NASA Orion Splashdown Safety Tests Completed

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NASA Orion Splashdown Safety Tests Completed

Posted by Soulskill on Friday September 28, 2012 @05:22AM from the now-to-work-on-the-going-up-part dept.

DevotedSkeptic sends this news from NASA: "The 18,000-pound test article that mimics the size and weight of NASA's Orion spacecraft crew module recently completed a final series of water impact tests in the Hydro Impact Basin at the agency's Langley Research Center in Hampton, Va. The campaign of swing and vertical drops simulated various water landing scenarios to account for different velocities, parachute deployments, entry angles, wave heights and wind conditions the spacecraft may encounter when landing in the Pacific Ocean. The next round of water impact testing is scheduled to begin in late 2013 using a full-sized model that was built to validate the flight vehicle's production processes and tools."

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Why water? by courcoul · 2012-09-28 05:29 · Score: 3, Informative

Why is it that USA space tech prefers water splashdowns instead of dry land like the Russians and Chinese?
"Softer landings" doesn't quite cut it as a reason, for at the speed of the impact, water is just as hard as terra firma. Then there's the risk of crew drowning and/or craft loss thru sinking. That doesn't occur in dry land.
1. Re:Why water? by YrWrstNtmr · 2012-09-28 05:39 · Score: 2
  
  Why is it that USA space tech prefers water splashdowns instead of dry land like the Russians and Chinese?
  
  Maybe because we also have a large enough Navy to support it.
2. Re:Why water? by rillopy · 2012-09-28 05:46 · Score: 3, Insightful
  
  In the 60's it used to have to do with geography/pop density - having a large enough unpopulated and flat area such that missing the landing zone by a large margin wouldn't land them in mountains or on a town. Russia has that, the USA did/does not.
3. Re:Why water? by mk1004 · 2012-09-28 05:57 · Score: 5, Informative
  
  Just as I remembered, NASA lands capsules in the water because that doesn't require braking rockets to slow down just before landing. http://en.wikipedia.org/wiki/Splashdown_(spacecraft_landing) Water landing allows cancellation of final velocity in a few feet rather than a few inches. At a few MPH, water isn't as hard as terra firma. And there usually aren't many icebergs around, nor other issues, regardless of Gus Grissom's experience.
  
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4. Re:Why water? by thatskinnyguy · 2012-09-28 06:10 · Score: 2
  
  We do have this place called Nevada.
  
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5. Re:Why water? by WegianWarrior · 2012-09-28 06:12 · Score: 5, Informative
  
  Why is it that USA space tech prefers water splashdowns instead of dry land like the Russians and Chinese?
  "Softer landings" doesn't quite cut it as a reason, for at the speed of the impact, water is just as hard as terra firma. Then there's the risk of crew drowning and/or craft loss thru sinking. That doesn't occur in dry land.
  Because landing in water means you can get away with a higher landing speed without putting too many Gs on the astronauts - ref the Wikipedia article on splashdown. The Russians (né Soviet) capsules lands on land because the Russians have so much open space available, but that means they have to carry either a larger parachute and/or one or more braking rockets to lower the impact speed to something tolerable. AFAIK the first Russian capsules that the cosmonauts rode all the way down - the jury-rigged Vostok they called Voskhod - carried their braking rockets attached to it's parachute lines...
  A capsule landing on land also needs to be sturdier to take the increased shock loads, both from the impact and from the application of the braking rockets. This means you either needs a bigger rocket to get it up there, or less internal space for the astronauts / cosmonauts to move about in. A landing on land may not sink, but it does run the risk of taking a roll once it's down - ref Soyuz 18a.
  Another reason given for the American preference for landing in water compared to the Russian preference for landing on land is the location of the launch sites. An American early abort will dump the capsule in the Atlantic ocean, whereas a Russian early abort will see the capsule come down on the steppe. That said, the current Russian capsules are rated for landing in water, just in cause - refer to Soyus 23 landing on a frozen lake and punching through the ice.
  The Chinese seems to favour a land landing as well, which makes sense considering their landmass, lack of a large blue water fleet and the simple fact that their Shenzhou spacecraft seems to be based on / borrows heavily from the Russian Soyuz capsule.
  In short; landing on water lets you get away with a lighter spacecraft, and does away with the need for a very large parachute and/or braking rockets. This means you can get away with a smaller rocket, or carry more supplies for a given size rocket.
  
