# Continuing discussion of SpaceX launches \[edited title\] **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [December 22, 2015, 12:37am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048 "2015-12-22T00:37:01Z")\ **Posts on this page:** 20\ **Page:** 26
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [February 7, 2018, 2:09am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/501 "2018-02-07T02:09:58Z")
Did I correctly see that the rocket was at a 45-degree angle while still below 5km altitude? How much will the launch have cost? Was there a reason they went for a PR payload instead of a scientific or commercial one? Was it deemed so risky that payload bids were insignificant? How scalable is the “more dakka” approach? Could you have 5, 7, 9 boosters? At what point would you start hitting severely diminishing returns? ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [February 7, 2018, 2:13am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/502 "2018-02-07T02:13:35Z")
> [@billfish678](#): > > I wouldn’t trust a Space X driver…that dudes hands are NOT in the 2 oclock and 10 o clock positions…for that matter you can’t even see his other hand…though if I had that view you might not see my second hand either… Don’t Teslas have and Autopilot mode 😃 ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [February 7, 2018, 2:18am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/503 "2018-02-07T02:18:25Z")
Two interesting things from news briefing. Musk mentioned that some re entry problems scale as the 8th power :eek: Also, they developed the heavy with about a measly 500 million dollars ! Impressive. That car should have had curb feelers on it…you never know how much space you are going to have for parking… ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [February 7, 2018, 2:26am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/504 "2018-02-07T02:26:22Z")
The live feed of Starman just ended a few minutes ago, and the third burn, to put it into its deep orbit, is supposed to be in about 20 minutes (21:45 ET). No live view of the burn? Damn it! ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [February 7, 2018, 2:27am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/505 "2018-02-07T02:27:44Z")
> [@Baron\_Greenback](#): > > There’s a live feed from the Tesla Roadster that is currently orbiting the Earth, and soon to be on it’s way much further. > > Hahaha. DONT PANIC I’m thinking of the opening sequence to the original _Heavy Metal_ movie… Edit: [https://www.youtube.com/watch?v=t\_KXgFpguE0](https://www.youtube.com/watch?v=t_KXgFpguE0) ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [February 7, 2018, 2:36am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/506 "2018-02-07T02:36:03Z")
> [@MichaelEmouse](#): > > Did I correctly see that the rocket was at a 45-degree angle while still below 5km altitude? Unlikely. On the Iridium missions (for example), the booster didn’t reach 45 degrees until ~100 s into flight, at which point it was at 25 km altitude. FH wouldn’t be all that different (not by a factor of 5, at any rate). Sometimes the camera angles can be deceiving. > [@MichaelEmouse](#): > > How much will the launch have cost? Was there a reason they went for a PR payload instead of a scientific or commercial one? Was it deemed so risky that payload bids were insignificant? What does the first flight of anything cost? Hard to count. But they’re charging customers $90M. Yes, they used a dummy payload basically because it was too risky otherwise. They’d otherwise use a stack of steel plates or the like. Boring. > [@MichaelEmouse](#): > > How scalable is the “more dakka” approach? Could you have 5, 7, 9 boosters? At what point would you start hitting severely diminishing returns? Musk says they can scale further, but didn’t elaborate much. You certainly do hit diminishing returns, especially without propellant crossfeed–which they don’t have. Ideally, you can drain pairs of tanks completely, and eject them when depleted, so you always carry minimal tankage (Kerbal Space Program players call this asparagus staging). But crossfeed is really hard and SpaceX doesn’t plan on pursuing it. I imagine that SpaceX considers the Falcon family more or less done (once Block 5 ships), and everything going forward will be on BFR. ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [February 7, 2018, 2:38am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/507 "2018-02-07T02:38:18Z")
> [@MichaelEmouse](#): > > Was there a reason they went for a PR payload instead of a scientific or commercial one? Was it deemed so risky that payload bids were insignificant? First flight of the launch system, I suppose nobody would insure a commercial payload either. > [@billfish678](#): > > Musk mentioned that some re entry problems scale as the 8th power :eek: > > Also, they developed the heavy with about a measly 500 million dollars ! Hey, it IS rocket science, not Kerbal Space Program we’re playing here. As in this is something where a half billion is “measly”. ETA: I swear **Dr. Strangelove** ’s post wasn’t there when I wrote this!) Whatever happens with the escape burn and in spite of the core stage loss, this was an outstanding performance. There’s folks in “establishment” space launch shops who dream of a first flight like this. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [February 7, 2018, 2:38am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/508 "2018-02-07T02:38:28Z")
> [@billfish678](#): > > Musk mentioned that some re entry problems scale as the 8th power :eek: I know of a better one–incandescent light bulb lifetime scales as roughly the inverse _12th_ power with respect to voltage. Still, 8th is crazy. I wonder what is happening there. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [February 7, 2018, 2:42am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/509 "2018-02-07T02:42:58Z")
