SpaceX Nails It Again
Looks like @SpaceX missed the center of their #Falcon9 first stage landing target by 1 meter – again. More practice required. pic.twitter.com/Be37gKMhhe
— NASA Watch (@NASAWatch) January 14, 2017
Looks like @SpaceX missed the center of their #Falcon9 first stage landing target by 1 meter – again. More practice required. pic.twitter.com/Be37gKMhhe
— NASA Watch (@NASAWatch) January 14, 2017
That was so much fun to watch. It even cheered ME up! Well done SX!
The live video feed of the landing was simply amazing, the general public has little interest in men in suits and ties telling us lots of facts and figures (however interesting they may be!) at a dull press conference but give them cool video like this and you’ve got their interest for a while, you just have to keep upping the ante so to speak which Space-X certainly seems to be doing with ever slicker presentation and video feeds, they even seem to use their dramatic failures to keep the public interested! Well done to all involved.
Also is it me or does the Landed F9 Stage seem a little on the wonk? it looked okay in one view but in the fish eye view it certainly doesn’t look too straight, may just be the angle though.
My mother was looking over my shoulder and was amazed.
Previously, she didn’t really understand what the fuss was about and really doesn’t know much about SpaceX beyond the borderline-obsessive media talk about their failures. Watching a rocket drop from the Karman Line to a soft landing was something she’d never imagined and it has seriously changed her perspective on the company.
“Also is it me or does the Landed F9 Stage seem a little on the wonk? “
Looks like the fisheye lens effect. We’ll see when JRtI gets back to harbor.
And, more importantly, all 10 payloads have been launched into the target orbit to the customer’s satisfaction. That’s the real test and that’s what SpaceX delivered today.
Keith, Your, hopefully, tongue-in-cheek comment reminds me of a conversation I had with some Rockwell Collins engineers about 20 years ago. Their auto landing system for airliners was still relatively new but they were already getting complaints from the airports that they were wearing holes in the runway from the planes landing in exactly the same spot. There were being asked to randomize the exact touch down point a bit so the runways would last longer.
Just my way of having a little fun with the extreme accuracy with which they land on the barges after falling back to Earth from the edge of space. π
I remember reading about discussions between the guidance guys and the crews for (a) the first precision-targeted entry of a Gemini and (b) Apollo 12’s first demo of a precision-targeted lunar touchdown (which was essential for later missions).
My recollection is that they jokingly discussed targeting the actual aircraft carrier in the former case…and then got seriously worried about it actually landing on the deck and opted to change it. I think it was close to the same with targeting the actual Surveyor spacecraft on the lunar surface; I kinda remember they left the lunar touchdown guidance aimed as planned, and Conrad ended up taking over manually with the Surveyor in sight to find a smoother & flatter place.
For the longest time, shuttle (and I’m pretty sure Apollo & Gemini) missions, from Ti (formerly TPI)β8 miles behind the target)βon in the guidance targeted for a direct intercept at (I vaguely recall) 4 ft/sec. Presumed dispersions in the trajectory made this the wisest thing to do, and it was the braking gates executed manually that bent the trajectory away from this intercept course up to a V-bar (“velocity vector” out front final approach). Finally, well into ISS of all programs when everyone recognized that the guidance had always been very good and they shifted to primarily R-bar (from directly underneath) approaches (which provided natural braking), they started targeting for exactly where they wanted to go, i.e., 600 feet below the target.
I wonder if the Space X guidance team will be awarded some sort of ‘carrier landing’ pin for setting their birds down on pitching decks, sometimes even in the black of night?
Looks like SpaceX got the money train rolling back on track today. Good for them..and good for us.
This is really great and gives me hope for the future. Do you think they will need a third boat to recover for the Falcon Heavy for those types of orbits? Do you think a reusable Falcon 9 or a Falcon Heavy will come first? I certainly hope they meet the extremely ambitious planned goal of a Dragon on Mars launching in July 2018.
I assume they will need more than three boats. From the photos, it doesn’t look like they have room for more than one core/first stage per boat, a Falcon Heavy has three, and they need one in the Pacific for launches out of Vandenberg (currently the _Just_Read_the_Instructions_.) That’s four boats, and presumably five once the Texas launch site comes on line.
