Federated Republic of Sean is a user on retro.social. You can follow them or interact with them if you have an account anywhere in the fediverse.

Dan Rasky of NASA Ames (just a few miles from here) talking about the NASA Ames Space Portal.

Startdust capsule reentry: fastest reentry of a manmade object, faster than Apollo.

Stardust mission was "a complete success".

Because it holds the record for fastest reentry, it has "a resting place of honor" at the Smithsonian in Washington, DC.

Also made a significant contribution to aerogels. As part of heat shielding?

Developed Curiosity rover heat shield. Original shield design would have been over its thermal flux limit.

Showing a still of the heat shield falling away.

(On my laptop in the back of the room so can't really get pictures easily)

Showing Osiris-REx, which is currently in flight and will come back (almost a carbon copy of the Stardust heat shield) in 2023.

Sorry, the whole reentry capsule is almost a carbon copy. (Aerogel is for particle capture).

Dragon cargo capsule also has their heat shield.

Showing Dragon crew capsule, which was flown this year.

The heat shield is PICA: "Phenolic Impregnated Carbon Ablator". (It also likes to eat dirt. -ed)

Ablative heat shields take heat away by evaporating or flaking away. A reusable heat shield has to be able to take the heat without ablating, either by insulating the vehicle and radiating the heat away, or through active cooling of some kind, either lossy by injecting a coolant over the surface that evaporates, or closed loop with a circulating coolant. The shuttle tiles insulate and radiate. I don't know of any active-cooled heat shields.

They consider PICA to be "multi-use". You change them out periodically like tires or brake pads. Can be reused 10-20 times(!)

I can't believe the advances that have been made in heat shielding since I joined ERPS in 1999.

Q: Status of commercialization of PICA, and how expensive is it?

A: Largest PICA sample when Stardust mission came was the size of a coffee cup. Needed about a meter. Used the SBIR program to scale it up to a meter. Need someone to be the supplier; "Elon is not big on being a supplier."

Q: Something about ceramics.

A: You can't have lose your whole vehicle over a minor failure. Ceramics are thermally robust but structurally fragile. Metals are structurally robust but thermally fragile. Have been some specialized areas where we've flown metallic TPS (thermal protection system), but it's been a "hard nut to crack."

Question about who's making them now (for SpaceX?), but I couldn't hear the name of the company. They also made the carbon tile substrate for the Shuttle.

Question about the IP. Answer is that "the recipe is out there on the web!"

Henry Vanderbilt (one of the confernece organizers): Who owns the patent?

A: Patent is expired now. It's public domain!

Federated Republic of Sean @freakazoid

Comment from me: that's a big reason to prefer patents over copyrights or trade secrets. Patents eventually expire. Copyright keeps getting extended. Trade secrets are forever.

· Web · 2 · 0