Blue Origin Thread (merged)

[sgt_flyer]

don't forget to add the various things an employer have to pay additionnal things for each employee - social security costs, taxes, insurances (healthcare, unemployement, advantages, etc)

and afterwards, it's not counting running costs - land taxes, pollution taxes, maintenance plans (for leased computers or equipments) electricity bills (and when you're metalworking, it's not a household electricity bill !), etc.

[PB666]

1 hour ago, PTNLemay said:

I've been wondering how much SpaceX sacrifices on performance by making the first stage come back, but the numbers are sort of hard to come by, and I'm not that good with the equations.

I found on Wikipedia https://en.wikipedia.org/wiki/Falcon_9 and here http://spaceflight101.com/spacerockets/falcon-9-ft/ that the Falcon 9 FT's total mass is around 541 tons.  The first stage propellant is around 409 tons.  So, using the Tsiolkovsky rocket equation, we can discern how much delta V the first stage provides.  Assuming around 3000 m/s exhaust velocity, (sea level ISP is 282, vacuum is 311, so 300 seems like a good average for the flight) I get around 4238 m/s deltaV.  How much of this needs to be kept for the re-entry?  Both for the ground landing and for the ocean landing.

When they release the payload the weight of the rocket suddenly decreases.  The equation for dV is equal to ISP * ln(starting weight/ending weight). Imagine then that you remove 8/10th of the ending weight and use the reamining fuel to drop the rocket to around mach 5 and allow the spoilers and the engine to slow the craft down with increasing atmospheric pressure. 

If you watch the technical video I supplied, the give callouts on when the burnback burns start the burn only for a few seconds, probably at a lower thrust, that slows them down.

Elon was concerned about this (the video frybert supplied just after my link), he basically threw out that heating is the cube of velocity, so his major concern was slowing the booster down only enough such that the spoliers and the engine seats did not overheat.

One of my projects today is to look up the v^3 equation for heating.

[AngelLestat]

ok good point, now to those 7000 lets add @sgt_flyer values which may give us 9000 US$ or 10000US$ per employee, then we add material and extra hardware cost to manufacture falcon9, other taxes, plant initial cost + maintenance, then we can add all that to the employee cost (because the higher average industry cost is related to their employee) and round a final rough estimation of 14000 or 15000 US$ for employee, we estimate than 40% or a 50% of spacex employee work just in the falcon9 launchs, 14500 x 2300 = close to 33 millons by month.
Then we need to pay the falcon9 development cost (with high launch rate is almost nothing) and we still have a lot of room for profits.
That is a really rough estimation, but at least in my mind makes sense.  I dont know about you.

Then half of the employee are busy with the development cost for falcon heavy, dragonv2 + spacesuits (2.6 billions), MCT, etc.
A company like spaceX is always receiving investors because it show future.
You can count google and others..

Edited April 10, 2016 by AngelLestat

[Jovus]

13 hours ago, Nibb31 said:

The barriers to reusability aren't technical, they are economical. The reason NASA or the historical aerospace industry haven't done isn't because they are stupid. It's because it has never got past the trade study review phase. With low launch rates, it isn't worth the effort. When the need for high launch rates and fast turnaround appears, then reusability will happen naturally, with or without SpaceX.

Indeed. The 'reusability' of the STS was practical for NASA as a way to retain much of the Apollo program's funding while pretending to cut costs.

When it comes to SpaceX, my impression is that they want to drive this in reverse; i.e. increase launch rates with the promise of reusability. Which makes me wonder: is re-certification of a 1st stage faster than the manufacture of a new one? Quite possibly. It remains to be seen.

[StrandedonEarth]

It's been stated somewhere that RTLS has a 30% payload penalty

[PTNLemay]

42 minutes ago, StrandedonEarth said:

It's been stated somewhere that RTLS has a 30% payload penalty

In order for me to win the argument, I'm going to need references.  lol

I would have thought that this would be somewhere on their site or something.  I checked but they only mentioned the 13 tons and 4.8 tons, or the costs for the rocket.  They also mention that the rockets can return, but offer no comparison between the mission specs of an ocean return or a ground return.

[Talavar]

For those who missed it!

  Gotta love the times we live in for "space stuff"

Edited April 10, 2016 by Talavar

[StrandedonEarth]

19 minutes ago, PTNLemay said:

In order for me to win the argument, I'm going to need references.  lol

From Wiki:

Quote

In order to make the Falcon 9 reusable and return to the launch site, extra propellant and landing gear must be carried on the first stage, requiring around a 30 percent reduction of the maximum payload to orbit in comparison with the expendable Falcon 9

 

[Wingman703]

19 hours ago, CatastrophicFailure said:

Wait, west? How far out was it in the first place? And why is it in the Gulf now?

Elon stated that this stage would not return directly to the cape, but would go to some undisclosed harbor in the Gulf(Elon said he "forgot" or "didn't know", I guess that was just an attempt to keep some secrecy? Not many places you can unload a rocket and ship it back to the Cape I would think, Alabama seems the most likely...)

I think the normal distance for the barge during an ISS mission is 200-300 miles off the coast? Probably wrong but that's what I'm remembering. 

Edited April 10, 2016 by Wingman703

[Motokid600]

How is it the Falcon upper stage pulls away so quickly upon separation? Are there solid retro motors on the first stage somewhere? Or is it the near instantaneous ignition of the second stage?

