Water or Land: The Orion Landing Choice
Written by Nancy Atkinson
Work is progressing on designing the new Orion Crew Exploration Vehicle (CEV), the next generation of NASA spacecraft that will take humans to the International Space Station, back to the Moon, and hopefully on to Mars. But one major question about the spacecraft has yet to be answered. On returning to Earth, will the CEV splash down in water, or land on terra firma?
NASA officials discussed various aspects of development that is currently underway for the Constellation program at a media briefing on December 10. The mobile launch platform for the Ares rocket is being built, landing parachutes have been tested and the first capsule structure of the new CEV will be constructed starting in early 2008. Design requirements for the booster rockets have been completed and just ahead are final design definitions for operational capabilities such as ground procedures at Kennedy Space Center, mission control in Houston and other areas such as spacesuit design.
Additionally research on the International Space Station has begun to help prepare for long duration spaceflights such as a measurements of microbe growth, a study of the formation of kidney stones, and a nutritional study to help understand what is ‘normal’ for the human body in space.
But questions from the media focused mainly on the yet unmade decision of whether the CEV will land in the water or on land.
NASA originally explored multiple options for landing in both water and land. After initial studies, the first assessment by NASA and the contractor for the CEV, Lockheed Martin, was that landing on land was preferred in terms of total life cycle costs for the vehicles. But now a splashdown in water seems to be favored.
“There are a couple of aspects that pop out at us," said Jeff Hanley, Manager for the Constellation Program. “One is the safety and the risks involved in landing. Looking at the landing itself, the event of actually touching down, water comes out to be preferable as less risk. Another aspect is the performance of the Orion vehicle as it is sent to the moon. In looking at what it takes to get a pound of spacecraft to low lunar orbit in terms of the cost, every pound that you send toward the moon is precious. From an efficiency and performance point of view, carrying 1500 lbs of landing bags to the moon and back when we have a perfectly viable mode of landing in the water near a US coastal site didn’t seem like a good trade in performance. We’ve tended toward updating our point of departure concept to now be a nominal US coastal water landing."
The Constellation program has always considered that for the first few missions, the spacecraft would land in water until the guidance system had been tested thoroughly and proven in actual landings.
But NASA is continuing to look at landing on land as a possibility for future flights. “We want to be able to land on land in a contingency and have the crew be able to get out and walk away….There’s limitation of what you can do on land but by the time we get done really looking at what the minimal capability of landing on land and having the crew walk away, we’ll see what the design looks like, and if the design is robust enough we could return to having nominal land landings."
One challenge for the Constellation program has been getting the CEV light enough for the Ares rockets to be able to launch it, and therefore eliminating the 1500 lb airbags for landing has its appeal.
“The predominant design philosophy for Orion and Ares 1 has been that we are designing for lunar missions," continued Hanley. “We will service the International Space Station within that set of capabilities. From that perspective, designing a lot of mass into the spacecraft just to enable land landings has not traded out to be an effective use of our performance. That’s the major consideration in play. Right behind that are life cycle costs."
Making the decision of land vs. water is the goal for 2008 for the Constellation program. “We’ve studied and have cost estimates for water landings against the infrastructure costs of having multiple landing sites on land and they are comparable," said Hanley. Right now, NASA is looking at a single target landing zone off the coast of California with one or two recovery vessels.
But they are keeping their options open for a land landing. “If the Orion team is able to come in at the preliminary design review later this next year with a concept for be able to land on land that is fairly robust but not cost a lot of mass to have to hurl to the moon and back, then it becomes an operational decision," said Hanley.
There’s been much debate about what type of landing would be best. “There’s been a lot of assumptions made that landing on land is going to be better, but there are lot of people in the technical community that do not buy into that," said Hanley. “There’s been a lot of debate surrounding whether or not land landing truly is better from a life cycle cost perspective and there isn’t a lot of quantitative data to really pull from."
Hanley feels there are assumptions being made but not a lot of substantive date to clarify what the right answer is. So the next steps are to get the spacecraft to a detailed preliminary design and really interrogate the water vs. land issue. That includes further developing the operational concepts , such as how long does the capsule stay in the water, and what loads does the spacecraft see from landing on water and land. Those are all questions that need to be answered in order to make a final decision on the type of landing that will be used. Stay tuned, as 2008 should be a year of decision for many details about Constellation and the CEV.
Original News Source: NASA News Audio
Filed under: Constellation, NASA
December 11th, 2007 at 1:22 am
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December 11th, 2007 at 1:59 am
If the (CEV) is going to launch to the Space Station,to the moon.and hopefully to Mars,how will it come back home? WIll it take the same steps backwards?
December 11th, 2007 at 6:23 am
There is a third option - have an aircraft catch it once it reaches terminal velocity. If the landing apparatus never leaves the atmosphere, then we could have second and third backups to hand. This might make it safer in the long run.
