Modern DSLRs can do an ISO of 64,000.
‘ISO’ in a digital SLR is simply the amount of gain applied to the sensor. This causes noise in the image. A lot of cameras also do automatic noise reduction before saving the picture, but if it’s agressive it can create artifacts or wipe out details.
It’s preferable to use a bigger lens and gather more light than to try to increase sensor sensitivity electeonically, but big lenses are expensive and heavy, so…
And in the case of the Falcon Heavy image above, there is no bigger lens.
You really need this baby:
It weighs 36 lbs and costs $99,000. 1200mm, F5.6
Yeah, but it might be too long to get that Falcon image. 50% more mm’s. And yeah, it doesn’t work like that, but still the crop vs the 800mm would be a pretty big one. And it’s not any faster – both f/5.6. I could see keeping the 800mm, if only for my back.
I should have said, “there is no faster lens at this length”, and there isn’t (AFAIK).
You could start pulling out telescopes, but that wouldn’t work out well, if only for IS.
throw in a 1.5 adapter, and use the $$$-difference to purchase a Cybertruck
… and yes, the last 1% is alway extremely expensive
My 8" Celestron Edge HD has a focal length of 2000mm at f10. With the focal reducer, 1366mm at f6.7. So you’d think it could do a pretty reasonable job of terrestrial photography. It’s not that much slower than the $99,000 1200mm Canon.
Not really. If you try terrestrial photos you notice a drop in contrast mostly, and the image just won’t be as sharp. There’s a reason those big canon lenses have a gazillion elements and weigh so much.
They’re great at picnics or for family portraits. A little unwieldy, though, I’ll admit.
Our first closeup view of Jupiter’s volcanic moon Io in many years:
Juno makes its first ultra-close flyby of the volcano-covered moon Io | Ars Technica
These videos are kinda neat, at least for a certain type of person. Hours of 1990’s shakycam footage from a couple of DC-X (Delta Clipper) flight tests. Raw, barely edited, clipped narration. A bunch of dudes in the desert, minimal equipment, launching rockets. Sometimes things go wrong, but a lot of things go right, too. Sky-blue LOX pooled in the craters left by the RL-10A engines, boiling away in the desert heat.
The DC-X, for the uninitiated, was a test vehicle for a vertical takeoff and landing rocket system. Also intended to require minimal ground support. Suborbital, but eventually intended to evolve into a full-size orbital rocket. They proved out a lot of things that hadn’t been tried before. Sadly, it was also a program without a happy owner–first, McDonnell Douglas, then NASA. The Delta Clipper program competed with NASA’s home-grown X-33/VentureStar project and eventually the former got cancelled. But the VentureStar itself was too aggressive and was itself cancelled.
While there were some other small programs Armadillo Aerospace, we didn’t get another serious attempt at vertical landing until SpaceX did it with Falcon 9.
Well, that didn’t quite work. But ULA is getting close, and Vulcan is scheduled for its first flight on Monday (Jan 8):
If it flies (and works), it’ll beat Starship to orbit and be the #2 methane-powered rocket to orbit. But its reuse story isn’t compelling. They’re at the mercy of SpaceX not cutting launch prices to the bone (they probably have >60% margin on launch), which is fine for the time being but not a viable long-term strategy. They can survive being #2 to SpaceX, but when Rocket Lab’s Neutron flies, I’m not sure there’s room to be #3 for very long.
I’m not so sure. IMO …
SpaceX and Rocket Lab are “new space” companies; commercial forward with a (large) first stage launch assist booster from government contracts.
ULA is simply a defense contractor in civvies. They exist to do government work with hope of a sidelight in commercial. As long as pork barrel and revolving door politics is involved in where government contracts go, ULA will be safe. If ULA’s prices eventually get 10x or 20x the other guys, something will give. Until that time I don’t see it.
YMMV of course.
So what do we think of the idea of dropping the engines by parachute to achieve ‘reusability’?
My first thought was, “Those BE-4’s must be incredibly expensive to warrant all this complexity just to save two of them.”
My second thought was that this was a half-assed attempt to check the ‘reusable’ box. It’s hard to see much cost savings from this, even if it works as intended.
I hadn’t heard of this. Link to whatever it is you’re talking about?
I hadn’t heard of this? The idea is to pop the engines off and drop them separately?
I’d like to see the info about this.
ULA calls it ‘SMART’:
It sounds like the rationale is less about money and more about launch cadence. Maybe Blue Origin can’t develop BE-4 engines fast enough.
Still… splashing this all down in the ocean? then reusing engines that have had salt water intrusion? Doesn’t exactly sound like a quick turnaround.
Thanks for the explanation. Yeah, that sounds pretty silly. ULA aren’t idiots though, they’re just stuck in old school. Maybe it could work.
It’s probably a compromise. Their investors are looking at reusable rockets and wondering why we should keep buiding throwaways. Somewhere along the way a ‘reusability’ requirement was added, and maybe this was the best they could do without throwing away the whole rocket and designing a new one.
But the added weight of the extra structure needed, the pyros, the heat shield and parachutes will all take away from payload, so there is a cost per flight for this just as there is for Falcon. They need to save enough money refurbishing those engines to account for all that. It will be interesting to see if this plan is real, or if it gets scrapped before they seriously try it.
let alone allow for the odd “oops, our booster engine just landed sideways in a 33 story tall building”
They would, ideally, be protected against salt water intrusion by the inflatable heatshield, which would act something like a liferaft. Could work if the seas aren’t too rough. SpaceX is doing pretty well with their fairing recovery, with the fairings keeping the water mostly on the outside. They can handle some splashing/misting if cleaned soon after.
It’s still bullshit, IMO; it’s not like you just detach a few bolts and the engine portion just cleanly separates. There are a zillion connections between the engine portion and the rest. Each one has to either have some kind of connector (which increases chance of flakiness, whether it’s data or electrical or fluid), or it’ll get cut by some explosive system (which makes refurb more difficult).
It might be better than nothing, but just barely. There’s only one reason to pursue this vs. landing the whole booster, which is that they are flying with just two big engines, which both can’t throttle low enough and for which there’s no center engine. The Falcon 9 can’t throttle below 1 G even with just the center engine (already down to 11% due to being one of 9, and throttled down to perhaps 50%), but it gets close enough for reliable landings.
I guess they could add a tiny landing engine, placed between the two large main engines, but that’s a lot of plumbing and complexity. SpaceX was either lucky or brilliant (or both) to pick 9 engines due to the engine-level throttling capability.