September 4, 2017

Pentagon Faces Delays in Shift Away From Russian Rocket Engines (Source: Wall Street Journal)
Technical and funding challenges will force the Pentagon to rely on Russian-manufactured rocket engines at least through the middle of the next decade, several years longer than originally anticipated. Despite bipartisan demands from Congress to quickly phase out the RD-180 engines on national-security grounds, it is proving harder than many lawmakers expected to secure an equally reliable domestic replacement. (9/4)

Trump's Pick to Lead NASA Would Be Terrible for the Planet (Source: GQ)
While in the House, Bridenstine has shown a real interest in space, particularly with getting private companies more involved with NASA. The more pressing issue is that Bridenstine is a climate change-denier, like pretty much everyone else working in relevant areas of the Trump administration. And he's critical of how much NASA spends on climate change research.

Unlike the EPA and similar agencies (where Trump can order them to stop saying "climate change" altogether), NASA is relatively free of federal interference, making Bridenstine's appointment a blatant attempt to inject political control into it. (9/4)

After Nuke Test, North Korea Readying Next Missile Launch (Source: AP)
South Korea’s Defense Ministry also said Monday that North Korea appeared to be planning a future missile launch, possibly of an ICBM, to show off its claimed ability to target the United States with nuclear weapons, though it was unclear when this might happen.

Following U.S. warnings to North Korea of a “massive military response,” South Korea on Monday fired missiles into the sea to simulate an attack on the North’s main nuclear test site a day after Pyongyang detonated its largest ever nuclear test explosion. U.S. Ambassador to the United Nations Nikki Haley says North Korea’s actions show that its leader, Kim Jong Un, is “begging for war,” and the time has come for the Security Council to adopt the strongest diplomatic measures. (9/4)

US Shoots Down Missile in Test Off Hawaii Coast (Source: Space Daily)
The US military shot down a medium-range ballistic missile target off the coast of Hawaii early Wednesday, in a successful test of a missile interception system Japan is seeking to bolster its defense against North Korea. The test was performed by the US Missile Defense Agency (MDA) and the US Navy from the USS John Paul Jones, a guided-missile destroyer, just one day after North Korea fired a ballistic missile over Japan.

Using Standard Missile-6 (SM-6) guided missiles, the test intercepted a medium-range ballistic missile launched from the Pacific Missile Range Facility on Kauai, Hawaii by using the USS John Paul Jones's onboard AN/SPY-1 radar. North Korean leader Kim Jong-Un has promised more missile flights over Japan, insisting his nuclear-armed nation's provocation was a mere "curtain-raiser," in the face of United Nations condemnation and US warnings of severe repercussions. (8/30)

House-Sized Near Earth Objects Rarer Than We Thought (Source: NOAO)
In 2013 a small meteoroid, the size of a house, hurtled through Earth’s atmosphere and exploded over the Russian city of Chelyabinsk. The explosion shattered windows, and more than a thousand people were treated for injuries from flying debris. How many similar-sized rocks have orbits that bring them close to Earth? A new study has answered that question using the Dark Energy Camera (DECam) on the Blanco telescope at the Cerro Tololo Inter-American Observatory. The result lends new insights into the nature and origin of small meteoroids.

While very large (10 kilometer-sized) impactors can induce mass extinction events like the event that led to the demise of the dinosaurs, much smaller impactors can also wreak havoc. The meteoroid that exploded in Chelyabinsk unleashed a powerful shock wave that destroyed buildings and blew people off their feet. Relatively petite at a ‘mere’ 17 meters in diameter, comparable to the size of a 6-story building, the impactor, when it exploded, released about ten times the energy of the Hiroshima atomic bomb.

“There are around 3.5 million NEOs larger than 10 meters, a population ten times smaller than inferred in previous studies. About 90% of these NEOs are in the Chelyabinsk size range of 10-20 meters.” While the surprising results do not alter the impact threat from house-sized NEOs, which is constrained by the observed rate of Chelyabinsk-like bolide events, they do lend new insights into the nature and origin of small NEOs. (8/30)