Blue Origin Thread (merged)

[Armchair Rocket Scientist]

How did the Patent Appeal Go ? (Would a Permanent Oil Rig style Platform attached to the Ocean floor count as a sea going vessel ? So many questions, such interesting times )

Well Done SpaceX team. Hope you get the hydraulic fluid issue solved for the next attempt.

PS Anyone know how much Payload increase or DeltaV savings (for the "Return to pad landing") would be gained by launching from the mountains in Ecuador, Maybe Nevado Cayambe or Antisana?

Bryce Ring.[h=3][/h][h=3][/h]Mt Anastasia or ??

Delta V savings? Probably a couple hundred m/s at best.

Payload increase? -100% because nobody will ever launch a rocket from anywhere near there.

Launching northward to a polar orbit is the best case scenario, in which case you still overfly more than a hundred miles of Ecuador and possibly Colombia. Southward, your ground track is over 400 miles long. If the stage's engines didn't relight for the boostback, or if any failure occurred during the first stage burn, the rocket would risk falling on a populated area. Launching eastward to an equatorial orbit, you overfly FOUR countries: Ecuador, Peru, Colombia, and Brazil.

Also, have fun building a launch pad on top of a snowcapped mountain where things are frequently incredibly windy, and having your ground crew have to carry bottled oxygen to avoid altitude sickness. Oh, and freezing temperatures and all that.

[Sean Mirrsen]

Freezing temperatures should at least reduce LH2 boiloff.

[bigdad84]

Freezing temperatures should at least reduce LH2 boiloff.

Always looking on the bright side.

[Frozen_Heart]

having your ground crew have to carry bottled oxygen to avoid altitude sickness. Oh, and freezing temperatures and all that.

that just sounds like good practice for working in Martian conditions!

[Bryce Ring]

Delta V savings? Probably a couple hundred m/s at best.

Payload increase? -100% because nobody will ever launch a rocket from anywhere near there.

Launching northward to a polar orbit is the best case scenario, in which case you still overfly more than a hundred miles of Ecuador and possibly Colombia. Southward, your ground track is over 400 miles long. If the stage's engines didn't relight for the boostback, or if any failure occurred during the first stage burn, the rocket would risk falling on a populated area. Launching eastward to an equatorial orbit, you overfly FOUR countries: Ecuador, Peru, Colombia, and Brazil.

Also, have fun building a launch pad on top of a snowcapped mountain where things are frequently incredibly windy, and having your ground crew have to carry bottled oxygen to avoid altitude sickness. Oh, and freezing temperatures and all that.

Why northward best case scenario ?

[EzinX]

Found the gif of it. Sorry if it's linked on another page. I came in here to say : this looks exactly like my bad landings on the Mun or when testing out a lander on Kerbin and messing up. That is, playing KSP, this happens more often than I succeed in a soft landing

https://t.co/JowUE6a1D7 ..

[Sean Mirrsen]

Why northward best case scenario ?

He does explain it in the post, even if it's not obvious that he is, or what exactly he's explaining. Flying north (from mountains in Ecuador) you fly over the shortest stretch of populated land, to minimize chance of property damage (and life loss) in case of failure, and fewest countries to have to negotiate airspace contracts with.

[Bryce Ring]

He does explain it in the post, even if it's not obvious that he is, or what exactly he's explaining. Flying north (from mountains in Ecuador) you fly over the shortest stretch of populated land, to minimize chance of property damage (and life loss) in case of failure, and fewest countries to have to negotiate airspace contracts with.

Thanks

That makes sense. But How long until it is in orbit. IE would it not be in orbit well before the east coast of Brazil ?

I have been thinking about it. I can not see it being just 200m/s (But even that is awesome)

Where am I wrong.

I was trying to think of ;

Starting gravity turn earlier

less drag loss (This may not be to much in DeltaV but it is a bit particularly if you started a gravity turn relatively early and late at the same time. IE early in flight time, late in alt.

oh and last two. the marginal ("Now I can take my Samsung Notepad pad with me" saving) lower start "local gravity" and "higher orbital speed" sitting on the pad while being closer to the equator.

