A fully and immediately reusable orbital heat shield, which (as you know) has never been made before, is the single toughest problem remaining.

Being able to iterate with many ideas on many ships is key to solving this.
Source: RT @elonmusk

I think we should try to catch the booster with the mechazilla arms next flight!
Source: RT @elonmusk

There was 3 CLEAR flashes from S29, Not only did we get successful landing, ALL 3 RAPTOR 2s RELIT!!!
Take that SN15
Source: RT @ScottLikesSLS

The little flap that could!
Source: RT @cstanley

‍Congrats to SpaceX on their fourth test flight for #Starship! Lessons learned from today’s test will pave the way for the rapid reusability needed for their Human Landing System approach.
Source: @Cathy_Koerner, @SenBillNelson

(she's the Associate administrator for Exploration Systems Development Mission Directorate, former NASA Orion program manager and flight director)

Speaks to the incredible resilience of stainless steel at temperature.

We will further hone our SX300 alloy to withstand even higher temperatures.
Source: @elonmusk

Today was a great day for humanity’s future as a spacefaring civilization!

Nothing unites us more than working together towards inspiring objectives.
Source: RT @elonmusk

One piece of info I, personally, found very interesting. The new tank farm (those horizontal tanks that got moved in a month or so ago) will be used for BOTH launch pads. CSI Starbase
Source: @VickiCocks15

Starship’s fourth flight test launched with ambitious goals, attempting to go farther than any previous test before and begin demonstrating capabilities central to return and reuse of Starship and Super Heavy.

The payload for this test was the data.

Starship delivered → spacex.com/launches/mission/?missionId=starship-flight-4
Source: @SpaceX

I think the WB57 should have some good footage of the landing burn. The final loop that it made lines up with the time of soft touchdown.

I can’t imagine them not sharing this footage in the recap video!
Source: @CSI_Starbase

Starship made a controlled reentry, successfully making it through the phases of peak heating and max aerodynamic pressure and demonstrating the ability to control the vehicle using its flaps while descending through the atmosphere at hypersonic speeds
Source: @SpaceX

Starship separates from booster
Source: RT @elonmusk

The night before #Starship's 4th flight, elonmusk described one of the main concerns about Starship's heat shield. He turned out to be right as it was the exact spot that burned through. More video to come!
Source: @Erdayastronaut

About the flap hinge:
We will have this nailed for next flight.

Note, a newer version of Starship has the forward flaps shifted leeward. This will help improve reliability, ease of manufacturing and payload to orbit.
Source: RT @elonmusk

Why is Starship made of stainless steel? This article from 5 years ago explains the reasons.

Worth noting that the ship would have failed on reentry if made of aluminum or carbon fiber, as they can’t take the heat.

https://t.co/QVAtv74quq
Source: @elonmusk