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  1. #1
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    Thumbs up SpaceX Falcon 9 historic landing thread (1st landing attempt & most recent missions)

    NOTE - Thread is for the first landing attempt thru the most recent missions. This first post and thread title will no longer be updated with the most recent mission, but all are encouraged to make new posts for the newest (and future) missions.

    -------------------------------

    Next launch is JCSAT-14, a Com Sat for Japan. very early Friday May 6th, 1:22 AM EDT (think of it more like launching late Thursday night after midnight). It will try to land on the ASDS Barge, OCISLY. News for this launch begins here: http://www.rocketryforum.com/showthr...74#post1577374

    [archive milestone link to first successful ASDS Barge landing]CRS-8 , an ISS resupply mission, is currently set to launch Friday, April 8th, at 4:43 p.m. EDT. It’s booster is planned to land at sea, on the ASDS Barge “Of Course I Still Love You”. Link for thread message with more info on the flight is here: http://www.rocketryforum.com/showthr...68#post1568868

    [archive milestone link to first successful landing]
    The SpaceX RTF (Return To Flight) mission for Orbcomm-2 successfuly launched its satellites.
    The first stage soft landed on land, back at the Cape, at the new landing facility previously known as LC-13.
    See message #547: http://www.rocketryforum.com/showthr...59#post1530659

    Here is the SpaceX Webcast link:
    http://www.spacex.com/webcast/



    [original December 11, 2014 message text below]

    Space-X is scheduled to launch an unmanned "Dragon" spacecraft on a resupply mission to ISS.

    But the biggest news about that is that it will attempt the first landing of a Falcon-9 first stage, onto a solid surface, so it can not only be recovered intact but hopefully reflown. If successful it will make history.

    The computer-generated image below is not depicting pre-launch, it is post-landing!



    There have been successful tests of controlled re-entry and soft landings in the ocean (and MANY soft landing test hops in Texas). This time, it'll try to land on a converted barge. Here's a link to one of many stories about it, and some photos. I'm including the text of the story at the end of this.

    http://www.dailymail.co.uk/sciencete...-everyone.html


    BTW - here is a very relevant youtube video of a test flight in Texas in July. It flew a kilometer up, and tested out the deployable steered grid fins. However, it does not descend very fast, so the steerable grid fins did not really get much of a test like they will during supersonic descent from 20-30 thousand feet.



    The steering grid fins are pretty important for trying to make a precise landing on the barge. The earlier "soft landings" in the ocean were , as far as I can tell, not attempting to land on an exact coordinate spot and really could not do so without some kind of aerodynamic (or some other additional) steering to tweak the trajectory path during descent. And the test hops in Texas could not simulate a long ballistic descent because they did not have the necessary huge safety area to be able to fly that high, across a long distance, to attempt to simulate such a thing. It seems like the above test flight to a height of 1 kilometer might be the highest they have flown (and descended to simulate landing), and that was pretty much vertical. They have done other tests, not quite as high, where it flew partly diagonally then flew back to the launch pad. So the aerodynamic steering is to help get it close enough to the ballpark for the powered landing to be able take it the rest of the way.

    Here is a video of a launch in August, the second stage put six Orbcomm satellites into orbit. The first stage did a successful powered soft landing in the Atlantic Ocean, it floated for awhile but broke up & sank.



    Here is onboard video from the same flight. Unfortunately, the view was obscured by accumulations of ice, but you can still make out some neat portions of the landing.



    If it makes it close to the barge, there ought to be some great video, even if the onboard camera gets obscured again. I would expect a lot of fixed cameras on the barge. Perhaps a few that also pan and tilt, either remotely human controlled or auto-computer controlled.

    Also, they have made some great use of multicopters ("drones") for video of many of the Texas flights, despite the FAA anti-drone crusade. So I am hoping they also have at least one of those in the air, done well it would make for incredible video. Sort of depends I guess on how close the support ship will be, to allow for one or more human R/C pilots, and/or the range of the R/C equipment if the ship is say 10 miles out. Or if that is not practical, I would not be surprised if they had a totally autonomous multicopter or two to automatically shoot the video from fixed position(s) in the sky, a few hundred feet off to the side from the barge, with the camera pointed at the barge. Once the Falcon launches, it'll be minutes before the multicopter(s) would need to take off, and get into position. Onboard battery life not a big issue since they'll know when the Falcon first stage should land, almost to the second, so they can plan out the timeline to get into the air, into position, video the landing, and to allow for time to fly back to the barge, maybe do a not-too-close circle around Falcon, then land on the barge.

    The Public Relations value of such would be tremendous, because while aerospace pros and junkies do not even need to see any video to know the importance of it, the general public needs to see something impressive. And that would be the most impressive way to show it...... if it works (Hope they don't use the old cold war Russian method of only showing successes, put the video on a time delay and cut the feed if something goes wrong. They never did release any video of the self-destruct explosion they had in Texas, AFAIK. But then that was a private test, and not a NASA-funded launch).

    - George Gassaway



    Aerial view of the actual barge


    View of the deployable steerable "grid fins" at the top of the first stage, with interstage at right.


    Previous Falcon 9 launch in July.







