A Green Moon?
by Ivor Clarke
How do you build a Moon base fit for the scientists and astronomers
of the 21st century without causing pollution problems from the base and
rockets?
Ask most astronomers where is the best place to build the next generation of telescopes and most of the replies will say, "On the Moon, because it has no atmosphere to spoil the seeing." And this is what will most likely happen within the next 10 to 20 years as the foundations of the first permanently manned lunar base are started.
Soon we will have the next generation of SSTO (Single Stage to Orbit) rockets to replace the aging Shuttles. Even though the Shuttles will still be able to fly for another 15 or so years with luck - they are expensive to launch, with massive back up needed on the ground. The newer SSTO rockets should come into service sometime around 2005 and will be more like todays AirBus 310 jets, with quicker turn round and much simpler maintenance. Simpler to fly by taking off from a runway, they will make travel into Low Earth Orbit cheaper and more cost effective.
Into Low Earth Orbit
Once into LEO it becomes easier to travel outwards into the solar system. With the first stop, the Moon. We also need to learn the technology to be able to build permanent bases on the other remote planets and moons. One of the main reasons for going back to the Moon will be science and tourists! When all of our planet can be visited within a few hours it will become the done thing to travel to the Moon so as to enjoy the feeling of the low gravity and the views of Earth. It will be necessary to gain the technology for safe space travel before allowing the travelling public access to first the Moon then, later, on to the planets. But there is no doubt that money from tourism will spur on the establishment of first a orbital space hotel and then a hotel on the Moon. Think how many folk booked a seat on the first rockets to the Moon back in the sixties. Wistful thinking them as it turned out, so this is looking some way ahead of cause.
A Moon Base
The first to return to the Moon will be the scientists and engineers to build the bases and to explore its surface. To build a permanent lunar base will require dozens of lunar shuttle landings to bring in all the necessary materials and equipment from Earth to start the mines to extract the minerals and metals needed to build the bases. Very soon after the establishment of a permanent base, work will begin on the building of the observatories for astronomy.
One of the main problems with building a Moon base will be trying to keep as much as possible of the surface of the Moon pristine and unblemished for future science and not covered in a layer of soot from the hundreds of landings and take offs from the rocket exhausts.
Once the base is manned by a semi-permanent crew, it will then be possible for them to start exploring the surface in earnest. It is possible that a base may be built near the South or North poles of the Moon if water is found in sufficient quantities inside the permanent shadow filed polar craters.
This is possible because craters near the poles of the Moon have never seen any sunlight shine onto their floors since they were blasted out billions of years ago. Why? Well the Moon spins on its axes within 1.3 degrees of vertical to the ecliptic, its path around the sun. The sun will forever be on or below the horizon for both polar regions during the lunar day. The water, or rather ice, if it does exist in sufficient quantities to be useful, will have come from the hundreds of comets which have crashed into the Moon over the billions of years since its formation, depositing water vapour over its surface. It will be in the form of a dirty frost, mixed in and covered by the rain of micro-meteorites scattering the surface bracca in ejecta splash. If this water frost is there in any quantity it will prove a unequalled source of value for any base, for water is heavy stuff to lug about as anybody who has camped for a weekend knows.
Science on The Moon
Because of the Moon's slow rotation period of a month, it provides a superb location on which to base telescopes, optical, micro-wave and radio. Not only is the sky totally black, but the entire micro-wave spectrum is visible, from gamma to long radio waves. As a bonus, the lunar surface is exceptional free of lunar quakes and surface movement to disturb the pointing accuracy of the telescopes. With only one sixth the gravitational pull on them compared with Earth based instruments, many of the problems of mirror flexing under gravity won't exist or be just a minor consideration. From its surface an exposure of days or even weeks could be made of objects much to faint to be seen from a fast moving position such as the Space Telescope in low Earth orbit.
The sunlight reflected from the Earth will cause problems if the telescopes are located on the near side of the Moon. The amount of light cast by Earth will vary throughout the lunar day, from almost none, to full Earth shine; which is about 50 times brighter than full Moon shine on Earth. So if an astronomy base is built on the near side of the Moon, there will be an Earth, 4 times larger than the Moon in our sky blocking out a lot of the lunar sky. During the lunar day of 27 Earth days, the position of the Earth will move about a point in the lunar sky about 3 times its diameter as the Moon rocks from side to side and so the Earth will be visible from about 60% of the Moon's surface!
