Author Topic: Orion Discussion Thread 2  (Read 78348 times)

Offline woods170

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Re: Orion Discussion Thread 2
« Reply #240 on: 03/08/2017 05:29 PM »

How is Dragon V2 designed for BLEO?

The first part of the answer is the heat shield. It is overbuilt for LEO. It will allow for higher speed re-entry that is required for BLEO missions. The moon free return mission is the case in point.

The second part is the ECLSS system can handle longer duration missions.

I understand the heat shield (otherwise the moon mission would be off the table) but the ECLSS?  I haven't seen anything indicating how long the ECLSS can support crew.

I have. And it's substantially longer than the few days required to hop crews to and from the ISS.

Offline Welsh Dragon

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Re: Orion Discussion Thread 2
« Reply #241 on: 03/08/2017 06:06 PM »
Don't forget it's designed for 7 people. Take 4 or 5 out, and you'll be able to stretch the ECLSS a lot further already.

Offline Khadgars

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Re: Orion Discussion Thread 2
« Reply #242 on: 03/08/2017 07:44 PM »

How is Dragon V2 designed for BLEO?

The first part of the answer is the heat shield. It is overbuilt for LEO. It will allow for higher speed re-entry that is required for BLEO missions. The moon free return mission is the case in point.

The second part is the ECLSS system can handle longer duration missions.

I understand the heat shield (otherwise the moon mission would be off the table) but the ECLSS?  I haven't seen anything indicating how long the ECLSS can support crew.

I have. And it's substantially longer than the few days required to hop crews to and from the ISS.

Understood and thank you for the update. 

Offline sdsds

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Re: Orion Discussion Thread 2
« Reply #243 on: 03/09/2017 06:21 AM »
Yet the mission for which Orion is designed includes staging in low lunar orbit.  That's pretty striking when you consider that access to the lunar poles was a design requirement.

It's all about the engine(s) used for LOI and lunar braking descent. In this context that is to say, "For Orion, lunar surface access was all about Altair."
« Last Edit: 03/09/2017 06:22 AM by sdsds »
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Offline b0objunior

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Re: Orion Discussion Thread 2
« Reply #244 on: 03/09/2017 06:32 AM »

How is Dragon V2 designed for BLEO?

The first part of the answer is the heat shield. It is overbuilt for LEO. It will allow for higher speed re-entry that is required for BLEO missions. The moon free return mission is the case in point.

The second part is the ECLSS system can handle longer duration missions.

I understand the heat shield (otherwise the moon mission would be off the table) but the ECLSS?  I haven't seen anything indicating how long the ECLSS can support crew.

I have. And it's substantially longer than the few days required to hop crews to and from the ISS.
What, like a week or more?

Online Flying Beaver

Re: Orion Discussion Thread 2
« Reply #245 on: 03/09/2017 08:56 PM »
Could the launch trajectory be changed for a crewed EM-1 to launch into the plane of the ISS? It would be still possible to get to the Moon (be it only one window a month), and it would allow the ISS to be used as a life-boat if a docking port was added to Orion for the flight (or maybe just EVA transfer :P).

Only real reason though would be orbital debris or MMO strikes to the heat shield in LEO.

Saw OG-2 Booster Land in person 21/12/2015.

Offline Norm38

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Re: Orion Discussion Thread 2
« Reply #246 on: 07/08/2017 09:00 PM »
NASA: "It's cool, we were going to clean it anyway".

http://www.cnn.com/2017/07/07/politics/mike-pence-nasa-picture/index.html
« Last Edit: 07/08/2017 09:01 PM by Norm38 »

Offline AnnK

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Re: Orion Discussion Thread 2
« Reply #247 on: 07/09/2017 10:50 PM »
Orion is a terrible waste of money and resourses. Boeing and SpaceX are going to be in space with their crewed product 5 years ahead of the first Orion flight. Really how long will it take for either to come up with a service module that surpasses Orion? The problem with Orion is it was designed by Congressional commitee. It is designed to deliver as much pork as possible to the Congressional leaders districts.

I am sure that SpaceX and even Boeing (If they want) will be on Mars before the Orion program can really start with flights. NASA is all about risk adversion and the horror about losing astronaughts. Life is well dangerous and driving our ground cars is taking our life in our own hands.

I think Orion should be canceled and NASA should support companies that will design and operate our next series of spacecraft. The orgional Apollo program had inspiration and not the crippling risk adversion of today. We are going to lose people and there is no getting around that fact.

Online Endeavour_01

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Re: Orion Discussion Thread 2
« Reply #248 on: 07/10/2017 03:04 AM »
Orion is a terrible waste of money and resourses. Boeing and SpaceX are going to be in space with their crewed product 5 years ahead of the first Orion flight.......