    SpaceX gears up to land a reusable rocket on a floating barge - and the breakthrough could make spaceflight more affordable for everyone
    • SpaceX is planning to land a rocket at Cape Canaveral on Monday
    • The first stage of their Falcon 9 rocket will attempt to touch down on a barge after launching a Dragon capsule into space*
    • It is the first ever attempt at landing a rocket on solid ground after launch
    • Elon Musk said the ambitious attempt has a 50% chance of working
    • The company*ultimately*wants all of its rockets to be reusable*

    By JONATHAN O'CALLAGHAN FOR MAILONLINE


    SpaceX has long spoken of its ambition to make rockets reusable.
    And on Monday, the firm plans to reach a major milestone as part of this endeavour when it brings back part of one of its Falcon 9 rockets after launch.*
    If all goes to plan, the first stage of the rocket will gently lower itself and land on solid ground for the first time ever.*

    The attempt will occur during the launch of the latest cargo-carrying Dragon capsule to the ISS at 7.31pm GMT (2.31pm EST) on Monday 16 December.
    The Falcon 9 rocket carrying Dragon will take off from Florida’s Cape Canaveral Air Force Station.
    After launch, at a height of about 56 miles (90km), the first stage of the rocket will separate from the second stage.
    While the latter continues its mission into orbit, the former would usually be left to fall back into the ocean - as is the case on all other rocket launches.

    However on this flight, for the first time ever, SpaceX will instead use a specially designed first stage capable of landing itself on a floating barge.
    In a previous flight, a Falcon 9 first stage hovered above the surface of the ocean - without a barge - in a successful demonstration of the technology.
    On that flight, the first stage was left to fall into the ocean after proving it could hover above the ground. But on this next flight, the rocket will touch down on a floating barge.

    The barge measures about 300 feet (90 metres) long by 100 feet (30 metres) wide, and also has wings that extend out to another 170 feet (50 metres).
    According to SpaceX chief Elon Musk, it also has ‘thrusters repurposed from deep sea oil rigs’ that can hold it in position within 10 feet (three metres) even in a storm.
    To control the rocket as it lands, grid fins on its side are used, which control its pitch, yaw and roll.
    These are ‘stowed on ascent and then deploy on re-entry for “X-Wing” [from Star Wars] style control,’ according to Musk.
    And to slow it down as it descends it will save 15 per cent of its original fuel, allowing it to lower itself towards the ocean without the use of a parachute.

    However, as the mission has never been tried before, he added that there was only a 50 per cent chances of the platform landing being a success on this first attempt.
    Whatever the outcome, though, SpaceX will use the data they glean to improve their technique and one day plan to perform this manoeuvre during every launch.
    Cameras on board the barge will capture the entire descent, although it’s unclear how much - if any - of this footage SpaceX will make public.
    Eventually, they will start bringing the upper - or second - stage of the rocket back as well.
    The ultimate goal is to make the entire rocket reusable - which will drastically reduce the cost of going to space.
    SpaceX has a £1billion ($1.6 billion) contract with Nasa to resupply the ISS. This launch of the Dragon capsule will be the fifth of 12 scheduled missions.

    Last edited by georgegassaway; 23rd May 2016 at 10:21 PM.

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  2. #2
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    Here's a link to another article, with more technical info and background:

    SpaceX’s Autonomous Spaceport Drone Ship ready for action
    November 24, 2014 by Chris Bergin

    http://www.nasaspaceflight.com/2014/...rt-drone-ship/



    The first stage leg-span is 60 feet, BTW. So if all four footpads are inside of the 80 foot yellow circle, that'll be pretty much a bulls-eye. The barge can keep station within 10 feet in high seas, so if Falcon landed 10 feet off.... it might not be Falcon that was off for all of the 10 feet, the barge might be off a few feet. Although I would expect the Falcon to be using some means of "homing in" for final corrections based on where the barge is exactly located as it is coming in to land, and not where the barge is supposed to be. Depending on what was technically more practical, possibly not "home" on the barge but for the barge to have GPS transponders that provide ultra-precise GPS coordinates for Falcon to get rapidly updated GPS data on where to exactly land.

    And here is a link with info on NASA TV's schedule for the launch. Set for December 16th at 2:31 EST

    http://www.nasa.gov/press/2014/decem.../#.VIlODmTF8rM

    Unfortunately, the info on that page is 100% focused on the Dragon's payloads going to ISS. No mention of the planned landing of the first stage on the barge. That would be sort of like focusing on two payloads named John Young and Bob Crippen flying into orbit and returning safely in April 1981, without mentioning what history was made by the vehicle they launched in.

    I hope NASA does not ignore the landing attempt. I am not a NASA basher, but man that would be ridiculous if they overlook it, and/or Space-X does not make a live feed available.

    So it may well be that it'll be necessary to follow a live feed from Space-X to see what may be the most important part of this flight. Although I just looked at their site and do not see anything to support live feeds, only multimedia files. If NASA isn't going to do it, Space-X would be foolish not to have their own live feed of the landing. I'm going to check some other places for info on whether Space-X or NASA or someone is likely to have a live feed of the landing attempt. Just do not have a good feeling that an answer has not come up yet..... if it's planned it should be easier to find.

    - George Gassaway

    Last edited by georgegassaway; 11th December 2014 at 11:04 PM.