If you build your observatory around the corner so to speak, away from the Earth's view, the sky will never be filled with the Earth ever. So for 14 days every month, you will get a perfectly clear BLACK sky when the sun has set with both the sun and Earth below the horizon.
Dream on all you deep sky folk.
Also don't forget, a radio telescope would have no interference at all from the radio din of Earth. This may be the only radio quite place in our solar system for a very long time!
Moon Atmosphere
To build a base will require an enormous amount of effort. With every lift off and landing adding a measurable amount to the extremely rarefied gasses in the lunar atmosphere. "What. . .", I hear you saying, ". . .atmosphere???" Well the Moon does have an atmosphere, of sort. It consists mostly of sodium and argon atoms along with gasses from the solar wind mixed in with traces of gasses escaping from the lunar interior at a density of around 100,000 per cubic centimetre. This is a high vacuum to us. The air in every cubic centimetre between this page and your eyes contains over 20 billion billion molecules! Lunar air is thin! It is so thin that the Apollo LEM's exhaust gasses where able to spread all across the Moon before dispersing. Each Apollo Lunar mission increased the lunar atmosphere's mass by 10 tons ~ or 30%. This would have dispersed within a few weeks as the molecules decay by sunlight ionizing their atoms, stripping off their electrons, so escaping the low gravity pull of the Moon. Some of the gasses are caused by solar ultraviolet light hitting the surface liberating atoms and molecules, lunar quakes also produce gasses which add argon, radon and polonium in small amounts.
Even more gasses will be added by the next century as work starts on the lunar base. It is calculated that once the mass of gas released starts to exceed 10,000 tons a day, it will then start to shield itself from the effects of the suns ionizing radiation. Thus the Moon will then have an atmosphere which will be difficult to remove and start to cause problems.
This amount of gas, and the chemicals released into the atmosphere by building the base will soon cause a major predicament to the telescopes of the future. The sooty gasses will start to deposit themselves on the super clean mirrors of the next generation telescopes installed in craters far from the main base, on the far side of the Moon from Earth.
What can be done to cut the deposits?
The Space Elevator
Back in 1979 Arthur C. Clarke wrote a science fiction book called "The Fountains of Paradise". This story, set in the middle of the 21st century, was about a project to build the first space elevator, or as he called it, "a bridge to the stars."
The general idea is that you invent a super strong filament which you can make by the ton in Earth orbit and from an orbiting geo-stationary satellite, lower it down to the ground. Then, when you have anchored both ends (the outer end will be orbiting further out than necessary to maintain geo-stationary orbit and will be pulling taught the lift as a stone whirled around your head on a length of string does), then you can start to build the ground power stations to propel capsules, both cargo and passenger carrying, along a track up and down to the satellite. Getting into space will then be the longest elevator ride in history, up to the geo-stationary space station 36,000 kms. above the equator.
Once the capsule was outside the Earths atmosphere it would reach speeds of several thousand miles an hour propelled by magnetic linear motors along the track. Once this major assembly was completed, the cost of getting into space would be minimal with all of the pollution from rockets and shuttles exhaust fumes in the upper atmosphere stopped. In MIRA No.35 Mike Frost wrote an amusing story called "The Interplanetary Dangerous Sports Club" where his college mates go off Geostationary abseiling on to remote planets and other bodies. . . . Needless to say this is dangerous stuff. But the principles of this operation is the same for a person or heavy loads being lifted into space from the surface of the Earth or any other body.
Clarke was not the first to think of this idea, as he acknowledges in his book, a Russian by the name of Y.N. Artsutanov in 1960 thought up the idea of using a long cable from synchronous orbit to lift heavy freight and passengers up to a station. Since then it has been "invented" several times by different people, obversely its time had come.
Making a rope or cable 36,000 kilometers long is no joke. And what do we make it out of? The very best climbing rope would snap under its own weight after a few 10's of kilometers had been layed out. So would steel cables and even Kevlar fibre woven into a rope would not make it from orbit down to the ground. So what can it be made of? Recently spiders web material has been made synthetically in a laboratory. Also pure carbon can be made into long strands and is used in all manner of things from fishing rods to tripod legs to replacement bones to aircraft wings. Material science is advancing rapidly, soon we will have a material strong enough.
