Comment Re:vs. a Falcon 9 (Score 1) 75
They don't have nearly as much to offer if they can't do launches quickly. I'm sure they would make that a feature of their offering.
They don't have nearly as much to offer if they can't do launches quickly. I'm sure they would make that a feature of their offering.
They can carry about 110kg to LEO, compared to the Falcon 9's 13150kg. That's 0.84% of the payload capacity. A launch is estimated to cost $4 900 000, compared to the Falcon 9's $61 200 000. That's 8.01%. That means cost per mass to orbit is nearly an order of magnitude worse.
Yes, this is a really small rocket. If you are a government or some other entity that needs to put something small in orbit right away, the USD$5 Million price might not deter you, even though you could potentially launch a lot of small satellites on a Falcon 9 for less.
And it's a missile affordable by most small countries, if your payload can handle the re-entry on its own. Uh-oh.
It's like how a real terrorist would not joke about a bomb at an airport. But someone who does is detained or arrested, and time is spent by TSA that could be better spent looking for real terrorists.
I studied and tutored experimental design and this use of inferential statistics. I even came up with a formula for 1/5 the calculator keystrokes when learning to calculate the p-value manually. Take the standard deviation and mean for each group, then calculate the standard deviation of these means (how different the groups are) divided by the mean of these standard deviations (how wide the groups of data are) and multiply by the square root of n (sample size for each group). But that's off the point. We had 5 papers in our class for psychology majors (I almost graduated in that instead of engineering) that discussed why controlled experiments (using the p-value) should not be published. In each case my knee-jerk reaction was that they didn't like math or didn't understand math and just wanted to 'suppose' answers. But each article attacked the math abuse, by proficient academics at universities who did this sort of research. I came around too. The math is established for random environments but the scientists control every bit of the environment, not to get better results but to detect thing so tiny that they really don't matter. The math lets them misuse the word 'significant' as though there is a strong connection between cause and effect. Yet every environmental restriction (same living arrangements, same diets, same genetic strain of rats, etc) invalidates the result. It's called intrinsic validity (finding it in the experiment) vs. extrinsic validity (applying in real life). You can also find things that are weaker (by the square root of n) by using larger groups. A study can be set up in a way so as to likely find 'something' tiny and get the research prestige, but another study can be set up with different controls that turn out an opposite result. And none apply to real life like reading the results of an entire population living normal lives. You have to study and think quite a while, as I did (even walking the streets around Berkeley to find books on the subject up to 40 years prior) to see that the words "99 percentage significance level" means not a strong effect but more likely one that is so tiny, maybe a part in a million, that you'd never see it in real life.
Microminiature accelerometers are really cheap and very very light, and you don't have to wait for them to spin up or deal with their mechanical issues. I doubt you will see a gyro used as a sensor any longer.
Similarly, computers make good active stabilization possible and steering your engine to stabilize is a lot lighter than having to add a big rotating mass.
When you last flew a jet somewhere, why wasn't it a seaplane? Surely such things would be an easier problem to solve than building airports.
Short of giving you the starter course in rocket engineering, I can only say no, it's not easier.
The booster can indeed make it back uprange to Kennedy Space Center, and they've leased a landing pad for it there. Besides the turn-around burn, they tilt the booster against the airstream and let aerodynamics push it back uprange during that 78 mile descent.
If there's one thing they should work on, it's not thrusters but having the capability to throttle to hover. That would potentially change the entire low approach. It is complicated by the fact that engine performance goes nonlinear in the low range.
Here is the barge on the way to port, possibly with debris onboard. Here's a video of the landing shot from the barge itself. And I am waiting to see the barge from the Carnival Fascination webcam.
A video from the barge is now online here. If you step through the final frames, you can see that the camera mount ends up knocked over and pointing at the ocean, but the lens and its cover are unbroken and all we see flying appear to be small debris. So not a really high-pressure event.
It's very tempting to think this should work like an airplane. Lots of people wrote that it was "too hot", etc. But it isn't an airplane. The plan was really to approach at 1/4 Kilometer Per Second, then brake at the very last second.
Obviously Crew Dragon, which carries people, will approach differently. But it's a lot lighter.
In the F9R test videos they catch some of the backscatter from the engine and seem to catch fire. Maybe they were trying to avoid that. They are very light carbon composite. Or perhaps they mess up the airstream for precision navigation, or they don't like the 250 m/s wind.
It looked to me that the barge was structurally undamaged but that some heavy equipment on the deck was forcibly ejected. It's clear to see in the HD version. Those 1000 HP thrusters are expensive, and it looked to me like one of them going overboard. But I suspect they were prepared to lose more than one vessel in testing this.
And I bet there was a range safety self-destruct charge onboard. F9R blew itself up with one. But it was probably so safe that it didn't go off.
If you want to put yourself on the map, publish your own map.