RocketLab Discussion Thread

[tater]

Nicely done.

[GoSlash27]

19 minutes ago, Ultimate Steve said:

Dead batteries.

I gather they use those to power the pumps?

Best,
-Slashy

[CatastrophicFailure]

19 minutes ago, Ultimate Steve said:

Dead batteries.

Is that for sure?

[Ultimate Steve]

1 minute ago, GoSlash27 said:

I gather they use those to power the pumps?

Yep, and jettisoning some of them would lead to more Delta-V.

1 minute ago, CatastrophicFailure said:

Is that for sure?

I'm 80% sure, I don't know where I read it but I read it somewhere.

[Kerbart]

3 minutes ago, GoSlash27 said:

I gather they use those to power the pumps?

Best,
-Slashy

Charged ones. Not the dead ones.

[GoSlash27]

That weird corkscrew in the contrail and the instability of the tracking camera... I thought they lost the vehicle for a moment there.

 

11 minutes ago, Kerbart said:

Charged ones. Not the dead ones.

That'd make way more sense than using the dead ones

-Slashy

Edited January 21, 2018 by GoSlash27

[.50calBMG]

Is it just me or does she sits on the pad for a while after the engines light? I just watched it in slow more about 10 times and to me it looks like those engines spool up almost instantly. I understand that they probably do gimbal checks and check battery and fuel flow, but I can't imagine that takes more than a second or so, and yet she sits on the pad for a good 3 seconds after ignition.

Also, holy crap that twr. Makes the Atlas's without boosters like like they are half asleep at liftoff.

Edited January 21, 2018 by .50calBMG

[RedKraken]

launch replay (forward to 18min) :

 

[Kevin Kyle]

Argh. I missed the live event, thanks much for posting a link to it. Looked like a pretty young crew that put that rocket up there. Congrats to them.

[Streetwind]

8 hours ago, GoSlash27 said:

That weird corkscrew in the contrail and the instability of the tracking camera... I thought they lost the vehicle for a moment there.

I guess that's what they meant when they said "upper level winds close to the limit" Must have been pretty turbulent there.

 

8 hours ago, .50calBMG said:

Also, holy crap that twr. Makes the Atlas's without boosters like like they are half asleep at liftoff.

The TWR isn't actually that high. I personally thought it was a bit more ponderous than I expected.

The thing about acceleration is that it doesn't care what object is doing the acceleration, it always ends up making the object move a certain distance over a certain amount of time. Which, in turn, means that if the object is small, it may end up moving several times its own length, whereas if the object is very large, it may only move a fraction of its own length. Even if the acceleration is the same in both cases.

Atlas is much larger than Electron. For a rocket the size of Electron, it didn't move off the pad very quickly at all. It probably has similar TWR to the Atlas and Falcon 9 rockets (1.3 to 1.4, definitely not much higher).

Another example: Europe's Vega and Ariane 5 launchers. Both are reasonably quick off the pad, thanks to primarily solid fuel launch stages, but Vega is quicker... that is, it looks quicker. But it actually isn't. Ariane 5 has the higher TWR. (In fact, at around 2.0, it has one of the highest TWRs of operational orbital launch vehicles today.) It's just that Vega is a much smaller rocket, so it appears like it covers more distance in the same time. Even though it doesn't.

This is also why hobbyist rockets are just gone in a flash. They are so small, you cannot even see the lift-off properly unless you tune them to have practically no acceleration at all. And if you did that, it wouldn't go very high.

Edited January 21, 2018 by Streetwind

[NSEP]

What was the payload actually?

Any news on Moon Express?

[tater]

Pretty awesome, and now we know that 100% composite rockets (tanks) are a thing, including cycling the thing more than once, too (it was all but liftoff the other day). Dunno how many prop load tests they have done on that vehicle.

[cypher_00]

Ofcourse i missed the live launch but i just watched the replay. Great launch the thing was alot louder then i expected.

Also the corkscrew made me think the thing was out of control for a bit but glad to see everything went well.

Well done Rocket Lab!

4 hours ago, NSEP said:

What was the payload actually?

Any news on Moon Express?

