Author Topic: Orion Discussion Thread 2  (Read 129769 times)

Offline AnnK

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Re: Orion Discussion Thread 2
« Reply #340 on: 02/11/2019 02:05 pm »
Another NASA waste of money, it would be better if they could recover the capsule. The capsule could be checked for structural damage. Now NASA will have to do another test with the parachutes activated. I do not think that drop tests equal a deployment of the parachutes in an abort situation.
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Offline whitelancer64

Re: Orion Discussion Thread 2
« Reply #341 on: 02/11/2019 03:36 pm »
Another NASA waste of money, it would be better if they could recover the capsule. The capsule could be checked for structural damage. Now NASA will have to do another test with the parachutes activated. I do not think that drop tests equal a deployment of the parachutes in an abort situation.

There are going to be no more Orion abort tests, there's no plan or budget for them.
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Offline rayleighscatter

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Re: Orion Discussion Thread 2
« Reply #342 on: 02/12/2019 12:24 am »
Another NASA waste of money, it would be better if they could recover the capsule. The capsule could be checked for structural damage. Now NASA will have to do another test with the parachutes activated. I do not think that drop tests equal a deployment of the parachutes in an abort situation.

It's not an actual Orion capsule, it's a boilerplate so there's no useful information to be gathered from the structure.

Offline woods170

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Re: Orion Discussion Thread 2
« Reply #343 on: 02/12/2019 08:43 am »
Another NASA waste of money, it would be better if they could recover the capsule. The capsule could be checked for structural damage. Now NASA will have to do another test with the parachutes activated. I do not think that drop tests equal a deployment of the parachutes in an abort situation.

The quoted post reflects a fine example of someone who didn't bother reading up on the subject before posting a clueless post.

Here are the six things wrong with said post:

1.  This test is not a waste of money: NASA rightfully will want the Launch Abort System thoroughly tested before risking the lives of its astronauts.

2.  The vehicle is not a capsule. It is a boilerplate that only simulates a number of key aspects of a real capsule. Such as outer moldline, mass, center of gravity, etc.

3.  There is no need for the boilerplate to be recovered. All data collected by the instruments on board is going out - in realtime - as telemetry. And for back-up the data recorders will be ejected and recovered. Once the LAS has done its thing the boilerplate becomes useless. Recovering it would be a waste of money.

4.  The in-flight abort parachute regime has already been tested on several of the drop-tests of the dedicated parachute testing vehicle (PTV). Therefore: no need to equip the in-flight abort boilerplate with parachutes. In fact: equipping the boilerplate with parachutes would not provide NASA with any new information and it would be a waste of money.

5.  The author of the post is ill-informed. Drop tests are very much capable of simulating an in-flight abort scenario for parachute deployment. See my point 4.

6.  The author of the post thinking that he/she knows better than the NASA- and contractor engineers who are actually involved in this test.
« Last Edit: 02/12/2019 12:31 pm by woods170 »

Offline A_M_Swallow

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Re: Orion Discussion Thread 2
« Reply #344 on: 02/12/2019 11:36 am »
{snip}
4.  The in-flight abort parachute regime has already been tested on several of the drop-tests of the dedicated parachute testing vehicle (PTV). Therefore: no need to equip the in-flight abort boilerplate with parachutes. In fact: equipping the boilerplate with parachutes would not provide NASA with any new information and it would be a waste of money.
{snip}

There are plenty of ways the force of the in-flight abort system along with its tendency to tip the capsule over could disrupt the parachute deployment systems. The sequence should be tested.

Offline woods170

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Re: Orion Discussion Thread 2
« Reply #345 on: 02/12/2019 12:33 pm »
{snip}
4.  The in-flight abort parachute regime has already been tested on several of the drop-tests of the dedicated parachute testing vehicle (PTV). Therefore: no need to equip the in-flight abort boilerplate with parachutes. In fact: equipping the boilerplate with parachutes would not provide NASA with any new information and it would be a waste of money.
{snip}

There are plenty of ways the force of the in-flight abort system along with its tendency to tip the capsule over could disrupt the parachute deployment systems. The sequence should be tested.

Emphasis mine.