The material used in Clarke's book was a continuous pseudo-one-dimensional diamond crystal. Well it sounds strong enough! But the real material would need to be light, easily made, conduct electric current, not suffer from Earth's atmosphere or from the effects of space or radiation or ultra violet radiation from the sun. . .
One of the problems we have seen is the weight of the material as it nears the Earth, if its not strong enough it will brake and fall to Earth. When you first start to spin out a rope from a geo-stationary point 36,000 kms. up, it will be weightless. As the length of cable gets closer to Earth it will begin to gain weight as its speed of rotation about the planet will stay at the geo-stationary speed of about 10 kms. per second and not increase in speed as orbiting spacecraft need to, in lower Earth orbits. The nearer the planet the faster the orbiting satellite or rocket must go to stay in orbit. This will quickly add weight to the system over the last few thousand kilometres.
So this is the scale of the problem today, material science is not up to the task of producing a strong enough product to support itself in such a length. If a material cannot be found strong enough to save itself from being destroyed by its own weight in the Earths gravity, then that's the end of the matter. Or is it?
There is another place to use a space lift and it could be put into place within the next 100 years. And its not on or off the Earth.
An Elevator on The Moon?
As we saw above, the Moon will become polluted with rocket propellant exhaust if nothing is done to stop it. So why not build a LUNAR LIFT.
The gravitational forces on it will be far less than in the Earth's environment, so the overall strength of the structure needs to be far less.
But wait, you can't do that because the Moon only rotates once in 27.32 days so if you are in orbit about it, you are going much to fast to stay over one point of the surface. If you move away from the Moon too far, the sun or the Earths gravity will capture you, so no stationary orbit.
But what if you just fell into the pull of the Earth's gravity and fastened the other end of your rope to the Moon? Why then, you have a lift from the Moon into the Earth's gravity well. Will it work?
At a position of around 80,000 kms. out from the Moon the gravity of Earth takes over. Once a space craft passes this invisible boundary travelling in either direction; its velocity will then increase as it falls towards that body, gaining speed the closer it gets. Most Lunar probes and the Apollo missions passed this boundary at just a few kilometers per hour to crossover into the other bodes gravity well.
Because the Moon's orbit is not a circular path around Earth, but elliptical, the exact distance of the neutral zone will change slightly during the month. The effects of the Moons orbit, the pull of the sun and the libration effects of the Moon will cause the platform to describe a figure of 8 path during the lunar month. The further into the Earth's gravity the platform rests, the less this effect will be, for the pull of the Earth neutralises the movement.
So if a platform could be assembled in lunar orbit, by shooting up material from the lunar surface using a rail gun or linear accelerator. This would perhaps be the cheapest method of building the station. When completed, it would slowly be moved out further away from the Moon using a series of small rocket motor firing to push it into higher orbits until it lay just in the gravity null points of the Earth - Moon system. Small jets would balance the gravitational forces for a short while as the long rope is fired from its container towards the Moon's surface. Once it had been fastened securely the platform could be gently lowered towards Earth so as to pull the complete system taught. With the platform resting just at the top of the Earth's gravity well, the pull on the station would be very weak with the crew each weighting just a few grams. But there would be an up and down and things would drop to the floor, albeit quite slowly! Also the showers would work and water would stay in the glass. So the station would hang there just over the edge of the invisible boundary between the conflicting pulls of the Earth and Moon.
Because the gravity of the Moon is only one sixth that of Earth all of the mechanical stress on the structure will be so much less. How much the Lunar Lift Receiving Station intrudes into the Earths gravity will depend on the weight of the platform compared with the weight of the connecting material and the weight of the cars running up and down the cables. A length of cable 80,000 kms. long will weigh thousands of tons even in the low lunar gravity.
Tourists Get Every Where
So let us imagine a journey to the Moon in 2075.
