NASA – get this – just launched 8 satellites from a rocket dropped from a plane at 40,000ft NASA's Cyclone Global Navigation Satellite System (CYGNSS) has made it safely into orbit after being air-launched from Orbital ATK's Stargazer aircraft. CYGNSS consists of eight mini-satellites that orbit around the tropical zone of Earth that spawns most of our hurricanes and cyclones. The birds will provide daily updates on …
"from faking climate data"
no, I'd havd to downvote that one, too. The data isn't fake. The predictive models are just wrong. No 'hockey stick' and California hasn't flooded [as predicted by AlGore]. Yeah he had to revise his numbers when reality caught up.
But NASA's data isn't fake. I doubt even the most aggresively political engineer could stomach the idea of faking data. The beauty of science is that, even if you're wrong about something, it's still just as interesting when you get to the right conclusion [based on experimentation, actual data, etc.]
[minor correction: AlGore believed the sea levels would rise significantly due to polar ice cap melting, which would flood california; however, the actual prediction would be that the earth would become a 'Frying Pan' by January 2016, 10 years after the Washington Post article]
The UK has managed to launch a meat and potato pie into space, we have the technology and the filling (although I always get nervous when something is advertised as 'meat' rather than being specific such as, beef, chicken, pork etc..... hmmm wonder what sort of meat)
http://www.bbc.co.uk/news/uk-england-manchester-38334437
"Hot sausages, two for a dollar, made of genuine pig, why not buy one for the lady?”
“Don’t you mean pork, sir?” said Carrot warily, eyeing the glistening tubes.
“Manner of speaking, manner of speaking,” said Throat quickly. “Certainly your actual pig products. Genuine pig.”
Yep,
I seem to recall pictures of the X1 (and other X series) craft being launched this way.
In military terms, the lauch process is called 'stand off' because the rocket thingy is dropped away from the mothership before the rocket ignites.
now that I think about it, don't air launched cruise missiles work this way?
But the X-1 etc seems to predate it.
Way to go NASA. Keep spending those tax dollars re-inventing the wheel (or in this case the X-1)
http://playithub.com/watch/eSg28TAixJw/ufo-1970-episode-2-computer-affair-p1-of-4.html
From 01m17 onwards...
And upwards!
First launch 1990. They don't fly too many missions for some reason.
I remember some comic from the early 90s where a neo-soviet satellite is blinded by a Pegasus-launched ASAT so that US B1s can enter Neo-Soviet Airspace unseen to drop bomb props on a city because POTUS wants a show of force because the Neo-Soviets are hacking the US, left, right, front and center. Unfortunately someone has replaced the props by actual VX-carrying ordinance to get some heat under the politicians' behinds. This leads to a red-phone call with the Neo-Soviet leader (who is likely an AI in any case). Can't even remember the name of the story...
Simple. It's the most expensive LV in terms of $/lb in the US inventory.
This might have something to do with the bulk of its structure being made by a solid rocket company who is a major stockholder in Orbital.
I wouldn't exactly call it an accounting scam to avoid the USG realizing how much profit is being made on the solids (which AFAIK are not available for any other application, so no comparison pricing is available) but it is curious the estimated price in development doubled when that supplier came on board.
They don't fly too many missions for some reason.
They are significantly more expensive than a scheduled launch from Airana Space, Space-X or the Russians. The payload is relatively small too - so they cannot launch the monstrous comms satellites which bring most of the bacon.
Is it an underlying cost or is it just marketed that way - no idea. The end result is that there is a feedback loop as well - as they cost too much they do not get that many launches, as they do not get too many launches they cost more and so on.
They are used primarily for flexibility and it is marketed that way. They claim that they will put a payload in orbit for you within weeks or months tops which is significantly shorter than the lead time on conventional launchers. For the same reason - they are happy to do weird orbits.
This one is in a perfect match for them (not something that comes along very often) - fairly high (580km), high inclination, low SAT mass - a big launcher would have had to run half-empty to do this job and that would have cost a fortune.
Re X1... That's different. You were launching a test aircraft at altitude so it can perform its test.
However. The US used an F16 to launch an anti-satellite missile many years ago. So the concept was proven long ago.
I would imagine that the large cargo airship (bimpy butt sitting in the UK) could do this too, but I would imagine it would have to bleed off a lot of helium after the launch.
This was tested with a Minuteman ICBM from a C-5: Watch a C-5 Galaxy drop a Minuteman Intercontinental Ballistic Missile during a test.
You could think of it as a traditional multi-stage rocket, only in this case the first stage is powered by jet engines, not rockets, and is reuseable.
