been born in 1894. her name was marguerite lewis, an african-american woman born in louisiana. more and in the shadow of slavery, born at a time when lynchings were commonplace, born at a time when african-americans and women could not vote. it took our country from the time of its founding to the bit 1980's to build up a national debt of $850 billion, which was the size of the so-called stimulus package when it came over here. so we are talking about real, borrowed money. >> 30 years of coverage of the u.s. senate on c-span2. >> each week, "american artifacts" takes viewers into archives, museums and historic , sites around the country. next, we visit the smithsonian national air and space museum located on the national mall.

our tour guide is valerie neal. head of the space history department at the museum, who shows us artifacts from the moon to mars. valerie neal: i am valerie neal. we are in the "milestones of all at the center of the museum. this is the hall where we display the pioneering aircraft and spacecraft that transformed the modern world. when this museum opened in july of 1976, almost every item on -- every space artifact on display had recently been on the move. -- on the news. this was very much a museum of contemporary spaceflight and for most people, it was their first chance to see what had been lauded in the 1960's and 70's during this heroic age of space exploration when humans first

ventured off the planet into space and all the way to the moon, when the united states and the soviet union began sending craft out to explore the nearby planets. all of this was exciting and thrilling, and people just flocked into the museum to see it. in the 40 years since the building opened, we have continued to acquire treasures of space history. we have about 17,000 artifacts related to space history. we have just over 1000 of them on display in our two locations here in the washington area. then we have another 1500 on display in other museums around the world. in our tour today, we are going to look at some of the original artifacts that were the stars of the show when the national air and space museum opened.

and we're also going to look at artifacts from history that have has been made since then. we will start our tour here with the lunar module. the icon for the landing on the moon in july 1969. it actually has a companion spacecraft. the apollo command module. the command module, the service module, and lunar module carried three astronauts. neel armstrong, buzz aldrin, and holland tolins -- the moon. the command module brought them back safely. this lunar module is an actual lunar module that never flew in space. it was intended to be used in an earth orbital test flight but the test was canceled as unnecessary, and so nasa

transferred this lunar module to the national air and space busy. it consists of two parts. the base which has the legs and the rocket engine in it, and then the oddly shaped top which is the crew cabin. this was attached to the command module for the flight from earth to lunar orbit. and once in lunar orbit, the two crew members who would descend to the surface, armstrong and buzz aldrin, flu into the lunar module separated from the command module where michael collins stayed to orbit the moon and began the descent down to the surface. >> 40 feet down. digging up some dust. forward, just into the right little. drifting to the right a

little. engines stop. >> we copy down, eagle. >> the eagle has landed. neal: this was a thrilling moment in history and almost everybody alive at this that moment remembers where they were, whether there were watching it on television in their own homes or if they were standing at an appliance store watching it on a television. people around the world stopped to watch the landing on the moon and the first steps of human beings on the moon. >> i will step off now. one small step for man, one giant leap for mankind. valerie neal: after the crew had

climbed out and done some exploration close to the lunar module, collected some samples, taken some photographs, placed a u.s. flag on the moon, they went back into the lunar module and this became the vehicle for the trip home. they launched the small top portion, leaving the base on the moon. they ascended back up into lunar orbit, rendezvoused with the command module, exited the lunar module and once they were secure , inside the command module, reunited with michael collins. the lunar module was detached and will back to the moon with an intentional crash on the moon because geologists and seismologists wanted to be able

to track what kind of impact it made on the moon. from a space historian's point craft are the two icons of the space race along with the suits worn by the astronauts on the moon. symbolize that very historic moment in time, july 16, 1969, when human beings first stepped on another body in our solar system and in effect won the space race. when children look at this spacecraft they say, that does not look like a spaceship. we tend to think that spacecraft are always streamlined and maybe they look like rockets more than anything else. this spacecraft has an interesting design and is fairly

primitive given the job that it had to do. it did not need to be streamlined on the outside because it was not going to operate in the atmosphere. it would only operate in the vacuum of space and would not be subject to strong gravitational field on the moon. it is actually fairly flimsy in some areas. the legs are obviously strong, the amount for the rocket engine is strong. but the craft itself and the crew module, crew cabin were fairly spartan. it had two windows. neel armstrong had command of the craft during the final descent to landing. both were standing and fully suited. they pretty much filled the interior volume in that position with the spacesuits on. it was not really designed for comfort.