You travel up to LEO on one of the new space planes to the new spinning wheel space station. Not at all like those old fashion module stations with all those panels and bits sticking out. The Moon still seems a long way off and you secretly admit those guys where pretty brave a century and more ago to go all that way in their little ships. You then board the Earth / Moon Bus which does look a little like the old Apollo command capsules but much, much larger. A short rocket burn and the Earth / Moon Bus speeds you out of LEO and into freefall for the long trip up to the Lunar Lift Station. From your seat you watch the Earth visible getting smaller by the minute.
The Buses velocity is just enough for it to reach the null point in the Earth - Moon system and the Lunar Lift Station 3 days later. Small docking thrusters manoeuvre your bus into its berth. After the days of weightlessness you suddenly realizes that you are falling slowly to the floor. But you can't walk because you don't have enough weight to make your feet grip the floor, so you pull your self along on the hand rails with your finger tips and can hold up all your weight on just your little finger. You now transfer to the capsule which will take you the long ride down the Lunar Lift cable to the Moons surface. The energy generated by the car falling down the cable will be converted into electricity to provide power to drive the twin car up.
The return will be just as easy from the Moon's surface, with a ride up to the Lunar Lift Station, on to the E/M Bus, which just undocks using just its manoeuvring thrusters and starts to fall back to Earth. On the way back a small correction burn puts the Bus into the attitude for the most exciting part of the trip, an atmosphere graze to knock off its momentum and rendezvous at the Space Station. The E/M Bus must hit the top of the Earth's atmosphere at just the right angle so as to slow down by the 5 kms. per second necessary to mach the orbital velocity of the LEO space station.
To the Moon and back with only one small rocket burn out of LEO. Is this the bargain of the century?
Will the Lunar Lift ever be built? I can't say, but who knows what will be discovered in the future to make the preservation of the pristine surface of our satellite a necessary requirement?
Steve Payne's
History of Astronomy
Part 3
A continuing look at the history of astronomy, (with a bit of fun added)
from 1984
AD 1984 Two loonies left the safety of the Space Shuttle to ride around
with jet propelled back packs on. With out a tie line, if the packs had
failed it would have been good bye for ever.
AD 1985 The construction of the largest telescope was started on top
of a Hawaiian mountain. The Keck telescope has a mirror 33 feet across. That's big by any standards. A brave little satellite called Giotto is
launched on board an Ariane rocket by the French. Giotto is the wonderful
name given to a small space craft which was to go through the tail of a
passing comet. It survived the passage and gave some spectacular shots
of Halley's Comet.
AD 1986 Uranus was visited by Voyager 2. Many photographs and much data
was sent back, processing of the information is still being done by loads
of PHD students around the world. It keeps them out of mischief as well. The Challenger shuttle exploded only a few days later after take off, killing
all seven crew members. Rubber O rings which sealed sections of the solid
fuel rocket body shell were to blame. The crew was not the first to be
killed in the space race and will unfortunately not be the last. MIR was
launched. The largest space station to be put into orbit by man. I just
hope it stays up there.
AD 1987 While on holiday Yuri Romanenko spent 326 days on the MIR space
station. A late sleeper in New Zealand called Ian Shelton was looking at
the night sky on the 24th of February when he saw the nearest Super Nova
to Earth since 1604. It was called 1987A
AD 1988 The shuttle flew again after a complete redesign of the O rings
in the solid rocket boosters.
AD 1989 Magellan space craft is launched by the Atlantis shuttle on
flight STS 30 towards Venus where it spent 3 years radar mapping the planet.
Galileo was reborn into a space craft and sent towards Jupiter for a long
awaited holiday. Soon after launch his brolly wouldn't open so he can't
pass on his messages easily. On arrival near Jupiter, he dropped off a
probe into the atmosphere to take a whiff.
AD 1990 A small European spacecraft called Ulysses is launched to look
at the poles of the sun. The shuttle Discovery left pad 39b in a vertical
fashion with the Hubble Space Telescope on board. As we all know it left
Earth without its contact lenses.
AD 1992 Comet Shoemaker/Levy 9 came within 40,000 km of Jupiter. This
was not a good idea. Its like trying to land on the Sun at night. Isaac
Asimov died from "stiffywristitous" after writing almost 500 books. Some
were science fiction but most of them were on subjects as varied as atomic
physics and the Bible.