December 11th, 2007 at 6:40 am
"We’ve tended toward updating our point of departure concept to now be a nominal US coastal water landing.�
This is one of the finest examples nonsense bureau speak I have ever seen. What is wrong with saying "We're planning on offshore water landings.", instead of the gobbledygook above?
December 11th, 2007 at 10:23 am
now they fly home to an airport and walk down a ladder -is this really progress?
December 11th, 2007 at 11:01 am
"now they fly home to an airport and walk down a ladder -is this really progress?"
The original idea of the shuttle was that it would have throttlable rocket engines and could go around once, if it had to, in the landing pattern. Way, way back, in the early '70's, they blew up two of the engines in a row at the test site in Huntsville. The explosions were so violent that they had trouble reconstructing enough of the engines to figure out what went wrong. The go around once concept went down the tubes. As a result, the space shuttle lands dead stick, one pass only, and it flys like a rock. They're lucky they haven't killed everybody in a landing. And that brings up the other issue. The shuttle has killed 14 astronauts so far. Apollo never killed any. Which way would you go?
December 11th, 2007 at 1:22 pm
I think water landings could be accomplished
also through deploying out-folding wings
as the craft descends, and with the addition of
a siphon engine and a hydrodynamic hull,
the craft could return itself to a port suitably
equipped.
December 11th, 2007 at 2:15 pm
The comment …The shuttle has killed 14 astronauts so far. Apollo never killed any. Which way would you go?… is incorrect.
From Wikipedia:
"Apollo 1 is the official name given to the never-flown Apollo/Saturn 204 (AS-204) mission. Its command module (CM-012) was destroyed by fire during a test and training exercise on January 27, 1967 at Pad 34 (Launch Complex 34, Cape Canaveral, then known as Cape Kennedy) atop a Saturn IB rocket. The crew onboard were astronauts selected for the first manned Apollo program mission and all three died in the accident: Command Pilot Virgil I. "Gus" Grissom, Senior Pilot Ed White and Pilot Roger B. Chaffee. Although the ignition source of the fire was never determined their deaths were attributed to a wide range of lethal design hazards in the early Apollo command module such as its highly pressurized 100% oxygen atmosphere during the test, many wiring and plumbing flaws, flammable materials in the cockpit, a hatch which might not open at all in an emergency and even the flightsuits worn by the astronauts." Oh, and don't forget Apollo 13…
December 11th, 2007 at 6:27 pm
Go with water landings. There– I've just completed the 2008 goal of the Constellation Program before 2008 ever got here.
From the article:
"Making the decision of land vs. water is the goal for 2008 for the Constellation program."
BTW- Apollo 13 never killed anyone….
December 12th, 2007 at 8:03 am
True, but it could have…
December 12th, 2007 at 10:55 am
"Mark X Says: " see above. True, I was thinking the fire was in the Gemini program. Apollo never killed anybody in flight, although 13 was too close. At any rate, the point is that putting winged atmospheric vehicles into space is a waste of time and money. It's incredibly expensive and very dangerous. The physics is inexorable; an object has to go 18,000 plus miles per hour to orbit, and that requires huge amounts of energy per pound. You've got to spend it going up, and get rid of it again going down. Best to carry as little extraneous weight to orbit as possible, thus big dumb boosters and capsules. At least until alternate ways to orbit are available, and even then the energy requirements are the same.
December 12th, 2007 at 5:06 pm
No American program(s) never killed any astronauts as a function of the landing system in place - so all those comments seem irrelevant to the current topic.
Intercepting a returning space-craft at terminal velocity? Or even while falling under chutes, would be a tremendously hazardous under-taking - perhaps even impossible when you think through the details of having a recovery aircraft in the right place, at the right time, without becoming a collision hazard, able to complete an interception within the few moments of re-entry/free-fall time available… nope.
Ideally the new craft would be built in space and never return to earth and be completely re-usable - a true "space(only) craft." And the astronauts/payload would travel to earth via either a re-usable space-plane/shuttle, or a space elevator.
I guess we're a long ways from these solutions, so I'm guessing quick and dirty(wet) will win out again as in the original Apollo.
December 13th, 2007 at 9:29 am
[...] Water or Land: The Orion Landing Choice [Universe Today] [...]
December 14th, 2007 at 11:24 am
Why not just have the vehicle return to the ISS, dock, and have the crew land in whatever method we want from there? You could use Soyuz, shuttle/shuttle replacement, or (even better if it works) have a module at the ISS waiting for the Orion vehicle whereby the Orion docks to it and it contains the landing apparatus. You could take out everything involved in the landing such as heat shields and parachutes and move them to the landing module, which could also make it possible to reuse the Orion vehicle.
December 14th, 2007 at 12:00 pm
So Soyuz lands on land w/o heavy airbags. How do they do it?