it was designed for the purpose of landing, giving the crew and exit so they could spend a couple of hours on the surface of the moon, and launching again with their precious cargo of lunar soil and rocks to bring back home to demonstrate they had been there and have those materials for scientists to begin analyzing to better understand the moon. it is also amazing to think that the computing power required to send these craft to the moon and to program them for the descent and launch was done with fairly primitive computer programs. memory was miniscule compared to the memory we have now. it is often said that the computing power we hold in our hands everyday with our smartphones is vastly more than it took to send people to the

moon and back. it gives you a sense of the ingenuity of the engineers in that day to devise solutions to get people to the moon and back safely. we have seen the iconic age ofts from the heroic spaceflight in the 1960's. just feet away from it is a more contemporary spacecraft spaceship one. ,the first craft that was privately developed, not by nasa or by the u.s. government, but by a company headed by burt rutan. an ingenious aircraft designer. spaceshipone was the first privately developed craft ever to be launched into space, returned to earth, be launched again and return with a human on , board.

by doing that in the year 2004, spaceshipone won a $10 million prize posted to encourage commercial development of spacecraft that could be used for space tourism. spaceshipone operates as the orbital craft. it does not going to orbit around the earth, but like alan shepard in 1961, it goes up, makes a loop into space and then glides back down to a landing like an airplane would land. there is a mothership that if the actual transporter aircraft and spaceshipone snuggled up under it, the mothership flies it around in the atmosphere than -- and then it is released from that. after it is released, the rocket

shoots straight up. spaceshipone is a very innovative design in that it has a hybrid rocket that is part and part solidnt propellant. it can hold three people though in the prize-winning flight it had only the pilot and some ballast to indicate the weight of two other people. it has a very distinctive design. right now, it is in a configuration with the wings up at 50,000 feet. those wings are down and it is very streamlined looking. as it shoots up into orbit and reaches the threshold of about 100 kilometers or 62 miles the , wings pivot up. that stabilizes the craft.

the loop lasts about six minutes during which the pilot and passengers would be able to experience weightlessness. if they want to unbuckle their seatbelts, they would rise out of their seats. they can look throughout the windows and get a wonderful view of the curvature of earth and the blackness of space. descent,aft begins to the feathered wings, what they're called, the feathered wings stabilize the craft in the way that a badminton birdie is stabilized so the nose stays down. it also creates more drag. it slows the spacecraft down more quickly so it does not need a bulky heat shield. spaceshipone comes back into the

atmosphere where there's enough air so that can fly aerodynamically again, the wings pivot down into the streamlined position. the whole thing glides back down to a landing on the desert or a runway. this. star-spangled craft is reminiscent of a race car. it is sleek and is aerodynamic and it looks sporty. and it just looks like the kind of craft that a person who wants to go up into space for a quick look and a quick experience of weightlessness might want to climb in and go for a ride. where this may go is to the next step which is a larger spaceship . ownsichard branson, who virgin atlantic airways,

partnered with burt rutan and his company to do a larger version of spaceshipone. he has named it virgin galactic and it will hold 12 people. and it is being developed for the express purpose of providing spaceflight to paying customers who want to have the experience of spaceflight. they don't have a set debut date yet. setbackfered a real when one of their test flights crashed. but it is still out there on the horizon as something likely to happen. virgin galactic is by no means the only such company. there are other companies developing spacecraft for the same reason. we may be on the threshold of a new era in human spaceflight. most of the spacecraft in the collection come from our space agency.

