Orion program delayed 2 years

[Frozen_Heart]

If you find yourself getting that a lot with him, remember the forum has an ignore function.

I like seeing both points of view personally. I find myself somewhere in between both opinions and watching a discussion is interesting as long as it doesn't get personal.

I agree you can't handwave and just throw out a cutting edge spaceship in a year for little cost, but having seen first hand the glacial speed some of these companies move things can be streamlined from there massively caompared to what they are now. Though it is easier for a small startup to do that than a large established company.

Edited September 21, 2015 by Frozen_Heart

[shynung]

Don't forget, SpaceX had NASA inject them funds. Falcon 9 and Dragon's R&D money comes from NASA contracts.

[Kryten]

Don't forget, SpaceX had NASA inject them funds. Falcon 9 and Dragon's R&D money comes from NASA contracts.

And Falcon I development money came from DARPA.

[Nothalogh]

I really can't picture NASA doing anything in the next 15 years, just a cycle of design, delay, cancel. Over and over.

This, the whole place needs a stalinistic purge

[CptRichardson]

This, the whole place needs a stalinistic purge

That would be the government, not NASA's fault.

[Guest]

That would be the government

Which needs a Stalinistic purge.

[Nothalogh]

That would be the government, not NASA's fault.

NASA is effectively a self sustaining bureaucratic human centipede, it lacks a focused or useful goal, and has no need to.

Shoveling money into NASA won't make it better or different, it will only amplify what you already had.

If you want to fix NASA they need to be given a singular task, and ruthlessly held to it

[Motokid600]

Are you serious? only dumb people will prefer the old system. And it does not have any drawback. Recomendation, try to analize again before answer.

Tell that to the engineers working on the Orion LES. Anyway.... You said a lot. Forgive me, But this caught my eye. How exactly is eight super dracos not cutting into payload capacity? A legit question. I am uninformed.

What else will those Draco motors do other then launch abort and landing? ( oms? ) If nothing else... Then yes they cut into payload capacity and reduce overall performance. Good for cost though.

Edited September 21, 2015 by Motokid600

[Frozen_Heart]

What else will those Draco motors do other then launch abort and landing?

They also acts as the OMS in orbit. Many spacecraft have separate OMS engines.

[Motokid600]

They also acts as the OMS in orbit. Many spacecraft have separate OMS engines.

All eight of them?

Also about cross feed. I read that the center booster uses a different fuel mixture. Which is why cross feed is on the back burner. That true?

[Kryten]

Also about cross feed. I read that the center booster uses a different fuel mixture. Which is why cross feed is on the back burner. That true?

No, it's just unnecessary. The falcon heavy launches that have been ordered so far are 4-5 ton sats to GTO, FH is already severely overpowered for that. It isn't even set up to do dual launches, so there's not much chance of it using more capability anytime soon.

- - - Updated - - -

That would be the government, not NASA's fault.

If you go after the people that are actually at fault, it ain't Stalinist.

[fredinno]

This place has gone so off topic from talking about the delay of ARM to 2023, it's not even funny. It's devolved to a "Orion program discussion thread" at best, and a "I hate Orion, SpaceX Dragon is better" at worst.

[1greywind]

Whole thread is complete *****. Reminds me absurdly long threads on NK (kosmonautics news journal) forum - years and years of pointless flame. Angara discussion thread is literally 13 years old (started in 2004) and goes.

Guys, any success in space exploration is possible only in cooperation between nations, governments, their space agencies and private companies. Where SpaceX will fly their manned Dragon's if there was no ISS? What private company will build next MSL rover? SpaceX and other private sector players does not have space program. NASA does (not very precise but much better than Musk's "let us build MCT and somehow send people to space with it). What private companies do better than NASA - is costs optimization. They do not have JPL on payroll and tens of ongoing missions that need money to keep going. NASA and SpaceX are not in competing positions. Dragon can not replace Orion for missions outside LEO. Orions is too pricey to be used as space taxi. Why even set them against each other?

[Motokid600]

There's also the fact that NASA employs a hell of a lot more people.

[AngelLestat]

Tell that to the engineers working on the Orion LES. Anyway.... You said a lot. Forgive me, But this caught my eye. How exactly is eight super dracos not cutting into payload capacity? A legit question. I am uninformed.

What else will those Draco motors do other then launch abort and landing? ( oms? ) If nothing else... Then yes they cut into payload capacity and reduce overall performance. Good for cost though.

Ok.. about super dracos cutting payload...

I guess these images will explain a lot more than me:

Vs

Ok, as you can see from the pictures, is obvious that orion system will cut more payload to orbit due how much massive it is.

