29
$\begingroup$

On July 2, 2019, the Ascent Abort 2 test of the Orion spacecraft was performed, with the Orion command module ascending on a solid rocket booster, then firing its launch escape system to safely separate it from the booster.

One of the announcers in the video states at 1:47 that the spacecraft is not parachute-equipped for this test; besides live telemetry it is equipped with several ejectable data recorders which are deployed near the end of the test and recovered from the ocean afterwards. The video simply doesn't show the impact of the spacecraft in the ocean.

It seems odd to me that the Orion wouldn't be equipped with parachutes for the test. Safe landing is an integral part of an abort. Correct deployment of parachutes in a dynamic environment is a tricky problem, worth testing repeatedly. No matter how stripped down the Orion might be (I've seen twitter sources claiming it's a "boilerplate article"), I have to assume even the hull alone has to be worth more than the cost of installing parachutes, let alone any instrumentation inside it; even if it couldn't be reused as a flight article after splashdown, it could be used for anything from future abort tests to training to a museum piece.

What rationale is there for not doing a complete parachute recovery test as part of the abort test?

$\endgroup$
  • 8
    $\begingroup$ Posting as a comment because unsourced, but my former coworkers who work on Orion discussing it on FB today claim it was because of $$ $\endgroup$ – Organic Marble Jul 2 at 18:59
  • 7
    $\begingroup$ I think you're seriously overestimating the cost of a boilerplate mockup, and seriously underestimating the cost of parachutes. A boilerplate mockup is simply slabs of cheap steel welded into an approximation of the shape of the capsule, with sandbags, concrete slabs, or other cheap ballast added to get the desired balance. $\endgroup$ – Mark Jul 2 at 22:54
  • $\begingroup$ Related, needs updating: space.stackexchange.com/q/5538/26446 $\endgroup$ – DrSheldon Jul 2 at 23:00
11
$\begingroup$

Here's an official response:

NASA has already fully qualified the parachute system for flights with crew through an extensive series of 17 developmental tests and 8 qualification tests completed at the end of 2018.

Test data from 890 sensors was sent in real-time to ground sites as well as recorded on board by 12 data recorders. The 12 data recorders were ejected from the crew module before Orion reached the water and were retrieved after the test

This means testing the parachutes once more is not necessary, and they also wouldn't have helped much with gaining data. Concluding this with some common sense, they decided to not use parachutes on this occasion for financial and/or schedule reasons.

$\endgroup$
24
$\begingroup$

The test they were doing didn’t require parachutes. Data-taking ended right after the capsule separated from the tower. Since the capsule’s behavior after that was not part of the test, it could be an inert item.

To extend the test through parachute deployment, the capsule would have to be much more complex with the parachutes, deployment system, and a reaction control system to stabilize for deployment. That’s a lot of cost. (The capsules are single use, so you’re throwing that away)

Perhaps more important than cost, though, it’s also a lot of time to build that. The AA2 test was on the critical path, and delaying it would only happen for a Real Good Reason.

$\endgroup$
  • $\begingroup$ of course if a parachute test had been factored in the schedule would have been set accordingly and either construction started earlier or the test scheduled for a later date. $\endgroup$ – jwenting Jul 4 at 10:12
  • $\begingroup$ ...and if they had done the test and it had failed, the critical path would be really screwed $\endgroup$ – Dave Gremlin Jul 4 at 21:36
15
$\begingroup$

From the article:

Tuesday’s launch was more focused on testing the launch abort system itself. The parachutes on Orion have been tested 47 times.

$\endgroup$
  • 1
    $\begingroup$ I really like this simple precise ad sourced answer $\endgroup$ – Manu H Jul 4 at 8:13
12
$\begingroup$

This is not a complete answer as I do not know the status of the parachute development, but here are some reasons a parachute is not needed:

  1. Ejected Data Recorders: These ~20 data recorders, literally Raspberry Pis with parachutes and waterproofing, all get the complete telemetry data from the test. This is made up of accelerometer, gyroscope, magnetometer (compass), barometer (altimeter), GPS, strain gauge, thermocouples, and more sensor data. The only data that would have been added to this if the Orion had a parachute are:

    • Material analysis, basically finding cracks
    • Launch loads on the parachute (not hard to emulate)
  2. Previous Parachute Tests: If I remember correctly, the Orion parachutes have been tested in a variety of scenarios already, including subsonic and supersonic / high altitude.

  3. High Cost of Refurbishment: A water-recovered test article would likely need refurbishment with a cost similar to its original cost to be able to be used in further tests. Also, further tests likely would use much different sensor arrangements.

Of course budget factors into this, but NASA is always on top of mitigating its risk.

$\endgroup$
  • 7
    $\begingroup$ "NASA is always on top of mitigating its risk" Sadly, not always. $\endgroup$ – Organic Marble Jul 2 at 23:17
  • 1
    $\begingroup$ @OrganicMarble They have learned from their mistakes in the Shuttle days. $\endgroup$ – CourageousPotato Jul 3 at 0:22
  • 9
    $\begingroup$ You are an optimistic person! They keep learning that lesson. $\endgroup$ – Organic Marble Jul 3 at 0:32
  • 6
    $\begingroup$ Didn't NASA think about having humans on the first SLS flight? That doesn't seem to me that they are on top of mitigating risks. $\endgroup$ – GittingGud Jul 3 at 8:59
  • 1
    $\begingroup$ @Joshua I single launch abort system test is in my opinion not enough. I just hope that the individual part such as the thrusters and explosive bolts were tested 100 time more. $\endgroup$ – GittingGud Jul 4 at 6:21
1
$\begingroup$

The parachutes and the heat shield were already tested with the EFT-1 launch, in 2014, with a real capsule!

$\endgroup$
  • $\begingroup$ well, there are possible reasons to use them anyway, like reusing the capsule. Which is of course theoretical as Orion capsules aren't reusable and boilerplates even less so. Which should have been part of any complete answer. $\endgroup$ – jwenting Jul 4 at 10:13
0
$\begingroup$

The parachutes were tested separately

NASA drop tested an Orion capsule 8 times in Sept 2018 using a C-17

Orion parachute test

Orion is behind schedule

The Orion is built to use the Space Launch System rocket. That rocket is still not ready to fly, and may not fly until 2021. Meanwhile, SpaceX has actually flown its Crew Dragon and (despite a catastrophic explosion) still looks like they may actually get people into orbit as early as next year. Orion could have waited for SLS to be ready, or used a very expensive Delta IV for the test, but they simply needed to prove the escape motor works, not that the whole system put together works. Instead, they put the whole apparatus on a Peacekeeper missile so they could get it to maximum dynamic pressure and shoot it off. In other words, they needed to show progress on a project that is well behind its competitors. As Orion Program Manager Mark Kirasich said

We wanted to get this test done as early and as quickly as possible. It was all about the launch abort system today.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.