I grew up with inches and feet and miles and over the past year or so I have using metric for most things. So much easier to follow. Now-a-days, less conversions to worry about too!
Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) operated by ESA orbit at around 250 km and to do so, they had ion thruster continuously firing to maintain that extreme low altitude. Although some satellites and spacecraft had been orbiting as low as below 150 km, they only doing it briefly. Cheers : )
@@mdellertson You'll find scientific papers if you search it with a browser. It is getting a fair amount of attention right now. Maybe try typing something specific like, "Ion Drive/whitepaper"
The 2017, Super Low Altitude Test Satellite (SLATS) or Tsubame using Ion engine propulsion has demonstrated a sustained orbit of 167 kilometers or about 104 miles for a duration of one week.
Communication satellites fly that high in order to stay in a geocentric orbit (23h, 56min, 4sec) in order to stay anove the same place in the earth, so people on the groud would have constant communication without changing the dish's orientation (for example satellite TV)
Nano-satellites, and they are an intriguing trend. Nono satellites represent are small m, as small as a cube a few inches square. Nations line Japan have been launching these; they are primarily research satellites. The advantage is the lower cost not just to produce them, but also the lower cost to put them into orbit. Because nanos are so small, they incur less aerodynamic drag at their very low orbits. Akso, there are now electronic propulsion systems capable of boosting nano-satellites to maintain minimal orbiting parameters. Separately, lowest satellite orbit ever was achieved by larger tyke satellite that skimmed the Earth with an 80 mile perigee while having a much larger apogee (elliptical orbit). It completed one revolution around the Earth before reentry.
I recently read a study proposing something like 54 km as the new boarder to space. The reasoning is, according to the person conducting the study, that is the statistically lowest altitude a satellite can still orbit before fully reentering. He said there were a few examples of satellites reentering that did at least two full orbits at that altitude, but I don't think that constitutes a better definition to the edge of space. Food for thought. Anyway, thanks for the video, and keep up the good work!
No, we haven't explored every corner of our solar system, that would be like saying we visited 8-9 landmarks under the ocean thus have explored every corner of the seas. There's a LOT of space out there and all our satellites have only traversed a tiny fraction of the total area that encompasses our solar system, but yes we've visited most of the major landmarks, not all the moon's yet, nor the belts, ort clouds or intergalactic visitors (omuamua).
there is research by ESA to collect the left air particles, decelerate them and use as fuel of Ion drives. Unfortunately I have no Idea at what altitudes they aim
GOCE flew at the edge of the atmosphere, and was kept in orbit by an ion thruster. To quote the ESA website, 'Launched on 17 March 2009, ESA's Gravity field and steady-state Ocean Circulation Explorer (GOCE) mission was the first Earth Explorer mission in orbit.' GOCE operated until late October 2013, when its fuel was exhausted, and it de-orbited on 11th November 2013. The craft was somewhat streamlined to reduce the effects of atmospheric drag. There are plans for another launch. You might want to make a video about this interesting satellite.
The Karmen line is simply the point at which there isn't enough air to provide useful lift to an aircraft in order to stay up. At that altitude, your horizontal speed has to be so high (from the thrust of your engines) that wings don't make a difference any more.
Minor correction - New Horizons didn't "end its nine year journey successfully" - it's still going! On Jan 1, it will pass Kuiper Belt object (486958) 2014 MU69 (which will get a "real name" after the flyby.) It is even scheduled to pass 1/3 the distance than it did in its pass of Pluto!
I should point out that the hubble telescope is a distant cousin to the KH-11 keyhole satellites, being designed and built by the same companies between the late 80's and 90;s, the hubble of course was optimized for looking outwards, with larger instrument bay and was made to be serviced. It still features the same basic design and 2.4 meter telescope. You may not have heard but the national reconnaissance office gifted a pair of unneeded keyholes (minus the CCDs and classified electronics) to NASA in 2012. These 'obsolete' observatories were made much later than the hubble and are somewhat more advanced, despite still having the same 2.4 meter aperture they have a secondary mirror allowing wider field of view as well as more focused zoom. Fitted with more modern scientific equipment they should be vastly superior to the hubble, especially if launched as a pair for stereoscopic observation. Though NASA probably doesn't have the budget for this. The WFIRST sattelite is planned using one of these satellites, as long as funding doesn't get cut it should launch in a few years.
