Using Space Telescopes (extra footage)

sometimes things can go wrong in an unexpected way and solutions can still be found to keep the spacecraft working so an example of this is the Kepler mission which went up with the aim of looking for exoplanets around distant stars same issue with the gyroscopes had mechanical spinning gyros just like Hubble and eventually came down to points of failure in which it really only had two that were left at this point it wasn't in Earth orbit like Hubble it didn't have the magnetic torque or bars to act against the Earth's magnetic field and so it was really not able to be pointed in the accuracy that it needed to be with the precision that it needed to be to do some mission and so call went up to the community for good ideas on how to make this work someone came up with a real genius idea of using the photon pressure from the Sun as the third stabilizer so getting those spacecraft in an orientation in its orbit so that every part of it was feeling the same photon pressure from the Sun that's that's the pressure from individual photons hitting the spacecraft and that was enough it didn't mean that you could point it anywhere you want it anymore you had to keep it in a really steady safe orientation but that allowed them to extend the mission looking at one particular patch of sky throughout most of the orbit of the spacecraft around the Sun for me the program that we had was a fairly large program it was we were awarded Aidan orbits on Space Telescope hello there in time so one orbit is about 19 minutes but a good fraction of that you're actually behind the Earth and so that's when all the maneuverings done any large-scale maneuverings are done when you're passing behind the earth and then you've probably got a depending on where you're pointing a window of about 50 55 minutes to make your observations with what were you looking at so I was looking at that area of that poster back there which is what I've spent much of my career looking at and that is an image from a ground-based telescope with one camera pointing covering an area about the size of the film and in a really wide field camera we then got time on Hubble to go back and make a panorama across that and we calculated we need 80 images with the Hubble Space Telescope we stitch them all together and then we cover that whole area with really high resolution imaging making during that 50 minutes that you have got Hubble four on the orbit presumably the telescope is kind of moving or slowing so it's continually pointing at that one bit of the sky you want that's where the gyroscopes come in and also the fine guidance sensors which are the final part of the the really fine-tuning of the pointing and so once you get in the region of your target you provide it with the locations of some guide stars and there's a special instrument on Hubble devoted to keeping those guide stars locked in place and not letting them move at all out of the field of view so in preparing for this video I went back into my email archive of 10 to 10 and 11 years ago and I'd actually kind of forgotten the incredible headache and complicated nature of scheduling these observations and exactly what happened because and I have a piece of paper here cool because instead of a nice symmetric up and down north-south-east-west lovely square mosaic what we ended up with in the end was this rather jaggedy looking outlined which is all 80 of our images stitched together so this square represents the area of that poster and this jagged region represents the observations that we did with Hubble of that region all stitched together it was thought you missed a few this well this was a complicated thing so when when we try to design the observations so you don't do get time and then get to point the telescope where you like you have to fill in very very technical instructions on what you want your observations to be when you want them to take place if that's important any other information that goes into the schedulers when they try their best to make that happen so we said right we would like everything to be oriented in a nice square pattern please but the complications that we had with respect to the pointing availability of the telescope with the earth with the solar panels this the direction to the target meant that there's very limited amounts of time in which the telescope could be pointed with that orientation and so what I'd forgotten is that in fact there was another survey that was already ongoing the cosmos survey which is a huge huge Dalek ation of Hubble time and they are not too far away on the sky from where we wanted to point and they paid basically locked up all the time that we call this the roll angle the orientation of the telescope's pointing on the sky basically locked all that up and so they came back to us and said sorry you can't have a mosaic that looks like that we can offer you this angle and so then we had to reject all of our observations and the location of all of 80 tiles to stitch together this is rather less aesthetically pleasing but still scientifically absolutely fine mosaic that we've used since then is it a nervous time when it's your hubble time or if they got it down so slick now that when you've got Hubble time you know it's all going to work or for those like a few days there you like having Escalus nice thinking oh I hope the images are coming out right I hope it doesn't break or you're pretty confident you get what you want when you've got a bolt I'm well I mean you can never be confident with the things in space space is hard Hubble is a wonderful facility but things have gone wrong instruments have failed in fact the fact that an instrument failed opened up the time that ended up being used for my program so in a sense you know our scientific exploits were founded on the back of someone else's disappointment which is really kind of sad but you can there's never a guarantee and I haven't used it recently but as I recall I didn't know to the to the hour of the military even the day when the observations were going to take place things are being shifted around even at that very late notice so essentially it was just sort of cross your fingers wait for the emails and then hope hope it all all came through in fact what happened with us so we designed the program so that we started from the inside and we worked out in kind of a spiral in case something went wrong we'd still at least have the central regions covered you can see some of these squares are marked in grey and that's because for these ones at the edge we didn't manage to fit them in before the window of observations closed so the one in the middle that observation failed because the guide stars didn't work out so what happened is they came back six months later when the telescope was in a complete 180 degree or different orientation and took the observations for us to complete that mosaic but everything else was done by our request very close together all in one chunk how do you get your data like do you open an email one day and see like an amazing photo of stars or is it more anticlimactic than that happy when do you first see your results when you have Hubble time we get an email that tells you can go to the archive and find your your data there it's yours to do what you want with for 12 months and then it gets opened up to the public to anybody who wants to access those files can register for an account I know a lot of manipulation are done the Hubble pictures to make them look like well I think Hubble pictures of like when you first see your Hubble pictures as raw data do they look spectacular or today the would I say they look boring well I mean one of the nice things about Hubble is that it has this wonderful pipeline that all the instruments are so well known and so well calibrated that software has been written that will take you from the raw images to a fairly complete image sort of automatically so to speak you can do it all again if you want and many many people do to try to fine-tune it for their own purposes but you can you can get a pretty good image out so it's not the color image it's not you know with all the nice blues and greens and reds but but the black and white data does come out pretty cleaned up with all the noise removed doesn't mean that if you're looking for something really faint you might be able to see it in a single frame you might still need to be combining frames that sort of thing if and when James Webb telescope gets up into space and starts doing the business is that one that you're going to want to use um yeah sure everyone wants yes so the strengths of James Webb telescope playing to the sort of science here you do well no that's actually that's that's not quite the case a lot of what I do needs big numbers of objects and wide areas and that's kind of the opposite of what James Webb does it does a small small area of sky and very high resolution but it doesn't mean you can't think of something to do with that reduces the amount of light and the wavelength of light otherwise you would you would fry your optics and you would fry your eye if you looked through an eyepiece on it this camera over here is connected to this computer that does all the image acquisitions

Channel: nottinghamscience

Views: 16,548

Rating: 4.994421 out of 5

Keywords: hubble, telescope

Id: M_TC_kKN0hA

Length: 10min 5sec (605 seconds)

Published: Tue Jun 27 2017