Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror

Slashdot videos: Now with more Slashdot!

  • View

  • Discuss

  • Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

×

Comment: Re:vs. a Falcon 9 (Score 1) 54

by Bruce Perens (#49501071) Attached to: Rocket Lab Unveils "Electric" Rocket Engine

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. :-)

Comment: Re:You Can See (Score 1) 110

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.

Comment: Re:New product (Score 1) 340

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.

Comment: Re:incredibly close to target is far from success (Score 1) 340

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.

Comment: Re:legs too late? (Score 1) 340

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.

Comment: Re:New product (Score 1) 340

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.

Comment: Re:Landing vs splashdown (Score 1) 340

Remember the reporters asking what was holding DC-X up? They couldn't see the rocket exhaust.

I sneaked inside of the Rotary Rocket the last time I was in Mojave. Someone left the bottom hatch ajar. But there wasn't a way to climb up to the cockpit from in there. Lots of pigeon droppings and it's used to hold the equipment for the multimedia kiosk nearby. Sad to see.

Comment: Re:Larger landing area (Score 1) 340

I learned an important lesson from Open Source, and it applies to SpaceX too: Things work a lot better if you just give the engineers the freedom to do engineering.

I think that in government projects and in most larger companies we tend to devalue the technical people in favor of the nontechnical. And we don't give them much power to actually run things. And then we wonder why efficiency is so low.

It has certainly given me ideas for how to run my own company.

"If truth is beauty, how come no one has their hair done in the library?" -- Lily Tomlin

Working...