> [@MichaelEmouse](#): > > Did I correctly see that the rocket was at a 45-degree angle while still below 5km altitude? Not sure if this link will work, but [this should show](https://www.flightclub.io/result?id=4a420ae2-ae50-43d3-b2d1-c60324c7d2a0&code=FHD1) a bunch of charts with a simulation of the Heavy mission. From the “velocity angle” graph, you can see that it hits 45 degrees at 118 seconds into flight. And then from the altitude graph, see that it’s 38.8 km up at 118 s. The charts are a simulation but it’s given very close results for previous missions, so I suspect it’s pretty good. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 7, 2018, 2:43am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/510 "2018-02-07T02:43:10Z")
> [@Magiver](#): > > I’m sorry but watching 2 boosters land simultaneously is beyond science fiction to me. That was spectacular. That was Flash Fucking Gordon. ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [February 7, 2018, 2:45am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/511 "2018-02-07T02:45:21Z")
'twas about time something about the future looked like The Future :p. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [February 7, 2018, 2:51am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/512 "2018-02-07T02:51:14Z")
BTW, the fact that they had a relatively high altitude for this 45 degree point indicates that they chose a fairly “lofted” trajectory for this mission. This is less efficient (though doesn’t matter here since the payload is light), but reduces aerodynamic stress since goes farther out of the atmosphere before really picking up speed. They were worried about aerodynamic interactions with the side boosters, so it sounds like they tried to make things a bit easier on themselves in this regard. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 7, 2018, 2:56am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/513 "2018-02-07T02:56:17Z")
> [@JRDelirious](#): > > 'twas about time something about the future looked like The Future :p. Emperor Ming will destroy the space car! ---
**Author:** ![Chimera](https://avatars.discourse-cdn.com/v4/letter/c/8e8cbc/32.png) [@Chimera](https://boards.straightdope.com/u/Chimera)\ **Post date:** [February 7, 2018, 2:58am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/514 "2018-02-07T02:58:52Z")
No one has mentioned so far that this is very [Heavy Metal](https://www.youtube.com/watch?v=DWMPe3wF9jQ). ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [February 7, 2018, 3:02am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/515 "2018-02-07T03:02:47Z")
Well finally…we got our flying car! At least 18 years behind schedule…and not quite as practical or cheap as we though…but damn good gas mileage one supposes. In reference to the 500 million. When I called it measly…I wasn’t be sarcastic. That is cheap IMO. ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [February 7, 2018, 3:06am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/516 "2018-02-07T03:06:46Z")
> [@Dr.Strangelove](#): > > Yes, they used a dummy payload basically because it was too risky otherwise. They’d otherwise use a stack of steel plates or the like. Boring. I remember Musk making the point that PR matters a significant amount when it comes to space. I guess this does a good job of promoting both SpaceX and Tesla. > [@Dr.Strangelove](#): > > Not sure if this link will work, but [this should show](https://www.flightclub.io/result?id=4a420ae2-ae50-43d3-b2d1-c60324c7d2a0&code=FHD1) a bunch of charts with a simulation of the Heavy mission. > > From the “velocity angle” graph, you can see that it hits 45 degrees at 118 seconds into flight. And then from the altitude graph, see that it’s 38.8 km up at 118 s. > > The charts are a simulation but it’s given very close results for previous missions, so I suspect it’s pretty good. Interesting graphs, thanks. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [February 7, 2018, 3:26am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/517 "2018-02-07T03:26:37Z")
> [@Dr.Strangelove](#): > > Confirmed that the spacesuit was a real production model (and you could “literally jump in a vacuum chamber and be fine”), but that it wasn’t instrumented with sensors or anything. Had a mannequin inside. Wait. Did they actually use the word “mannequin” in the press conference? If they said “dummy”, that could mean… something else. > [@Dr.Strangelove](#): > > Jeff Bezos hasn’t tweeted today. Coincidence? Like that. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [February 7, 2018, 3:47am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/518 "2018-02-07T03:47:24Z")
> [@billfish678](#): > > Well finally…we got our flying car! At least 18 years behind schedule…and not quite as practical or cheap as we though…but damn good gas mileage one supposes. > > In reference to the 500 million. When I called it measly…I wasn’t be sarcastic. That is cheap IMO. To put it into context, advertisers spent $419 million on the Super Bowl. So cheap indeed. ---
**Author:** ![Cell\_Guy](https://avatars.discourse-cdn.com/v4/letter/c/df705f/32.png) [@Cell\_Guy](https://boards.straightdope.com/u/Cell_Guy)\ **Post date:** [February 7, 2018, 3:57am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/519 "2018-02-07T03:57:08Z")
According to Elon’s tweet the third burn was successful—and they have exceeded Mars orbit and are heading towards the asteroid belt. Too bad they didn’t include any way to track the Roadster as it orbits the sun. I think it would be cool to pull up a website and see where it’s located. We’ll have to let the amateur astronomers out there set up something. ---
**Author:** ![Chimera](https://avatars.discourse-cdn.com/v4/letter/c/8e8cbc/32.png) [@Chimera](https://boards.straightdope.com/u/Chimera)\ **Post date:** [February 7, 2018, 3:58am UTC](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048/520 "2018-02-07T03:58:54Z")
> [@Cell\_Guy](#): > > According to Elon’s tweet the third burn was successful—and they have exceeded Mars orbit and are heading towards the asteroid belt. Well, NO. They haven’t passed Mars. That would require a sizable percentage of light speed. They’re merely headed in that direction. [Previous page](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048.md?page=25) [Next page](https://boards.straightdope.com/t/continuing-discussion-of-spacex-launches-edited-title/741048.md?page=27)