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6. Re:Why water? by Medievalist · 2012-09-28 08:25 · Score: 3, Informative
  
  Why is it that USA space tech prefers water splashdowns instead of dry land like the Russians and Chinese?
  IAAFRS. It's cheaper, safer, and fails more elegantly (more likely to give you a recoverable crew module that can be analyzed). Korolev might have preferred wet landings but the USSR's leadership did not trust the US Navy.
  
  "Softer landings" doesn't quite cut it as a reason, for at the speed of the impact, water is just as hard as terra firma.
  Nope, the capsules land very slowly, on the end of parachutes after significant braking.
  Early Soviet designs eject the pilot & flight recorder on a sled which then parachutes down. The actual capsule pancakes at fairly high speed and is completely destroyed, unlike water-landed capsules.
  
  Then there's the risk of crew drowning and/or craft loss thru sinking. That doesn't occur in dry land.
  Those are very real risks, but keep in mind that the capsule is a viable space environment, so pretty similar to a submarine.
Wait'll you see the Star Destroyer! by Impy+the+Impiuos+Imp · 2012-09-28 06:00 · Score: 2, Insightful

I'm still irritated they're misusing the name Orion, which is already associated with a particular type of spacecraft.

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Because gee, why not? by fm6 · 2012-09-28 06:02 · Score: 2

The Russians have Kazakhstan (6 people km^2), The Chinese have Inner Mongolia (1 person per km^2). I'm not sure how large a landing zone is needed, but I suspect nothing big enough exists in the U.S.
The lame thing is that we're back to uncontrolled re-entry and disposable spacecraft. I personally consider the Orion a huge step backwards. My dislike is tempered somewhat by the knowledge that the same short-sightedness that gave us such a useless vehicle also guarantees that no serious mission for it will ever be funded.
1. Re:Because gee, why not? by thrich81 · 2012-09-28 06:15 · Score: 5, Informative
  
  The Apollo Command Module was not "uncontrolled" on reentry. Its center of gravity was intentionally offset from the spacecraft's centerline. This gave it a semi-gliding (admittedly steep but not non-existent) capability. Thus they could control the direction of the reentry aerodynamically by using thrusters to rotate the spacecraft and so control the direction of "glide". There was a lot more capability to that Apollo-Saturn stack than is visible or well known!
2. Re:Because gee, why not? by nospam007 · 2012-09-28 08:49 · Score: 2
  
  "The Russians have Kazakhstan (6 people km^2)"
  The Kazakhs will be glad to hear, that 21 years after their independence from Russia Americans still haven't got the news.
3. Re:Because gee, why not? by fm6 · 2012-09-28 09:35 · Score: 2
  
  Yeah, I had heard about the breakup of the Soviet Union. (It was in the news) I guess you hadn't heard that Russian launch and recovery operations are still operating there.
Didn't they? by camperdave · 2012-09-28 06:16 · Score: 2

Didn't they already do splashdown tests a couple of years ago? I can remember NASA conducting airbag tests for landing on land.

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Sea better as doesn't need terminal speed arrest by PerMolestiasEruditio · 2012-09-28 06:56 · Score: 2

Really the only downside to splashdown is potential corrosion of parts of the capsule, but given amount of refurb work that will go on anyway this is probably a pretty minor consideration.
Capsule trajectory prediction is good enough that you don't need to land on water when you have a Nevada dry lake bed available. The recent SpaceX Dragon Capsule flight had a touchdown within (I believe) about 1 mile of target.
Transporting a big heavy capsule overland to the launch site again is a bit tricky, anything more than 3-4m diameter starts to be a problem on roads (Orion is 5m diameter). But you could also use heavy lift helicopters - at 8 tonnes it could be carried by a Chinook to an airport without too much trouble.
For a parachute landing you can hit water pretty fast without damaging the capsule - whereas for a hitting dirt you need landing gear to prevent point loading and a clever terminal speed arresting system to kill your parachute sink rate of a few m/s just as you touch the ground.
The sea is far more accessible for Cape Canaveral. Ultimately a relatively small boat and crane with a small crew could recover the capsule and return it to Canaveral for reprocessing. (Though that would not be the SpaceX rather than the Nasa way of doing things).