Testing Warmth Shields for Totally different Atmospheres

Testing is among the unsung steps within the engineering course of. Speak to any product improvement engineer, and they’ll inform you how huge 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 house atmosphere. It is usually tougher 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 check lab to assist V&V with a few of its most crucial elements – their warmth shields.

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

One distinctive check setup at Sandia is called the photo voltaic testing facility. It’s a area with over 200 “heliostats” – large mirrors that may focus the sunshine from the Solar that they replicate on a specific level. With all of them centered on the identical level, it may well 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 will possibly check items of fabric as much as 1 m (3 ft) in diameter. This makes it superior to different check services that intend to check the identical sorts of supplies, similar to those who use arc jets or lasers. Price can be a consideration, with arc jet or laser testing costing greater than $100,000 each 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 know-how over the past 12 months to check the warmth shields of a few of its most essential 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. Generally known as a Phenolic impregnated Carbon Ablator, this materials has already been efficiently used for missions similar to Stardust, OSIRIS-REx, and Mar Science Laboratory.

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

For its half, Dragonfly has to take care of a world with a a lot thicker ambiance than Earth itself. Titan’s ambiance is 4 occasions denser than Earth’s. Given the interplanetary speeds at which the mission will likely be touring when it reaches orbital insertion, Dragonfly’s accompanying lander will likely 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 check setup for the exams, together with operating gasoline traces to the pattern from the bottom of the tower to raised mimic the ambiance the warmth shields will likely be encountering. They had been additionally readily available to assist with troubleshooting, which included a number of situations the place some fiber surrounding the pattern caught hearth earlier than the check might be accomplished.

V&V testing hardly ever completes with out some changes and infrequently with none fires. Testing on such a setup is simply a part of NASA’s check plan for the warmth protect use case, with different exams occurring elsewhere. Given the significance of this explicit materials to the general success of those essential missions, the extra testing they’re able to endure right here on Earth, the higher.

Study Extra:
Sandia Nationwide Laboratory – Sandia tests heat shields for space
UT – NASA is Persevering with to Construct the Titan Dragonfly Helicopter. Listed here are its Rotors
UT – NASA and ULA Efficiently Check a Big Inflatable Warmth Protect That Might Land Heavier Payloads on Mars
UT – An Revolutionary Warmth Protect That Doesn’t Must Be Changed Between Missions

Lead Picture:
Smoke billowing off NASA’s warmth protect materials throughout a current check at Sandia Nationwide Laboratories’ Nationwide Photo voltaic Thermal Check Facility.
Credit score – Picture by Craig Fritz