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Tesla SpaceX many comparisons

Discussion in 'SpaceX' started by Peter Egan, Jan 1, 2016.

  1. Peter Egan

    Peter Egan Member

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    Lots of similarity between Telsa and SpaceX technology development - as we should expect with Elon in charge of both.

    Tesla, the newer company, has a product development portfolio which is briefly described as:
    -- The Roadster - a commercial proof of concept for its electric drivetrain with a large onboard electricity source. A similar story to the Falcon 1 and its Merlin engine.
    -- Model S - an EV from the ground up, leading the luxury/mid-price segment, that is also used for continuous development - particularly in regard to autopilot and safety features. Falcon 9 equivalent.
    -- Model X - larger vehicle that adds depth to the Model S range with some features (windscreen extends back to the B-pillar, Falcon wing doors, HEPA filter). Falcon Heavy equivalent.
    -- Model 3 - smaller vehicle in the mid-price segment that will build on Tesla core technologies - drivetrain and autopilot. Model X novelties, except perhaps the windscreen, are unlikely to survive in base model. The world waits to see what the package will look like. It also waits to see what the new SpaceX Rapter powered rocket will look like - an announcement is promised early in 2016.
    -- Tesla is building "refuelling" stations for its worldwide customers.
    -- Reusing the batteries and recycling the whole car are Telsa objectives.

    SpaceX, the older company, has a product development portfolio looking like this:
    -- Falcon 1 - Technology demonstrator for Merlin engined, kerosene (RP-1/) and oxygen fuelled, rocket - flown from the Kwajalein Atoll. Same fuel used for both first and second stages.
    -- Falcon 9 - the commercial rocket capable of launching most satellites and resupplying the space station at a fraction of the cost of Space Shuttle and at a fraction of the cost per seat for a ride in the Soyuz spacecraft. Development and production costs kept low by use of nine small rockets on first stage. Continuous development, particularly of engines and avionics, has allowed reuse of the first stage by flying it back to launch field. Can lift 13.15 tonnes to low earth orbit - an increase of 60% on the first version of Falcon 9.
    -- Falcon Heavy - will use three Falcon 9 cores in first stage to lift 53 tonnes to orbit (3 cores gives 4 times the capacity for various reasons). It will also have a reusable first stage whose 3 cores will separately fly back. Comparable to the Model X in that it uses same technology in a bigger vehicle.
    -- Reusability is a key goal for environmental and cost reasons - achieved for first stage with 21 Dec 2015 Orbcomm launch (11 satellites with one launch). Reusable second stage and satellite payload launcher not feasible at present due to re-entry heat.
    -- Dragon spacecraft developed after winning separate NASA commercial crew and pressurised cargo to ISS contracts. Reusable spaceship that can carry 7 astronauts and cargo, or do all cargo flights as at present.
    -- Due to high launch-success rate and low prices, SpaceX has so far won $7b in contracts from NASA and commercial businesses for 60 launches (20 completed, 40 to go).
    -- SpaceX is building its 4th launch site, in south Texas, to serve more customers and cut costs. In years to come, it could attract Cape Canaveral-like crowds to its launches. The site is so close the border that Mexico will be a great viewing point.
    -- Falcon X (100 tonnes to LEO class), Falcon XX (200 tonnes to LEO class) - The primary aim of developing these vehicles is to transport humans to the Moon and Mars. Model 3 will necessarily have new technology and so will Falcon X. It will use a methane-oxygen engine, called Raptor, with the fuel and oxidizer stored in liquid form (Oxygen below -183 deg C, Methane below -162 deg C). The slightly warmer liquid methane can use liquid oxygen technology. Methane-Oxygen engines are more energetic and cleaner burning and need less maintenance than RP-1/Oxygen engines. In space, 3% of liquid hydrogen will boil off if it is not used or chilled - a major problem for long duration flights.

    While Elon would like to send thousands of people to Mars, in our life time it will be more like crewing the ISS. Flights will be relatively few until someone builds a hotel in Low Earth orbit with its fantastic views.

    The first Raptor will have 3 times the lift capacity of the Merlin. As they will need to prove its reliability, it is likely to take over Falcon Heavy lift tasks. One core with 9 Raptor engines will surely be cheaper and less complex than 3 cores with 27 Merlin engines. They could even use the Raptor engines on a Falcon 9 replacement.

    Methane is much easier to keep chilled on long duration spaceflights than hydrogen. Thus, SpaceX may switch totally to methane-oxygen rockets for first and second stages to low Earth orbit and onward into the solar system. Blue Origin is also developing a methane-oxygen rocket. The big US (and world) history of hydrogen-oxygen, kerosene-oxygen and 'solid' fuelled space rockets may be ending due to cheaper SpaceX solutions.

    As an interim measure, NASA could allow SpaceX to produce a version of the Space Launch System (SLS) converted to methane-oxygen and using the Raptor engine which will have a similar thrust to the SLS RS-25s. NASA already intends that its Moon and Mars landers be methane-oxygen powered. The SLS would have less lift capacity when methane powered, but will be cheaper to operate. By the time the US is ready to send people back to the Moon and on to Mars, SpaceX will have its SLS class rocket ready for the task - surely at a much cheaper price. We will drive our Teslas out to the launch site to watch.