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    George- Thanks for taking the time for this extensive update. Your invaluable insights into the PR aspect of video feeds and the use of drones are dead on and I'm excited about the possibilities of seeing this evolve as a useful tool. I am not a "NASA basher" either (hell, they paid the bills in one form or another for 20 years) but I have my fingers crossed for SpaceX to prove we can do without the political pork barrels and infighting, budget restraints and 'non-engineering' inputs we suffered thru the latter half of our so called 'space program'. Myself, I see the Orion as so much static and noise destined to be heaped on the pile of dead ends that the politicos find so easy to discard for votes from the aging baby boomers when they want free hearing aids after decades of disco and heavy metal from their boom boxes. Clean signals and green lights to these guys!
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    Cool post George! Its certainly going to be exciting!

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    This certainly bears watching. I hope they have complete success and excellent coverage, especially from drones! Watching the parachute sequence and splashdown of Orion from their drone was VERY cool!

    I wonder why they didn't try to do a more 'long range ballistic arc' test at White Sands?? WSMR is a BIG place... not quite as big as they'd need for a full "100%" scale test of the path, altitude, and distance flown by a Falcon 9 stage 1, but for a grasshopper test article, they COULD have more closely approximated the kind of ballistic arc, descent, and landing that would be required of the larger Falcon 9 first stage, and remained within the WSMR safety zone, which is pretty huge...

    I guess perhaps working with the military or range fees or red tape or something is probably the reason they've simply kept testing to their own "test range" in central Texas. That, and just doing "on the side" flight testing as part of their contracted NASA launches under their COTS program contracts... very good use of "expended hardware" (which the first stage is after staging, anyway, at this point...)

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    Well, I have not found any info on a live feed of the landing.

    I did ask on a space site where there ought to be answers.... but nobody had any solid info.

    Sadly a few came up with some petty excuses such as Space-X might not have a live feed in case it does not succeed, only release video much later if it works.

    So, Cold War Russian Space Program style. I hope not. I have very SLOWLY built up my impressions of Space-X. If they didn't show something this historic for petty reasons, they are not the company I thought they are and not worth that trust.

    But again it's fanboys who wrote some of those pre-emptive petty excuses. So they may be wrong and Space-X perhaps has not made info on how/where to see a feed of the landing in an easy-to-find way (yet?). But it's very troubling that if there is to be a live feed of the landing, it's this hard to get info on. I'm not as high on this as I was 24 hours ago.

    What does come thru clear is that NASA is "the customer", and the NASA TV feed is not going to cover anything beyond launching the spacecraft into orbit and getting supplies to ISS. Just another routine unmanned launch of supplies to ISS.......which if it was true most space buffs would not bother to watch to begin with.

    UPDATE - Launch has slipped to Dec 19th:

    http://spaceflightnow.com/2014/12/11...ips-to-dec-19/

    - George Gassaway
    Last edited by georgegassaway; 11th December 2014 at 11:34 PM.

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    Quote Originally Posted by luke strawwalker View Post
    I wonder why they didn't try to do a more 'long range ballistic arc' test at White Sands?? WSMR is a BIG place... not quite as big as they'd need for a full "100%" scale test of the path, altitude, and distance flown by a Falcon 9 stage 1, but for a grasshopper test article, they COULD have more closely approximated the kind of ballistic arc, descent, and landing that would be required of the larger Falcon 9 first stage, and remained within the WSMR safety zone, which is pretty huge...

    I guess perhaps working with the military or range fees or red tape or something is probably the reason they've simply kept testing to their own "test range" in central Texas. That, and just doing "on the side" flight testing as part of their contracted NASA launches under their COTS program contracts... very good use of "expended hardware" (which the first stage is after staging, anyway, at this point...)
    You know SpaceX has a lease with Spaceport America (right next to WSMR) for doing high altitude testing of Grasshopper/F9R?
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    Quote Originally Posted by georgegassaway View Post
    Well, I have not found any info on a live feed of the landing.

    I did ask on a space site where there ought to be answers.... but nobody had any solid info.

    Sadly a few came up with some petty excuses such as Space-X might not have a live feed in case it does not succeed, only release video much later if it works.

    So, Cold War Russian Space Program style. I hope not. I have very SLOWLY built up my impressions of Space-X. If they didn't show something this historic for petty reasons, they are not the company I thought they are and not worth that trust.

    But again it's fanboys who wrote some of those pre-emptive petty excuses. So they may be wrong and Space-X perhaps has not made info on how/where to see a feed of the landing in an easy-to-find way (yet?). But it's very troubling that if there is to be a live feed of the landing, it's this hard to get info on. I'm not as high on this as I was 24 hours ago.
    SpaceX has publicly stated that they are weaning themselves off holding a webcast for every launch, as they intend to make launches fairly regular and, for lack of better term, mundane. They pull engineers and managers off their normal jobs to do those webcasts, so the plan is only to do live webcasts of major milestone launches (Dragon v2, etc.). I would guess they might have a webcast for landing on a barge, but I cannot say for sure. If they do, it would be spacex.com/webcast. After all, their job is launching rockets, not broadcasting launches.
    Joseph Mattingly
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    Quote Originally Posted by jmattingly13 View Post
    SpaceX has publicly stated that they are weaning themselves off holding a webcast for every launch, as they intend to make launches fairly regular and, for lack of better term, mundane. They pull engineers and managers off their normal jobs to do those webcasts, so the plan is only to do live webcasts of major milestone launches (Dragon v2, etc.). I would guess they might have a webcast for landing on a barge, but I cannot say for sure. If they do, it would be spacex.com/webcast. After all, their job is launching rockets, not broadcasting launches.
    Thanks very much for posting that link. You have done what nobody on nasaspaceflight.com was able to do.