While I think everybody knows that Orion has many issues I think comparing something designed for BEO flight to a system (Starliner) designed for LEO taxi duty is unfair. Starliner's job is to get people from Earth to LEO. Its heat shield and ECLSS are insufficient for BEO flight. It is a perfectly good spacecraft for the job its being asked to do but it can't (without major, major mods and redesigns) go BEO manned.

As for Dragon, which has been designed with BEO capability, we still don't know the extent of its usefulness in the BEO regime. Its heatshield is BEO rated but in terms of propulsion and ECLSS Orion is superior AFAIK.

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I am sure that SpaceX and even Boeing (If they want) will be on Mars before the Orion program can really start with flights.


If you mean "on Mars with humans" (in 6 years) I have some ocean front real estate in Oklahoma to sell you.  :)Elon and SpaceX have been making lots of progress with their Mars plans but even the rosiest of schedules doesn't show manned landings in 6 years.

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NASA is all about risk adversion and the horror about losing astronaughts. Life is well dangerous and driving our ground cars is taking our life in our own hands.

While I agree with you that groups like ASAP sometimes push for unrealistic safety standards I think going to the other extreme isn't helpful either. Remember, astronauts are real people with real lives and real families. Balance must be kept between maintaining the safety of astronauts and pushing the boundaries of spaceflight.

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I think Orion should be canceled and NASA should support companies that will design and operate our next series of spacecraft.

NASA is already supporting Boeing and SpaceX through commercial crew contracts.
I cheer for both NASA and commercial space. For SLS, Orion, Falcon 9, Falcon Heavy, Dragon, Starliner, Cygnus and all the rest!
I was blessed to see the launch of Space Shuttle Endeavour on STS-99. The launch was beyond amazing. My 8-year old mind was blown. I remember the noise and seeing the exhaust pour out of the shuttle as it lifted off. I remember staring and watching it soar while it was visible in the clear blue sky. It was one of the greatest moments of my life and I will never forget it.

Offline AnnK

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Re: Orion Discussion Thread 2
« Reply #249 on: 07/10/2017 11:00 PM »
Going straight from a Mars to Earth reentry is an old fashion NASA concept. Any returning craft need just to enter Earth orbit and at the right time reenter the Earths atmosphere. The Orion is over engineered and has too much mass. The Dragon 2 or Starliner will work better with the right service module. NASA loves to waste money and throw away the entire spacecraft. Boeing and SpaceX can develop new service modules long before the overprice, overengineered Orion will ever make a crewed flight. It is time to remove this pork from the picture.

Offline whitelancer64

Re: Orion Discussion Thread 2
« Reply #250 on: 07/10/2017 11:22 PM »
Going straight from a Mars to Earth reentry is an old fashion NASA concept.

No, it's efficient.

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Any returning craft need just to enter Earth orbit and at the right time reenter the Earths atmosphere.

Entering Earth orbit after returning from Mars would require lots of fuel. If you think Orion has too much mass now, it would require much, much more fuel mass to enter Earth orbit after returning from Mars. A direct reentry is more efficient.

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The Orion is over engineered and has too much mass. The Dragon 2 or Starliner will work better with the right service module. NASA loves to waste money and throw away the entire spacecraft. Boeing and SpaceX can develop new service modules long before the overprice, overengineered Orion will ever make a crewed flight. It is time to remove this pork from the picture.

Neither Dragon nor Starliner are capable of doing much what Orion is designed to be able to do, regardless of the capabilities of their service modules.

NASA for the most part does the best it can with the money it gets, which really isn't much, all things considered. And NASA has to work within the constraints of the directions it receives from Congress, they can't just do whatever it wants to do.
« Last Edit: 07/10/2017 11:23 PM by whitelancer64 »
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Offline Jim

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Re: Orion Discussion Thread 2
« Reply #251 on: 07/11/2017 01:11 PM »
Going straight from a Mars to Earth reentry is an old fashion NASA concept. Any returning craft need just to enter Earth orbit and at the right time reenter the Earths atmosphere.

That is idiotic.  The propellant required to enter earth orbit would necessitate a stage the same size that was used to leave earth orbit.

Online Lars-J

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Re: Orion Discussion Thread 2
« Reply #252 on: 07/11/2017 05:51 PM »
Going straight from a Mars to Earth reentry is an old fashion NASA concept. Any returning craft need just to enter Earth orbit and at the right time reenter the Earths atmosphere.

That is idiotic.  The propellant required to enter earth orbit would necessitate a stage the same size that was used to leave earth orbit.

A more generous interpretation of the comment would be that aerocapture is used to enter Earth orbit. But that is also tricky and requires a spacecraft capable of handling the aerocapture.

Offline Jim

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Re: Orion Discussion Thread 2
« Reply #253 on: 07/11/2017 06:07 PM »

A more generous interpretation of the comment would be that aerocapture is used to enter Earth orbit. But that is also tricky and requires a spacecraft capable of handling the aerocapture.

