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Enlarge / SpaceX has rapidly grown its Starship production facilities over the last six months. Here's a view from the east side in late February. (credit: Eric Berger)

A little less than two months have passed since SpaceX unexpectedly destroyed its latest Starship prototype in South Texas. Shortly after a static-fire test of this vehicle in late May, dubbed Serial Number 4 or SN4, an issue with the ground systems prompted a dramatic explosion, destroying the large vehicle and seriously damaging its test stand.

Since that failure, SpaceX has, if anything, accelerated work in South Texas. The company completed development of a second test stand for Starship and began construction of several new prototypes. In addition to finishing SN5—which was moved to the test stand earlier this month—components of the sixth, seventh, and even eighth Starship vehicles are in various states of construction at SpaceX's South Texas rocket factory.

There have also been signs that SpaceX may begin development and testing of the Super Heavy rocket relatively soon in South Texas. This is the gargantuan first-stage rocket that will power the Starship vehicle, which is the upper stage, into low-Earth orbit. NASASpaceflight.com's weekly video update from Boca Chica showcased development of both a high bay in which to stack the Super Heavy rocket, as well as preliminary construction of a launch pad.

Enlarge (credit: Flickr user Normanack)

If you're anything like me, you have a set of kitchen knives so dull that you could swap the handle and the blade with no noticeable effect on your fingers. And yet these knives will still cut—you just have to saw away at that soft tomato with less downward pressure. Surprisingly, although physicists had a general idea of why sawing with a knife helps cut soft material, no one had really looked at the details. Luckily, this oversight has been corrected and you can now optimize your cutting technique using—as certain radio personalities put it—the power of science.

Too squishy to crack, too solid to flow

Gels—a tomato is a gel with a skin—fall into a funny category. A gel is a liquid (usually water), at least if you decide by volume. However, a gel doesn’t really flow, because the liquid is contained within a polymer network. You could say that a gel is a bit like a sponge: if you squeeze a gel hard enough, water will be expelled, and when you relax your grip, water will be sucked back into the network. But not all gels hold their shape if they dry out, while a dry sponge still retains its structure.

Although gels are flexible, they are still breakable. If you stretch a gel, the gel becomes strained. As long as the strain is below a certain limit, it will always return to its original shape when you stop stretching it. The maximum strain for which this is true is called the elastic limit. To cut a gel, the strain has to be above the elastic limit.

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The search for a replacement for the US Navy's "little crappy ship" is over. On April 30, the US Navy announced that Fincantieri Marinette Marine, the US shipyard subsidiary of Italian shipbuilder Fincantieri, had beaten out the rest of the field to take on the FFG(X) frigate program, the shipbuilding effort that will replace the Navy's Littoral Combat Ship (LCS).

Frigates were once the workhorses of the Navy—small, fast escort ships that hunted submarines, acted as part of the air defense ring around carriers and other big combatants, and could patrol the seas on their own when necessary. The Oliver Hazard Perry (FFG-7) class of frigates, the first US Navy ships with gas turbine engines, were worked far beyond expectations during their service; they survived attacks by errant Iraqi anti-ship missiles (in the case of the USS Stark) and Iranian sea mines (the USS Samuel B. Roberts) during the US Navy's confrontation with Iran in the 1980s.