[sojourner]

56 minutes ago, Wingman703 said:

Elon stated that this stage would not return directly to the cape, but would go to some undisclosed harbor in the Gulf(Elon said he "forgot" or "didn't know", I guess that was just an attempt to keep some secrecy? Not many places you can unload a rocket and ship it back to the Cape I would think, Alabama seems the most likely...)

I think the normal distance for the barge during an ISS mission is 200-300 miles off the coast? Probably wrong but that's what I'm remembering. 

Not sure where you guys are getting this from. The barge is in the Atlantic and will be in Port Canaveral late today/early tomorrow.

[Wingman703]

Your right, I mis-remembered the clip. Going back and rewatching, Elon simply stated that it would evenly end up at the Cape, but was unsure if that was the initial destination. 

 

Here's to some great shots of the rocket perched upon the barge in harbor!

[tater]

Dragon is at ISS.

[sgt_flyer]

2 hours ago, Motokid600 said:

How is it the Falcon upper stage pulls away so quickly upon separation? Are there solid retro motors on the first stage somewhere? Or is it the near instantaneous ignition of the second stage?

there's several things - notably, pneumatic separation systems between the two (spaceX doesn't use explosive bolts for stage separation, for reusability) 

then, the second stage has some RCS (likely cold gas thrusters, or even possiby gas from the lox boiloff, to not have to deal with too much hassle with toxic hypergolics) for attitude control (roll control, all the time, pitch & yaw when coasting) depending on the RCS arrangment they can provide some forward thrust to settle the liquid propellants before turbopump startup (maybe not needed at stage sep, but definitely for engine reignition).

if there's no reward facing RCS, maybe they use the fact that they need to pre-chill the engine before ignition - maybe they can use the lox used for engine chilldown to give a slight forward thrust by ejecting the used lox through the combustion chamber (it'll be very low, but enough to accelerate separation - an it'll be action-reaction between the upper stage and the 1st stage)

 

[Spaceception]

Just now, Talavar said:

For those who missed it!

  Gotta love the times we live in for "space stuff"

We've covered this pretty thoroughly;

 

[AngelLestat]

The spacex twitter account has some nice videos

https://twitter.com/SpaceX

My favorite is the landing camera from above the grid fins

Edited April 11, 2016 by AngelLestat

[sevenperforce]

3 hours ago, Motokid600 said:

How is it the Falcon upper stage pulls away so quickly upon separation? Are there solid retro motors on the first stage somewhere? Or is it the near instantaneous ignition of the second stage?

The biggest factor is probably drag. The air is very thin at this point, but the vehicle is traveling very fast, and drag forces are still very much active. The much longer first stage has considerably more drag than the second stage, and falls away rapidly after the pneumatic pushers give it that first shove. 

[Talavar]

11 minutes ago, Spaceception said:

We've covered this pretty thoroughly;

 

Yeah, an admin merged it with this thread just a little bit ago.

[softweir]

10 hours ago, sevenperforce said:

The biggest factor is probably drag. The air is very thin at this point, but the vehicle is traveling very fast, and drag forces are still very much active. The much longer first stage has considerably more drag than the second stage, and falls away rapidly after the pneumatic pushers give it that first shove. 

Not to mention that the first stage is mainly empty tank with a high drag-to-mass ratio, while the second stage still has very full tanks plus payload.

[wumpus]

For those wondering where to put a falcon9 booster in a museum, the booster is 41.2m.  A Redstone missile just *barely* fits in the Smithsonian hanger where the Discovery is housed, and it is only 21m tall.  The Skylab copy is 25m and just barely fits in the cutout downtown.  Presumably it can only fit on its side in the Smithsonian (although I remember a few rockets/missiles being parked outside of the Castle pre-1976).  I'd guess the only other place they could stand up would be in the "rocket garden" in Florida.

[Wingman703]

Who said its going in a museum? SpaceX is bringing the OG booster back to Hawthorne to show off at their HQ, and this one that just landed is being refired and hopefully reflown. 

[wumpus]

4 hours ago, Wingman703 said:

Who said its going in a museum? SpaceX is bringing the OG booster back to Hawthorne to show off at their HQ, and this one that just landed is being refired and hopefully reflown. 

The first one (land landing) was suggested for such a thing.  I was just down there and checked the lengths of the displayed exhibits against the recovered booster (Falcon 9 is twice as tall as anything on display).  I'm sure I've seen comments on such things, but this thread is (of course) wildly more informed than even the most science enthusiastic sites.

[Frybert]

Found this over on OF thought people here might also be interested Patent Decision May Not Spell End of Blue Origin-SpaceX Dispute.

[CatastrophicFailure]

Dragon is now the sixth spacecraft docked to the station... so are there two Progresses as well? Cygnus, pair of Soyuz's, at least one Progress...?

 

---------

25 minutes ago, Frybert said:

Found this over on OF thought people here might also be interested Patent Decision May Not Spell End of Blue Origin-SpaceX Dispute.

Interesting, was not aware of this. That certainly explains the snippiness between the two. 

Edited April 11, 2016 by CatastrophicFailure

[tater]

In the press conference I posted, Musk says that the first landing (RTLS) is going outside HQ, they just got permission from the FAA because it's taller than anything else around the airport there (hence having to ask). He said the one that just landed will probably fly in May.