The current schedule calls for the first reused first stage to fly on a Falcon 9 before the initial Falcon Heavy launch. Although I think SpaceX prefers to call it “flight tested” or “flight proven” rather than “reused.”
Thanks!
They’ll only need one barge, even for Falcon Heavy, since FH boosters will always land back at the launch site. Only core will need a barge for landing.
But that means of course they they’ll need a landing site capable of landing two boosters at the same time.
Already planning to build two auxiliary landing pads at LZ-1 at the Cape.
I think that the plan for FH is to have the outboard cores to return to launch site and the central core to land on a barge.
It iall depends on the payload mass being lofted to orbit. AFAIK there is about a 30% payload mass penalty for a booster to return to the launch site. Since you need propellants for boost back burn, entry burn & the hoverslam landing burn. Recovering a booster down range on a floating platform only requires the entry burn and the hoverslam landing burn.
Think SpaceX will have to consider larger recovery platforms in the future. The current barge conversions can only be towed at about 6 knots. So tunaround time for the recovery droneships for down range operations beyond 250 kilomeers become problematic.
Is that 30% number correct? It’s huge.
I was curious about this as well so I looked at the profiles of a couple of launches. One that landed on a barge and one that landed back at the launch site. I did some very rough back-of-the-envelope calculations.
Barge landing:
launch to MECO 160s X 9 engines =1440s
Reentry 20s X 3 = 60s
landing 35s X 1 = 35s
1440 + 95 = 1535 engine seconds
95/1535 = .06 or 6% fuel cost.to return
Return to launch-site
launch to MECO 141s X 9 = 1269s
course reversal 50s X 3 = 150s
Reentry 20s X 3 = 60s
landing 35s X1 = 35s
1269+245 = 1514s engine seconds
245/1514 = .16 or 16% fuel cost.to return
Note that the is only 21 seconds difference in fuel between the two launches. The rocket is the same size so there is no other added cost except fuel.
There really isn’t a payload penalty for returning to launch site. If the payload is too big, you land on the barge. If it’s still to big, you toss the first stage and charge accordingly.
I’ve heard that when the 1st stage lands at the cape there’s a triple sonic boom. It’ll be wild when a FH launch occurs and there are 3 1st stages landing at once.
The triple sonic boom is going to be from FH landing because there’ll be 3 first stages landing which is what you effectively have with an FH. You only get the one with F9.
Cheers
Individual vehicles create double sonic booms. With aircraft, the nose creates a shockwave and so does the tail. The two are related aerodynamically because the second shock will raise the static air pressure back up to ambient after the first drops it below ambient.
I think the Blackbird produced 2 sonic booms. If I’m not mistaken the POW’s in Hanoi Hilton used to hear them every day around noon.
I watched one of the land recoveries from my house and it looked like it was coming straight at me, but I don’t recall a sonic boom. The returning Falcon booster is going almost straight down, so the sonic boom is directed downward and only spreads out a few miles. On the land recoveries at night you can see the entire trajectory from the ground, from separation to landing. Spectacular!
Thanks Bob. I thought I was correct on this one but you’ve prompted me to research this topic and learn. Also you pointed out my failure without any belittlement or other nasty stuff. A rare occurrence these days to say the least.
Many thanks for being a gentleman and sharing your knowledge so politely.
Cheers
There’s a quite stern taskmaster lurking in these parts, making NASAWatch about the only place I comment.
I’ve heard there’s 3 sonic booms from a single stage landing although in the videos I’ve only heard 2. The speculation was that they were from the top, bottom and control vanes 2/3 the way up. Could be the top and control vanes are so close it’s hard to hear those as 2 separate booms. With 3 stages landing, it seems like it will be boom town at the cape with 6 to 9 booms occurring at about the same times.
Which will be very cool.
Hmm. I didn’t hear it over on the west coast- maybe it’s too far considering the boom probably happens some miles off the east coast? We heard the shuttle regularly unless it approached from a northerly bearing.
You likely heard the shuttle because it passed overhead. I believe the drone ship landings are likely too far away to hear any sonic booms. Those reported from the cape landings were when it was landing on land, not at sea.
If you google it, there are numerous links describing it.
http://www.spaceflightinsid…
and video https://www.youtube.com/wat…
Well done SpaceX! Another success, more data and a public that really enjoys seeing it all unfold live on video. Can’t ask for more than that.