Posted on 04/20/2014 5:39:21 AM PDT by lbryce
Original Title:Watch: Amazing Drone Footage of a Space X Reusable Rocket’s First Test Flight
Make sure to watch this at full screen view.
Direct Link:YouTube:F9R First Flight Test|250m
This is awesome. The Falcon9 reusable rocket launches and then within minutes lands on its own four feet. Videoed by a drone high above the launch pad meeting up with it to close proximity as the rocket approaches the drone in mid-air.
Published on Apr 18, 2014
Video of Falcon 9 Reusable (F9R) taking its first test flight at our rocket development facility. F9R lifts off from a launch mount to a height of approximately 250m, hovers and then returns for landing just next to the launch stand. Early flights of F9R will take off with legs fixed in the down position. However, we will soon be transitioning to liftoff with legs stowed against the side of the rocket and then extending them just before landing.
The F9R testing program is the next step towards reusability following completion of the Grasshopper program last year (Grasshopper can be seen in the background of this video). Future testing, including that in New Mexico, will be conducted using the first stage of a F9R as shown here, which is essentially a Falcon 9 v1.1 first stage with legs. F9R test flights in New Mexico will allow us to test at higher altitudes than we are permitted for at our test site in Texas, to do more with unpowered guidance and to prove out landing cases that are more-flight like.
(Excerpt) Read more at thenextweb.com ...
Good Luck with that marketing.....
A 747 has a 15:1 glide ratio, so if they’d just run the fuel tanks dry at 45000 feet and glide the rest of the way in, they could get another 110 nautical miles of range out of it - a 1.5% improvement. If they left off the landing gear and just pulled a Sully in the nearest river every flight, that’d save thousands of pounds of weight increasing the range even more - the tires alone weigh over two tons.
Lamenting a loss of throw weight when you’re able to reuse the launch vehicle is like lamenting the loss of range imposed on your 747 from having to carry tens of thousands of pounds of landing gear.
Yes, but you have a reusable vehicle, instead of throwaway stages.
The ROCKET has a 0:1 glide ratio.
It must sustain thrust all the way back to the landing pad.
Additionally, there is significant structural mass added to the vehicle to be able to land.
Refurb and Recycle costs are also significant, as we learned with Shuttle.
It would have been cheaper to throw the SRBs away than the total costs of making them reusable.
It was a political design, not an engineering, cost/benefit design, because the concept of recycling was sexy.
See post #25
You’re comparing refurb costs of politicized 1970’s technology to the Falcon 9-R? Say what? We’re talking about SpaceX, not the Shuttle.
And in any case you seem to be missing my point. The mass of the landing gear of a 747 may be “significant” too, even if they were made out of carbon fiber and aluminum honeycomb like the F-9R’s landing gear, but the fact that it allows the reuse of a $30-40 million vehicle is more important than the added mass in both cases.
And it’s not actually true that it must sustain thrust all the way to the landing pad. After the three-engine retro burn, the center engine only needs to impart enough delta-V to offset the terminal velocity of the falling, nearly-empty stage close enough to the ground for a soft landing.
I’m not “missing” anything.
Here are “some” of the offsets:
Additional:
Propellant to lift the landing prop load.
The Landing prop load.
Structural additions for both.
Overall add’l structure for entire vehicle to support both.
Add’l structure & test to support reuse.
Fac/labor for recycle & test (dif from original factory location.
More robust engines to support reuse.
Range safety changes to support this landing profile.
Did anyone point out that these vehicles don’t go straight up and down?
They fly several hundred miles down range....OVER THE OCEAN, before MECO (Main Engine Cut-off)
Soooo....WHERE are they going to land?
Highly unlikely that we’ll be re-writing Range Safety rules to allow over-land space launches.
We’ll leave that to Russia and China.....
"The payload penalty for full and fast reusability versus an expendable version is roughly 40 percent," Musk says. "[But] propellant cost is less than 0.4 percent of the total flight cost. Even taking into account the payload reduction for reusability, the improvement is therefore theoretically over a hundred times."
And the downrange distance 11 seconds before MECO and 14 seconds before staging on the CRS-3 launch was about 60km (about 40 miles), not "several hundred miles."
If you have more robust engines to support reuse, that could offset the offsets, right? You can use titanium instead of stainless steel even though it costs four times more because you're going to reuse the engine 30 times or more, and so you get a higher thrust-to-weight ratio.
I addressed Propellant to cite mass and volume, not its cost.
How many miles does it travel in those last 14 seconds?
How is it going to retrace that path?
Using your Musk provided numbers, he wouldn’t grow the vehicle, rather reduce the throw weight. So, 5,000 lbs becomes 3,000 lbs.
I contend the folks writing the Range Safety rules knock that down to 2,500 lbs. max. (50% penalty rather than 40%)
Include Facilities, equipment, test, and labor for refurb....
Just color me skeptical.
It’s accelerating towards Mach 10 in those last 14 seconds, so what, the cosine of another 10-15 miles?
It retraces the path by using three engines with 144,000 pounds of thrust to impart horizontal delta-V to a nearly-empty stage that has a 30:1 gross-to-dry mass ratio.
And the expendable Falcon 9 can get nearly 29,000 pounds to LEO, not 5,000 pounds, so accepting your range safety assumption you’re down to 14,500 pounds to LEO, but without having to trash millions of dollars worth of equipment. So you’re in the same ballpark as the Antares or Soyuz-U throw for tens of millions of dollars less money, and you still have enough throw to get a crewed Dragon into orbit.
I’d pay to sit in the Range Safety meetings that address the return and landing constraints.
He says that the boost stage is about 70% of the cost of the launch, per the press conference, so recovery and reuse of only that piece is apparently a pretty large savings.
He says that the turnaround time to reuse an ocean-recovered stage would be about 2 months, but with a dry land recovery they could in principle relaunch it the same day.
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