Photo and Illustration Credit: NASA, unless noted otherwise.
Orion, Part 1
08 December 2015
Previous posts have presented some introductory information about NASA’s Voyage to Mars. Now, it is time to begin looking into details about the hardware required for the Journey, starting with the Orion MPCV.
First, an import bit of history - - about year ago, 05 December 2014, Orion passed it’s first test, called the Exploration Flight Test -1 (EFT-1) with flying colors and a blazing reentry into earth’s atmosphere.
Although most of the multitude of parts that make up the Space Launch System (SLS) rocket had been tested individually, the rocket had not been tested as a complete unit at the time of the Orion's EFT-1 test, so the launch vehicle used for the Orion's test was a Delta IV, Heavy, which did a fine job of taking Orion to the 3,683 mile altitude required.
In any event, the test was considered to be a complete success by the engineers who had been working so long and hard to make Orion ready for it’s initial "live" test.
The photo, below, shows the Delta IV rocket with Orion on top waiting for the launch count-down to reach zero.

Below is a photo of "lift-off" 05 December 2014.

When Orion returned to the top of Earth’s atmosphere it was traveling about 20,000 mph and the Heat Shield reached a temperature of about 4,000 degree F before Orion slowed down enough to deploy the parachutes which took it to splashdown at about 20 mph.

Both U.S. Navy and NASA divers rushed from the navy recovery ship USS Anchorage to place a retrieval harness under Orion in preparation for being pulled to the recovery ship.

The photo, below, shows the retrieval harness is in place below the heat shield, ready to be pulled to the recovery ship USS Anchorage.

Some evidence of heat charing is visible on the ablative material covering the heat shield, but there is little heat damage to the black ceramic tiles that make up the Back Shell covering the body of the vehicle.
After it was established that everything was OK, Orion was pulled to the recovery ship and secured in the "Well Deck" for a trip to Dan Diego harbor.


For this test flight there was NO crew in Orion, and the multitude of sensors placed inside the vehicle indicated that a crew would have been just fine throughout the test.
Speaking of crew, this is a good place to show the following illustrations . . .

The illustration above shows the layout inside Orion for a crew of 4, which will be the number of astronauts landing on Mars in the mid 2030s.
Orion can also carry up to six crew members for flights to the ISS and missions into the Proving Grounds beyond the Moon. The six-crew layout is similar that for four, as illustrated below . . .

While we are looking at the interior, the cutaways illustration, below, shows a bit more detail . . .

Notice that there is quite a bit of storage area around the circumference above the Heat Shield.
The photo, below, shows the heat shield being inspected BEFORE it was attached to Orion during assembly.
The titanium framework visible in the photo provides strength and rigidity. The good news is that the data collected during flight and reentry will allow the framework to be "tweaked" so that it will weigh less and cost less. Notice the smooth orange color on the body of the shield - that is the Avcoat ablative material that carries heat away from Orion during reentry into the atmosphere. While the ablative material did meet the objectives for EFT-1, there were concerns that the monolithic coating of ablative material might not suffice for future, more demanding flight and reentry conditions.
In any event, the engineering team decided to change the physical characteristics by using individual Avcoat filled honeycombed tiles instead of the monolithic coating used for EFT-1.
In the year since the test in December 2014 the engineers have been building a new version of the Heat Shield, making changes suggested by the data from EFT-1. The partially completed new shield will look a bit different from the version tested, as shown below.
The heat shield is 16 ½ feet in diameter.
So, what did the Heat Shield that was tested look like after the EFT-1 test? (You might want to know.)
It looks rather sad . . .

. . . be that as it may, remember that this charred Heat Shield from EFT-1 did it’s job, it met or exceeded all the objectives for the test, and the new shield will perform even better.
That’s the way things are done at NASA: Design/Build/Test, then do it all over again in order to come as close to perfect as humanly possible. This is, after all, the equipment that will insure the safety and health of the astronauts traveling to Mars, and back.
The photo below shows a group of NASA employees checking out the Orion after the Ceramic Back Shield was removed.

Notice the pristine condition of all the parts that were protected by the Heat Shield and the Back Shell. The green colored Pressure Vessel where the crew will ride is partially visible beyond all the things that were stowed between the Pressure Vessel and the Back Vessel for the test.
I think that’s enough Orion history to prepare us (YOU and me) for information about how Orion is built. More about that, next time.
- - - End of Orion, Part 1 - - -
No comments:
Post a Comment