You can see the ISS at night with your bare eyes if the conditions are good. It has a very destinctive light that is brighter than any star, and it moves faster than any plane. At my location it passes overhead nearly every night, sometimes more than once, since it only needs 90 minutes to orbit once.
I spend time watching ISS passes, have seen many Starlink trains, and always looking for other satellites. I’ve wondered about lowest possible orbits since witnessing a dim satellite moving west to east at an apparent speed I’m guessing was 4-6 times faster than ISS passes. No idea if it was something in a stable orbit, or if it was something destined to re-enter shortly. If it was in an eccentric orbit, and seen at perigee, it could have been quite low so apparent speed would appear much faster. Do you have any examples of things that can be seen demonstrating very low altitudes? Assuming a near circular orbit, it seems one could calculate a satellites altitude by by rigging a movable fixture / framework with a couple glow in the dark strings stretched across it, parallel and at a distance from ones eye that can remain fixed. Measure the time it takes for ISS to cross between strings, check time for others to do the same, and do a little math.
Check your math. I enjoy the videos but often get hung up on silly mistakes like you saying 350 is 1/10th of 35,000. Dude! You can fix these kinds of things to take your channel to the next level
Apollo 15-17 achevied an even lower 'parking' orbit at ~170km before trans lunar injection. These parking orbits are not stable in the long term. It should also be noted that failing/uncontrolled objects like Tiangong-1 made a few orbits at even lower altitudes before reentry.
The lower the orbit of a satellite, the faster it has to be, right? I was kinda expecting this fact as a part of this video (just because of thumbnail and name), because the max. speed could also be a limit to how low a satellite could fly I guess.. or is the "drag-problem" much more significant than the "max. speed-problem" ? maybe you could do an extra video on this topic or get to it on the spy satellite video. thanks!
The difference in size of a 100 km orbit and a 200 km orbit is negligible when the body being orbited is 6380 km in radius about its equator. Kepler's Third Law: The square of the orbital period of an object is directly proportional to the cube of the semimajor axis of its orbit. Or, simplified for a negligible mass orbiting a much larger one in a circular orbit: Orbital velocity is proportional to 1/square root of the radius. That's about 0.76%
Theres no such thing as a "max speed problem". you can fly any speed you want. On earth the max speed of an object is determined by the amount of drag and the amount of propulsion against the drag. But if theres no drag, theres no max speed either. New horizons is going something like 16.26km/s, while a spacecraft in low earth orbit is going something like 7.8km/s, so you see that speed is not a problem. Only limit to your speed is the speed of light. But thats not a concern.
Interesting subject. I recall reading that the heaviest satellite launches on ULA's Delta-4 heavy platform were all coincidentally classified military payloads. I guess all that camera glass weighs quite a lot!
Yes, please do a video on spy satellite 🛰 I was blown away when I was told that the Hubble telescope has design features and technology which most likely came from spy satellites
You forgot one of the main factors to why ISS is placed in its current orbit and its how high the Space Should could send useful payloads back in the day when the station where build. They could only reach so high while carrying the components that made up the station. The exeption is Hubble whom was placed in a much higher orbit but that took some extra effort to get there when they build and repaired that telescope. Johan.
There's currently a development of a satellite with scramjet engine. The engine will use solar power as it's energy source. Soon, satellite can fly as low as 80 km above the Earth.
Hi Lei, I love the work you do! Keep it up. Some things I want to point out, your pronouncing Uranus wrong and we haven't explored every corner of our Solar System yet! That would imply that we have checked every single moon, asteroid and comet in our Solar System and that is not the case. But overall amazing job! Can't wait for a video talking about spy satellite and how they reboost their orbits!