nasa is our principal donor. and at the end of their need, the agency will transfer spacecraft, spacesuits, and a great variety of other equipment to the museum so that it can be preserved and displayed and even used for research. spaceshipone is a different case at it came from private enterprise. and so in this case, we worked directly with the owner, manufacturer, designer, burt rutan, and also his business partner, paul allen one of the , cofounders of microsoft and if -- microsoft. we approached them after the first flight in june of 2004, regardless of whether you win or not, we think spaceshipone deserves to be in the national collection because it was the first privately developed spacecraft piloted by a human

being to go into space and return. you might notice the small dent in the nozzle on the back of the engine. that is not damaged. it was caused by transporting it to the museum -- it was not caused by transporting it to the museum. that buckled in space during its first test flight when the engine ignited and the heat and force of the engine ignition buckled the nozzle for the -- the nozzle. for the second and third flight different nozzle was used and , a they also made some corrections so they did not have the buckling problem again. when we asked to have spaceshipone delivered to us for the national collection, we

asked to have it returned to its original configuration from the first flight. the first flight was not the prize-winning flight, but it was the record-breaking flight. they went to the trouble to reinstall the dented engine nozzle on it. our next stop will be skylab. we are going to look at that because it was one of the original artifacts on display since before this museum opened. skylab is so large that it was brought into the museum before the building was closed. now i'm standing in front of a model of skylab that is as tall as i am. but the real skylab absolutely dwarfs the model and me. it reaches from the floor up into the skylights of this holding, -- building two stories , tall.

skylab was the united states ' first space station. placed into orbit in 1973. and in 1973-74, three different nasa astronaut groups spent time there. one group was there for one month, another group for two months, and a third group for three months. the whole point of the missions was to get some experience living and working in space. when the apollo program came to an end, there was still some hardware left over. nasa thought what can we do with , this? we have developed this tremendous capability to launch spacecraft all the way to the moon. we still have a couple powerful rockets on hand. can we repurpose them into something else? the decision reached was to take the third stage of the gigantic saturn rocket that powered the

spacecraft away from earth on a trajectory to the moon and turn that into a habitable module for , sort of a miniature space station the crews could live in what they were getting the experience of living and working in space. the actual element that is behind me is the full cylinder that is marked by this band here. you can see from the cut away that it is two stories inside. those were floors where the astronauts could actually live. earth'ss to moon and in orbit, they had been in spacecraft that were essentially cockpits. they had no more room in them than a sports car but skylab was like having a house. it actually had rooms. there was a galley room where they could fo prepare food,

meet around the table, eat together. they were still eating out of cans, butgs and tin at least it was more homelike and more sociable. they had sleeping quarters. the little bunk area is about the size of a closet. but each member had a private area to retire for solitary time and some sleep without being confined to the flight seat in a capsule. most important, it had an actual bathroom. it had an actual toilet. previous missions, the little-known dirty secret is that the astronauts were using plastic bags to collect their waste. but they finally had a toilet. they did not have to deal with the mess of taking care of their bodily functions. it had a sink where they can

wash up and shave. it even had a shower which was athentially a tunnel-like she' that the astronaut pulled up around him and then could use water from a sprayer inside the container. the trip after the shower was all the water had to be wiped off the body and enclosure. they finally decided it was more trouble than it was worth. they would just take sponge baths. there was also room to have an exercise bicycle and to have some experiments set up and then they had a huge attic above the living area where extra supplies were stored and a lot of the system elements were there. it was so big that they could run track around the perimeter

of it and do tumbling around the perimeter. just running and tumbling across the tops of the lockers. that was for fun, but they also too.t for serious reasons, they were testing out a jet backpack that might be used on spacewalks and they were able to operate that in the attic space that was so commodious. ,elow their living deck floor there was the remainder of one of the propellant tanks and that became a big trashcan and they put the trash through the hats ch and it would go through the lower level. the orbital workshop was the largest part of the skylab. but above it, there was an airlock module that enabled them to go outside into this big -- and service this big

observatory which was a wonderful scientific facility attached to the orbital workshop. using the instruments, a variety of cameras and detectors on the apollo telescope mount, we got our first really detailed view of activity on the sun and we understood for the first time how dynamic our sun is. roiling withst activity all the time, and spewing out explosions of matter. it has holes in it and storms on it. it was an amazing thing to get this new information through the telescopes on skylab. here at the top, one can see the docking port for the apollo command and service module which

was the shuttlecraft to bring the astronauts to skylab and bring them back home again. this whole thing is 22 feet in diameter. when you think of the ingenuity of turning a stage of a rocket, which is basically a big fuel tank, into a home that people can live in and you can provide them with plumbing and comfort and room to move around, a window to enjoy the view, this was a kind of turning point in our space program. skylab was the test run. for what the next thing was supposed to be. from the late 1950's and early 1960's on, planners in the an ed states had foreseen