(Jet engines get a much better specific impulse than conventional chemical rockets.)
I think you'll find that way back in the day, USAF lobbed a Minuteman ICBM out of a plane and got it to perform a successful air launch. I think the rationale in that case wasn't anything to do with the flight profile but to look at ways of distributing the land-based ICBM fleet to make it less vulnerable to a first-strike attack.
Still, it is good to see NASA doing this stuff. They've made a mess of manned spaceflight since forever, IMHO, but they deserve kudos for their science and unmanned-lift work.
I wonder if that's the last Tristar flying? I used to love those things: most comfortable airliner I ever flew in, even now.
> I wonder if that's the last Tristar flying?
To my knowledge there are eight remaining Tristars flying with various operators, it's nice to see Orbital ATK keeping this one in good condition as well! Fantastic aircraft!
> but they deserve kudos for their science and unmanned-lift work.
Whilst I agree with the "science" part.. The Pegasus is owned and operated by Orbital ATK, the most involvement NASA had with this launch was supplying the chase aircraft... I agree though, for all the awesome things NASA have done, they have made a right royal hash of manned spaceflight to the extreme. As impressive as the shuttle was, it was functionally unfit for purpose in almost every single way.. not to mention being the most dangerous space system to ever fly.
Don't even get me started on the SLS, I struggle to find a reason why they're even bothering to build it. By the time it flies I fully expect SpaceX to be ferrying people all over the solar system ^.^
(okay, perhaps I'm exaggerating a little on the last sentence.. but I don't think I'll be far off)
> As impressive as the shuttle was, it was functionally unfit for purpose in almost every single way.
That's because it was mainly a political device (as well as meant for "cutting edge" civilian spaceflight as well as "fast turnaround" military spaceflight). A receipe for disaster.
What really screwed STS was the insane project funding rules it had to be designed and built under, courtesy of Caspar Weinberger, Richard Nixon's loyal stooge head of the Office of Management & Budget.
Basically NASA reckoned full reusability needed 2 stages and probably 2 new engines. The OMB funded 1 stage and 1 new engine.
Only an ex-pat British engineer figured out the Mother-of-all-drop-tanks-and-RATO-packs could make it work on the budget given.
Yeah, there were a lot of military requirements that screwed things up -- like they wanted a large amount of cross-range capability, to help hide the orbits of spy satellites they'd be deploying. That required a very large wing in order to get back to the normal landing sites, adding unnecessary weight and drag during launch.
Unfortunately, while building stuff tailor-made for civilian flights makes for cheaper operating costs, it's also a lot harder to get funded.
I'm not convinced a reusable spacecraft is that good an idea, anyway. It sounded good, but comparing the American and Soviet space programs suggests that non-reusable systems are cheaper overall. The extra weight of a reusable system ends up costing you too much in terms of fuel and engine design.
Probably not. The cross range was to allow the Shuttle to return to it's original launch site within 1 orbit, theoretically in case of a serious, but non fatal, systems failure. Otherwise you'd have to wait about a day till the launch site came back under it's ground track.
It now seems to be generally agreed the purpose of this "feature" was to allow a military Shuttle to snatch a foreign spacecraft out of orbit You Only Live Twice style.
It didn't seem to occur to anyone at the time that this would only happen in the middle of WW III or that if you did it you'd probably be starting WW III with whoevers satellite you just stole.
Getting it probably consumed the bulk of the 40-50 000 hrs of wind tunnel time it took to design.
"They take their signals from the GPS system ... and use those to work out the wind speed on the surface."
I thought it was illegal, or impossible, or something like that, to know both where you are and how fast and in what direction you're travelling. So these satellites can expect a visit from the Quantum Enforcement Police, who will collapse their probability waveforms with extreme prejudice.
In the meantime though - how does this method of launching satellites compare with the traditional method of ground-launched rockety things, in terms of cost and reliability? Wouldn't it be easier to launch everything orbit-bound like this?
It'll be down to payload weight, as well as desired height. If you're using micro-satellites you don't need as much fuel to get them up to orbital velocity, so you don't need a bloody great rocket that's too heavy for the plane to carry up to 40,000 feet.
I might be off my my numbers as it's a long time since I read about it, but the Redstone rockets that the US used to launch the first couple of Mercury flights could only get something silly like 7kg into orbit. i.e. a uselessly small amount. Which is why Shepard and Grissom flew sub-orbital hops and why Glenn was their first orbit on Mercury-Atlas.
They had to use Redstone first as the Atlas ones kept blowing up.
