Space Science Sixty-Three: Laboratories In Space (1963?)

[Music] [Music] space science 63 with John Fitch is a presentation of the National Aeronautics and Space Administration today's program Laboratories in space [Music] hello I'm John Fitch and this is Nimbus Nimbus is a weather satellite the first of its kind will go into orbit sometime in the next 6 to 12 months now on this program we're going to be talking about Nimbus and some of its many many cousins the instrumented satellites actually we could probably spend a whole half hour just naming all the satellites that are in orbit or the ones that are being readed for future experiments there are so many of them that I admit it does seem confusing at times but maybe would be a little clearer if we sort of group them into four main categories I guess the one we're most familiar with is man space flight project Mercury that was one man in orbit around the Earth Project geminy two men going around the earth and finally project Apollo which will send three men to the Moon in Back Then There are the deep space probes like Ranger to the moon and Pioneer in orbit around the Sun and of course Marina which sent back such interesting information about the planet Venus the rocket soundings don't go into orbit of course these are instrument packages which are hoisted aoft on Rockets gather information and send it back to Earth and finally our subject for this program the unmanned instrumented satellites and these fall roughly into two categories the application satellites and the scientific satellites many of these instrumented satellites are being planned and tested out at The Goddard space flight center in Green Belt Maryland we're very fortunate and having the director of g Dr Harry J get to tell us about some of these satellites Dr get it seems to me with so many of them that some of these programs must uh overlap or even duplicate um other programs for instance we have weather satellites like tyros and Nimbus well it is true that both tyus and Nimbus are weather satellites but Nimbus is a much improved version of tyros for instance it's has the same relationship to tyos as you might say the DC3 airplane had to the right Brothers airplane at Kitty Hawk oh I see it's really an advanced version then that's so well now we have a model of tyros perhaps you could explain to us how it works yes this is a half scale model of tyros it's up in orbit now we have two of them up in orbit at 400 miles above the Earth and it spins about this axis and when this surface looks down here we have a camera which looks down on the are and uh takes a picture of the cloud cover it takes a picture on a u what in effect is a television tube very similar to the tube that you have in your home television set except that it's a sticky tube and for the two seconds that it holds this picture we scan it we pick off electrical impulses which are then recorded on this tape recorder here and then when the satellite comes back over our ground station it's possible to transmit the signal that is stored on this tape recorder down to the ground now when you get it back to the ground then how do you put the picture back together again well of course then we have a bunch of electrical impulses and we put it back together in a manner that's very similar to the operation of this faximile machine that has been in use for years on Earth here for transmitting pictures to a distance the electrical signal actually actually is put into the machine it is then converted reconverted back into a picture into light impulses and out of it we get a picture for instance here is a picture that was developed as a uh satellite passed over the Mediterranean as you can see here the Mediterranean the uh Nile and the Red Sea very clear yes if anybody had any questions in their mind about the accuracy of the geography books you can see here that they were they're right but now we get a series of these pictures 32 of them in sequence and by putting these pictures together you can get an idea of to the general Cloud pattern uh over this region of the earth uh here is a typical one and I happen to have selected one which uh shows the development of a of a um hurricane isn't it true that tyros actually gave us our first indication of that uh tremendous hurricane I think it was Esther back in uh 1961 uh this is so as you see we purposely are launching these satellites uh during the hurricane season so that they can do precisely this and uh hurricanes generally uh born on in the Atlantic west of Africa and uh tyos actually did observe hurricane esta and other satellites some two or three days probably before they would have been observed by any other means that can be very valuable then to someone who wants to protect his property getting that additional warning uh yes indeed well now if tyros works so well why do we need Nimbus well trouble with tyros is that it only spends less than 25% of its time looking at the Earth and uh we want to make it so that we our next satellit spends 100% of its time looking at the earth I have to go over here and uh show you on this globe uh why tyus uh Works in this way and what we hope to do in order to uh fix it up do you recall uh earlier when I showed you the model of tyos I said it was spinning in orbit which means that it it's like a gyro up there and it looks at a given region in space then all the time so as it passes over the Earth here uh at this point in orbit the camera is looking down on the earth and therefore it if the Earth is sunlight at this time it's possible to take a picture of it but now as it passes over on this side as you can see the camera is looking out into outer space so obviously we can't take any pictures comes back again and then when it gets on this side again it is looking at the Earth so what you'd like is a satellite that'll look at the Earth all the time that's right uh we we want a satellite that will go around the earth and and and look at it like this how how you going to be able to do that well