Orion spacecraft in orbit
June 4, 2014

Orion Exploration Flight Test 1 To Take Place In December, Inspired By Apollo 10 And Space Shuttle Program

Alan McStravick for redOrbit.com - Your Universe Online

If you thought the scientists and engineers at NASA were just sitting around Houston and central Florida after the retirement of the manned shuttle program playing pinochle and waiting for their government pensions to kick in, you would be sorely mistaken. In fact, with the recently passed 45th anniversary of the Apollo 10, the agency took the opportunity to announce the upcoming 'Apollo 10' for the new millennium.

The excitement of the space program of the 1960's piqued the interest and sparked the imaginations of an entire generation, regardless of any one person’s physical location on this spinning rock that careens through the heavens. But it is safe to say that Apollo 10, unlike its successor Apollo 11, doesn't engender the same instant recall of the time and place where one was when it was in flight as the latter. To be certain, however, Apollo 11 would never have been able to claim its place in history when it touched down on the face of the moon had it not been for the Apollo 10 mission.

Responsible for the final testing of the procedures and components required for the eventual moon landing, Apollo 10 was the fourth piloted mission in the lunar landing phase of the program. The crew of John Young, Thomas Stafford and Eugene Cernan left from the Earth on May 18, 1969 and tracked through space for three days before entering lunar orbit.

Short of actually landing on the moon, the crew performed each and every operation that would be required of the Apollo 11 crew, whose planned mission was scheduled for two months after the return of the Apollo 10 astronauts. But they had one more important part of their mission to complete: successful re-entry through the unforgiving atmosphere at a dizzying velocity. Their return from the moon earned Apollo 10 the record for the highest velocity attained by a piloted vehicle. Even slowing from 24,791 miles per hour was going to make for a stressful re-entry. Cernan remarked that the view out his window looked like “a ball of white and violet flame.”

While Cernan came maddeningly close from entering the history books as the first man to set foot on the moon on that day in May, he does hold the bookending distinction of having been the last man who left a boot print on the soft lunar surface.

The modern NASA is gearing up for the next big space adventure. The Apollo 10 of the new Orion Spacecraft, known as Exploration Flight Test 1 (EFT-1) was conceived and designed for the purpose of carrying humans farther from the grasp of Earth than we have ever traveled before. EFT-1's mission is meant to test the capabilities of the craft, with regard to affecting an emergency abort of the mission, sustenance of life during deep-space travel and withstanding the harsh conditions of re-entry. Apollo 10's record-breaking velocities will look like kids play compared to the speeds the Orion craft will be traveling through deep-space.

"Measuring the performance of the heat shield and other thermal protection material is one of the main focuses of EFT-1," said Stu McClung, deputy director of Orion Production Operations, in a NASA statement. Based at Johnson, he is assigned to Kennedy to assist with preparations for the upcoming flight.

Launching unpiloted, Orion EFT-1 will soar above central Florida atop a Delta IV Heavy this upcoming December. Mission objectives in this first test will be to evaluate launch and high speed re-entry systems such as avionics, attitude control, parachutes and the heat shield.

"The Delta IV Heavy will give us enough thrust to send Orion out 3,600 miles on the second orbit," McClung said. "That will allow the spacecraft to hit the atmosphere performing a high-energy re-entry at about 20,000 miles per hour. This will give us about 80 percent of the heating we'd have coming back from a deep-space mission. We believe this will be a very representative entry profile."

Orion has drawn on NASA's history from both the Apollo and Shuttle Space Transportation System missions to develop heat shields and other thermal protection materials necessary for a safe re-entry.

"We've picked some of the best from both," McClung said. "The heat shield on the bottom and the edge shoulders of Orion is ablative material. The back shell sides will be covered with ceramic tiles similar those used on the underside of the shuttle."

An ablative heat shield relies on a layer of plastic resin that, when exposed to extreme heat, becomes a gas that serves to deflect heat from the vehicle via convection. Each ablative layer simply burns off in succession, dissipating the heat energy caused by the friction of the vehicle entering the Earth's atmosphere.

The ceramic tiles, a reusable style of heat shield, use an insulating material that both absorbs and radiates heat away from the spacecraft. These will cover most of the vehicle and will be covered with a reinforced carbon-carbon material at the vehicles most vulnerable sections, like the nose and leading edges of the wings.

Orion will be unmanned for its first mission because NASA's projections of temperatures reaching as high as 4,000 degrees Fahrenheit on the bottom and approximately 800 degrees Fahrenheit on the sides of the capsule are, as yet, unproven. EFT-1's re-entry will confirm whether those estimates are correct.

"We have a good idea how Orion should perform on entry based on Apollo historical data and our computer models," he said. "We will have 50 to 60 sensors and 210 instrumentation channels on the heat shield out of a total of 1,200 on the spacecraft to gather data to tell us how the thermal protection performs."

The Delta IV, responsible for December's launch of EFT-1, will be replaced in the future by NASA's new heavy-lift rocket, the Space Launch System (SLS). This new heavy-lift rocket will be the most powerful rocket ever built and will be capable of sending future Orion capsules to deep-space destinations such as an approaching asteroid and, eventually, Mars. The first SLS launch with an Orion capsule is currently scheduled for 2017.

"EFT-1 will be an excellent first test case," McClung said. "It will help us see how well Orion will perform on an actual flight."

This is all welcome news for space enthusiasts who are, to be certain, very happy to learn that the hiatus for US manned space flight since the end of the shuttle program will soon be over.