Has already been done thru the PTV drop tests.
« Last Edit: 02/12/2019 12:34 pm by woods170 »

Offline Steven Pietrobon

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Re: Orion Discussion Thread 2
« Reply #346 on: 02/13/2019 05:05 am »
In 1965, when NASA's Apollo budget was $20.8B in today's money, NASA could afford to fly capsules with parachutes in their abort tests, to get that extra bit of data. Today, NASA is only getting $4.3B for SLS/Orion and is trying to minimise cost as much as they can. There are other examples where NASA is cutting costs, for example, having the first flight of the crew environmental control system go all the way to the Moon, instead of first testing in LEO, like Apollo 7 did in 1968.

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Online ncb1397

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Re: Orion Discussion Thread 2
« Reply #347 on: 02/13/2019 07:54 am »
They have already done an abort test with parachutes: PA-1



Offline woods170

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Re: Orion Discussion Thread 2
« Reply #348 on: 02/13/2019 09:37 am »
They have already done an abort test with parachutes: PA-1




Yes, but that was the pad-abort test which is not quite valid for in-flight abort scenario for multiple reasons:

- Very early design iteration of the CPAS (Capsule Parachute Assembly System). The flight CPAS is substantially improved compared to the one used on PA-1.
- Different flight regime (much lower altitude, lower velocity, different decceleration levels, etc)

Therefore, several of the CPAS dev and qual PTV drop-test explicitely explored and characterized in-flight abort chute deployment scenarios. These test were much more representative for in-flight abort chute deployment than was PA-1.
« Last Edit: 02/13/2019 09:43 am by woods170 »

Offline A_M_Swallow

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Re: Orion Discussion Thread 2
« Reply #349 on: 02/13/2019 12:24 pm »
{snip}
4.  The in-flight abort parachute regime has already been tested on several of the drop-tests of the dedicated parachute testing vehicle (PTV). Therefore: no need to equip the in-flight abort boilerplate with parachutes. In fact: equipping the boilerplate with parachutes would not provide NASA with any new information and it would be a waste of money.
{snip}

There are plenty of ways the force of the in-flight abort system along with its tendency to tip the capsule over could disrupt the parachute deployment systems. The sequence should be tested.

Emphasis mine.

Has already been done thru the PTV drop tests.

I do not require a full capsule with life support just equip the abort boilerplate with the latest CPAS (Capsule Parachute Assembly System). The two things are meant to work together in the correct sequence.

Offline woods170

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Re: Orion Discussion Thread 2
« Reply #350 on: 02/13/2019 12:47 pm »
{snip}
4.  The in-flight abort parachute regime has already been tested on several of the drop-tests of the dedicated parachute testing vehicle (PTV). Therefore: no need to equip the in-flight abort boilerplate with parachutes. In fact: equipping the boilerplate with parachutes would not provide NASA with any new information and it would be a waste of money.
{snip}

There are plenty of ways the force of the in-flight abort system along with its tendency to tip the capsule over could disrupt the parachute deployment systems. The sequence should be tested.

Emphasis mine.

Has already been done thru the PTV drop tests.

I do not require a full capsule with life support just equip the abort boilerplate with the latest CPAS (Capsule Parachute Assembly System). The two things are meant to work together in the correct sequence.

Emphasis mine.

It seems to me that you think you know better than the engineers that are actually involved in the development of Orion.
Having said that I will add a bit more explanation to aid in your education.
CPAS working in the correct sequence with the LAS has already been proven on PA-1.
The two systems work in a specified sequence, but activation of the second system (CPAS) is not triggered by jettison of the first system (LAS).
That applies to both pad abort and ascent abort.

This disconnect is exactly one of the reasons why testing of the CPAS under in-flight-abort conditions can be decoupled from flying an in-flight abort test.
« Last Edit: 02/13/2019 12:51 pm by woods170 »

Offline Lar

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Re: Orion Discussion Thread 2
« Reply #351 on: 02/13/2019 02:49 pm »
We had an outbreak of political sniping. It referenced previous outbreaks that hadn't been cleaned. It's too disruptive to go back to July and delete stuff... but all the more recent stuff is gone. Whether Obama deliberately snubbed Houston by not giving them a shuttle?  Oddly, that's off topic for an Orion thread. Crazy I know...

Let's not have more political sniping in this thread please.
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Offline A_M_Swallow

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Re: Orion Discussion Thread 2
« Reply #352 on: 02/13/2019 03:03 pm »
{snip}
4.  The in-flight abort parachute regime has already been tested on several of the drop-tests of the dedicated parachute testing vehicle (PTV). Therefore: no need to equip the in-flight abort boilerplate with parachutes. In fact: equipping the boilerplate with parachutes would not provide NASA with any new information and it would be a waste of money.
{snip}

There are plenty of ways the force of the in-flight abort system along with its tendency to tip the capsule over could disrupt the parachute deployment systems. The sequence should be tested.

