratory" . NASA . Retrieved
2011-11-26.
15. ^ Associated Press (26 November 2011).
"NASA Launches Super-Size Rover to Mars:
'Go, Go!'"
. New York Times. Retrieved 2011-11-26.
16. ^ "ExoMars Rover ESA Portal" . ESA.
17. ^ "Science Definition Team for the 2020
Mars Rover"
. NASA . Science Ref. 21 December 2012.
Retrieved 21 December 2012.
18. ^ NASA's Space Exploration Vehicle (SEV)
0 comments:
Post a Comment