You cannot eject it way too soon, because if something happen after, you are in trouble, and if you do it too late it would penalize a lot of deltav.

-Dragon does not need all that extra heavy faring.

-Dragon will use the same system as its primary landing option and parachutes as secundary.

This allows extra soft landing and it is able to choose location.

-Orion needs extra parachutes to have the same redundancy (which also add mass)

You can use dragon v2 extra deltav in any emergency you need, not just as an abort system.

The orion system needs more steps in the ejection, as detach the side farings far enoght to not hit the same capsule. Also you need to make a new ejection system each launch.

I am forgeting something?

Edited September 22, 2015 by AngelLestat
corrections

[Red Iron Crown]

I am forgeting something?

That they aren't remotely comparable in capabilities? It's like comparing an RV to a taxi and complaining about mileage.

[AngelLestat]

I dont understand, can you elaborate please?

I am comparing "abort launch systems", not capsules.

And even if the orion system has a bit more power, its because the capsule is bigger (and maybe the SLS produce more G, not sure).

If the orion would have its engines included, then it could be used to land in the moon or mars, and the service module would be just an external tank. In my opinion the dragon system does not have any cons with respect the orion system.

It would not need those extra parachutes and that heavy faring, its volume would be a bit higher to keep the aerodynamic coefficient.

[Nothalogh]

Dragon can not replace Orion for missions outside LEO.

Which is ridiculous to propose it for such in the first place.

BEO travel should be based on a dedicated vehicle optimized for that purpose, more specifically that is the one specific goal that NASA should have been focused on since the end of the Skylab program

[Red Iron Crown]

I dont understand, can you elaborate please?

I am comparing "abort launch systems", not capsules.

And even if the orion system has a bit more power, its because the capsule is bigger (and maybe the SLS produce more G, not sure).

If the orion would have its engines included, then it could be used to land in the moon or mars, and the service module would be just an external tank. In my opinion the dragon system does not have any cons with respect the orion system.

It would not need those extra parachutes and that heavy faring, its volume would be a bit higher to keep the aerodynamic coefficient.

SuperDracos are not really suitable for the high dV missions that Orion is designed for, it's vacuum efficiency is compromised for better atmospheric performance. For a LEO taxi like Dragon it makes sense, most of its fuel is likely to be burned in atmo. For Orion, which needs a specialized orbital propulsion system that won't work for LES, it doesn't make sense to lug the specialized LES system along for the entire mission as the mass penalty eats into the dV too much.

The missions they are intended for are so different that the compromise that makes the most sense for one might not apply to the other.

[AngelLestat]

Ok, now I understand where are you going..

You said that we would lose deltaV if we use the superdraco with an ISP of 240s with slightly tilt as in-space propulsion VS the service module of orion that has 320s?

But what it means lose deltav? Less payload / more expensive?

What about the extra deltaV that is lose in the Orion launch due LES mass plus extra parachutes?

Depending the SLS format (light, heavy, etc), it needs a special LES design for each setup due different G-forces. So the development cost increase a lot.

The superdraco engines have that ISP because they use the same fuel than the draco engines (RCS), something that Orion still needs, so it waste mass in extra tanks and devices, and the worst part, it can not use the same fuel for different purposes, which is harded to set the fixed amount of proppelent for each one.

Furthermore we can highly vary the thrust with the superdracos from:

57600N --> 4 engines at 20% throttle

576000N -->8 engines at 100% throttle

(a superdraco orion´s version would have to be more powerfull of course, is just matter of scaling up)

Dragon v2 with its 1400kg in proppelent has 650m/s of detalv (full crew)

In the trunk you can carry extra proppelent and all the things you include in the service module without engines (which is like have an extra stage)

The benefic of the draco engines to land in the moon or mars, is that they are tilt out and at higher height from the ground.

This prevent any dust to enter in the engines, something that NASA was very concern in its mars landers designs lately.

So when you add all these factors, you found that you dont get much more deltav, and for sure your mission ends up being more expensive.

Edited September 22, 2015 by AngelLestat

[fredinno]

The same LES is being used for all SLSs.

The Orion LES is 6 T, but that's partially due to having to lug 2x the mass out to safety, though it also only carried through part of the ascent to orbit, before 2nd stage ignition.

Dragon also would need to be modified to carry extra propellent, easiest done by simply attaching the fuel to the top docking port. However, it would also be larger than Orion SM, as 1. lower ISP, and 2. having to put a tunnel through it, to allow it to connect properly to a lander, for example. This increases weight and cost.

Dragon is also 2x smaller than Orion, in terms of mass- it would be a more crowded fit, carrying less provisions and downmass (most importantantly).