*....Great Video!! Can you please send me a Link to a Satellite Orbiting the Earth? I've been searching for myself over 22 years and I can only find CGI Cartoons of Satellites Orbiting the Earth.. Any information or help would be greatly appreciated.. Thank You....*
those spy satellites are HUGE. Those things are bigger than the hubble telescope. they carry more fuel than you might think. Also, they don't fly at a constantly low altitude. and the keyhole satellites have a strongly eliptic orbit, which of course lowers the overall drag.
Don't forget dron military spaceship like X-37-B, OTV. How many spy and military satellites are there today? I think that there are thousands, and some U.F.O cases are these vehicles sometimes. Thanks for this video. Have you got a nice weekend!
What would be really interesting is showing an actual real satellite in the vacuum of space, cartoons, animations, cgi are not real satellites, just show one satellite video in real time...thanks
Even lower orbits would be parking orbits of spacecraft going to GTO or those who leave earth. They can go as low as 160 km because they only stay in that orbit for up to an hour before they do their apogee raise burn or their escape burn.
Theres no limit for how long you can stay in an orbit. You can stay as long as your fuel lasts you. Because in an orbit that low you'll need to make a lot of correction burns either way. The slats spacecraft is supposed to descend down to 180km(it'll go down in steps) and stay there for a week, or until it fuel runs out.
Well yes! We surely want to know deep about spy satellites. Please do make a video on it. And mention the America's biggest Intelligence failure as well which occured during May 1998, the Nuclear test in India!
Would love to see more videos on spy sats. Speaking of spy sats, I would interested to see another follow up video on Zuma. Its surprising how quick that story got dropped by the media considering the enormous costs involved.
Oh I wouldn't say that we have explored every corner of our solar system. Uranus and Neptune have only gotten a brief fly by and the sun itself still leaves us with mysteries which especially Parker Solar Probe is going to solve within the next decade. But we do certainly know a low more about the solar sytsem than 100 years ago.
t. gobold, Agreed. 👍🏼 Saying we’ve explored every corner of the Solar System is like saying visiting a handful of islands means you’ve explored every corner of the Ocean. 🤔
3:00 : FYI the plural of 'spacecraft' is spacecraft! Not 'spacecraftS'. This noun is an irregular. 'Sheep' is another. As in: "I have one sheep, ypu have two sheep". "Car" and "horse" are 'regular: one horse, two horses, etc.
There’s a satellite with an air breathing ion engine being developed, I’m pretty sure it will fly below the Karman line, it will fire its engine non stop to stay up. You should do a video on that
You forgot to mention this one with a propulsion and unique design (254 km orbit): en.wikipedia.org/wiki/Gravity_Field_and_Steady-State_Ocean_Circulation_Explorer
also any internet based satellites in teh leo orbit can get close to 200. I know I thought was a communications statellite for a foreign customer of spaceX was going lower but might be wrong about that. Again we have to much garbage up there right now
satellites are very far away from each other. you know. like when you are on an airplane.. you dont see planes everywhere. doest that mean that planes dont exist? or that earth is bit bigger than you thought?
What is the lowest possible orbit on a planet/moon without an atmosphere ? Can someone do a 10m orbit on moon (assuming moon a perfect sphere)? (or in other words what is the equation to find out lowest possible orbit of a perfect sphere object in space ? )
I believe the Zuma-Mission by SpaceX was a success and the satellite is flying very low. It was a land landing, which is an indication of the low altitude. (conspiracy theory end)
Half a m resolution, yeah, they can go a lot smaller than that. Smallest thing you see clearly is about 90 ~ 100mm. 10cm. You can lay a car registration plate on the ground, so you are looking at it on a right-angle, and you can usually read that. A big bold simple headline on a newspaper, can be read. The limit is largely the air. When looking up & out, we have adaptive optics, with a laser to tell them what they should do, but when looking down & in, you don't have that. Do you know what the Hubble Space Telescope is? It's basically a US spy satellite that's been turned around to face outwards... Do you know why the optics on the Hubble were wrong when it was first launched? Because it was not designed with an infinite focal length. It was designed to focus about 200 ~ 400 km away.... Now the cameras & sensors fitted to the Hubble for astronomy, are very different to what the office of reconnaissance fits, but the basic optics and canister, they're the same.