Then again the Russians did an early test mission of the R7 with a live nuke on board - the previous launch having gone 200 miles off course and having had to be destroyed by range safety. This was a full nuke test, where they flew it to some even more uninhabited bit of Siberia than usual, and actually nuked it. I'm assuming the KGB had shot all the health and safety officers...
Just a case of cost and payload weight.. It makes sense for very small payloads, but for anything bigger than a few Kg's (cygnss was about 29Kg iirc) the rocket equation quickly means the booster gets too big for even the biggest aircraft to lift. You either develop and MUCH bigger aircraft, which most likely wouldn't fly, or you just say **** it and build a big first stage booster like everyone else!
Air launch looks good, but really you're only getting to 4% of orbital altitude and about 3% of orbital velocity before launching - it doesn't make THAT much of a difference.
That math is hard to argue with, and it makes me wonder why Scaled Composites has doubled down on this approach. They're building a truly gigantic air launch vehicle called Stratolauncher out of a couple of junked 747s they presumably found behind the shed.
There are a couple of benefits of air launch such as flexibility in where the launch takes place from (basically anywhere a couple of hours flying time from a suitably large runway) and fewer problems with weather on the ground or range safety which can abort or hold a launch at the last minute.
Rockets work better in vacuum or close to it since there's less back pressure so an air launch at altitude is more efficient, but only by about 10% or so.
"Air launch looks good, but really you're only getting to 4% of orbital altitude and about 3% of orbital velocity before launching - it doesn't make THAT much of a difference."
Getting above 90% of the atmosphere's density does though, if you already have Pegasus (which they did) and want to increase the usable payload (which they did)
"CYGNSS satellites just have receivers. They take their signals from the GPS system [PDF] and use those to work out the wind speed on the surface."
I can see how GPS gives their position and any possible movement but how does that give "wind speed on the surface." Tracking cloud movement is the best I've though of.
Following the PDF link to http://clasp-research.engin.umich.edu/missions/cygnss/docs/CYGNSS_FactSheet_October2014.pdf and googling over to https://www.esrl.noaa.gov/psd/psd3/multi/remote/using_reflections.html (section 4), it looks a bit like the sort of thing you'd laugh your arse off if it were used in a film as a plot device.
Semi-plausibly, you can use the reflections of GPS signals off the ocean surface like a radar to figure out large wave profiles and (from that) broadly infer ocean surface conditions. I say broadly because the height that is inferred in this way will depend on the wave's direction of travel and you have to know that from some other way, and the height of a wave will in any case also depend on how many miles it has been building up, which again you have to know by other means.
However...
Much less plausibly, if you have a black belt in boffinry, you can also use the GPS signals that are *scattered* from *surface ripples*, producing an interference pattern. The spectra of these waves apparently depend very sensitively on the actual local wind conditions so you can skip all that "other means" crap and proceed directly to omniscience.
So they are watching the slight fuzziness of a ripple, from a hundred miles up, through a hurricane, using someone else's transmitter. (And, as various folk have remarked upon in these forums over the years, the other guys transmitter is already compensating for both Special and General Relativity to be even vaguely useful in the first place.)
Launching the satellite on-the-wing looks positively pedestrian in comparison.
From the Wikipedia article, they are using " bi-static scatterometry". "Bi-static" merely means the transmitter and receiver are not co-located. "scatterometry" is the extraction of information from the ways in which a radio wave is modified by a surface that reflects it. Use of the GPS satellite as the transmitter is clever: the receiving satellite uses the GPS system itself to learn the position of the transmitter and of itself with extreme precision. However, the GPS signal is quite weak even before it hits the surface and is reflected, so I'm sure they must integrate over a long time. The GPS signal is intended to be used for exactly this type of signal integration (i.e., spread spectrum), but the reflected signal has got to be at least another 30 dB down in the dirt, so this is pretty impressive.
"Scatterometry" is apparently a well-developed discipline. I assume they get loads of calibration against physical surface measurements, probably pretty much continuously, as they measure the conditions near monitoring buoys.
Pegasus is pretty much ideal for this very specific satellite's size/weight/orbit parameters, probably because the design team chose to stay within Pegasus' parameters. Expensive in terms of $/lb-to-orbit, but very inexpensive on a $/launch basis, so they can launch more to extend coverage or extend mission life.
Very carefully indeed.
Mentioning the word "rocket" inside a US airport in earshot of any staff is likely to make people very twitchy, leading to the arrival of a bunch of young men with automatic weapons to make further enquires. *
* Paraphrased from a talk by a US rocket boffin on how to take a rocket engine in as cabin luggage. They tend to equate "rocket" with Surface to Air Missile.
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