Sierra Nevada has begun the testing program of Dream Chaser’s engines.

The competition heats up: Sierra Nevada has begun the testing program of Dream Chaser’s engines.

These tests were to verify that the engine test stand will function properly when they begin testing the engines themselves. Note also that Sierra Nevada provided the engines for SpaceShipTwo, and that Dream Chaser’s engines appear to be some variant of that hybrid engine design.

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The repairs to the cracks in the first Orion capsule have withstood static stress tests.

I’m so glad: The repairs to the cracks in the first Orion capsule have withstood static stress tests.

In addition to the various loads it sustained, the Orion crew module also was pressurized to simulate the effect of the vacuum in space. This simulation allowed engineers to confirm it would hold its pressurization in a vacuum and verify repairs made to superficial cracks in the vehicle’s rear bulkhead caused by previous pressure testing in November.

The November test revealed insufficient margin in an area of the bulkhead that was unable to withstand the stress of pressurization. Armed with data from that test, engineers were able to reinforce the design to ensure structural integrity and validate the fix during this week’s test. [emphasis mine]

I love how this NASA press release describes the cracking of the capsule bulkhead during the November testing, indicated in bold. “Insufficient margin”, eh?

Normally I am very forgiving when things fail during engineering tests, but for the bulkhead of this capsule to crack during these tests was actually pretty shameful, considering the decades of engineering work previously done in the building of space capsules and submarines. Things can certainly go wrong when you build something new, but I don’t see anything particularly revolutionary about Orion’s design. Lots of things might fail, but making sure the bulkhead could withstand the normal and well known stresses of spaceflight should not have been one of those things. The bulkhead failure suggests to me some sloppy engineering work took place in Orion’s initial design.

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Stratolaunch officially announced today that Orbital Sciences will build the system’s second stage rocket.

The competition heats up: Stratolaunch officially announced today that Orbital Sciences will build the system’s second stage rocket.

The rocket that Orbital will build for Stratolaunch will launch from the air, the first stage being a giant airplane which will carry that rocket aloft, much like Virgin Galactic’s WhiteKnightTwo and Orbital’s Pegasus rocket. Clark Lindsey at the same website also notes that the efforts of SpaceX (and to my mind Stratolaunch) to make the first stage reusable will likely revolutionize the rocket industry.

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Russia’s Proton rocket successfully launched a commercial satellite today.

The competition heats up: Russia’s Proton rocket today successfully launched another commercial communications satellite.

The troublesome Briz-M upper stage still has to get the satellite to its proper orbit, so stay tuned. Nonetheless, this launch, only a few weeks after their last commercial Proton launch, suggests they were serious about launching nine more commercial launches this year.

Meanwhile, we wait for SpaceX’s first commercial launch by the Falcon 9 rocket. Their launch manifest still claims there will be three such launches before the next Falcon 9/Dragon mission to ISS later this year, but two of those launches were supposed to have occurred already. The non-occurrence of the March MDA/Cassiope launch out of Vandenberg is especially puzzling, as there are few scheduling conflicts at that rarely used spaceport.

The Falcon 9 delays at this point are beginning to be worrisome, and suggest the skepticism of some about SpaceX’s ability to compete might have merit. SpaceX has got to launch a commercial satellite soon in order to quell those doubts.

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Data collected by a radiation sensor inside Curiosity during its journey to Mars suggest that it will be possible to build ships with sufficient shielding to protect humans on such a voyage.

Data collected by a radiation sensor inside Curiosity during its journey to Mars suggest that it will be possible to build ships with sufficient shielding to protect humans on such a voyage.

Zeitlin and his colleagues analysed the radiation recorded by a small detector on board the craft that was active during most of the 253-day cruise to Mars. Although the craft was not uniformly protected from exposure to Galactic cosmic rays and charged particles from the Sun, the MSLโ€™s shielding on average approximated that of human space-flight missions. ….

At NASA Langley, Thibeault and her colleagues are testing new types of shielding that consist of hydrogenated materials. Hydrogen offers protection because it breaks apart heavy charged particles without creating secondary particles that add to the radiation dose, she notes. One of the materials under investigation, hydrogen-filled boron nitride nanotubes, looks particularly promising because it is robust and lightweight enough to double as both the skin of a spacecraft and its shield. Using separate materials to build and shield a craft would add too much weight to a Mars-bound mission, Thibeault notes.

Thibeault says that she is heartened by the new study because she had feared that the radiation dose might be considerably higher. The results suggest โ€œthat this is a problem we can solveโ€, she adds.

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