eventual space station. in fact, the original plans were to put a space station first and then go to the moon. president kennedy decided to reverse that and send the united states to the moon first as part of the cold war competition with the soviet union. in the back of everybody's mind, there was still a space station. skylab was the first step to what now has become the international space station. a huge new facility in the earth's orbit. this behemoth behind me is the backup skylab space station. it is flight ready. nasa built two of them in case they wanted to do to skylab -- two skylab missions or in case there was a problem with the first workshop. we did make a modification. ordinarily, we don't modify flight ready hardware. but in this case, we cut a

passageway into it and laid down a sort of hallway through the middle of this living quarters so people can walk inside, they quarters,e living look into the bathrooms, and see a mannequin at the table with some food out at the table. the exercise bicycles are setup up. they can see that trash airlock. and if they look up, they can be wowed by the amount of free space there is. i mentioned that skylab was occupied in 1973 and 74. the last crew to leave skylab buttoned it up and put it into sleep mode with a view towards a future crew possibly coming back. then nasa got very busy developing the shuttle.

what happened to skylab? time, it's orbit began to deteriorate somewhat. it started dropping lower and lower, and there was an early plan to use the space shuttle to go up and rendezvous with it and boost it back up to a higher altitude so it could still be available for use. but the shuttle was not yet ready to fly. what happened is after the orbit diminished, nasa had to bring it back in a controlled reentry. in 1979, skylab was brought back down. it streaked into earth's atmosphere like a meteor. it broke up over the indian ocean and a few pieces fell into parts of australia and were recovered. fortunately, no one was hit. no injuries. -- no one was injured. no property was damaged.

this was still news in 1976 when the museum open. people streamed in here by the millions that first year. they were thrilled not only to see the old aircraft, but to see the new spacecraft, to see what had been happening in space that they had had seen on the news and heard about. skylab was one of the featured attractions. skylab was about settling down in space. throughout the 1960's, the this had been to get into space, to get into orbit, to get to the moon. after the space race was won by the united states with the landing on the moon in 1969 through 1972, both the soviet space program and u.s. space program began to shift gears.

as we built skylab in the early 1970's, the soviets were also beginning to develop a space station. in fact, a series of space stations. there was a moment there in the early to mid-1970's when soviet and u.s. tensions abated somewhat and the two space programs, the two nations, decided to do a cooperative venture in space. and that occurred in 1975. it was a rendezvous and docking in space of an apollo spacecraft from the united states and one from the soviet union. it was billed as a historic handshake in space. when the two crafts docked and opened the hatch is, the

american and russian commander came together and shook hands. thise time, it was hoped might be the beginning of a new era of cooperation in space. but that thaw in relations did not last very long. throughout the latter 1970's and 80's, the u.s. went on with developing the space shuttle. the soviets went on with developing the space stations. and a much larger space station. it was not until the collapse of 1992oviet union in about that another opportunity arose to have a cooperative relationship in space. at that point, the u.s. and its international partners, europe, japan, and canada, invited the new russia into partnership on the international space station.

since then, our activities in space have been carried out on a cooperative basis. now we are in the "moving beyond earth" gallery. this is where we treat human spaceflight in the era of the space shuttle and international space station. basically everything depicted in this gallery happened since the museum opened in 1976. in fact in that year, the first space shuttle enterprise made its debut and it was greeted as a revolution in spacecraft design. this was the first spacecraft to look like an airplane. the first reusable spacecraft that would be able to return to earth, land, be serviced, and fly again. the space shuttle era is all about practical uses of space. practical access to space.

practical benefits from space. the distinctive feature of the space shuttle was that it was reusable. it was supposed to be more economical and more readily used for routine spaceflight. in fact, early on the planners and designers thought it might operate as regularly as an aircraft. it did not work out that way. it turns out even though it was a reusable craft, it was in many ways an experimental craft. it was a very complicated and sophisticated spacecraft. i'm standing in front of one of the distinctive features of the space shuttle. one of the three main engines. these are reusable liquid propellant engines that had not been done before. they operate with a greater degree of efficiency and

reliability than any other rocket engine had done before. wasspace shuttle engines one of the great technical challenges of the space program and we are fortunate to have one here made up of parts and components that flew on quite a variety of missions. as a whole, it was not flown in space. it has flight components on it. we are very pleased to have that. we do have the space shuttle discovery on display at the second location. it was delivered to us without main engines. it was delivered only with nozzles because nasa chose to save those engines. they were so highly prized. they chose to save them for possible use on the next launch vehicle.