As for the ground crew,. Toughen up! or get outsourced;)

Edited January 17, 2015 by Bryce Ring
Changed West coast to East coast

[Nibb31]

Thanks

That makes sense. But How long until it is in orbit. IE would it not be in orbit well before the east coast of Brazil ?

I have been thinking about it. I can not see it being just 200m/s (But even that is awesome)

Where am I wrong.

I was trying to think of ;

Starting gravity turn earlier

less drag loss (This may not be to much in DeltaV but it is a bit particularly if you started a gravity turn relatively early and late at the same time. IE early in flight time, late in alt.

oh and last two. the marginal ("Now I can take my Samsung Notepad pad with me" saving) lower start "local gravity" and "higher orbital speed" sitting on the pad while being closer to the equator.

As for the ground crew,. Toughen up! or get outsourced;)

The tiny amount of fuel you save with those 200m/s (out of 9500 m/s required to get to orbital speed) is totally offset by:

- The cost of building a launch complex on top of a mountain.

- The cost of paying people to work in a remote location.

- The cost of transporting the rocket to the top of the mountain.

- The insecurity of building a strategic asset in a foreign country.

It's a stupid idea that has been debunked repeatedly ever since people started launching rockets in the late 1940's.

Edited January 17, 2015 by Nibb31

[Bryce Ring]

Seems I was wrong about the Gimbals on the Rocket motors.

Elon Musk ✆@elonmusk Follow @ID_AA_Carmack Before impact, fins lose power and go hardover. Engines fights to restore, but …

Bryce Ring

Man I am so Stupid lol (Now I have been told)

[Iskierka]

The engines are likely to power their own closed-loop hydraulics, as they would form a very small contained unit that wouldn't be too heavy. The grid fins are likely on a separate open-loop system due to the separation from the engines - at that distance a closed system would no longer be lightweight, so a separate open system is used.

[magnemoe]

The tiny amount of fuel you save with those 200m/s (out of 9500 m/s required to get to orbital speed) is totally offset by:

- The cost of building a launch complex on top of a mountain.

- The cost of paying people to work in a remote location.

- The cost of transporting the rocket to the top of the mountain.

- The insecurity of building a strategic asset in a foreign country.

It's a stupid idea that has been debunked repeatedly ever since people started launching rockets in the late 1940's.

Yes, for spaceX it would be more interesting to launch from south east Asia where you have islands you could land both the boosters and the core without fly back.

Russia has an natural benefit here as they fly over land for a long time, downside is that they need to fly the stage back on the back of a plane or ballistic.

[Camacha]

Yes, for spaceX it would be more interesting to launch from south east Asia where you have islands you could land both the boosters and the core without fly back.

Russia has an natural benefit here as they fly over land for a long time, downside is that they need to fly the stage back on the back of a plane or ballistic.

Remember that a separate landing site would require more transport, site and personnel costs. I do not know enough about the specifics to calculate anything, but both have their merits.

[DBT85]

Sorry if it's been discussed but why is a powered landing a more desirable option than chutes?

I'm guessing that chutes alone would mean that nasty sea water will get everywhere when going into the sea, but an inflatable lifeboat type option could be viable no? I'm just wondering about the weight of the fuel needed to slow it down versus the cans of air and chutes to slow it down.

Very excited they are trying anyway and hope for success next time out. Will be watching, again.

[Camacha]

Parachutes will only get you so far, reentry is very violent, so you will need some kind of complex combination of a powered landing a parachutes will all sorts of failure modes because of interaction between the two. Any flotation device is going to be heavy.

[Nibb31]

Parachutes and the systems to make them work are heavier than the little extra fuel needed to land. They are also labor intensive and must of the system can't be easily reused (cords, pyros, covers, etc...).

Engines are already there and don't need any extra systems or consumables to work. Just refuel and go (gross oversimplification, but you get the idea).

Edited January 17, 2015 by Nibb31

[sgt_flyer]

Well, one of the main issues you'll get with parachutes, is their inherent lack of precision landing (the parachutes' canopies making a huge drag surface for sideway winds - so it's almost impossible to make pinpoint landings with those. (Unless it's a steerable design - but are controllable through gliding, which'll give you horizontal velocity, so it's not suitable for landing on legs.