    This will be the most historic flight Space-X has made, if the anding is a success. So even if they are weaninng off of webcasts, this is most deserving. And now that I see they have the previous ISS supply flight webcast up, it would make no sense to have posted that flight and not post this.

    Even a likely future launch of NASA astronauts to ISS won't be as fundamentally history-making as safely landing a re-useable rocket stage that helped launch a spacecraft into orbit.

    Of course that does not mean it will be a live video feed, but clearly that link is the place to "tune into" for the news about the landing attempt.

    - George Gassaway

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    That camera view from the July test flight looked uncannily like a a keychain camera view from a model rocket. Well, except the absolutely no roll and that fact that the rocket stopped, then went back down.
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    I'm confused about the grid fins. In a few threads I have seen it said that tube fins act as solid cylinders to supersonic flows, do grid fins not exhibit similar aerodynamics?
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    How do they plan to recover the second stage, if the new clipping is accurate and they do want to do that... my understanding is the second stage ends up pretty close to orbital velocity which either introduces serious heating problems or uses massive amounts of fuel to slow waaaay down....

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    Quote Originally Posted by Wingarcher View Post
    How do they plan to recover the second stage, if the new clipping is accurate and they do want to do that... my understanding is the second stage ends up pretty close to orbital velocity which either introduces serious heating problems or uses massive amounts of fuel to slow waaaay down....
    They're not trying to recover the second stage at this point. Elon's goal is to make everything recoverable if possible, but for the reasons you've stated, the second stage is not quite there yet.
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    Quote Originally Posted by jmattingly13 View Post
    They're not trying to recover the second stage at this point. Elon's goal is to make everything recoverable if possible, but for the reasons you've stated, the second stage is not quite there yet.
    Also another reason why SpaceX might have wanted the "landing barge" thingy. While the first stage might be able, eventually when proven capable and safe, to fly back to the launch pad (or nearby), the second stage is going to be WAY downrange and flying back would seem to be highly unlikely.
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    Rocket beef!

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    Quote Originally Posted by Peartree View Post
    Also another reason why SpaceX might have wanted the "landing barge" thingy. While the first stage might be able, eventually when proven capable and safe, to fly back to the launch pad (or nearby), the second stage is going to be WAY downrange and flying back would seem to be highly unlikely.
    Interesting point. I hadn't thought of that.
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    I wrote this earlier but somehow it didn't get posted (probably in preview mode and didn't hit post). Fortunately the text was still in my "clipboard" when I saw it wasn't here.

    A wiki about grid fins:

    http://en.wikipedia.org/wiki/Grid_fin

    One thing I read recently was that added grid fins to Falcon because at supersonic speeds, the thrusters they used were not effective enough to steer it.

    And one of Elon Musk's tweets refers to them as "hypersonic" grid fins (Hypersonic means Mach 5+), and they will be deployed on re-entry.

    BTW - do take note that "re-entry' for the Falcon first stage is relatively mild and nowhere near the heating and stresses of a re-entry from orbital velocity. This is very relevant to some of the issues involved with a reuseable second stage, which the first stage does not have to deal with to those extremes.

    One bit of news i read as I googled for this, is an earlier failure to land safely was due to the RCS thrusters using so much fuel to try to steer it that they ran out of RCS fuel .That then left the Falcon unable to point itself the right way for gravity (well, technically, the relative G-force vector due to drag as it fell unpowered) to make the fuel to flow into the fuel lines so the engines could ignite.

    Quote Originally Posted by Wingarcher View Post
    How do they plan to recover the second stage, if the new clipping is accurate and they do want to do that... my understanding is the second stage ends up pretty close to orbital velocity which either introduces serious heating problems or uses massive amounts of fuel to slow waaaay down....
    Well, recovering the second stage is a goal for the future. Lots of problems to overcome before they will lbe able to try that. And indeed the 2nd stage will make it all the way into orbit. Suffice to say that the biggest cost for the rocket hardware is for the first stage, so recovering the first stage for re-use over and over will be a massive game-changer for the cost of space flight (it will remain to be seen how many times that the recovered stages and engines can be re-used before wearing out, and how much inspection and refurbishment they will need between flights). Recovering and re-using second stages will be the cherry on top, but nowhere near the financial impact of being able to reuse the first stage.

    Well, the second stage has 18.7% as much fuel and oxidizer as the first stage, and only one Merlin engine compared to nine Merlin engines for the first stage. Though it is a specialized vacuum version so it would tend to cost a bit more. So accounting for relative size of tankage needed and cost of engine, the second stage may cost around 1/6th the cost of the first stage. Or perhaps more like 1/5th. The cost per per stage might be out there in Google-land but it was not in the wiki so I'm not going to try digging any further, I think that 1/6 to 1/5 the cost of the first stage is a reasonable estimate in comparing the financial factors of reusing the first stage only versus also recovering and reusing the 2nd stage.

    Now that does not include the cost of lost parts like aerodynamic fairings. And some speculated schemes for a re-useable 2nd stage have involved structures that do not have a jettisoned fairing but instead the nose section stays with the 2nd stage for reentry, the stage would open up in some manner (sideways like a shuttle payload bay, or for the nose to be hinged to swing up) to let the payload (and a likely "kick" stage to reach higher orbits) come out then close back up for reentry. But the more involved it gets, the more that potential payload mass is lost in trading off for the mass of the reuseable 2nd stage. The cost of the guidance systems….. both stages have guidance systems and such, Falcon-9 is not like the old Saturn-I B or Saturn-V with the guidance system all mounted into the Instrument Ring at the top of the uppermost stage (S-IVB stage).