AD 1993 The American AA fixed the Hubble Telescope with a set of new
glasses.
AD 1994 The Americans finally got around to sending another spacecraft
to the Moon, Clementine did its bit around the Moon but decided not to
go on and visit a passing asteroid. Space, the Final Frontier. It was confirmed
by NASA that Star Trek creator Gene Roddenberry had been into space aboard
one of the shuttle flights. He didn't know anything about it though because
he had been cremated back in 1991. Mind you he had been where no ashes
had gone before.... Shoemaker/Levy 9 came back for the second attempt at
this dangerous sport of skimming Jupiter. Slight miscalculations resulted
in "Wipe Out Mode". Jupiter takes no prisoners.
AD 1995 Both Russians and Americans kissed and made up in MIR. The space
station now has a mass of around 60 tons.
Finally, I'm sure that other information could be added to this list especially covering the last couple of decades. But there is so much happening it is a daunting task due to the speed of technology these days.
Maybe someone in the Society could do a month by month history and send it in to MIRA.
The Space Exploration of the Solar System
List of spacecraft launched to the Moon and planets between 1959 and 1994
SPACECRAFT MISSION LAUNCH ARRIVAL RESULTS
Luna 1 Lunar flyby 2/1/59 Passed the Moon at
4,660 miles
Pioneer 4 Lunar flyby 3/3/59 4/3/59 Collected radiation data
near Moon
Pioneer 5 Solar orbit 11/3/59 Spacecraft entered solar
orbit after launch, data on
radiation, particles & fields
Luna 2 Lunar impact 12/8/59 First crash landing on the
Moon
Luna 3 Lunar flyby 4/9/59 First photos of far side of
the Moon
Mariner 2 Venus flyby 27/2/62 14/12/62 First craft to visit another
planet
Ranger 7 Lunar impact 28/7/64 31/7/64 Photographic resolution
better than 1,000 times
Earth based telescopes
Mariner 4 Mars flyby 28/11/64 14/7/65 First view of craters on
Mars
Ranger 8 Lunar Impact 17/2/65 20/2/65 Impact into the Sea of
Tranquillity
Ranger 9 Lunar impact 21/3/65 24/3/65 Photographic resolution
as fine as 0.28 meters
(10 inches)
Zond 3 Lunar flyby 18/7/65 Passed Moon at 5,730 and
returned 25 pictures of
far side
Pioneer 6 Solar orbit 16/ 12/65 Data on the Sun &
Interplanetary space
Luna 9 Lunar landing 31/1/66 First landing on the Moon
in the Oceanus Procellarum
Luna 10 Lunar orbit 31/3/66 Orbited Moon at a distance
of 218 miles for 460 orbits
Surveyor 1 Lunar landing 30/5/66 2/6/66 Simulated Apollo flight &
landing
Lunar Orbiter 1 Lunar orbit 10/8/66 14/8/66 First of this extremely
successful series, found
rougher than expected
Pioneer 7 Solar orbit 17/8/66 Same as Pioneer 6
Luna 11 Lunar orbit 23/8/66 Orbited Moon at 99 miles
for 277 orbits
Luna 12 Lunar orbit 22/10/66 Minimum height of orbit 62
miles, with photographic
resolution down to 50 ft
Lunar Orbiter 2 Lunar orbit 6/11/66 10/11/66 Search for possible Apollo
landing sites
Luna 13 Lunar landing 21/12/66 Landed on the Oceanus
Procellarum
Lunar Orbiter 3 Lunar orbit 4/2/67 8/2/67 Mapping surface, examined
gravitational field
Surveyor 3 Lunar landing 17/4/67 20/4/67 Sampled soil; photographed
Earth
Lunar Orbiter 4 Lunar polar orbit 4/5/67 8/5/67 Orbit allowed photos of polar
regions
Venera 4 Venus landing 12/6/67 18/10/67 Data transmitted during
descent
Mariner 5 Venus flyby 14/6/67 19/10/67 Confirmed harsh surface
conditions
Lunar Orbiter 5 Lunar polar orbit 1/8/67 5/8/67 Most successful of all Orbiter
missions, almost complete
coverage of near side
Surveyor 5 Lunar landing 8/9/67 11/9/67 First chemical analysis of
lunar soil
Surveyor 6 Lunar landing 7/11/67 10/11/67 3D photos of surface