    Google became a SpaceX shareholder in early 2015. Alphabet (name of Google parent company) would go a long way towards filling the alphabet if it managed to buy Solar City, Tesla and SpaceX - such has been Elon's success.
     
  2. ggr

    ggr Roadster R80 537, SigS P85 29

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    I'd add a couple of things to your otherwise excellent summary.

    You left out Tesla Energy, battery storage solutions for homes and utilities; this has the potential to be bigger than the car business. This is also why the gigafactory is necessary (but not sufficient... there will be more!)

    Methane has another major advantage, from SpaceX's point of view. It can be manufactured on Mars from solar power and the atmosphere.
     
  3. pmadflyer

    pmadflyer Member

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    There will not be a falcon x or falcon xx. Those plans were cancelled because the low cost of the falcon heavy can justify not having an intermediate between falcon 9 and falcon heavy. This is similar to the cancellation of falcon 5. At least, this is my understanding.
     
  4. ggr

    ggr Roadster R80 537, SigS P85 29

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    I was unsure of the X and XX terminology. SpaceX is definitely working on the new Raptor engines, methalox fuel, and a Big Rocket commonly referred to as the BFR.
     
  5. Ben W

    Ben W P85 #61, Roadster #108

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    Here’s a link that shows the relative sizes of the rockets, with the naming as I understood it:

    http://spaceflight101.com/spacex-launch-vehicle-concepts-designs/

    Pmadflyer, can you clarify which of these you believe have been canceled?
     
  6. ggr

    ggr Roadster R80 537, SigS P85 29

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    I hadn't seen that, it clarifies things a bit. There is not going to be a "Merlin 2" engine. So that pretty much cancels the X and XX as written. In the meantime, the optimal thrust for the new Raptor engine has been reduced a bit, so for the BFR they are going to again use a largish number of them. This has resulted in the BFR being even more squat-looking than the XX in that picture. ISTR that it's now about 12m across, according to various rumors. I have no idea how they're going to transport it, given that the diameter of the Falcon 9 core is the currently limiting factor for road transport. The website http://nasaspaceflight.com has lots of detail about stuff like this, although sorting out the facts from the knowledgeable rumors from the rampant speculation can take a while. (Note: just an interested subscriber, not doing any kind of commercial plug here.)
     
  7. Peter Egan

    Peter Egan Member

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    Big versions of the RP-1-Lox Merlin engines have been cancelled. SpaceX has moved on to developing engines (named Raptor) using the more energetic liquid Methane-Oxygen fuel. Reusable first stages allow more focus on life cycle cost - which leads to more capital intensive higher-performing engines with lower operating costs.

    I have seen varying descriptions applied to Falcon X and Falcon XX. SpaceX goals have not changed, only the rocket fuel it will use to achieve them. A 50 tonne to LEO class rocket (Falcon 9 Heavy) will not meet NASA's exploration goals. The starting benchmark must surely be a rocket with similarly lift capacity to the Saturn V and the NASA's high cost Space Launch System (130 tonnes to LEO) but could be applied to rockets over 100 tonnes - I assume this to be Falcon X class. Falcon XX class, I assume, has twice the lift capacity of Falcon X - Thus Falcon XX should be 200 tonne class. 200 tonne class fits with Elon's description of a rocket with a core diameter of over 10 metres. 9 engines of the power of the Saturn V's F-1 engine have 200 tonne to LEO lift capacity and can be fitted to a rocket of at least 11 metres diameter.
     
  8. Grendal

    Grendal Active Member

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    I don't understand why there must be larger rockets when, with reusability, you can make lots of trips for less. I'd much rather have a F9H deliver 4 50 tonne payloads to orbit and recover 12 booster stages than have one FXX deliver 200 tonnes to LEO and lose the massive booster.

    This is a whole new ball game and the old school launch philosophy needs to be re-evaluated. Heck, If they perfect the F9 I'd rather send 15 F9's with reusability over a FXX without it.

    In 5 years time SpaceX could have over 100 launches a year with all the boosters they will have accumulated. And that is just using the boosters and recovered boosters between now and then. You add in using a booster more than once a year and you double the number to 200 launches.

    That is just an entirely new playing field.
     
  9. MacroP

    MacroP Member

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    I have wondered that myself but as I think about it - perhaps physical size (not mass) of the payload might come into play more so. Sure the F9H can carry 53 tonnes into LEO but that all has to fit within the second stage fairing so they may never reach that load (weight) limit for LEO launches. The BFR allows for a much physically larger satellite/space station/transport module with plenty of load capacity too. Why spend time assembling smaller bits in space when you can send it all up in bigger (but less) bits. All of the ISS module sizes were dictated by the Space Shuttle orbiter's cargo bay size it seems.

    Perhaps they can use one BFR to get their completed Mars transporter into some sort of earth orbit and use the Falcon Heavy to send the fuel and supplies (numerous times) to it before it leaves on its journey.
     

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