if we are lucky, one day, we may get one of those and that would be one that had flown in space. on the wall behind the main engine is a cross-section of the other main propulsion element of the shuttle. that is a slice of a solid rocket booster. or it is actually a slice of a model of a solid rocket booster. in addition to the rocket engines physically integrated into the shuttle orbiter there , were these twin solid rocket boosters mounted on the sides of the giant liquid propellant tank . as ammissioned that model cross-section to show the pattern in that rocket booster where the solid fuel first begins to burn. it is like a star shaped or snowflake pattern. that increases the efficiency of

the fuel burn and produces a tremendous amount of thrust through the twin solid rocket boosters. they burned out within two minutes of ignition and fell away from the shuttle. the main engines consumed fuel from the external tank for 8.5 minutes and then the tank on his way just before the shuttle enters orbit. a totally revolutionary way of sending a spacecraft into orbit. that is the theme of this whole gallery is a new way of doing space flight. as a mentioned, the subtle euro began in a way -- the shuttle era began in a way in 1976. the first actual shuttle launch into space was not until 1981. for the 30 following years, there were 135 space shuttle missions.

all but two of them completely successful. the two that failed worthy challenger and columbia accidents. the 25th shuttle mission and the one in 2003. in talking about the shuttle in this gallery, we do talk about what was revolutionary about it . we also do acknowledge that it was not a perfect technological system. it did not perform exactly as planned and did result in two tragedies. we did not want to gloss over any of that. we wanted to make the point that doing something revolutionary always entails risks and working with new technology operating at the far margins of performance adds to that element of risk.

at the other hand, the whole space shuttle system consisted of millions of components they -- that had to work perfectly every time. and in most occasions, that is exactly what happened. we have a section in here about the design of the shuttle. the various options considered before the final design was settled on, whether to make it fully reusable or partially reusable. partial won out. for economic reasons. we also talk about living and working in space on the shuttle because the shuttle served various purposes. it was a delivery truck. it could carry satellites into orbit. it was a short-term space station. when a laboratory was in the payload bay, it actually served as the research center in space.

it served as a servicing station with the hubble space telescope. astronauts could do repairs in orbit and prolong the life of the observatory there. finally, it was a construction site for the international space station. all the modules and solar arrays and trusses that make up the international space station were carried up into space from the payload bay of the shuttle. the space shuttle also had a profound impact on the astronaut corps and on our perception of human spaceflight. up until that point, the astronaut corps had consisted entirely of men. and the majority of them were test pilots, many of them combat pilots who were very experienced in high-altitude flight under extreme conditions.

some scientists had been admitted into the astronaut corps and one of those scientists went to the moon and three of them served on skylab. but because the shuttle had a different kind of mission to do research and useful work in space, it needed a crew that was more versatile than just pilots. it needed scientists and engineers to carry out its missions. needed morere scientists and engineers, that opened up a pool of eligible candidates to become astronauts. in 1970 eight, nasa selected the first astronauts for the space shuttle era. they chose of the 35, 6 for 35. women, three were african american men one was an

, asian-american heritage man. and from that point on, the shuttle astronaut program was much more diverse and it became more reflective of who we are as american people. in 1983, within the first 10 missions, a woman flew in space on the seventh mission, sally ride, and an african-american flew on the eighth mission. we have on display in this gallery their flight suits that they presented to the museum after their historic flights. certainly sally ride became a hero to girls and women. she was one of six women in the astronaut corps and happened to be the one chosen to fly first, so she ended up being the one who got credit for breaking the barrier and became a hero for the rest of her life.