    For some of the payloads, they need jettisoned fairings, such as for Dragon and other large satellites that are too big to go "inside" of a reusable second stage. So for payloads that need to sit on top of the second stage the second stage would need some other design approach.

    Among the problems of recovering the second stage:

    Stability-wise the heavy engines at back will make it want to re-enter tail-first. But the engines could not survive the intense re-entry heat. Any heat shield system based on nose-first re-entry will have to solve how to keep it pointed nose-first. A lifting body or stubby-winged design would do it, but a lot more mass for that so less payload mass delivered (of course, if the launch vehicle can put a LOT of payload into orbit, then the tradeoff of the payload mass lost for a heavy reuseable 2nd stage is better since most payloads would tend to be lighter than "a LOT").

    The second stage not only will need to have the extra fuel (let's say 15%) to do a powered landing, it will also need some fuel to do the re-entry maneuvers. That will not only include the fuel to reduce orbital velocity to re-enter the atmosphere (which actually is not a whole lot from a low orbit, just enough to dip into the atmosphere correctly), but also some fuel to make a change in the orbital plane so it will come down the correct left-right path towards the landing spot.

    The shuttle did not have to do an orbital plane change burn because it used the wing lift and even had the cross-range ability to be able to land back at KSC after one orbit (Those banked "S" turns it did on re-entry, if they did a "C" turn instead in one direction it could have veered 1100 miles to the side of its orbital path). For a reuseable second stage, it will need to come back down within landing windows about 12 hours apart (if night and/or overflight of certain populated areas is not an issue), or 24 hours (if night and/or overflight of certain populated areas is an issue), due to the rotation of the Earth. The orbital timing won't tend to match exactly in 12 or 24 hour increments, unless the orbit was exactly 90 minutes in duration, so every minute before or after the optimum 12 hour increments will require more and more of an orbital change burn. It might even practical to raise or lower the obit slightly (shortly after payload release) to try to make the timing of the orbit match up closer to the 12/24 hour increment so as to minimize the fuel needed for an orbital plane change.

    Now, if the second stage had grid fins, it could make a tiny change in crossrange. But those grid fins could NOT be deployed during the worst part of reentry (they'd burn up), when the stage would need to make the best and most effective use of any aerodynamic maneuvering to affect the cross range.

    So, lots of things for them to work out before recovering and reusing second stages. Several years. And as I said, nowhere near the financial payoff to do that compared to reusing the first stage. So if the first stage cost say 40 million, the current expendable 2nd stage might cost about 6.7 to 8 million. Which is nothing to sneeze at, but not a lot compared to $40 million for the first stage and a 2nd stage that is not hobbled by the extra mass added to make it reuseable, Of course the reusable first stage is also compromised in that sense, an expendable version can put a greater payload into orbit. . They are cutting the engines off early and staging early, leaving about 15% of fuel to do the reentry and landing maneuvers with.

    But that might be a chicken-or-the-egg scenario. To have an ultimate goal of reusability, they would design the rocket from the start so that it could put a desired payload mass into orbit while having 15% of fuel left over. Well, originally Falcon-9 was shorter. Then they made the tanks longer…..probably in large part to being able to land and be reused (I wonder if the tanks were stretched by 15% plus the fuel needed to CARRY that extra 15%, hmmmm).

    Some experts think Space-X won't be able to do a reusable 2nd stage. But then many of them thought that having a reusable first stage was just sci-fi too and Space-X is ready to try it with a pretty good chance of success.

    - George Gassaway
    Last edited by georgegassaway; 13th December 2014 at 12:48 AM.

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    The landing barge has been an interesting "new development". Although more in the form of being announced in the last few months, but in retrospect probably planned for years.

    The announced plan for landing the first stage, was to fly back to the launch site. Although that would require a lot more fuel (cost of payload mass) to stop the downrange momentum then thrust back. So it is a lot more efficient to let it fall on a mostly ballistic path and put a barge pretty much right under where it was going to splash down on a normal trajectory, requires a lot less fuel and therefore allows more payload to orbit. But of course more operational costs in having a barge and associated people, ship(s), and equipment at sea. The 15% of fuel left over that has been stated as needed for the landing..... it does not look like it burns the engines for THAT long on the successful ocean landings they have made. So that 15% might be the fuel needed to thrust back to the launch site and they only need a small amount of that 15% for sea/barge landings (they are only igniting three of the nine Merlin engines for the landings, and of course it is way lighter without all of the used up fuel mass and upper stage/payload gone).

    Anyway, they have applied for permission to have flights land back at CCAFS (Cape Canaveral Air Force Station), where they launch from. There are major safety issues though with a rocket coming "inboound". If things go wrong, a "self destruct" means that lots of pieces would fall down over a large area, very bad if it was coming down over populated land. There are ways of reducing those risks, it looks like a good plan, but in any case they do not have permission to land there yet.

    So, the news of the barge came out in recent months, sounding like a temporary plan for a handful of test flights. So if the landings succeed, then that may help to pave the way to getting permission to land back at the Cape. But the work that's been put into this barge does not seem to fit into a temporary 2-3 test flight program, then they'd not need it anymore.