157 239n - Can I give a source? Um, not really. It launched in 1990 and the patch-up mission was '93... I think I heard about the original source of it (the office of national reconnaissance) in '95 or '96. I just had a look at the wikipedia page, which does contradict my version completely, but that's the story I heard back in '95. I have heard more or less the same story, with very minor variations, a number of times over the last 20 years. Slightly different versions of the story I've heard, one was that Regan wanted at least 6 of them, but by the time they had 3 in orbit (and Regan no longer in office) they found the results from those were so good they simply didn't need to have 3 more... Another version said that after the first 3, they wanted the next one to have slight design changes, but the next one had already been built... so it was surplus to requirement. At that time, the plan was well under way to make the Hubble, so they quietly approached some senior people in that project, and asked if they'd like to buy a pre-built telescope cheap...
Barry Woods HST is in earth orbit and it's much closer to earth than the moon so it could be the case that HST can't see stuff on the moon but can see stuff on earth. The same site at hubblesite.org/reference_desk/faq/answer.php.cat=topten&id=78 said that the HST can't see stuff on earth due to tracking reasons as it is designed to track stars which move slow and can be easily tracked from our vantage point.
Spy sats: yes!, please.
I am happy that you use metric system for the description of the video.
I grew up with inches and feet and miles and over the past year or so I have using metric for most things. So much easier to follow. Now-a-days, less conversions to worry about too!
miles yards is better
Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) operated by ESA orbit at around 250 km and to do so, they had ion thruster continuously firing to maintain that extreme low altitude. Although some satellites and spacecraft had been orbiting as low as below 150 km, they only doing it briefly. Cheers : )
it was also designed to be aerodynamic to combat drag, which for a satellite i find super cool
We have ion thrusters? Where can I read more about those?
@@mdellertson Google/ UA-cam ;)
It's as easy as leaving a UA-cam comment!
Josh Kaufman thanks but I’d like to “read” about them not “watch”. I was actually thinking a scientific paper or something of the like. :-)
@@mdellertson You'll find scientific papers if you search it with a browser. It is getting a fair amount of attention right now. Maybe try typing something specific like, "Ion Drive/whitepaper"
The 2017, Super Low Altitude Test Satellite (SLATS) or Tsubame using Ion engine propulsion has demonstrated a sustained orbit of 167 kilometers or about 104 miles for a duration of one week.
Communication satellites fly that high in order to stay in a geocentric orbit (23h, 56min, 4sec) in order to stay anove the same place in the earth, so people on the groud would have constant communication without changing the dish's orientation (for example satellite TV)
Nano-satellites, and they are an intriguing trend. Nono satellites represent are small m, as small as a cube a few inches square. Nations line Japan have been launching these; they are primarily research satellites. The advantage is the lower cost not just to produce them, but also the lower cost to put them into orbit. Because nanos are so small, they incur less aerodynamic drag at their very low orbits. Akso, there are now electronic propulsion systems capable of boosting nano-satellites to maintain minimal orbiting parameters.
Separately, lowest satellite orbit ever was achieved by larger tyke satellite that skimmed the Earth with an 80 mile perigee while having a much larger apogee (elliptical orbit). It completed one revolution around the Earth before reentry.
I recently read a study proposing something like 54 km as the new boarder to space. The reasoning is, according to the person conducting the study, that is the statistically lowest altitude a satellite can still orbit before fully reentering. He said there were a few examples of satellites reentering that did at least two full orbits at that altitude, but I don't think that constitutes a better definition to the edge of space. Food for thought. Anyway, thanks for the video, and keep up the good work!
No, we haven't explored every corner of our solar system, that would be like saying we visited 8-9 landmarks under the ocean thus have explored every corner of the seas. There's a LOT of space out there and all our satellites have only traversed a tiny fraction of the total area that encompasses our solar system, but yes we've visited most of the major landmarks, not all the moon's yet, nor the belts, ort clouds or intergalactic visitors (omuamua).
there is research by ESA to collect the left air particles, decelerate them and use as fuel of Ion drives. Unfortunately I have no Idea at what altitudes they aim
That's very interesting
Besides the left air particles, if they could take everything what is far left and make use of it?
