Elon Musk indicates that the SpaceX Starhopper was damaged after being crashed in a 50 mph wind. The repair takes a few weeks.
I just heard. 50 mph winds broke through the berths late last night and the fairing was blown. The repair will take a few weeks. – Elon Musk (@elonmusk) January 23, 2019
Elon Musk mentioned in a tweet on January 5, 2019, that unexpected problems could delay the Starhopper by four weeks. This turned out to be an accurate prediction of bad weather leading to damage and delays.
4 weeks, probably 8 weeks, due to unforeseen problems ̵1; Elon Musk 5 January 2019  The wind damage came after several weeks of rapid progress on the SpaceX Starhopper and the conversion of the Super Heavy Starship on the use of stainless steel instead of carbon fibers.
Elon Musk said in an interview with Popular Mechanics that 300's stainless steel alloys can withstand higher temperatures than carbon fiber or aluminum. Carbon fibers can theoretically have higher temperatures, but in practice, the resin has problems when exposed to longer temperatures in excess of 300 degrees Fahrenheit.
~ 1750K is a peak warming expected for about 20% of the starship for LEO entry, ~ 1600K for 20%. The remainder falls below 1450K, so no heat shield is required. Radiative cooling at T ^ 4 provides 60% of the ship. Another reason for steel. – Elon Musk (@elonmusk) January 23, 2019
The new metal rocket design will add some water and fuel to cool parts of the rocket. Overall, the new metal design is lighter, more stable and less expensive. A big plus is that the new design should greatly reduce development time for the new rocket.
It will be very interesting to see if SpaceX and Elon Musk are right about their design choices. Will SpaceX complete a fully reusable rocket with a load capacity of 100 tons or more in less than four years?
Yes, it is crazy that stainless steel is close to the reentry heat without being cooled !!! There are stainless steel upper classes that have even survived the reentry. It seems almost obvious now. Super Cool.- Everyday Astronaut (@Erdayastronaut) December 25, 2018
Written by Brian Wang of Nextbigfuture.com