And if you are going to do that, might as well just go all the way and land
« Last Edit: 07/11/2017 06:07 PM by Jim »

Offline Coastal Ron

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Re: Orion Discussion Thread 2
« Reply #254 on: 07/11/2017 08:25 PM »
Neither Dragon nor Starliner are capable of doing much what Orion is designed to be able to do, regardless of the capabilities of their service modules.

We need to keep in mind though that the Orion is just a transportation system. It doesn't have an airlock, and is not meant to be occupied for more than 21 total days during it's mission - and keeping more than 2 people in that small of space for 21 days would be very taxing for passengers. It is basic transportation for Earth-local trips.

Alternative transportation systems, if needed, are already near-term possibilities.

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NASA for the most part does the best it can with the money it gets, which really isn't much, all things considered.

Through 2015 the Orion program had consumed $11B, and it is projected to consume another $9B by the time it is able to become operational - for a total of $20B. And that is just the development cost, it does not include the cost of building each expendable CM+SM shipset.

As a comparison, the ISS program started in 1985 and thru 2015 it was estimated that NASA's part of it would end up being $72.4B in 2010 dollars. And the ISS is a reusable vehicle/space station.

The cost difference - the value that NASA & the U.S. Taxpayer gets from the money spent - is certainly part of the reason why the Orion is not universally loved...

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And NASA has to work within the constraints of the directions it receives from Congress, they can't just do whatever it wants to do.

As the existence of the Orion proves.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline AnnK

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Re: Orion Discussion Thread 2
« Reply #255 on: 07/12/2017 05:20 AM »

A more generous interpretation of the comment would be that aerocapture is used to enter Earth orbit. But that is also tricky and requires a spacecraft capable of handling the aerocapture.

And if you are going to do that, might as well just go all the way and land

Of course land as in how much of the spacecraft? NASA will throw almost all of theirs away. It reminds me of Apollo and their launch vehicile/ reentry vehicile reminds me too much of the shuttle. Modified center tank, soild boosters and tiles are a recipe for diaster.

I believe like Elon Musk that as much of the spacecraft needs to be reused as possible. It is my understanding that aerobraking will be used at first but in the future all things are possible.

My experience is mostly aviation but has a space element. My biggest complaint with NASA is that is is just another type of pork.

Offline envy887

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Re: Orion Discussion Thread 2
« Reply #256 on: 07/12/2017 03:52 PM »
Going straight from a Mars to Earth reentry is an old fashion NASA concept. Any returning craft need just to enter Earth orbit and at the right time reenter the Earths atmosphere.

That is idiotic.  The propellant required to enter earth orbit would necessitate a stage the same size that was used to leave earth orbit.

This is only true if pushing the same vehicle with the same payload into the same orbit for entry as for departure. But almost no proposed Mars architectures do this.

For example, a chemical Mars Orbital mission needs to send its return fuel through TMI, which already makes the departure stage FAR larger than the return stage. And chemical departure is typically proposed from LEO (vs SEP from HEO), while capture is typically into cislunar Earth orbit, which requires about 1/4 the delta-v compared to a LEO departure.

A chemical return craft could propulsively capture into high earth orbit for on the order of 1,000 m/s (depends somewhat on the type of return), for a cislunar Orion rendezvous and return. This will be more efficient than dragging Orion through TMI, Mars orbit injection, and TEI for any return craft that masses under 40 tonnes. This uses Orion to do what it is actually designed for: a cislunar taxi. It's not an interplanetary vehicle.

Offline Jim

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Re: Orion Discussion Thread 2
« Reply #257 on: 07/12/2017 04:02 PM »

1.  Of course land as in how much of the spacecraft?

2.   Modified center tank, soild boosters and tiles are a recipe for diaster.

3.  My experience is mostly aviation but has a space element. My biggest complaint with NASA is that is is just another type of pork.

1.  Doesn't matter.  The change in velocity is the same.

2.  Irrelevant for this topic, not to mention blatantly wrong.

3.  And that type of incorrect sweeping characterization discredits any further statements.

Offline envy887

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Re: Orion Discussion Thread 2
« Reply #258 on: 07/12/2017 04:41 PM »
Entering Earth orbit after returning from Mars would require lots of fuel. If you think Orion has too much mass now, it would require much, much more fuel mass to enter Earth orbit after returning from Mars. A direct reentry is more efficient.

Orion is 20+ tonnes of dead mass in interplanetary space, it doesn't have the endurance for more than a trip to cislunar space and back. Replacing it with an equivalent mass of fuel and propulsion would allow a large in-space-only transfer hab to propulsively brake into HEO for rendezvous with an Orion taxi.

This is the current plan for using Orion, the DSG, and the DST. Orion isn't going to Mars, and it isn't doing direct entry from Mars.

Offline Jim

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Re: Orion Discussion Thread 2
« Reply #259 on: 07/12/2017 05:04 PM »
Orion is 20+ tonnes of dead mass in interplanetary space,

Wrong, it serves as a safe haven and backup control center.

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