Pioneer 8 Solar orbit 13/12/67 Same as Pioneer 6
Surveyor 7 Lunar landing 7/1/68 10/1/68 87,674 photos returned in
Surveyor program
Luna 14 Lunar landing 7/4/68 Orbited Moon at 100 miles
Pioneer 9 Solar orbit 11/8/68 Same as Pioneer 6
Zond 5 Lunar fly-round 15/9/68 21/9/68 Flew round Moon and
returned to Earth, seeds,
insects etc. Recovered from
Indian Ocean
Zond 6 Lunar fly-round 10/11/68 17/11/68 Circum-Lunar probe, photos
of far side and return to
USSR
Apollo 8 Lunar orbit 21/12/68 First manned orbit of the
Moon by F. Borman,
J. Lovell, W. Anders
Venera 5 Venus landing 5/1/69 16/5/69 Data transmitted during
descent into dark side of
Venus
Venera 6 Venus landing 10/1/69 17/5/69 Data transmitted during
descent into dark side of
Venus
Mariner 6 Mars flyby 24/2/69 31/7/69 Concentrated on equatorial
region, passed Mars at
2,110 miles returning
76 photos
Mariner 7 Mars flyby 27/3/69 5/8/69 Concentrated on southern
polar region, 126 photos
returned
Apollo 10 Lunar orbit 18/5/69 31 orbits of the Moon by
T. Stafford, E. Cernan,
J. Young
Apollo 11 Lunar landing 16/7/69 25/7/69 ".. one small step .."
N. Armstrong, E. Aldrin,
M. Collins
Zone 7 Lunar orbit 7/8/69 14/2/70 Lunar orbit at 1,240 miles,
colour photos of surface
returned to Earth
Apollo 12 Lunar landing 14/11/69 19/11/69 Touched down on the
Oceanus Procellarum,
C. Conrad, M. Bean,
R. Gordon
Apollo 13 Lunar orbit 11/4/70 17/4/70 Near disaster of exploding
tank left spacecraft crippled
with J. Lovell, J. Swigert,
F. Haise on board
Venera 7 Venus landing 17/8/70 15/12/70 Transmitted for 23 minutes
after landing
Luna 16 Lunar landing 12/9/70 24/9/70 Returned 3oz lunar sample
to Earth from the Mare
Fecunditatis
Zond 8 Lunar orbit 20/10/70 27/10/70 Moon orbiter and returned
photos to Earth
Luna 17 Lunar landing 10/11/70 Lunokhod 1 rover travelled
over 6 miles returning over
20,000 photos during its
11 month life
Apollo 14 Lunar landing 31/1/71 5/2/71 Landed near Fra Mauro,
A. Shepard, E. Mitchell,
S. Roosa
Apollo 15 Lunar landing 26/7/71 30/7/71 Landed in Hadley-
Apennines, D. Scott,
J. Irwin, A. Worden. Used
first Lunar Rover to visit the
Hadley rille
Mars 3 Mars landing 28/5/71 2/12/71 Contact lost 30 seconds
after landing
Mariner 9 Mars orbit 30/5/71 13/11/71 Mapped entire planet &
both moons for 11 months
returning 7,329 images
Luna 19 Lunar orbit 28/9/71 Covered over 1,000 orbits
Luna 20 Lunar landing 14/2/72 25/2/72 Returned lunar sample to
Earth from the edge of
Mare Fecunditatis 75 miles
north of Luna 16
Pioneer 10 Jupiter flyby 2/3/72 3/12/73 First examination of an
outer planet, passed within
81,670 miles
Venera 8 Venus landing 26/3/72 22/7/72 Landed 1,800 miles from
Venera 7, lasted for 50
minutes
Apollo 16 Lunar landing 16/4/72 21/4/72 Landed in Descartes area,
J. Young, C. Duke,
C. Mattingly
Apollo 17 Lunar landing 6/12/72 11/12/72 Landed in Taurus-Littrow,
E. Cernan, H. Schmitt,
D. Evens. Returned 113 kg
of samples
Luna 21 Lunar landing 8/1/73 Landed 112 miles from
Apollo 17 with Lunokhod 2
rover; travelled over 23
miles sent back over 80,000
photos during its 6 month
life
Pioneer 11 Jupiter, Saturn 5/4/73 2/12/74 Additional observations,
used Jupiter's flybys gravity
to speed craft on to Saturn
on 1/9/79
Explorer 49 Lunar orbit 10/6/73 Orbited Moon at 689 miles
to study radio conditions on
far side
Explorer 50 Lunar orbit 26/10/73 Study of Moon magnetic
fields, 58,855 mile orbit
Mars 5 Mars orbit 25/7/73 12/2/74 Few pictures returned
before contact lost
Mariner 10 Venus. Mercury 3/11/73 5/2/74 First photos of Venus; used
Venus flybys gravity to bend
path to Mercury 29/3/74 and
also 21/9/74 & 16/3/75.