Also, a BEO Dragon would be bascially Dragon V3.0, meaning it would be developped even later than Orion, as DragonV2 development ends 2017, while Orion ends 2018, mostly.

Can't we just accept that both are being developed regardless?

[Nibb31]

Dragon also would need to be modified to carry extra propellent, easiest done by simply attaching the fuel to the top docking port. However, it would also be larger than Orion SM, as 1. lower ISP, and 2. having to put a tunnel through it, to allow it to connect properly to a lander, for example. This increases weight and cost.

The IDS docking ring doesn't have provisions for fuel transfer, neither does the trunk ombilical. Those would require a major rework of the fuel plumbing system, in addition to a new ECLSS, new waste management, long-range communications and navigation, higher thrust engines, and additional EVA capability. So you're right, a BEO Dragon would really have to be a Dragon V3.

Can't we just accept that both are being developed regardless?

Exactly. The LES is a fundamental design element of the entire spacecraft, and in both cases was designed for the requirements of that spacecraft, which are different because their missions are different, their flight environments are different, and their economical and political background are different. It's like comparing the wheels on a Hummer to the wheels on a Formula 1 race car or a shopping trolley, which are all well designed for the job they have to do.

There is no "single best spacecraft", like there is no "single best aircraft" or "single best car". Is an Airbus A380 better than an F-22? Is a Tesla better than a Land Rover? It all depends on what your requirements are and how each vehicle meets those requirements.

Edited September 22, 2015 by Nibb31

[Red Iron Crown]

Ok, now I understand where are you going..

You said that we would lose deltaV if we use the superdraco with an ISP of 240s with slightly tilt as in-space propulsion VS the service module of orion that has 320s?

But what it means lose deltav? Less payload / more expensive?

Less delta-V means it can reach fewer destinations. That Isp difference means that, for similarly massive vessels, the SuperDraco-powered one needs 33% more propellant mass to reach the same dV budget.

What about the extra deltaV that is lose in the Orion launch due LES mass plus extra parachutes?

It doesn't carry the LES for the entire launch, let alone orbital maneuvers. So LES mass has zero effect on Orion's delta-V. It eats a bit of the launcher's, but launcher delta-V is cheap compared to on-orbit delta-V.

Depending the SLS format (light, heavy, etc), it needs a special LES design for each setup due different G-forces. So the development cost increase a lot.

As I understand it Orion is using a standardized LES across its variants, but I could be wrong.

The superdraco engines have that ISP because they use the same fuel than the draco engines (RCS), something that Orion still needs, so it waste mass in extra tanks and devices, and the worst part, it can not use the same fuel for different purposes, which is harded to set the fixed amount of proppelent for each one.

It's not wasted mass if that is what is needed to meet its requirements. As for propellant split, I agree that is useful to be able to use the same for both RCS and main propulsion (for unexpected circumstances), but I guess that's the compromise that made sense for Orion.

Furthermore we can highly vary the thrust with the superdracos from:

57600N --> 4 engines at 20% throttle

576000N -->8 engines at 100% throttle

(a superdraco orion´s version would have to be more powerfull of course, is just matter of scaling up)

Ah, some hypothetical scaled up Orion-equivalent. "Just a matter of scaling up" is never as simple or cheap as it seems.

Dragon v2 with its 1400kg in proppelent has 650m/s of detalv (full crew)

In the trunk you can carry extra proppelent and all the things you include in the service module without engines (which is like have an extra stage)

The benefic of the draco engines to land in the moon or mars, is that they are tilt out and at higher height from the ground.

This prevent any dust to enter in the engines, something that NASA was very concern in its mars landers designs lately.

Dust is not going to enter an engine when it is thrusting. Once it's off, dust enters an angled engine as easily as a straight one. There are also the cosine losses to consider from angled engines.

So when you add all these factors, you found that you dont get much more deltav, and for sure your mission ends up being more expensive.

I disagree. Adding some hypothetical, cost-unknown expansion or revision to a hypothetical future Dragon and declaring it less expensive is not overly convincing. Dragon is a good design, and well suited to its mission, but that mission is not the same as Orion's. It will be interesting to see what SpaceX comes up with if/when they ever make a crewed spacecraft for longer missions. They've done quite well with incremental improvements to their designs so far, I'd imagine they will take the lessons learned so far (and ones they will learn from Dragon V2 operation) and apply them to their next step.