Van Allen said 'NOPE' to moonlanding...
GOCE flew at the edge of the atmosphere, and was kept in orbit by an ion thruster. To quote the ESA website, 'Launched on 17 March 2009, ESA's Gravity field and steady-state Ocean Circulation Explorer (GOCE) mission was the first Earth Explorer mission in orbit.' GOCE operated until late October 2013, when its fuel was exhausted, and it de-orbited on 11th November 2013. The craft was somewhat streamlined to reduce the effects of atmospheric drag. There are plans for another launch. You might want to make a video about this interesting satellite.
The Karmen line is simply the point at which there isn't enough air to provide useful lift to an aircraft in order to stay up. At that altitude, your horizontal speed has to be so high (from the thrust of your engines) that wings don't make a difference any more.
Hi Lei, it would be really cool to see a video breaking down the elements of a modern Spaceport. Thanks!
Love to hear more about the spy satellites Lei
A great channel in the making.
Spy secret satellites would be very interesting
Minor correction - New Horizons didn't "end its nine year journey successfully" - it's still going! On Jan 1, it will pass Kuiper Belt object (486958) 2014 MU69 (which will get a "real name" after the flyby.) It is even scheduled to pass 1/3 the distance than it did in its pass of Pluto!
they really played you like a dumbo - they aint going no where you cant
@@melvinp1324 wut?
@@AnonymousFreakYT been confirmed now they are on baloons
@@melvinp1324 What are on balloons?
@@AnonymousFreakYT Space X being one .. dont tell me you thought rockets take them up ..
I should point out that the hubble telescope is a distant cousin to the KH-11 keyhole satellites, being designed and built by the same companies between the late 80's and 90;s, the hubble of course was optimized for looking outwards, with larger instrument bay and was made to be serviced. It still features the same basic design and 2.4 meter telescope. You may not have heard but the national reconnaissance office gifted a pair of unneeded keyholes (minus the CCDs and classified electronics) to NASA in 2012. These 'obsolete' observatories were made much later than the hubble and are somewhat more advanced, despite still having the same 2.4 meter aperture they have a secondary mirror allowing wider field of view as well as more focused zoom. Fitted with more modern scientific equipment they should be vastly superior to the hubble, especially if launched as a pair for stereoscopic observation. Though NASA probably doesn't have the budget for this. The WFIRST sattelite is planned using one of these satellites, as long as funding doesn't get cut it should launch in a few years.
It would be cool if we could see all the satellites once a year they should turn on a light or something
You can see the ISS at night with your bare eyes if the conditions are good. It has a very destinctive light that is brighter than any star, and it moves faster than any plane.
At my location it passes overhead nearly every night, sometimes more than once, since it only needs 90 minutes to orbit once.
Satellites don't fly, they are constantly falling down to the planet they're orbiting. It's just that they go so fast, that they don't hit the planet.
Same with birds.
Wow, that's crazy
Yep, they are going fast enough along outside of curve to maintain altitude
@@prioris55555 like my mind is just blown. That's just insane if you think about it.
Well yeah true, but I think Lei uses "flying" to make it more familiar to people
Yes we need spy satellite video
A video on Spy satellites please!......
Let's go for a spy satellite video!!
I spend time watching ISS passes, have seen many Starlink trains, and always looking for other satellites. I’ve wondered about lowest possible orbits since witnessing a dim satellite moving west to east at an apparent speed I’m guessing was 4-6 times faster than ISS passes. No idea if it was something in a stable orbit, or if it was something destined to re-enter shortly. If it was in an eccentric orbit, and seen at perigee, it could have been quite low so apparent speed would appear much faster. Do you have any examples of things that can be seen demonstrating very low altitudes?
Assuming a near circular orbit, it seems one could calculate a satellites altitude by by rigging a movable fixture / framework with a couple glow in the dark strings stretched across it, parallel and at a distance from ones eye that can remain fixed. Measure the time it takes for ISS to cross between strings, check time for others to do the same, and do a little math.