impactford had the same on the african american community. the time the shuttle program ended in 2011, about 20% of the astronaut corps had been women. about 12% had been african american. women and african americans had served in every role. they had been pilots, commanders, mission scientists. they had demonstrated very well that people who are capable, who have the right skills and right drive and motivation could be successful astronauts. the last big task for the space shuttle was actually its original task. the task for which it was designed with the large payload bay, and that was construction of the international space station. it took about 40 missions to

assemble the international space station in orbit. starting in 1999 and completing in 2011. the space station as it exists now, it is depicted in the gallery in a model that we have suspended. 1-100 scale model. the actual international space station is the size of a football field. that gives you a sense of the tremendous technological endeavor to build something of that size in space. we have been in earth orbit for a few minutes, why don't we go to mars? just outside the gallery is viking, the first spacecraft to land on mars. here we are at viking. the first spacecraft to land on mars. actually, it is one of two

vikings that landed on mars. this is another thing that was in the news at the time that this museum opened in 1976. to have landed on mars after a number of trials and misses was very exciting. both the russians and the united states had been trying to put a craft onto the surface of mars. this was equipped as a sort of observatory and a sort of laboratory. it had a scoop at the end of a scoop upthat would soil and dump it into a little container where it would be subjected to some chemistry tests to determine if there were any organic compounds or any moisture in it. anything conducive to life.

in a very simplified version of things, the viking lander was going to look for signs of life. that is how the public perceived it. the scientific community was interested in a whole variety of other questions. what was the composition of the rock, what was the surface environment like? it had a weather station, a variety of instruments. this was the first chance to really touch and feel the surface soil and surface rocks on another planetary body other than the moon. tremendously exciting in the -- and the beginning of what has become a long history of returning to mars. each time with more sophisticated instruments, each time to learn more about the hashboring planet which

long occupied the people's imagination as the likeliest next destination for human exploration. landers like the viking open the door toward that possible eventual human exploration of the planet mars. vikings one and two have been dormant for a number of years. they are just sitting there on the surface of mars waiting to be rediscovered either by a rover or by some eventual human explorer. this viking is an exact duplicate, or triplicate of the two that went to mars. this viking lander was kept at the jet propulsion laboratory in california. during the mission, they used it as a test case to try out any procedures, to do

troubleshooting for any problems they detected with the surface landers on mars. this lander was really part of that family. planetary exploration has developed according to a well thought out strategy. you have to remember that back in the 1960's when all of this was brand-new, we did not know exactly where the moon was or exactly where mars or venus was. we knew approximately where they were, but you need to know that much more exactly if you're going to launch a spacecraft from planet earth in motion. the spacecraft will be in motion and the planetary destination will be in motion. there is a lot of calculations that go into that. in the early 1960's and mid-1960's, there are a lot of misses. we would shoot something toward the moon, and it would sail

right past or miss it by a long shot. the soviets would do the same thing. we would try to land something on the moon and it would crash into it instead. it was kind of a demolition derby in the 1960's. but that was the essential first stage to start sending crafts , out to fly by and increasingly get closer and closer to determine exactly where they were and what the celestial mechanics of spaceflight really were at an exacting level. after the flyby was perfected, and the purpose of that was to get a good first look. cameras on board could send back images. to get a sense of what that body was like. the next step was to send something to go into orbit with camerasain

and instruments to try to likemine what the surfaces , what is the atmosphere like. what more can we learn by being closer and staying in orbit? again, there were some near misses on those orbiters as well. but by the early 1970's, that problem was pretty well solved. you have flybys, going to orbit, then you send a lander. the next step is to send a rover so that you can learn about not only the immediate landing site where a static craft like viking fits, but you can also ranging out around it and start doing what human beings do, go exploring. extend the range, look around the next hill to see what is there.

the next phase in the exploration of mars has been rover. our next stop will be to take a look at three generations of mars rovers. now we are in the "exploring the planets" gallery where we focus on recent events in planetary exploration. as we learned with viking, the strategy tends to move from having a static lander which viking was to having mobile landers. this is one of my favorite parts of the museum, because this is where we display the three rovers doing research on the planet mars over the last 20 years. the first rover to land and operate successfully on mars was identical to this. it was part of the pathfinder mission of 1996. a little rover named sojourner was put down on the surface of

mars and it operated long beyond its expected lifetime exploring. it has six wheels and they are called rocker wheels that enable it to go over rocks without tipping over. it is about the size of a microwave oven. if you imagined a microwave oven having wheels. it had solar panels on top to keep it powered. and it was really a little geologist put down on the surface of mars to do some of the investigations that a human geologist would do. it is equipped with a device to touch up against a rock and determine what chemical elements are in the rock. it had a camera for guidance and it could pick up information about the ambient environment of mars.

