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Skylon

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1 minute ago, NSEP said:

I love the gigantic fuel pipe!

If you're referring to the things between the stages, those appear to be landing legs, although they might also function as a way to fuel the rocket.

Just now, CatastrophicFailure said:

Of all the flarping... :mad:

 

Gaaaaaaaah!

NOOOOOOOOOOOOOOOOOO!

I had a friend lined up to come over and watch it with me! :( I mean, we we are going to be doing other stuff (Minecraft, school project, showing him KSP, etc) but this is a bit of a bummer.

I don't know when the cutoff is, but beyond a certain date they have to delay for a month or two because of InSight which takes range priority.

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Hmmm...

But is this GNC analysis of Falcon 9, or of TESS? I'm guessing F9, since this is a weird orbit they're launching to...

On the other hand, they managed to launch DSCOVR to a weirder place back in the day, and any halfway decent (i.e. post-1970's) GNC program should be able to handle going to pretty much any orbit.

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1 hour ago, sevenperforce said:

nothing new

yeah but nobody posted them here and I didn't want to ruin the hype... :blush: *shhh*

TBH I hadn't seen them in high resolution. From the small leaked clip it looks like the video is an updated Mars transit animation btw, I hope they release that.

1 hour ago, CatastrophicFailure said:

Of all the flarping... :mad:

Aw, c'mon!

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1 hour ago, NSEP said:

I love the gigantic fuel pipe!

BFR upper stage has lots of empty space between the engines so no reasons to run an external pipe like you do on Soyuz or dragon who have an heat shield in bottom. However here its not fuel but power, cooling an life support for  Soyuz. 
BFR uses the pipes to fill the upper stage on pad so they don't need an extra connector. I assume boil of during launch will go down to first stage and be used then it burns. Later the pipes will be used for refueling in orbit. 
 

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GNC on F9, definitely. SpaceX would say it was payload otherwise.

Like it or not, SpaceX is definitely going to need to get a wee bit better at some of this stuff before it can support the kind of launch cadence it needs.

"If your payload absolutely, positively has to go to space today...."

And what's more, I just flew this entire mission in KSP (and realized that KSP's engine does NOT like semisynchronous halo orbits).

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I was about to ask "Won't they miss the Moon if they launch a couple of days later?" but then realized they can just wait until the Earth rotates and the launch window makes it so that it passes the Moon as planned just in a different place in orbit.

Is that ballute second stage recovery going to be the one that puts TESS into its orbit? It would make sense since TESS's mass is low and the speeds they will be reentering it at would make for some good data.

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1 hour ago, Wjolcz said:

Is that ballute second stage recovery going to be the one that puts TESS into its orbit? It would make sense since TESS's mass is low and the speeds they will be reentering it at would make for some good data.

No. TESS's second stage will end up orbiting the sun.

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16 hours ago, DAL59 said:

IT BEGINS

fa6.jpg

 

16 hours ago, Ultimate Steve said:

AWW YEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!!!!!!!

Although the diagram seems to be outdated, with the same 106m height and only 2 SL Raptors, so no new info from that.

BUT YEAAAAAAAAAAAAAAAAA!!!!!!!!!!!!!!!

 

15 hours ago, NSEP said:

ALL JOIN THE HYPE TRAIN ROCKET!

Now we know all we can do is hope it all goes well.

1224966.jpg

Am I the only one not understanding the hype? Like, there's nothing in that tweet that we hadn't already known. 

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25 minutes ago, sh1pman said:

 

 

Am I the only one not understanding the hype? Like, there's nothing in that tweet that we hadn't already known. 

The tweet made said it was official that BFR is being constructed. So there wasn't much new, but now we know that the BFR is going to be (at least) somewhat real, and its not a myth anymore or something.

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42 minutes ago, sh1pman said:

Am I the only one not understanding the hype? Like, there's nothing in that tweet that we hadn't already known. 

Getting a tweet about BFR construction from a non-SpaceX source is surreal...like, "finally this is no longer just Musk head-canon".

11 hours ago, Wjolcz said:

I was about to ask "Won't they miss the Moon if they launch a couple of days later?" but then realized they can just wait until the Earth rotates and the launch window makes it so that it passes the Moon as planned just in a different place in orbit.

The launch yesterday would have been at 6:30 EST, the launch on Wednesday is planned for 6:50 EST, which will phase the argument of periapsis by only 5.0 degrees. The moon orbits through 24.4 degrees in the span of two days. So that's not enough.

Instead, TESS is being tossed into an elliptical high earth orbit with its apogee about 60% of the way to the moon. It will use its own thrusters to precisely adjust the size (and thus the period) of its orbit, over multiple orbits, so that the moon will catch up to it at exactly the right time. A day or two difference in launch timing is easy enough to compensate for; it will just enlarge its orbit slightly less than it otherwise would have, so it completes its several orbits at the perfect moment.

Spoiler

Specifically, TESS will burn once at its first apogee to raise its perigee, then again at its new perigee to raise its apogee, then repeat. It completes a total of three full orbits before performing its TLI burn at perigee. Originally, its first orbit was to take six days followed by two ten-day orbits, but since it was delayed by two days, it will probably burn to a slightly lower apogee on its second burn, so each of its second two orbits takes only nine days.

TESS_orbital_maneuvers.jpg

This doesn't really save propellant, though, because it's still got to burn to the same perigee (to avoid exosphere drag) and so its apogee is the only thing that will change (probably raising to only ~335 km instead of 375). Just means slightly more dV later for the TLI burn.

Those adjustments are too fine to be performed by the MVac.

Quote

Is that ballute second stage recovery going to be the one that puts TESS into its orbit? It would make sense since TESS's mass is low and the speeds they will be reentering it at would make for some good data.

No, the TESS upper stage is going hyperbolic. It's so close to escape anyway; easier to just toss it out of the solar system Earth-moon system than to try a retroburn.

Edited by sevenperforce
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