Mixing engine / fin steering with parachutes assist would prove to be quite unreliable - you only need a small random change in wind pushing the canopies away to overcome the rocket's other steering capabilities.

Besides, waters at sea are rarely calm so an inflatable system would need to be able to cover everyhting on the booster to prevent salt water from getting in. (And if a tall thing like a booster would topple due to heavy seas, the booster would likely be very damaged with it's top impacting water at these kind of speeds (rocket boosters are not meant to handle much sideways forces)

Afterwards, a small emergency drogue chute (which could be cut before landing) could eventually help recover from bad boosters angles - but you'll need to cut it away after it's done it's job, to prevent it from interferring with the landing / postlanding. (Though if the rocket is moving with a bad angle, a drogue / parachute could easily fail to deploy because the relative winds force it back into it's housing)

Other methods for reusable stage with pinpoint landings would be to use winged flyback boosters-

But those winged boosters came with lots of tradeoffs : you need to include landing gears, eventually jet engines, wings and the support structures to resist to both vertical and horizontal forces, giving you a stage with a quite bad dry weight.

There are researches on those systems anyway - old Energia II uragan concept would have used zenith rockets fitted with deployable wings as side boosters, current Angara could be using Baikal boosters (provided they get them out of concept / mockup phases)

And from the US, there's the Starbooster concept.

Now, spaceX worked a lot to give their falcon 9 the lowest possible dry weight - so all those kind of heavy equipments would be almost out of question - ok they have to keep additional fuel + lox for the flyback phase - but winged flyback style also has to keep fuel to run the jet engines they need to get back home (in addition to the dry weight created by having to haul such engines)

So, the spaceX system is quite a good call - with the added benefit of allowing you to be able to launch heavier payloads with the same rocket (but they don't recover the stage) without any hardware difference (rockets with winged style booster would also need to design standard expendable boosters to achieve the same versatility)

Edited January 18, 2015 by sgt_flyer

[Camacha]

An additional problem with the sea is that even if you are not submerged it still causes a lot of corrosion. Cars tend to rust a lot faster on the seaside too, and unfortunately aluminium is the opposite of noble. Add a bit of electrolytic action and you might have a weakened structure very quickly.

If you want to keep your hardware intact, you generally stay well away from the sea.

[Rakaydos]

Rocket engines are designed to be the most efficent way of turning weight (fuel) into velocity change.

SpaceX simply noted that at this point, they're good enough that a parachute would weigh more than the fuel to run the engine a little longer.

[B787_300]

http://www.cnn.com/videos/tech/2015/01/16/spacex-rocket-crash-landing-crane-orig-mg.cnn i dont believe it CNN had a decent clip on the SpaceX landing

[zarakon]

Sorry if it's been discussed but why is a powered landing a more desirable option than chutes?

I'm guessing that chutes alone would mean that nasty sea water will get everywhere when going into the sea, but an inflatable lifeboat type option could be viable no? I'm just wondering about the weight of the fuel needed to slow it down versus the cans of air and chutes to slow it down.

The shuttle SRBs were around the same size and mass as the F9 first stage. They used parachutes to land in the ocean.

Those parachutes were the largest ever used - almost 4 tons, not even including the support structure or deployment mechanisms.

The SRBs still hit the water at about 50mph.

The F9 would need absurdly large parachutes to reduce the landing speed enough to prevent damage to its engines

[meve12]

Would a drogue ballute be a good investment at this point?

Doesn't need to slow down the rocket much, just ensure it's more stable going down.

[B787_300]

meve12 that would be a bad idea because a Ballute does not have enough control

[meve12]

Wouldn't need the ballute to control the landing either; the grid-fins and the rocket can do that anyway. Just needs to make it more aerodynamically stable going backwards.

[Ralathon]

Wouldn't need the ballute to control the landing either; the grid-fins and the rocket can do that anyway. Just needs to make it more aerodynamically stable going backwards.

It already is. All the heavy stuff is on the bottom while the giant empty tank acts as a wind vane. Its stable with engines first in freefall. No need to lose control for no reason by strapping chutes to it