as you can appreciate in order to do that we have to do two things we have to do something which will tell the satellite where the Earth is and then secondly we have to give it some muscles so that it can nudge the satellite around and make it look at the earth I think in order to show you how we do that I have to take you over here to this fullscale model of nimbus which we hope to launch within a year from now now the way Nimbus knows which way is down in other words which way the Earth is is by means of this Horizon sensor up here this Horizon sensor will tell the difference between where the Earth starts and where space begins it transmits a signal to the control system of nimus which consists of inertial Wheels here and these Jets and by these inertial wheels and jets we can nudge nus so that it can in fact stay keep looking at the earth now if it's looking at the Earth the how does it get its power from the sun because it won't be pointed towards the sun well uh as you can see these are the solar paddel which get the power from the Sun and what we would like to do is keep them perpendicular so the sun shines right down on them this way what we do is that we have a shaft here and they can rotate around this shaft and they'll have a sun sensor on it so that they will always they will rotate with respect to the satellite but always stay oriented with respect to the sun well that pretty well tells us story of our weather satellites and what about the rest of our applications program well the other part of the applications program that is close to fair to application is is the communication satellites we go over here we have a few models of the communication satellites that we have launched this one as you will recognized as a small scale model of echo oh yeah which was that 100 foot sphere that was launched you can still see that can't you every once in a while if you look in the right direction in the sky you can see it now Echo is a passive communication satellite now what this means is is that uh all it does is reflect the radio waves uh the station will transmit say from the East Coast here it can't see the station on the west coast because of the curvature of the Earth but it can send a radio beam up here can bounce off and can be intercepted by the station on the West Coast mhm now in distinction to this passive satellite we have the active satellites represented here by Reay here by sycom and then of course there is telar which you have also heard uh the difference between these satellites and this one is that they're active because they not only intercept the beam and reflect it but also they amplify it and they they transmit back they have their own little transmitter that's right now there are brought two types here one is real which is very similar to to telar it's characteristic that has been put into a low earth orbit in order to get Constant Contact communication contact we'd have to put some 30 of these satellites in in orbit at a time what syncom tries to do is to put the satellite up much higher into what we call a sychronous orbit this mean this means it goes around the earth just once every 24 hours instead of once every 90 minutes as this one does and if we get this located just above us all the time or halfway between us and Europe we'll stay up at this portion of the sky and we'll be able to look transmit to it and from it constantly see isn't it true that some of these um applications satellites also carry scientific experiments which have nothing to do say with the communications uh this is so although this is sort of a byproduct you see in the first place in order for these satellites to be economically feasible they have to last for some 5 years so we send up some instruments which will tell us what is the environment they're going to be exposed to what will be the damaging effect of the particles but uh our scientific exploration of space uh we really do from a completely different set of satellites which are specifically made for this purpose well now what is it that we're trying to find out well probably best to go over here and look at this uh simplified map of space which shows you the various areas of interest to us and they really can be divided into three areas we know that what goes on up at the sun affects us very very importantly down here at Earth so our one objective is to get some satellites up above the atmosphere here so we can look at the Sun and that we can observe what is going on up there we do know is that every once in a while the sun puts out a big solar flare these are huge explosions on the face of the sun you can get a better feeling for just what they are from a look at the film clip we show here and what our objective is now is to look at these explosions in considerably greater detail to determine what are the temperatures inside them what are the magnetic fields and what the like that produce them now they do spew out we know uh a magnetic field and a particle and plasma flow out into this region here which we call interplanetary space now in order to better understand just what they do throughout we have another set of satellites which operates in this interplanetary space region and samples these particles now the third region is that surrounding the earth as you know the Earth is not only surrounded by the atmosphere which to a certain degree Shields it from these particles but it also is surrounded by magnetic field lines coming from the Earth's magnetic field and we call this a magnet magnetosphere now this magnetosphere acts as a huge magnetic shield and these particles come and bounce off it some of them come on and penetrate down in hit the upper atmosphere and uh in so doing create a new set of particles which become the population of the Van Allen radiation belts we have all come to know it is our objective then to investigate the population of this Van Allen belt but more importantly to determine where these particles go because we do know they follow the field lines down and up