IIRC they use braking rockets in the parachute harness, but my refs are at home.
December 14th, 2007 at 12:04 pm
Nice idea to make a travel to ISS and then go on. But wouldn't it be a waste of a lot of energy to make this "pitstop"?
I though out-of-orbit starts were a total different story than shutte-station-flights. Maybe I am wrong?
December 14th, 2007 at 12:28 pm
No American program(s) never killed any astronauts as a function of the landing system in place
I'm not sure I see how Columbia wasn't a product of the landing system. Sure, the immediate cause was the foam collision at launch. But its vulnerability to that was a function of, in part, a landing system that required a relatively thin, low weight thermal protection system exposed during the whole launch process — unlike the relatively robust, protected Apollo heat shields.
December 14th, 2007 at 12:49 pm
"Why not just have the vehicle return to the ISS, dock, and have the crew land in whatever method we want from there? . . . You could take out everything involved in the landing such as heat shields and parachutes and move them to the landing module"
The fuel required to brake the Orion spacecraft into low earth orbit would far outweigh the heatshield, parachutes, and other landing paraphernalia. Landing directly, rather than coming to a stop in orbit means you only have to do three big burns to get to the moon and back (trans-lunar injection, lunar orbit insertion, and trans-earth injection), rather than four (TLI, LOI, TEI, and earth orbit insertion). Dumping all that excess velocity through atmospheric friction is a lot more efficient than carrying enough fuel to slow down.
December 14th, 2007 at 5:20 pm
Don't use fuel for braking, use aerobraking. You do still need some fuel to match ISS orbit, but both deceleration and orbital plane change to match the ISS can be done with aerodynamics. The nice thing about docking with the ISS first is that you can wait around nearby for weather to change, which you can't do with a direct-from-the-moon return. When we drown the first crew due to a storm that blew up in the three days it took to return from the moon, we'll finally realize we made a mistake.
December 14th, 2007 at 10:26 pm
The problem with aerobraking is that it takes a large number of passes skimming the atmosphere to dissipate energy without overheating the spacecraft. With the orbit extending to the moon, it could take years to bleed off enough energy to reach LEO. To avoid the additional mass of food, water, and oxygen for the astronauts for additional orbits aerobraking would have to bleed off enough energy to reach LEO in one pass. Then you'd have to burn to circularize the orbit and rendezvous with ISS. At this point you've already got a heatshield, additional propellant, and greater risk to the mission than just going in.
It seems that most objections to the capsule/water landing are variants of "We've done that before" or "The shuttle was so much cooler". The fact is that the Apollo design is still the simplest, most robust, mass efficient, and /cost effective/ design available, even with current technology.
December 15th, 2007 at 4:05 am
On there way back from the Moon, Mars or any other planets that they have walked on, they should stop at The International Space Station. Have them Quarantine to make sure it is safe for them to come back to Earth. To make sure that they are still the same crew that had left here to go to another planet and back. Then have the new shuttle bring them back home safely. If the new shuttle could be made to land on water too that would be great as well. Maybe the Moon mission may not have to be quarantine, and then maybe they should still be quarantine, mostly if they landed in new territory or new area of the Moon. Maybe even at the old area, you never know what could have developed there since they left the first time.
We have seen the facts that Apollo design would still work. But we must continue to improve our current Technology even further like we have in the pass, for the safety of our crew and now for the safety of our planet and all who lives here.
We could not pay enough for any lives lost (if it were our crews) now we also have our planet and all that lives here.
December 17th, 2007 at 12:50 pm
I think that the advantages of less weight and a large set of landing locations makes the water landing better. Once the touchdowns can be shown to be accurate, we could make the whole thing more secure - and less corrosive - by landing in a fresh water shallow landing pond or maybe a specific lake somewhere within US soil.
February 13th, 2008 at 5:17 am
Insert from December 15th, 2007 at 4:05 am.
If we could capture them or refuel them so that they have fuel to maneuver
their space craft. This will allow them time and control to maneuver their space craft for example to slow down, to be able to dock on to the space station or maybe even land on the moon instead to get quarantine (checked out, inspected, medical) or possibly even land on Earth, but might be better at the space station or on the moon first then Home for our species.
The advantage of this would be that they would not have to bring with them the extra fuel or parachute, and in exchange to it would be the capturing or refueling device.
Now thinking about the advantage just now, if they could carry and or save enough fuel to be able to slow down the craft and be captured or refuel. Maybe even they could capture a plan craft in their path that will match their speed so that they will be able to control before and after they captured it.
February 13th, 2008 at 5:33 am
Land and Water anywhere with our best Technology then as our Technology get better and we learn more from our pass then we do what we did in the pass use our best Technology and work from their again. Just like the computer it started out big and did a lot of work, but now they are smaller and doing more work with less power.
July 29th, 2008 at 7:26 pm
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