1 Dove CubeSat
2 Lemur-2 CubeSats

[RedKraken]

Some reporting :

https://www.nasaspaceflight.com/2018/01/rocket-lab-second-electron-launch/

https://spaceflightnow.com/2018/01/21/rocket-lab-delivers-nanosatellites-to-orbit-on-first-successful-test-launch/

http://spaceflight101.com/still-testing-rocket-labs-electron-reaches-orbit-on-second-test-flight/

and some commentary :

https://www.reddit.com/r/space/comments/7ruud9/rocketlabs_electron_rocket_has_successfully/

 

Edited January 22, 2018 by RedKraken

[YNM]

Congratulations kiwis ! This really looks like a mini Falcon 9... albeit with a (relative to the whole) longer upper stage !

It looks almost like having a very high TWR, but I believe their size also matters in giving that look. It really is a mini launcher-rocket...

[KSK]

On 1/21/2018 at 2:50 PM, tater said:

Pretty awesome, and now we know that 100% composite rockets (tanks) are a thing, including cycling the thing more than once, too (it was all but liftoff the other day). Dunno how many prop load tests they have done on that vehicle.

A working smallsat launcher with composite tanks - this is a good day for commercial spaceflight! 

And whilst I doubt that Rocket Lab and say, for example, SpaceX will be working together on composite rocket parts, having one company introduce an innovation can only be a good thing in terms of getting the market used to that innovation. In other words if and when BFR (or any other large rocket for that matter) flies with all-composite tanks, it'll hopefully be less of a big deal if Rocket Lab have been flying smaller versions  for a couple of years beforehand.

The same goes for any other launch vehicle innovation - it's only crazy until one company does it. The second company to use it is 'catching up', the third and fourth companies are 'adopting best industry practice'.

Or maybe I'm just getting overexcited. Regardless - go Rocket Lab!

[wumpus]

5 hours ago, KSK said:

A working smallsat launcher with composite tanks - this is a good day for commercial spaceflight! 

And whilst I doubt that Rocket Lab and say, for example, SpaceX will be working together on composite rocket parts, having one company introduce an innovation can only be a good thing in terms of getting the market used to that innovation. In other words if and when BFR (or any other large rocket for that matter) flies with all-composite tanks, it'll hopefully be less of a big deal if Rocket Lab have been flying smaller versions  for a couple of years beforehand.

The same goes for any other launch vehicle innovation - it's only crazy until one company does it. The second company to use it is 'catching up', the third and fourth companies are 'adopting best industry practice'.

Or maybe I'm just getting overexcited. Regardless - go Rocket Lab!

I'm equally impressed by the electric motors.  Even if asparagus staging never happens on Earth, we can still expect "drop batteries" to replace "drop tanks".  And while the engines might not be all that wildly efficient (thanks to the mass of the battery), I'm still curious if this can scale up to human throwing sizes.

I'm also curious as to exactly what is included in the "lowest price to orbit": Orbital quoted a $6M price to orbit [absolutely bare bones] back in the 1990s for roughly four times the payload (or maybe not, 4x is current pegasus payload).  But the "real price" is close to $40M (NASA is paying $60M for the latest flight, and it has been awhile since a Pegasus flight).

[Nightside]

Really enjoyed that video, from the shaking camera at liftoff to the weird color blotches as the signal deteriorated at the end.  I did think the smoke trail loop was bit show-offy for a New Zealander though.

[KSK]

4 hours ago, wumpus said:

I'm equally impressed by the electric motors.  Even if asparagus staging never happens on Earth, we can still expect "drop batteries" to replace "drop tanks".  And while the engines might not be all that wildly efficient (thanks to the mass of the battery), I'm still curious if this can scale up to human throwing sizes.

I'm also curious as to exactly what is included in the "lowest price to orbit": Orbital quoted a $6M price to orbit [absolutely bare bones] back in the 1990s for roughly four times the payload (or maybe not, 4x is current pegasus payload).  But the "real price" is close to $40M (NASA is paying $60M for the latest flight, and it has been awhile since a Pegasus flight).

Yes - the electric pumps are pretty cool too! I've seen commentary on other forums suggesting that they're not very scalable, (so a human throwing rocket is unlikely) but on the other hand there's a lot of battery R&D going on elsewhere which Rocket Lab can essentially take advantage of for free. Although they're currently using lithium polymer cells which are already pretty light and energy dense if I remember rightly.

[CatastrophicFailure]

17 minutes ago, KSK said:

Yes - the electric pumps are pretty cool too! I've seen commentary on other forums suggesting that they're not very scalable, (so a human throwing rocket is unlikely) but on the other hand there's a lot of battery R&D going on elsewhere which Rocket Lab can essentially take advantage of for free. Although they're currently using lithium polymer cells which are already pretty light and energy dense if I remember rightly.