in the polar regions they impinge on the ionosphere and the upper atmosphere and so doing they heat the atmosphere and we think they are the cause of the changes in weather so as you can see we have three regions that we want to look at one the sun itself second is the interplanetary region and the what goes on there and third is the magnetosphere now can you give us an example say of a satellite that would be used to study the region near the Earth this magnetosphere well one of them is this satellite of which we have a small scale model here this is the aerial satellite known as the International bonosphere satellite it has the international uh tinge to it because it in fact was built at goded but the eight experiments that are on board it were furnished by British experimenters now these experiments were designed to investigate the uh characteristics of the upper ionosphere the how many electrons are up there what is the electron temperature how this varies with solar vents because we can observe fluctuations in it here and this little ball up here was a u a magnetometer which told us something about the magnetic field there now it is from satellites such as this and there have been a number of others launched into the ionosphere or upper atmosphere that we are studying this particular region and what about satellite that would be used to study that interplanetary region that you mentioned well here is an example of this this is explor a 10 this satellite was launched and went up to an altitude of some 185,000 mil which took it well beyond the influence of the Earth's magnetic field that's more than halfway to the Moon isn't it uh that's right uh now uh obviously out there the the magnetic field is of much lower value than the magnetic field is here for instance uh it's 60,000 times here the value that we expected to find up there therefore in this uh ball up here there was a rubidium magnetometer which could measure very very low magnetic fields and in this portion of the uh satellite uh separated from the ball so that it wouldn't influence the magnetic field up here where energetic particle experiments now a typical energetic particle experiment is a Gea counter which counts the number of particles well there are different ones so with this we're able to determine what goes on in interplanetary space and we were very very fortunate that when this was out there a solar vent occurred and we were able to sense first the quiescent condition in the absence of a solar vent and then the hu the very turbulent fluctuations in the magnetic field and the energetic particles that were carried along with it well now what about the source of these disturbances the sun itself that was the third item that you mentioned that you wanted to study yes uh we study that from the orbiting solar Observatory which one of which has been up there for a year now now this is a full scale model of the orbiting solar Observatory well tell me Dr G I mean we can see the sun perfectly well from right here on Earth with telescopes and and other means why would we need a an orbiting Observatory well order to explain that I think I have to go over to this little setup over here and demonstrate what the Earth's atmosphere does to the sun first place Let's uh assume that This Little Light here is the Sun and as you can see it not only puts out visual radiation which we can see but it also is putting out some UL Violet radiation which we're measuring right here actually we have an UltraViolet sensor here and this needle shows the amount of ultraviolet radiation that is impinging on it right now first now let's then take this U little piece of glass and simulate the atmosphere with it if I put this glass in front of the light you can still see the visual uh radiation through there on the other hand when I put it in front of the light you can see from watching that meter that it cuts off the ultraviolet radiation Dr get does the atmosphere filter out other types of radiation besides this ultraviolet that you've mentioned yes it uh filters out all the shorter wavelengths which means that the X-ray in the X-ray region and in the gamma ray region as well as the ultraviolet these this radiation is filtered out so that's why you have this uh orbiting Observatory which I gather we'll be able to measure these radiations from the Sun that's right uh this opening obervatory its purpose is to point the instruments which are in this particular part of the satellite at the sun now the way this is done is that this once again is a gyroscope in space this particular portion of it rotates at about 30 RPM whenever it drops below this uh rate of rotation some little Jets of compressed nitrogen that in this this bottle here speed it up so this means that this whole vehicle here is stabilized in space and you will notice that this portion of the vehicle the upper portion is in effect what we call a sail this is not rotating but this is I see so now we have a p platform in space and there are jets up here which can press this around so that in the end it ends up with this section of the instrument here pointed at the Sun and this portion of the uh satellite has a number of different experiments that will look at the sun in the different wavelength regions and tell us what's the temperature tell us uh for instance is there iron or helium or what have you that is causing uh in these areas that they're looking at mhm now in addition there are some experiments in the wheel which is rotating which every time it comes around at this point we'll be looking up at the Sun what happens when this goes around behind the sun well that's a behind the Earth is what I really mean good point here is that every time it goes around behind the Earth it it loses sight of the sun this means it has to point at the sun uh again so once every 90 minutes it has to point back at the Sun and this is a fairly neat uh trick because uh uh pointing at the Sun at this distance is about the equivalent of uh pointing at a u beach ball