Thanks for doing a well organized presentation, as usual!
A video about the spy satellites is definitely welcome 👍
I would love to see a video on spy satellites! You have such interesting vids. TY Lei;)
Great video, very clear and easy to understand explanation for non-scientists. Good job
Check your math. I enjoy the videos but often get hung up on silly mistakes like you saying 350 is 1/10th of 35,000. Dude! You can fix these kinds of things to take your channel to the next level
Wouldn't it make sense for low earth orbit satellites to be streamlined to lower their drag coefficient?
I am very thankful to you for giving valuable information about very hard and difficult technical subject in very simple way
Do one on the Black Knight satellite
More of these videos, please. And thank you for not having those terrible background music productions, like is common place in netvideos.
Apollo 15-17 achevied an even lower 'parking' orbit at ~170km before trans lunar injection. These parking orbits are not stable in the long term. It should also be noted that failing/uncontrolled objects like Tiangong-1 made a few orbits at even lower altitudes before reentry.
Yeah we r really interested in info about spy satellites... Waiting for upcmg video....
Your vids are so well made the quality is unbelievable keep up the great quality videos 👍
The lower the orbit of a satellite, the faster it has to be, right? I was kinda expecting this fact as a part of this video (just because of thumbnail and name), because the max. speed could also be a limit to how low a satellite could fly I guess.. or is the "drag-problem" much more significant than the "max. speed-problem" ?
maybe you could do an extra video on this topic or get to it on the spy satellite video.
thanks!
The difference in size of a 100 km orbit and a 200 km orbit is negligible when the body being orbited is 6380 km in radius about its equator. Kepler's Third Law: The square of the orbital period of an object is directly proportional to the cube of the semimajor axis of its orbit. Or, simplified for a negligible mass orbiting a much larger one in a circular orbit: Orbital velocity is proportional to 1/square root of the radius. That's about 0.76%
Theres no such thing as a "max speed problem". you can fly any speed you want. On earth the max speed of an object is determined by the amount of drag and the amount of propulsion against the drag. But if theres no drag, theres no max speed either.
New horizons is going something like 16.26km/s, while a spacecraft in low earth orbit is going something like 7.8km/s, so you see that speed is not a problem.
Only limit to your speed is the speed of light. But thats not a concern.
Interesting subject. I recall reading that the heaviest satellite launches on ULA's Delta-4 heavy platform were all coincidentally classified military payloads. I guess all that camera glass weighs quite a lot!
Yes, please do a video on spy satellite 🛰
I was blown away when I was told that the Hubble telescope has design features and technology which most likely came from spy satellites
I love this channel i hope this channel gets a million subs soon
That was very interesting Lei, well done.
5:26 is it Fedor?
You forgot one of the main factors to why ISS is placed in its current orbit and its how high the Space Should could send useful payloads back in the day when the station where build. They could only reach so high while carrying the components that made up the station. The exeption is Hubble whom was placed in a much higher orbit but that took some extra effort to get there when they build and repaired that telescope. Johan.
Superb video, i want the video on spy satellites😊
Do a video on spy satellites, and also the components and infrastructure of future spaceport so! !
There's currently a development of a satellite with scramjet engine. The engine will use solar power as it's energy source. Soon, satellite can fly as low as 80 km above the Earth.
Yeah! Videos about spy satellites would be awesome! They also do not deviate from this channel's main interest...
Incredible content. 👍
Your videos are always well created and interesting
How does spy satellites maintain orbit against air resistance ?
please do one about the spy satellites
Got a question
Can we make an object
Orbit as low and long as possible/forever
In a air-less perfect sphere/spheroid earth?
Nicito Sta. Ana yes
But what was the altitude of the parking orbit of the Saturn V?
190 km, if wikipedia is correct.
~200 km
The later missions, Apollo 15-17, had a parking orbit as low as 170 km.
Don't forget Skylab, launched by a Saturn V, yet parked in an orbit higher than the ISS.