Three successful flybys
imaged half of Mercury
Luna 22 Lunar orbit 29/5/74 Made over 4,000 orbits with
a minimum distance of 15
miles until contact lost
during Oct. 1975
Helios 1 Solar orbit 10/12/74 Joint mission with Germany,
orbited close to the Sun
Venera 9 Venus landing 8/6/75 21/10/75 One picture from surface
Venera 10 Venus landing 14/6/75 25/10/75 One picture from surface
during 65 minute
transmission
Viking 1 Mars orbit 20/8/75 19/6/76 Orbital high resolution photos
and landing, soil sampling,
contact lost in May 1983
Viking 2 Mars orbit 9/9/75 7/8/76 Continued orbital & surface
activity & landing
Helios 2 Solar orbit 15/1/76 Continued solar studies of
the Sun
Luna 24 Lunar landing 9/8/76 22/8/76 Landed on Mare Crisium
and returned 2m deep
sample to Earth
Voyager 1 Jupiter & Saturn 5/9/77 5/3/79 High resolution images &
data on Jupiter flybys and
moons and Saturn on
12/11/80
Voyager 2 Outer planets 20/8/77 9/7/79 Additional observations.
As Voyager 1 successful
flybys allowed retargeting of
Voyager 2 to the outer
planets. High resolution
images & data on Jupiter
and moons, Saturn on
25/8/81, Uranus on 24/1/86
and Neptune on 25/8/89.
Flybys extremely successful.
Both craft still operational to
some degree
Pioneer Venus Venus orbit 20/5/78 4/12/78 Detailed, long-term
atmospheric Orbiter
observation, rough surface
mapping
Pioneer Venus Venus 8/8/78 9/12/78 Main body and 4 probes
Muiltiprobe atmospheric probes profiled atmosphere
International Positioned 12/8/78 Examined solar wind.
Sun-Earth between Renamed ICE after
Explorer 3 Earth and Sun mission was accomplished
(ISEE 3)
Venera 11 Venus landing 9/9/78 25/12/78 Transmitted for one hour
after landing
Venera 12 Venus landing 14/9/78 21/12/78 Landed 500 miles from
Venera 11, lasted for one
hour after landing
Venera 13 Venus landing 30/10/81 1/3/82 Transmitted for two hours
sending back 8 colour
pictures
Venera 14 Venus landing 4/11/81 5/3/82 Transmitted for over one
hour
Venera 15 Venus orbit 2/6/83 10/10/83 Radar mapping from polar
orbit
Venera 16 Venus orbit 7/6/83 16/10/83 Radar mapping from polar
orbit
International Comet 11/9/85 Renamed probe (ISEE 3),
Cometary Giacobini-Zinner was retargeted to make
Explorer (ICE) flyby comet flyby, went through
tail
Vega 1 Halley's comet 15/12/84 11/6/86 Passed Venus and dropped
balloon probe into
atmosphere on way to
comet
Vega 2 Halley's comet 20/12/84 15/6/86 Passed Venus and dropped
balloon probe into
atmosphere on way to
comet
Sakigake Halley's comet 8/1/85 11/3/86 Passed comet by 93,850
miles
Giotto Halley's comet 2/7/85 14/3/86 Passed within 370 miles of
the nucleus of the comet
Phobos 2 Mars orbit 12/7/88 1/3/89 Contact lost after few
pictures returned
Magellan Venus orbit 5/5/89 10/8/90 High resolution radar
mapping of Venus
Galileo Jupiter orbit 18/10/89 7/12/95 Long term observations of
Jupiter and moons also
atmospheric probe
Hagomoro Lunar orbit 24/1/90 10,000 mile circular orbit of
Moon
Ulysses Solar polar 6/10/90 Study of solar southern pole
orbit 6-11/94 and northern pole
6-9/95
Clementine Lunar orbit 25/1/94 19/2/94 Over 2 million pictures taken
of the Moon from polar orbit
during 70 day mission
This list is a complete record of all of the successful lunar and planetary probes / missions to date.