Some humans are larger than others... 

But going back to your earlier comment, it would be an interesting collaboration between, say, RocketLabs, SpaceX, and Tesla... RL shares their experience with flight-ready composite tanks, maybe does some deep cryo research for SpaceX, and in turn Tesla shares battery technology. 

Fat chance, I know, but one can hope. 

[wumpus]

3 hours ago, KSK said:

Yes - the electric pumps are pretty cool too! I've seen commentary on other forums suggesting that they're not very scalable, (so a human throwing rocket is unlikely) but on the other hand there's a lot of battery R&D going on elsewhere which Rocket Lab can essentially take advantage of for free. Although they're currently using lithium polymer cells which are already pretty light and energy dense if I remember rightly.

My understanding is that lithium iron phosphate is where it is at if you want to pull out a lot of power quickly.  They are even in mass production.

[magnemoe]

3 hours ago, KSK said:

Yes - the electric pumps are pretty cool too! I've seen commentary on other forums suggesting that they're not very scalable, (so a human throwing rocket is unlikely) but on the other hand there's a lot of battery R&D going on elsewhere which Rocket Lab can essentially take advantage of for free. Although they're currently using lithium polymer cells which are already pretty light and energy dense if I remember rightly.

Electric motors scales well however its less efficient than turbo pumps. its the turbo pumps who don't scale well down down in size so it will be expensive on an small rocket. Now this could be an interesting engine for upper stages, trust is lower and you need restart capability. 

 

[CatastrophicFailure]

Kick it!

[PB666]

11 hours ago, KSK said:

Yes - the electric pumps are pretty cool too! I've seen commentary on other forums suggesting that they're not very scalable, (so a human throwing rocket is unlikely) but on the other hand there's a lot of battery R&D going on elsewhere which Rocket Lab can essentially take advantage of for free. Although they're currently using lithium polymer cells which are already pretty light and energy dense if I remember rightly.

That really depends on the type of engine. If you are talking about a cryogenic engine you can have an expansion cycle, and apparently they have a theoretical limit of 300 kn (which is why the RL10b has such dismal  performance but fantastic efficiencies. The fuels (and in space the differential between ATM pressure and vacuum) drives fuel flow, but pressurized fuels drive very high thrust, and pressurization feeds on ISP. However, the thing about electric is that it does not tax your thrust and thus does not tax your ISP. So if we can imagine a space craft on a higher launch trajectory (having separated its first stage), if it needs the solar panels of the second stage for some other function, it can drop them close to 160km in altitude and then use them to power the turbopumps giving more thrust to the engines. Theoretically this should not harm ISP and theoretically you could have a gate in which the pumps function is additive to the expansion cycle at some point, therefore not hurting ISP. Theoretically also, since zero energy is being absorbed by the nozzle into the fuel allowing the greatest expansion in the combustion chamber you could get a few more ISP . . .approaching that 500 limit. You could push an RL10 like engine into the 400-500 kN range.

The problem is that with increased thrust there is increased structural requirements of the solar panel. There are applications in which having high storage density Li+ batteries would be useful (particularly in Solar prograde bound LEO exiting space craft that are ION driven). And you could take an engine that was producing 110kn of thrust and tweek it to say 190 kn of thrust and that would probably serve most functions.

You probably could not, or would not use an electric motor to drive RS25 or RS68A because these really require too much power, but you might be able to afford the same thrust with smaller and simpler engines and more of them.

11 hours ago, CatastrophicFailure said:

Some humans are larger than others... 

But going back to your earlier comment, it would be an interesting collaboration between, say, RocketLabs, SpaceX, and Tesla... RL shares their experience with flight-ready composite tanks, maybe does some deep cryo research for SpaceX, and in turn Tesla shares battery technology. 

Fat chance, I know, but one can hope. 

SpaceX and Electron are not really competing in the same market, in fact electron might make a keen purchase opportunity for Space X. With FH, space X is pushing in the direction of heavier payloads . . . .Which I have to reminde everyone those payloads will come if SX can drive the cost down, and the F9 market will eventually shrink and become more competitive with or without the Electron. SX needs to quickly move into markets which there competitors cannot service.

Edited January 23, 2018 by PB666

[Ultimate Steve]

Hilarious!