Testing Warmth Shields for Completely different Atmospheres

Testing is without doubt one of the unsung steps within the engineering course of. Speak to any product improvement engineer, and they’re going to inform you how massive of a milestone passing “V&V” – or verification and validation – testing is. Testing is much more essential whenever you work on tools meant for the cruel area setting. Additionally it is more difficult to imitate these harsh environments on Earth. Fortunately for a few of NASA’s extra essential upcoming missions, one other authorities company has a singular take a look at lab to assist V&V with a few of its most important parts – their warmth shields.

That different authorities company is the US Division of Vitality (DoE), particularly its Sandia Nationwide Laboratory. The US’s nationwide labs have been initially developed to coordinate nuclear weapons analysis, however they’ve since taken on a broader position within the nation’s basic scientific analysis efforts. That features offering take a look at tools unavailable anyplace else on the planet.

One distinctive take a look at setup at Sandia is called the photo voltaic testing facility. It’s a subject with over 200 “heliostats” – big mirrors that may focus the sunshine from the Solar that they replicate on a selected level. With all of them targeted on the identical level, it might get as scorching as 3,500 occasions the standard daylight on an space.

That space can be one of many promoting factors of the photo voltaic testing facility. It could possibly take a look at items of fabric as much as 1 m (3 ft) in diameter. This makes it superior to different take a look at amenities that intend to check the identical sorts of supplies, resembling those who use arc jets or lasers. Value can be a consideration, with arc jet or laser testing costing greater than $100,000 every day. Comparatively, photo voltaic testing prices solely $25,000 per day, primarily as a result of decrease vitality prices of working the heliostats. 

NASA has used all of that testing expertise over the past yr to check the warmth shields of a few of its most necessary missions – the Mars Pattern Return (MSR) mission and Dragonfly, the helicopter mission to Titan. Every mission has its challenges, however the supplies for his or her warmth shields are the identical. Referred to as a Phenolic impregnated Carbon Ablator, this materials has already been efficiently used for missions resembling Stardust, OSIRIS-REx, and Mar Science Laboratory.

MSR and Dragonfly every have distinctive challenges that different missions didn’t face. MSR might be carrying a major payload of samples again to Earth, which means it is going to be heavier than the OSIRIS-REx asteroid pattern return mission. Will probably be so heavy that some NASA engineers deliberately bent the take a look at materials at Sandia’s take a look at lab to mannequin what occurs to materials present process the pressure of reentry.

For its half, Dragonfly has to cope with a world with a a lot thicker environment than Earth itself. Titan’s environment is 4 occasions denser than Earth’s. Given the interplanetary speeds at which the mission might be touring when it reaches orbital insertion, Dragonfly’s accompanying lander might be subjected to each excessive warmth and stress because it descends onto the Moon’s floor.

Sandia’s lab technicians made quite a lot of enhancements to the take a look at setup for the checks, together with operating gasoline traces to the pattern from the bottom of the tower to raised mimic the environment the warmth shields might be encountering. They have been additionally available to assist with troubleshooting, which included a number of situations the place some fiber surrounding the pattern caught hearth earlier than the take a look at may very well be accomplished.

V&V testing not often completes with out some changes and infrequently with none fires. Testing on such a setup is simply a part of NASA’s take a look at plan for the warmth defend use case, with different checks occurring elsewhere. Given the significance of this specific materials to the general success of those essential missions, the extra testing they’re able to bear right here on Earth, the higher.

Study Extra:
Sandia Nationwide Laboratory – Sandia checks warmth shields for area
UT – NASA is Persevering with to Construct the Titan Dragonfly Helicopter. Listed below are its Rotors
UT – NASA and ULA Efficiently Take a look at a Big Inflatable Warmth Defend That May Land Heavier Payloads on Mars
UT – An Modern Warmth Defend That Doesn’t Must Be Changed Between Missions

Lead Picture:
Smoke billowing off NASA’s warmth defend materials throughout a latest take a look at at Sandia Nationwide Laboratories’ Nationwide Photo voltaic Thermal Take a look at Facility.
Credit score – Photograph by Craig Fritz