Of cause some missions failed in the early days due to the lack of reliable rockets and the electronics left much to be desired compared with today.
It must be remembered that the American Lunar Orbiters in 1968 used photographic aerial film, not video technology, to image the lunar surface. The film was developed in orbit around the Moon, then the data was read off the processed film by shining a fine spot of light through the negative image and broadcasting back to Earth the result for reassemble back onto film. The Apollo astronauts used clock-work watches on the Moon because digital displays didn't exist.
One of the most remarkable missions of the late 20th century must be the Voyager 2 journey to the outer planets. This small space craft has revolutionised our understanding of our solar system, giving us views of the gas planets never seen before, and its all been done on the back-up radio after the main radio failed soon after take off
Pam's Page
Our Galaxy -
The Milky Way
by Pam Draper
A galaxy is an island of matter in space. Our galaxy is essentially a spiral of matter rotating about its central disc of stellar material. The milky way is about 100,000 light years across and is one of about 30 galaxies within what's called the local group?. The Andromeda galaxy and the large and small Magellanic clouds are also within this group. When mapped in the light of Atomic Hydrogen, it reveals thicker emissions to the far right and left of the galactic center. This indicates that the plane of our galaxy is slightly warped, it is also extremely flat - like a twisted record. Our galaxy rotates more rapidly towards its centre than further out.
Towards the centre there is an almost spherical bulge of stars extending above and below the galactic plane. A halo of older stars within Globular Clusters lies further out. Our Sun lies about three quarters of the way out from the galactic nucleus, near the plane of the milky way. It takes our Sun about 225,000,000 years to complete one journey around the galactic center. Observing the milky way at different wavelengths has given us much information on its structure, temperature, velocity and mass.
At optical wavelengths our view is often obscured by dust particles and clouds of gas. At radio wavelengths plumes of electrons or atomic nuclei can be seen arching along lines of magnetic fields along the milky way. In near-infra-red the galactic plane is seen stretched out in a long strip with hot new stars showing the brightest. Far-infra-red shows new stars blue, cooler dust red and the location of old giant stars. X-ray emissions reveal some of the hottest material within the galaxy, such as the remnants of a super-nova explosion.
Pam's Favourite Quotes
The universe is an infinite sphere,
The centre of which is everywhere,
The circumference no-where!
Pascal. Penseés
Out on the lawn I lie in bed
Vega conspicuous overhead
In the windless nights of June . . . .
W.H. Auden
I keep six honest serving men,
They taught me all I know,
Their names are what and why and when and how and where and who.
I know a person small -
She keeps ten million serving men,
Who get no rest at all
She sends them abroad on her own affairs from the second she opens
her eyes,
One million hows, Two million wheres, And Seven million whys.
Rudyard Kipling
Listen; Theres a hell of a good universe next door; Lets go .
. .
E.E. Cummings
Many a night from ivied casement, ere I went to rest,
Did I look on great Orion, sloping in the west.
Many a night I saw the Pleiades, rising through the mellow shade,
Glitter like a swam of fireflies in a silver braid.
Here about the beach I wandered, nourishing a youth sublime,
With the fairy tails of science, and the long results of time . . .
. . .
Tennyson
It is nightfall, the clouds have vanished
The sky is clear, Pure and cold . . .
Silently I watch the river of stars, turning in the jade vault . .
.
Tonight I must enjoy life to the full,
For if I do not, Next month, Next year
Who can know where I shall be?
Su T'Ung-Po. 11th Cent poet