Emphasis mine.

Has already been done thru the PTV drop tests.

I do not require a full capsule with life support just equip the abort boilerplate with the latest CPAS (Capsule Parachute Assembly System). The two things are meant to work together in the correct sequence.

Emphasis mine.

It seems to me that you think you know better than the engineers that are actually involved in the development of Orion.

EASILY. Neither the CPAS nor the LAS design engineers are in charge of the entire sequence. That will be some manager somewhere.

I am reminded of the unplanned roll the Falcon 9 had on its first flight caused by the exhaust from the gas generators. Everything worked but not together.
https://www.popularmechanics.com/space/rockets/a5852/spacex-falcon9-first-flight

Quote
Having said that I will add a bit more explanation to aid in your education.
CPAS working in the correct sequence with the LAS has already been proven on PA-1.
The two systems work in a specified sequence, but activation of the second system (CPAS) is not triggered by jettison of the first system (LAS).
That applies to both pad abort and ascent abort.

This disconnect is exactly one of the reasons why testing of the CPAS under in-flight-abort conditions can be decoupled from flying an in-flight abort test.

A drop test would have to include separation from a boilerplate LAS to be valid.

Offline whitelancer64

Re: Orion Discussion Thread 2
« Reply #353 on: 02/13/2019 03:08 pm »
A drop test would have to include separation from a boilerplate LAS to be valid.

Why?
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Offline A_M_Swallow

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Re: Orion Discussion Thread 2
« Reply #354 on: 02/13/2019 11:24 pm »
A drop test would have to include separation from a boilerplate LAS to be valid.

Why?

The LAS covers the top of the vehicle so the parachutes cannot deploy until the LAS has separated from the capsule. Plenty of ways things can go wrong, or slowly, there.

p.s. As a test of the reentry systems no LAS is valid since it would have departed several days before. As a milestone test of a sub-assembly of the abort system it is valid but not of a test of the entire system.
« Last Edit: 02/14/2019 03:47 am by A_M_Swallow »

Offline woods170

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Re: Orion Discussion Thread 2
« Reply #355 on: 02/14/2019 07:31 am »
A drop test would have to include separation from a boilerplate LAS to be valid.

Why?

The LAS covers the top of the vehicle so the parachutes cannot deploy until the LAS has separated from the capsule. Plenty of ways things can go wrong, or slowly, there.

Emphasis mine.

That has already been flight-tested twice: PA-1 and EFT-1. And will flight-tested again on AA-2. It is not a concern for deployment of chutes under ascent-abort conditions.

Again: if there was any validity in your concerns regarding no-chutes on AA-2 than NASA would be doing the test with chutes.
The fact that NASA chooses to do the test without chutes serves to invalidate your concerns.

Online russianhalo117

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Re: Orion Discussion Thread 2
« Reply #356 on: 02/18/2019 05:42 am »
A drop test would have to include separation from a boilerplate LAS to be valid.

Why?

The LAS covers the top of the vehicle so the parachutes cannot deploy until the LAS has separated from the capsule. Plenty of ways things can go wrong, or slowly, there.

Emphasis mine.

That has already been flight-tested twice: PA-1 and EFT-1. And will flight-tested again on AA-2. It is not a concern for deployment of chutes under ascent-abort conditions.

Again: if there was any validity in your concerns regarding no-chutes on AA-2 than NASA would be doing the test with chutes.
The fact that NASA chooses to do the test without chutes serves to invalidate your concerns.
Correct. NASA retired several concerns after various drop and propulsive tests so several planned abort tests were cancelled although hardware is available if cancelled tests end up needed but would delay EM-1 and EM-2 because their LAS's would be needed to perform additional propulsive abort tests.

Online jacqmans

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Re: Orion Discussion Thread 2
« Reply #357 on: 02/22/2019 09:06 am »
Credits: NASA/ESA/ATG Medialab

Online jacqmans

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Re: Orion Discussion Thread 2
« Reply #358 on: 02/22/2019 09:07 am »
Credits: NASA/ESA/ATG Medialab

Online jacqmans

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Re: Orion Discussion Thread 2
« Reply #359 on: 02/22/2019 09:08 am »
Credits: NASA/ESA/ATG Medialab

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