    Because even if/when they get permission to land at the cape, they will need the barge anyway. Because of Falcon-9 Heavy:



    It will take off using three Falcon-9 first stages. BUT, the center core will get most of its fuel at first from the two side boosters, a cross-feed that IIRC has never been used on a real rocket vehicle, but is an extremely popular method in the game Kerbal Space Program (and VERY efficient. It is like being able to do a 2-stage rocket where the second stage engines get to also fire with the first stage engines, improving thrust to weight ratio by 50%, allowing for heavier upper stages/payload).

    So, it will fly on the three first stages until the outer boosters have to be separated, with enough fuel left for them to fly back and land. Then the core first stage will continue on with its fuel tanks nearly full, and fly a lot farther downrange until it needs to shut down to save some fuel for landing. It will separate, the second stage will fly on, and then that core stage will descend for a soft landing on....... something like a barge. So they will eventually need the barge for Falcon-9 Heavy. But it will come down a LOT farther downrange, so the barge will have to be stationed many hundreds of miles (maybe 1000 miles or more) farther out than for the current version. it would require a massive amount of fuel to be left over, shutting down way earlier, to try to get THAT stage to fly back to the Cape, due to its downrange velocity and distance. So my personal opinion is they have planned to use a barge for Falcon-9 Heavy's core all along, betting on the landing technology to work. And they may have figured they might need to have the barge for first test landings anyway, to prove themselves before they might be allowed to land them back at the Cape.

    At least, this is the case if the test landings work out and they can re-use those first stages. If there was some fatal flaw in the concept and they could never get it to work reliably, well, they would not have the game-changing savings they expect, but it looks like even the current expendable versions are cheaper than any other launch vehicles delivering similar payload masses into similar orbits.

    - George Gassaway
    Last edited by georgegassaway; 12th December 2014 at 09:33 PM.

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  19. #19
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    Quote Originally Posted by georgegassaway View Post
    The landing barge has been an interesting "new development". Although more in the form of being announced in the last few months, but in retrospect probably planned for years.

    The announced plan for landing the first stage, was to fly back to the launch site. Although that would require a lot more fuel (cost of payload mass) to stop the downrange momentum then thrust back. So it is a lot more efficient to let it fall on a mostly ballistic path and put a barge pretty much right under where it was going to splash down on a normal trajectory, requires a lot less fuel and therefore allows more payload to orbit. But of course more operational costs in having a barge and associated people, ship(s), and equipment at sea. The 15% of fuel left over that has been stated as needed for the landing..... t does not look like it burns the engines for THAT long on the successful ocean landings they have made. So that 15% might be the fuel needed to thrust back to the launch site and they only need a small amount of that 15% for sea/barge landings (they are only igniting three of the nine Merlin engines for the landings, and of course it is way lighter without all of the used up fuel mass and upper stage/payload gone).

    Anyway, they have applied for permission ot have flights land back at CCAFS (Cape Canaveral Air Force Station), where they launch from. There are major safety issues though with a rocket coming "inboound". If things go wrong, a "self destruct" means that lots of pieces would fall down over a large area, very bad if it was coming down over populated land. There are ways of reducing those risks, it looks like a good plan, but in any case they do not have permission to land there yet.

    So, the news of the barge came out in recent months, sounding like a temporary plan for a handful of test flights. So if the landings succeed, then that may help to pave the way to getting permission to land back at the Cape. But the work that's been put into this barge does not seem to fit into a temporary 2-3 test flight program, then they'd not need it anymore.

    Because even if/when they get permission to land at the cape, they will need the barge anyway. Because of Falcon-9 Heavy:



    It will take off using three Falcon-9 first stages. BUT, the center core will get most of its fuel at first from the two side boosters, a cross-feed that IIRC has never been used on a real rocket vehicle, but is a much-loved method in the game Kerbal Space Program (and VERY efficient). So, it will fly on the three first stages until the outer boosters have to be separated, with enough fuel left for them to fly back and land. Then the core first stage will continue on with its fuel tanks nearly full, and fly a lot farther downrange until it needs to shut down to save some fuel for landing. It will separate, the second stage will fly on, and then that core stage will descend for a soft landing on....... something like a barge. So they will eventually need the barge for Falcon-9 Heavy. But it will come down a LOT farther downrange, so the barge will have to be stationed many hundreds of miles (maybe 1000 miles or more) farther out than for the current version. it would require a massive amount of fuel to be left over, shutting down way earlier, to try to get THAT stage to fly back to the Cape, due to its downrange velocity and distance. So my personal opinion is they have planned to use a barge for Falcon-9 Heavy's core all along, betting on the landing technology to work.

    At least, this is the case if the test landings work out and they can re-use those first stages. If there was some fatal flaw in the concept and they could never get it to work reliably, well, they would not have the game-changing savings they expect, but it looks like even the current expendable versions are cheaper than any other launch vehicles delivering similar payload masses into similar orbits.

    - George Gassaway
    They may have always planned to use the barge for some flights, even with permission to fly all the way back to the launch site. Depending on what amount of servicing the booster would need to be flown again, you might choose to do it just for fuel reasons. Instead of needing to save say 25% or 30% of the fuel to return all the way back to the launch site, maybe you could land the booster on the barge with only 10% to 15% of the fuel remaining. Then you could service and refuel the booster right there on the barge and THEN fly it back to the cape. That would allow more fuel to be used for a heavier payload or a higher orbit and less to be saved for the landing.