Hi Lei, I love the work you do! Keep it up. Some things I want to point out, your pronouncing Uranus wrong and we haven't explored every corner of our Solar System yet! That would imply that we have checked every single moon, asteroid and comet in our Solar System and that is not the case. But overall amazing job! Can't wait for a video talking about spy satellite and how they reboost their orbits!
*....Great Video!! Can you please send me a Link to a Satellite Orbiting the Earth? I've been searching for myself over 22 years and I can only find CGI Cartoons of Satellites Orbiting the Earth.. Any information or help would be greatly appreciated.. Thank You....*
Just a small correction, we haven't literally explored the entire solar system. Far from it. Awesome video!!!!!!!
Love the channel,
I'd love a video on spy satellites, very interesting topic!
But how do spy Sat maintain orbit since its not possible to carry fuel to do course correction for the entire lifespan of the sat.
those spy satellites are HUGE. Those things are bigger than the hubble telescope. they carry more fuel than you might think.
Also, they don't fly at a constantly low altitude. and the keyhole satellites have a strongly eliptic orbit, which of course lowers the overall drag.
So, when will that video of spy satellites be available?
Also, have you found information about any satellites with an altitude, say, 160km? ;)
Don't forget dron military spaceship like X-37-B, OTV. How many spy and military satellites are there today? I think that there are thousands, and some U.F.O cases are these vehicles sometimes. Thanks for this video. Have you got a nice weekend!
More and more bro good job and waiting for spy satellites
Awesome vid bro, very informative, thanks.
Satellite
Sat i llite
Sat I lite
That I like
Half Life 3 confirmed!
What would be really interesting is showing an actual real satellite in the vacuum of space, cartoons, animations, cgi are not real satellites, just show one satellite video in real time...thanks
Even lower orbits would be parking orbits of spacecraft going to GTO or those who leave earth. They can go as low as 160 km because they only stay in that orbit for up to an hour before they do their apogee raise burn or their escape burn.
Theres no limit for how long you can stay in an orbit. You can stay as long as your fuel lasts you. Because in an orbit that low you'll need to make a lot of correction burns either way. The slats spacecraft is supposed to descend down to 180km(it'll go down in steps) and stay there for a week, or until it fuel runs out.
how many satellites reached Uranus?
1
I see what you did there ;)
Very nice video, thanks
Well yes! We surely want to know deep about spy satellites. Please do make a video on it. And mention the America's biggest Intelligence failure as well which occured during May 1998, the Nuclear test in India!
Okay, a better video after a while
Would love to see more videos on spy sats. Speaking of spy sats, I would interested to see another follow up video on Zuma. Its surprising how quick that story got dropped by the media considering the enormous costs involved.
Oh I wouldn't say that we have explored every corner of our solar system. Uranus and Neptune have only gotten a brief fly by and the sun itself still leaves us with mysteries which especially Parker Solar Probe is going to solve within the next decade. But we do certainly know a low more about the solar sytsem than 100 years ago.
t. gobold, Agreed. 👍🏼 Saying we’ve explored every corner of the Solar System is like saying visiting a handful of islands means you’ve explored every corner of the Ocean. 🤔
Take a look around the corner Lei!
Excellent,
Learned a lot.
Cool man!
3:00 : FYI the plural of 'spacecraft' is spacecraft! Not 'spacecraftS'. This noun is an irregular. 'Sheep' is another. As in: "I have one sheep, ypu have two sheep". "Car" and "horse" are 'regular: one horse, two horses, etc.
I wonder if SpaceX's lower StarLink satellites would use air breathing ion thrusters to keep their orbit from decaying.
So how many kilometers?
I'm a little upset you didn't mention the upcoming air breathing ion thrusters that would allow sats to orbit much lower.
Great video
What is the orbiting speed at 200km
Very good ...we need more information about earth orbit...
How will rocket lab send satalites in space when bfr is cheaper
Dylan Foulston Pretry sure the cost for using Electron is like 6 million. I'm not sure BFR can get it cheaper.
