Discussion
http://www.bbc.co.uk/news/technology-24803511
I kind of don't want the SR-71 to be outshone.
What are the chances of this actually getting off the ground?
Thoughts?
I kind of don't want the SR-71 to be outshone.
What are the chances of this actually getting off the ground?
Thoughts?
doogz said:
JVaughan said:
so 3600mph (Mach 6) ... high altitude survelance.
Is there a point for this when they can put a satellite up for maybe 10 plus years, needs less fuel, maintenance, less risk & being in orbit, there is minimal friction on the vehicle so theoretical speeds are much higher..?
Putting an aircraft where you want it, when you need it there is easy. Is there a point for this when they can put a satellite up for maybe 10 plus years, needs less fuel, maintenance, less risk & being in orbit, there is minimal friction on the vehicle so theoretical speeds are much higher..?
If the satellites not in the right place, you'll not get an image.
JVaughan said:
so 3600mph (Mach 6) ... high altitude survelance.
Is there a point for this when they can put a satellite up for maybe 10 plus years, needs less fuel, maintenance, less risk & being in orbit, there is minimal friction on the vehicle so theoretical speeds are much higher..?
this....Is there a point for this when they can put a satellite up for maybe 10 plus years, needs less fuel, maintenance, less risk & being in orbit, there is minimal friction on the vehicle so theoretical speeds are much higher..?
JVaughan said:
doogz said:
JVaughan said:
so 3600mph (Mach 6) ... high altitude survelance.
Is there a point for this when they can put a satellite up for maybe 10 plus years, needs less fuel, maintenance, less risk & being in orbit, there is minimal friction on the vehicle so theoretical speeds are much higher..?
Putting an aircraft where you want it, when you need it there is easy. Is there a point for this when they can put a satellite up for maybe 10 plus years, needs less fuel, maintenance, less risk & being in orbit, there is minimal friction on the vehicle so theoretical speeds are much higher..?
If the satellites not in the right place, you'll not get an image.
It's not replacing satellites just filling the gap between what they can do and what current surveillance aircraft can do.
If satelites are so good, why did the US ask us to send a pair of Canberra PR-9's to Afghanistan to fill the hole left by the SR_71's being retired? Satelites can be moved, but it takes a while to be positioned where they're needed, whereas the SR-72 can zip to the area take a load of data and zip back with uptodate info on say a rapidly developing situation.
<sigh> everyone's a comedian & every one knows better .... <sigh>Read the comment about GPS as an example of a ring of satellites circling the earth
If it was a viable solution, why arnt the SR-71's pulled back into operation and given digital data links?
Afghanistan has been going on long enough they could have re-commissioned one if they thought it was a solution instead of a horrendous logistical nightmare to keep in the sky.
Theoretically, you can get global coverage with Geostationary satellites with as little as 3 all across the equator (120 degrees apart) but this would have reduced visibility towards the Poles ...
... and even if they build an SR-72 ... I bet that "scramjet" will drink fuel so fast its range will be seriously limited. ..
Edited by JVaughan on Tuesday 5th November 12:18
JVaughan said:
If it was a viable solution, why arnt the SR-71's pulled back into operation and given digital data links?
Afghanistan has been going on long enough they could have re-commissioned one if they thought it was a solution instead of a horrendous logistical nightmare to keep in the sky.
Why on earth would anyone re commission a long retired aircraft and fit it with new equipment and all the associated testing/training and massive ground support etc when you can develop a newer, two times faster, aircraft that is un manned? Afghanistan has been going on long enough they could have re-commissioned one if they thought it was a solution instead of a horrendous logistical nightmare to keep in the sky.
There's a gap in intelligence gathering and this or another UAV is going to fill it. The technology will lead to hypersonic armed UAVs.
Sorry JV, but any hope of having a ring of geostationary satellites for intelligence gathering (possibly with the exception of SigInt) is pure fantasy.
Most sats, spy included, are in low orbits of around 200-2000km altitude; for geostationary orbits you're way up to 35,786km. What use do you think an optical camera will be at that height? Simple optical physics gives us the smallest possible object that you can observe given a camera size, distance and observed wavelengths.
For example, putting a hubble-sized optical camera (with 2.5m aperture, an absolutely enormous feat of engineering at gigantic cost) in a geostationary orbit would mean the absolute smallest size you could resolve would be 9.6m across. Factor in a loss of efficiency due to other factors and you're talking 15m resolution. Useless.
In a low polar orbit (i.e. what's used at the moment) you generally have an orbital time of ~90 minutes, the SR-72 could be on the scene of trouble from 1000 miles away in 15-20.
Most sats, spy included, are in low orbits of around 200-2000km altitude; for geostationary orbits you're way up to 35,786km. What use do you think an optical camera will be at that height? Simple optical physics gives us the smallest possible object that you can observe given a camera size, distance and observed wavelengths.
For example, putting a hubble-sized optical camera (with 2.5m aperture, an absolutely enormous feat of engineering at gigantic cost) in a geostationary orbit would mean the absolute smallest size you could resolve would be 9.6m across. Factor in a loss of efficiency due to other factors and you're talking 15m resolution. Useless.
In a low polar orbit (i.e. what's used at the moment) you generally have an orbital time of ~90 minutes, the SR-72 could be on the scene of trouble from 1000 miles away in 15-20.
just to respond to the idea or re-introducing the SR71, aside from the technical difficulties (spares/trained personel) are the anti-air missiles now of greater tech/performance than the Blackbird? therefore rendering what advantages it had obsolete?
The US has advanced UAV technology, and in a spyplane, the lack of the biological component means that the performance doesn't need to be limited for its survival, instead of life support, more fuel capacity or surveilance equipment.
The US has advanced UAV technology, and in a spyplane, the lack of the biological component means that the performance doesn't need to be limited for its survival, instead of life support, more fuel capacity or surveilance equipment.
If it is anything like the SR-71, it took HOURS to get both the aircraft and crew ready for a mission. The SR-71 was not an ordinary aeroplane. It was very, very specialised and demanded extreme care in getting it ready for flight. An SR-71 operation was much closer to a rocket launch than an aeroplane take off.
I'm sure a newer technology replacement might be a bit easier to get ready but it still will be a tricky business to get right.
If the SR-72 is intended for higher speeds than the SR-71, then we are entering a new era for sustained, controlled, hypersonic flight in the earth's atmosphere and there is a LOT we have yet to learn.
So far, sustained speeds at Mach 6 and above have not been successfully achieved ever.
I'm sure a newer technology replacement might be a bit easier to get ready but it still will be a tricky business to get right.
If the SR-72 is intended for higher speeds than the SR-71, then we are entering a new era for sustained, controlled, hypersonic flight in the earth's atmosphere and there is a LOT we have yet to learn.
So far, sustained speeds at Mach 6 and above have not been successfully achieved ever.
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