[AngelLestat]

Ok, before start, I guess you are not being complete honest here, some of the arguments that often are used to criticize designs as (complexity and extra components, lower safety, etc) now for the orion case it seems they are a good choice.. how is not that being biased? XD

The same LES is being used for all SLSs.

yeah it seems that I misunderstand one of my sources, sorry. (I will edit my previous post)

The Orion LES is 6 T, but that's partially due to having to lug 2x the mass out to safety, though it also only carried through part of the ascent to orbit, before 2nd stage ignition.

Is 6.8T which only a 30% of that is proppelent. The orion capsule mass is 9T, this mean that the LES system needs the 75% of the capsule mass, and we need to add 400kg for the reserve parachutes (which dragonv2 does not need), so we have almost 80%.

In the DragonV2 case, the proppelent + 4x2 engines + hellium tanks (I have to estimate the superdraco 4x2 mass from the picture) 1400kg + 4x100kg + 100kg = 2T aprox, which is less than 40% of the dragon capsule. (dragon v2 dry mass is 4.2 T, this include the tanks and engine mass)

Orion LES system=80% of the capsule mass.

Dragon LES system= 40% of the capsule mass. (reusable and throttleable)

If the Orion eject the LES system before the burn to orbit ends, then it risk to have a failure after that event.

Dragon also would need to be modified to carry extra propellent, easiest done by simply attaching the fuel to the top docking port. However, it would also be larger than Orion SM, as 1. lower ISP, and 2. having to put a tunnel through it, to allow it to connect properly to a lander, for example. This increases weight and cost.

Why you will connect the fuel tank in the top? Why it can not be in the trunk? How do you think the orion makes all connections (less fuel) to the service module?

https://upload.wikimedia.org/wikipedia/commons/thumb/a/af/Orion_Service_Module_elements_2015.jpg/800px-Orion_Service_Module_elements_2015.jpg

Of course the Dragon should be higly modify as a dragonV3, but you can have 4 connections for each x2 superdraco engines by the side.

Dragon is also 2x smaller than Orion, in terms of mass- it would be a more crowded fit, carrying less provisions and downmass (most importantantly).

Also, a BEO Dragon would be bascially Dragon V3.0, meaning it would be developped even later than Orion, as DragonV2 development ends 2017, while Orion ends 2018, mostly.

We are not comparing functions and roles of each capsule, just the benefics of each LES system.

Less delta-V means it can reach fewer destinations. That Isp difference means that, for similarly massive vessels, the SuperDraco-powered one needs 33% more propellant mass to reach the same dV budget.

Is less than that if you figure out the service module proppelant mass and all the other aspects.

If you accept one step further in development, it will be possible to have a methane/ox fuel for RSC and main thrusters reaching +350 isp.

As this study with test show.

About my draco dv estimation of 650, I forget to have the 10^o tilt into account, is closely to 600m/s

It doesn't carry the LES for the entire launch, let alone orbital maneuvers. So LES mass has zero effect on Orion's delta-V. It eats a bit of the launcher's, but launcher delta-V is cheap compared to on-orbit delta-V.

again this mean extra risk, also as I prove, the mass for this LES system is much higher in mass % than the Dragon LES.

Ah, some hypothetical scaled up Orion-equivalent. "Just a matter of scaling up" is never as simple or cheap as it seems.

why is hypothetical? the draco RSC thruster was scale up to become a superdraco thruster, of course is a complete different design, but you can always scale up things with develpment. And we are not talking about a huge difference between Dragon requirements and Orion requirements.

Dust is not going to enter an engine when it is thrusting. Once it's off, dust enters an angled engine as easily as a straight one. There are also the cosine losses to consider from angled engines.

I will need to look for this, is something that I have read about manned mission to mars and the power of the engines (which will be more powerfull than the ones used in rovers) hitting the dust and producing an inverse flow from above which may damage the engines.

I disagree. Adding some hypothetical, cost-unknown expansion or revision to a hypothetical future Dragon and declaring it less expensive is not overly convincing.

I can not prove it with 100% certainty, but I guess everybody knows including you, that dragon LES design choice it has the potential to be a lot cheaper than Orion. Edited September 22, 2015 by AngelLestat

[Kibble]

If the Orion eject the LES system before the burn to orbit ends, then it risk to have a failure after that event.

AJ10 has enough thrust to get Orion away after LAS is jettisoned.

Why you will connect the fuel tank in the top? Why it can not be in the trunk? How do you think the orion makes all connections (less fuel) to the service module?

Niether IDS or Dragon's trunk umbilical can route fuel to the capsule - you might as well just put a little rocket stage in the trunk!

If you accept one step further in development, it will be possible to have a methane/ox fuel for RSC and main thrusters reaching +350 isp.

Cryogenic non-hypergolic RCS is a very bad idea!