you can think of them as the first geologists to set foot on mars and to go roaming around so that they could explore a broader area. this is the backup for the pathfinder mission. this one could have gone to mars itself. 10 years later, after the pathfinder mission, we had another mission that landed a somewhat larger rover on mars. this is a model of "spirit and opportunity." this is an engineering model not ready to go to mars. you can see the growth since the first rover. this is more like the size of a golf cart, perhaps. again, it has the special wheels so that it can operate well on the uneven terrain. and it is equipped not only with solar panels to keep it powered,

but with larger and more sophisticated instruments. it has a robotic arm and has almost a head here at the front at the top of this long neck. are is where the cameras for movement around enabling scientists here on earth to see where it is going and see what it is seeing. it has various other scientific devices on it. and again, a type of mars weather station to determine the environment. what is the wind like? what are the temperatures at different times during the martian day? what is it like when a dust storm blows up and passes through? again, this is a more capable geologist now on the surface of mars. but one that is mimicking some of the capabilities that a human being has.

"spirit and opportunity were launched in 2004. opportunity is still operating. still roaming around on mars sending back data. again, long outliving its life. now we will have a look at the third rover on the surface of mars. this landed in 2012. it is still working today. this is the model of curiosity. curiosity has grabbed public attention because, first of all, it is so big. it is like having a car on mars . and this is the one that has a very dramatic landing sequence where it was dropped from a crane that was descending from the orbital spacecraft.

it was called seven minutes of terror to get on the surface without being damaged. it was a very successful landing. curiosity has been roaming for kilometers on the surface of mars studying planes, on the rim of a crater, going into the crater, to have a look at the surface geology. the main mission of curiosity is to follow the water. scientists have a lot of evidence that at some point in the past, mars had a lot of water. the evidence is in sedimentation on mars and portions of land that look as if they had been washed over by water which evaporated. and the thrust of the curiosity rover is to investigate sites that seem to have an abundance

of water at some time in the past. once again, this is a circuit -- surrogate for a human geologist. much larger in scale than the spirit of and the opportunity rovers. much sturdier structure, a the sizehat really is of a compact car. camera and weather station instruments on board. this is also a chemistry lab. there are several devices that can do analysis of the chemicals in the soil and rocks. it is a very exciting mission and has no end in sight. i think the public has become very fond of these rovers because they sense they are surrogates for us and

pathfinders for us. they are doing the initial reconnaissance of the surface of mars so that if in the future humans actually go there, they will know a lot more about the terrain and know a lot more about sites that might still harbor moisture, if not actual water. this pattern replicates what we did when we went to the moon. we started with missions that flew past the moon. one of the next things we did a lander on the moon just to determine how firm is this soil. if humans land, will they be able to walk on the moon? i think we are quite confident about mars that humans will be able to move around on the surface of mars very well. the rovers have demonstrated how easy it is to do that.

one other thing about the rovers is they don't operate alone. there are whole teams on earth that are charting out their itineraries and scheduling their activities. and when they are working on the mission, in their heads they are on mars with the rover. they even wear watches where they set their watch to martian time. the martian day is 24 hours and 39 minutes. their day is just enough longer than ours that for the people working on earth, each day they start work 39 minutes later. the days creep ahead for them. when this museum opened in 1976, we were wrapping up a golden age

of human exploration with the apollo missions to the moon and we were launching into the first golden age of planetary exploration with the missions of the 1970's to mars and the outer planets. we are now in another golden age of planetary exploration particularly on mars with curiosity rover so actively exploring. we are right in the present moment when we are with the mars rovers. i wonder what we might see here in 10 years or 20 years as planetary exploration continues. with great success. we hope. there is much talk about having a human mission to mars by 2030 or so. if that should happen, that will

probably be the stellar attraction in the museum by the time the next major anniversary rolls around. this or otherh "american artifacts" >> next on american history tv, historian jason h. silverman talks about his book "lincoln and immigration." his encounters persuaded president lincoln that immigration is did america's economy. the lincoln group of the district of columbia was host of this event. this lasts about an hour. >> for our speaker this evening, jason h silverman. he's professor of h