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August 12, 2013

Orion Space Explorer Closes in on Launch Date

It's just 15 months until the Exploration Flight Test-1 (EFT-1) launches. The Orion launch teams are preparing a major test of the next exploratory spaceship constructed by NASA. Milestones in the test include: testing the parachute, storage at Kennedy Space Station, heat shield functionality, and recovery at sea.

The Orion is about two years old. Construction started at the Michoud Assembly Facility in New Orleans in 2011. It was transferred to the Kennedy Space Center's Operations & Checkout Building in 2012, where it will be outfitted for its upcoming launch.

Load and pressure testing

One milestone, recently attained, was to ensure that static load and pressure testing was successful. This testing ensured that the Orion will be able to handle the stresses typically experienced during launch.

Somewhat fortunately, the test also uncovered some cracks in the capsule that needed to be repaired. Since that time, engineers have improved the structure of the bulkhead by adding doublers. Further tests were successfully completed, during which the module was pressurized to more than twice the level it is expected to withstand in outer space.

The load testing used hydraulic devices to push and pull on the capsule in an effort to simulate the type of stress that will be experienced during launch. The spaceship held up fine, having experienced loads between 14,000 pounds and 240,000 pounds, as measured by 1,600 strain gauges. Eight of these types of tests were successfully completed.

"The static loads campaign is our best method of testing to verify what works on paper will work in space," said Charlie Lundquist, who is the spaceship's crew and service module manager at the Johnson Space Center.

Re-entry testing

As of this writing, testing continues for certain events during re-entry and ascent. One of the more recent tests relates to the jettison of the spacecraft's three fairings. Each of these fairings is 13 feet wide and 14 feet high. They will be released once the vehicle reaches 560,000 feet during ascent.

NASA has stated that the first test, which was directed by Lockheed Martin (News - Alert), was a success. All the bolts and pyrotechnic mechanisms separated as planned. However, testing failed during the third round. One of the fairing panels did not properly detach, probably because of some contact interference.

"This was a challenging system to design and test," said Mark Geyer, program manager. "Completing this test helps us evaluate our design and assure mission safety and success."

The next test is scheduled for later this summer. That will increase thermal loads by heating one of the panels to about 200 degrees Fahrenheit. The final test is scheduled for early next year.

Another major milestone, dubbed Heat Shield A, will provide important information about how well heat shield integrity is retained during re-entry. The heat shield is a Thermal Protection System (TPS) that is currently under development by Textron Defense Systems.

Textron has already assembled some of the gunning cycles used on the so-called "shoulder sections" of the shield. These cycles complete about 25 percent of the 320,000 required cells on a honeycomb overlay. The shield uses a honeycomb pattern to ensure structural integrity for the Avcoat material, which bonds the shield's substructure.

Parachute testing

Finally, work continues on the Orion Capsule Parachute Assembly System. The latest tested feature, known as the Parachute Test Vehicle-4 air-drop, was a success. This test involved rigging one of the test craft's parachutes to actually miss a stage of its inflation, which produced increased stress on the capsule once it opened.

Edited by Alisen Downey
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