at uh some two miles distance and this opening solar Observatory has succeeded in doing this someplace between 5,000 and 10,000 times during the year of its existence amazing now I've also heard this uh referred to as a street car satellite what does that mean well uh you appreciate that the previous satellites that we have uh talked about uh they were sort of special purpose satellites they were specially designed for a given purpose in contrast this one here carries some 13 different experiments we intend to launch it at about a rate of once a year with a different set of experiments right it comes around like a street car that's that's right the the analogy is is that U the other ones are like taxis which go to a special place and uh just especially for this purpose this one uh will run a given route which will be to the sun in effect and will be people by different passengers each time it is launched every year that it's launched are there other street car satellites besides this one uh yes there are uh and just like street cars which run to various points each one of these Observatory satellites has a different purpose this one has the Sun as is clear now this one over here the street car satellite that runs out to interplanetary space uh or the magnetosphere it's a pretty strange looking Contraption well now the reason it looks like such a rub Goldberg contraption is that because it does carry between 20 and 30 experiments uh but these experiments want to do different things and they want to look out in different directions we have a set of experiments that will be down in this end this end will be pointed at the Earth so in this end we will put the experiments I want to look at the earth now in these boxes here see we always have to keep these solar panels pointed at the Sun so here we'll put the experiments that want to look at the sun here we put the experiments that want to look in the direction the satellite is moving in the oval plane here the the satell ites I want to look back and uh here are The Satellites that uh that want to look out or the experiments I want to look out in still another Direction this particular one here carries a magnetometer and it uh it has to get far away from the rest of the magnetic elements in the satellite here so that we be sure we're measuring the uh magnetic field of interplanetary space not the vehicle you can well imagine that we can't launch a vehicle of this nature in this particular uh configuration so actually it is as you can see it's a very complicated folding uh mechanism which which all these will fold together these things will pull in and the they will be launched in the folded condition then when they get into space they will be deployed are there still other kinds of observatories uh there's one other type of Observatory which is over here and this is directed at a region of space that I haven't yet mentioned you notice all my discussion so far has concentrated on the uh the solar system MH uh now the purpose of this Observatory which is the orbiting uh astronomical Observatory is to uh look out at the stars first thing I should say is that this is a relatively small scale model of it this particular section here will stand some 10 to 12 feet high and really what we have here is uh uh the objective of this orbiting astronomical Observatory is in one sense the same as the objective of the mount Palama Observatory uh now obviously we don't carry a 200 in telescope but we do in effect carry a 30in telescope in here and what we have to do is the same as you do uh on the um Mount palom telescope we have to point this accurately at the stars with a very very high degree of accuracy so there's quite an engineering problem of Designing this spacecraft to so that you can point accurately and hold this accuracy over long periods of time in discussing some of these more advanced uh satellites it seems to me Dr G that you have mentioned uh that that we take what we learned from one set of experiments one set of satellites and uh use that information in designing the new satellites is that true uh that's true it seems to be uh true of any area of research and it's surely true of space research during this time when we're sort of in the exploratory uh era is that we find out a lot of things but in the process we spawn a lot of new questions as a result of what we have found out for instance the U oring Soul Observatory has already told us a lot about the Sun but we're just aching to get another satellite up there so that we can look at specific regions of the sun to see where these high temperatures are located that it has detected earlier you also you pointed out the International satellite aerial which I believe is in cooperation with the United Kingdom what about some of the other countries are we going to have an international program in that respect uh the work we're doing in space is a lot more of an international Venture than most people realize uh it not only includes the cooperation on the satellites themselves such as the cooperation with the uh the British but here is another example of a second satellite in which the Canadians built it we launched it and it's up there but really the uh the broad-based cooperation is is that there are many ground stations in a number of countries that are receiving the data that is transmitted from the satellit and the scientists in these countries are actually in a position to analyze these data uh you also will get a feeling of uh of this from the fact that now it got it in order to do our job and receive the data from our various satellites we have some 30 Ground tracking stations located in 14 countries throughout the world and uh we're quite uh this is quite an extensive International cooperation well thank you very much Dr again well I think you can see that we've certainly come a long ways in The Last 5 Years From This little grapefruit called Vanguard 1 to the tremendous Nimbus weather satellite I wonder what the next generation will be like h [Music]