    For this flight, if they land successfully on the barge, are they planning to return it to shore by ship/barge? Or are they planning to fly it back?
    Last edited by ThirstyBarbarian; 12th December 2014 at 09:03 PM.

  20. #20
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    Quote Originally Posted by ThirstyBarbarian View Post
    For this flight, if they land successfully on the barge, are they planning to return it to shore by ship/barge? Or are they planning to fly it back?
    Well, they will not be able to fly it back to the Cape since they do not have permission to do so, period. And I figure your question meant via rocket power. Not via helicopter even if a Sikorsky SkyCrane could even lift it safely, much less travel that distance.

    So for now, at least, the question is moot.

    Some have interpreted things Musk has said or tweeted, to imply that if they did have permission to land then it would be refueled and flown from the barge to the Cape. But the more I look at this, the more I realize how cagey Musk has been about some things (like the "sudden" existence of the barge "for a few tests"). So take what people interpret Musk has implied with a grain of salt. Same for speculations, including mine.

    Only go by what they have said specifically. And they do not say specific things as much as people think they do. Often lot of generalities that can be interpreted different ways, or at the least not "promises".

    Indeed when Musk first mentioned that the next flight would try to land "on a solid surface", it was awhile before he said WHAT that solid surface was going to be, rather than just plain saying so to begin with.

    Oh, BTW, in early forum discussions of not having permission to land at the Cape, and then suddenly there was the barge, some thought that the barge would simply be placed in shallow and sheltered waters a few miles from shore. But no, it's going to be stationed right where the first stage's ballistic path will take it. Now maybe that would be to make a landing on the barge easier for the first few times, otherwise if they wanted to do tests to simulate a return to launch site (RTLS), the barge would indeed be stationed only a few miles out from the pad. Now maybe that would be for later testing. Or never part of the plan.

    Grain of salt. Musk. Cagey.

    - George Gassaway
    Last edited by georgegassaway; 13th December 2014 at 01:09 AM.

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    Musk should see if he can buy a volcanic island somewhere in the middle of the ocean and fly his rockets from inside the volcano like a Bond villain.

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    Quote Originally Posted by ThirstyBarbarian View Post
    Musk should see if he can buy a volcanic island somewhere in the middle of the ocean and fly his rockets from inside the volcano like a Bond villain.

    Sounds Evil….



    Long as Musk does not try to build large rockets that look like Bob's Big Boy…..

    Last edited by georgegassaway; 13th December 2014 at 01:33 AM.

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    Quote Originally Posted by georgegassaway View Post
    Some experts think Space-X won't be able to do a reusable 2nd stage. But then many of them thought that having a reusable first stage was just sci-fi too and Space-X is ready to try it with a pretty good chance of success.
    The best way to ensure SpaceX achieves a reusable second stage is to tell Elon it can't be done.
    Joseph Mattingly
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  24. #24
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    Quote Originally Posted by ThirstyBarbarian View Post
    Musk should see if he can buy a volcanic island somewhere in the middle of the ocean and fly his rockets from inside the volcano like a Bond villain.
    Well, Kwaj was pretty close to that...
    Joseph Mattingly
    President Emeritus, Georgia Tech Ramblin' Rocket Club
    NAR 92646 | TRA 14079
    L1 Calhoun, GA (2 Apr 2011) | L2 Muncie, IN (26 May 2012)
    "I'm a Ramblin' Wreck from Georgia Tech and a helluva rocketeer..."
    Ramblings of a Rocketeer

  25. #25
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    Quote Originally Posted by ThirstyBarbarian View Post
    Musk should see if he can buy a volcanic island somewhere in the middle of the ocean and fly his rockets from inside the volcano like a Bond villain.
    I talked to Steve Jurvetson about their buying an island for an evil lair. He said they had looked and the only one available was covered with bombs, an old Navy range near Puerto Rico. We agreed the bombs make it better but his lawyers would likely object.

    M

  26. #26
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    Quote Originally Posted by georgegassaway View Post
    Well, I have not found any info on a live feed of the landing.

    I did ask on a space site where there ought to be answers.... but nobody had any solid info.

    Sadly a few came up with some petty excuses such as Space-X might not have a live feed in case it does not succeed, only release video much later if it works.

    So, Cold War Russian Space Program style. I hope not. I have very SLOWLY built up my impressions of Space-X. If they didn't show something this historic for petty reasons, they are not the company I thought they are and not worth that trust.

    But again it's fanboys who wrote some of those pre-emptive petty excuses. So they may be wrong and Space-X perhaps has not made info on how/where to see a feed of the landing in an easy-to-find way (yet?). But it's very troubling that if there is to be a live feed of the landing, it's this hard to get info on. I'm not as high on this as I was 24 hours ago.

    What does come thru clear is that NASA is "the customer", and the NASA TV feed is not going to cover anything beyond launching the spacecraft into orbit and getting supplies to ISS. Just another routine unmanned launch of supplies to ISS.......which if it was true most space buffs would not bother to watch to begin with.

    UPDATE - Launch has slipped to Dec 19th:

    http://spaceflightnow.com/2014/12/11...ips-to-dec-19/

    - George Gassaway
    Well, whaddya expect??

    At least they're not as "top secret!" as Blue Origin, from which we only have rumors and a few vague press releases over the last handful of years.