@@christianpenchev2689 bfr is going to be 7mil
There’s a satellite with an air breathing ion engine being developed, I’m pretty sure it will fly below the Karman line, it will fire its engine non stop to stay up. You should do a video on that
You forgot to mention this one with a propulsion and unique design (254 km orbit): en.wikipedia.org/wiki/Gravity_Field_and_Steady-State_Ocean_Circulation_Explorer
Nice vide, would be nice to show the correct perspective of earths size to LEO/GEO distance.
When did we explore the Oort Cloud?
also any internet based satellites in teh leo orbit can get close to 200. I know I thought was a communications statellite for a foreign customer of spaceX was going lower but might be wrong about that. Again we have to much garbage up there right now
I would have loved some relatively accurate orbits..even though not too scale but 400km and 340km looks like 2000km and 400km
Yet when we see a live stream from the ISS we don't see any , are there NO satellites or they forgot to put them ??
satellites are very far away from each other.
you know.
like when you are on an airplane..
you dont see planes everywhere.
doest that mean that planes dont exist?
or that earth is bit bigger than you thought?
Yes more Spy sats!
Yess i would love to watch...😀
Don't forget Zuma, currently orbitting at... 20,000 leagues under the sea OR dipping along at 200km!
more info from Scott Manley on low flying (and even airbreating!) satellites:
ua-cam.com/video/srmtxK44YXk/v-deo.html
Yessssssssss plz make video on spy setallite....plz
Some people keep it still lower by links to upper atmosphere.
Hi Lei! Have you heard about atmosferic fed ion thrusters which will allow satelites to spend long time much lower than 200km?
What is the lowest possible orbit on a planet/moon without an atmosphere ? Can someone do a 10m orbit on moon (assuming moon a perfect sphere)? (or in other words what is the equation to find out lowest possible orbit of a perfect sphere object in space ? )
I believe the Zuma-Mission by SpaceX was a success and the satellite is flying very low. It was a land landing, which is an indication of the low altitude. (conspiracy theory end)
So designing them aerodinamically will decrease the orbit height? Never thought about that.
Ya Of course! About spy stattelites!
Half a m resolution, yeah, they can go a lot smaller than that. Smallest thing you see clearly is about 90 ~ 100mm. 10cm. You can lay a car registration plate on the ground, so you are looking at it on a right-angle, and you can usually read that. A big bold simple headline on a newspaper, can be read.
The limit is largely the air. When looking up & out, we have adaptive optics, with a laser to tell them what they should do, but when looking down & in, you don't have that.
Do you know what the Hubble Space Telescope is? It's basically a US spy satellite that's been turned around to face outwards... Do you know why the optics on the Hubble were wrong when it was first launched? Because it was not designed with an infinite focal length. It was designed to focus about 200 ~ 400 km away.... Now the cameras & sensors fitted to the Hubble for astronomy, are very different to what the office of reconnaissance fits, but the basic optics and canister, they're the same.
Interesting... I've never heard about the Hubble Space Telescope in that context. You have some articles or posts?
157 239n - Can I give a source? Um, not really. It launched in 1990 and the patch-up mission was '93... I think I heard about the original source of it (the office of national reconnaissance) in '95 or '96.
I just had a look at the wikipedia page, which does contradict my version completely, but that's the story I heard back in '95. I have heard more or less the same story, with very minor variations, a number of times over the last 20 years.
Slightly different versions of the story I've heard, one was that Regan wanted at least 6 of them, but by the time they had 3 in orbit (and Regan no longer in office) they found the results from those were so good they simply didn't need to have 3 more... Another version said that after the first 3, they wanted the next one to have slight design changes, but the next one had already been built... so it was surplus to requirement. At that time, the plan was well under way to make the Hubble, so they quietly approached some senior people in that project, and asked if they'd like to buy a pre-built telescope cheap...
Ahhh, no. hubblesite.org/reference_desk/faq/answer.php.cat=topten&id=77
Barry Woods HST is in earth orbit and it's much closer to earth than the moon so it could be the case that HST can't see stuff on the moon but can see stuff on earth. The same site at hubblesite.org/reference_desk/faq/answer.php.cat=topten&id=78 said that the HST can't see stuff on earth due to tracking reasons as it is designed to track stars which move slow and can be easily tracked from our vantage point.