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Can the Falcon Heavy rocket handle sending payloads past Jupiter like the Atlas V?

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    $\begingroup$ This is like asking if a UPS truck could send a package to 50th floor of an office building. Deep space doesn't work that way. $\endgroup$ – user3528438 Feb 12 '18 at 23:16
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SpaceX published numbers on their website near the bottom of the page.

I snapped an image to show here, since their formatting is prettier than I can do in Markdown.

Heavy performance numbers from website

You can see that it can do pretty much any of the missions.

Now you could probably do a better job with a third stage/kick stage, because while the second stage Merlin-1D Vac has a lot of thrust, its Isp is not the worlds greatest for an upper stage. (It is actually kind of sucky).

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  • $\begingroup$ Surely payload to Pluto would be highly dependent on the positions of the planets at the time of launch? $\endgroup$ – Brian Gordon Feb 12 '18 at 22:57
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    $\begingroup$ @BrianGordon I presume they assume non-stupid launch windows. I.e. Sure, launch to Mars out of window and the payload goes way down. Would be interesting to know what the standard they use for these numbers is based upon. Betcha no two launcher vendors use the same methods either, making comparisons useless in reality. $\endgroup$ – geoffc Feb 12 '18 at 23:05
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    $\begingroup$ To give the "Payload to Pluto" number some context, it looks like the Falcon Heavy could have thrown New Horizons and NH's Star 48B upper stage to Pluto with lift capacity to spare. Or it could put New Horizons, the Star 48B, and the Centaur second stage from the NH launch into GTO. $\endgroup$ – Mark Feb 12 '18 at 23:19
  • $\begingroup$ AFAIK an updated upper stage for FH with different engine is under development, the prototype used existing F9 hardware with some modifications. $\endgroup$ – jwenting Feb 13 '18 at 9:54
  • $\begingroup$ @jwenting The Air Force is funding some of Raptor development hoping SpaceX will use it in an upper stage for better performance. But Musk has said, once they hit Block 5 (next few months) they are stopping new development for Falcon 9 and all hands on BFR/BFS. So a source would be helpful, since it seems contrary to known details. $\endgroup$ – geoffc Feb 13 '18 at 11:34
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Well, it looks like it can get 141,000 lbs into low earth orbit. That is quite a bit of mass. With the right second and third stages you should be able to get enough delta-v for deep space. It isn't demonstrated capability yet, but I'd be thunderstruck if there wasn't a road map for a variety of upper stages for various payloads and targets.

ETA: Centaur is about 50,000 lbs, so it could loft one easily. There would be the usual integration issues, but raw weight isn't an issue.

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  • $\begingroup$ I understand that the Atlas-V had a centaur upper stage for the New Horizons and Juno Missions, wasn't seeing anything that says that the FH has that capability. $\endgroup$ – CBredlow Feb 12 '18 at 19:38
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    $\begingroup$ ...yet. Keep in mind SpaceX is doing things differently than your typical military-industrial powerhouse like Boeing or Lockheed Martin. Instead of getting a massive government contract with capabilities specified years before delivery, they are funding primarily with private money and delivering incrementally as the technology is proven. I fully expect to see a much more capable Falcon Heavy delivery platform with more options in the future, but yes, that is not yet demonstrated nor has much been announced. $\endgroup$ – user5932 Feb 12 '18 at 22:13
  • $\begingroup$ How about adding four more side boosters (and throttling the center booster and one pair of side boosters down to just a "pilot" level to maintain ignition) and jettisoning opposed pairs two at a time a few seconds apart (to avoid collisions) such that these four represent the "first stage", that last pair of side boosters (which would throttle up just before the second pair is jettisoned) becomes the "second stage", the center booster is the "third stage" and the 2nd stage proper is the "fourth stage"? That way, they use components that have already been tested in the Falcon Heavy flight? $\endgroup$ – Monty Harder Feb 12 '18 at 22:19
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    $\begingroup$ @CBredlow Atlas V always has a Centaur second stage. Of course Falcon Heavy doesn't use it, they have their own second stage that they make in-house. There's nothing special about Centaur--it has better specific impulse than Falcon's upper stage, but a worse mass fraction and shorter burn time. Or are you referring to the Star 48B third stage used in the New Horizons launch? If that's what you meant, that booster is launcher agnostic and Falcon Heavy would be perfectly capable of including it with the payload. $\endgroup$ – Toast Feb 12 '18 at 23:59
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    $\begingroup$ Centaur and DCSS (a) are made by ULA and (b) don't fit under the Falcon fairing. SpaceX hasn't discussed building a hydrolox engine at all. A Raptor-based Falcon upper stage, now, might be interesting, but they haven't given any indication they're planning such a thing. $\endgroup$ – Russell Borogove Feb 12 '18 at 23:59

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