    SpaceX IS a private company... one which I've heard rumors is thinking of going public. (Publicly traded). If that's the case, you don't want to "scare off" investors with high-profile failures broadcast to the world (IF it happens to fail, which even Elon Musk only quotes a 50-50 shot of it working right). At any rate, public offerings aside, as a PRIVATE company, they don't *have* to broadcast ANY of their activities; though I think it is really to their benefit if they DO. But as far as an "obligation" goes, not so much-- their dime, their choice...

    NASA is NASA... they're only interested in what *NASA* does, what the flight has to do with *NASA*. There's plenty of PTB's that are VERY threatened by "nu-space" commercial companies and don't want to do *anything* that actually promotes them or benefits them. Some of those PTB's are within NASA; most are within the political structure that supports and benefits from NASA funding and policy (and usually has a mighty hand in making it). SO, I wouldn't say NASA *not* covering SpaceX's reusability activities is in any way surprising...

    Actually, I think SpaceX has been THE most forthcoming and open of the nu-space companies. They've been a little tight-lipped at times, but then who hasn't? If you want to compare a company to "Cold War secretive" only-broadcast-if-successful type stuff, well, Blue Origin has probably been more secretive in a lot of ways than the old Soviet space program ever was... or was during its darkest days in the late 50's/early 60's...

    All IMHO... Later! OL JR
    The X-87B Cruise Basselope- THE ultimate weapon in the arsenal of homeland defense and only $52 million per round!

  27. #27
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    Quote Originally Posted by jmattingly13 View Post
    You know SpaceX has a lease with Spaceport America (right next to WSMR) for doing high altitude testing of Grasshopper/F9R?
    Nope, didn't know that... interesting!

    Thanks! OL JR
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  28. #28
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    Quote Originally Posted by jmattingly13 View Post
    They're not trying to recover the second stage at this point. Elon's goal is to make everything recoverable if possible, but for the reasons you've stated, the second stage is not quite there yet.
    "Not quite there yet" is a MASSIVE understatement... LOL

    Later! OL JR

    PS. Truth be known, MOST of the cost of the rocket is in the FIRST stage anyway-- it's the largest, the most structurally robust, and has the greatest amount of propulsion hardware (lots of engines or big powerful engines to get the thing off the launch pad and up to several times the speed of sound and about 40 miles high for the second stage to take over. While slowing something down and reentering the dense lower atmosphere, descending to a stable, controlled hover and pinpoint landing isn't trivial by ANY means, (else it would have been done before! The best Werner Von Braun and the NASA engineers did in the 60's was propose huge folding rogallo flex wings or parachute recovery for Saturn IB and Saturn V first stages), it is MUCH easier to accomplish from the, relatively speaking, MUCH lower velocities and energy levels of a first stage, and with the more robust construction (though larger dimensionally) of a first stage, and frankly there's more to be gained by reuse of a first (booster) stage.

    Not to say there's NO value in recovering upper stage(s), far from it. BUT, recovering something reentering from Mach 20 and 100 miles altitude halfway around the world, and recovering something from Mach 4+ reentering from 40 miles altitude a few hundred miles downrange from the pad, are orders of magnitude apart in complexity and difficulty. When you add in the fact that upper stages are usually built much lighter (since every pound of dry mass saved on the upper stage usually converts 1:1 to additional payload) the difficulties are compounded, because basically you're trying to recover an eggshell from orbit without breaking it. Reentry heating and loads are MUCH harder to deal with as well, and the extra weight of a heat shield, or extra propellant for deceleration and a "plug nozzle" heat shield, evaporatively cooled heatshield, whatever, landing gear, additional guidance/recovery hardware, etc... ALL that extra mass detracts virtually POUND FOR POUND from payload capability. (On first stages, depending on the particular design, it takes an extra 10 pounds of weight on the first stage to reduce payload by ONE pound!) When one adds in the inevitable reduced payload capacity and complexity and cost of a reusable upper stage, it's FAR less lucrative than recovering first stages.

    Later! OL JR
    The X-87B Cruise Basselope- THE ultimate weapon in the arsenal of homeland defense and only $52 million per round!

  29. #29
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    Quote Originally Posted by Peartree View Post
    Also another reason why SpaceX might have wanted the "landing barge" thingy. While the first stage might be able, eventually when proven capable and safe, to fly back to the launch pad (or nearby), the second stage is going to be WAY downrange and flying back would seem to be highly unlikely.

    Probably more like "once around" recovery...

    Anybody heard of "dynamic soaring"?? (Dyna-Soar).

    Seriously, yeah, a second stage doing a "ballistic reentry" will probably be over the Indian Ocean or South Pacific, depending on the trajectory. So an ocean recovery would seem necessary.

    The reason for the barge is this...
    Click image for larger version. 

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    Which profile looks safer and uses less fuel/more efficient to you??

    Later! OL JR
    The X-87B Cruise Basselope- THE ultimate weapon in the arsenal of homeland defense and only $52 million per round!

  30. #30
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    This stuff is awesome - thanks for posting George. I'm a huge fan of Elon and SpaceX - browsing their webstore last year and seeing that there was a model rocket which
    "needed engines to fly" and my subsequent internet research and purchase of an Estes launch set is what go me into model rocketry - 15 months later I'm HPR level 2

    I'm looking forward to this launch and really hoping they land the first stage as planned.


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