Universe Today – Astronomers have announced Nobel Prize-worthy evidence of primordial gravitational waves — ripples in the fabric of spacetime — providing the first direct evidence the universe underwent a brief but stupendously accelerated expansion immediately following the big bang.
In about three weeks, after sending cargo towards the International Space Station, the first stage of the Spacex Falcon 9 rocket used for the flight will return nearly immediately after liftoff and return and fire its engines for the second time. The burn will allow the rocket to reenter the atmosphere in controlled flight, without breaking up and disintegrating on the way down as most booster rockets do. There was an analysis of a reusable launch system where the cost of developing the reusable launch system was $36 billion. If Spacex is successful they will have developed reusability for about $100 million.
There were also prior ideas involving large ground infrastructure such as giant magnetic launching systems
“The payload penalty for full and fast reusability versus an expendable version is roughly 40 percent,” Musk says. “[But] propellant cost is less than 0.4 percent of the total flight cost. Even taking into account the payload reduction for reusability, the improvement is therefore theoretically over a hundred times.”
A hundred times is an incredible gain. It would drop cost for Musk’s Falcon Heavy rocket—a scaled-up version of the Falcon 9 that’s currently rated at $1000 per pound to orbit—to just $10. “That, however, requires a very high flight rate, just like aircraft,” Musk says. Musk tells us that with daily flights, the cost will run about $100 per pound. Musk says he expects “single-digit hours” between landing and next flight, at least for the lower stages. “”For the upper stage, there is the additional constraint of the orbit ground track needing to overfly the landing pad, since cross-range [the distance to a landing site that it can fly to either side of its original entry flight path] is limited. At most this adds 24 hours to the upper-stage turnaround. Will there be demand for forty thousand flight per year ? 100 space flights per day at $100 per pound for ten reusable rockets ? Daily launches of one reusable rocket is 365 launches. If you have 100 reusable rockets all flying daily then you need demand for 36,500 launches. If the payload capacity is 8 to 50 tons. This would be 180,000 tons to 1.8 million tons.
Nextbigfuture – Tom Mueller, head of Spacex rocket engine development, has his main focus being the development of the reusable Raptor engine. It will use liquid methane and oxygen to achieve 1 million pounds of thrust. Nine of them will be combined on one rocket. It will put over 100 tons of cargo to Mars.
Raptor’s current design is to have 1Mlbf (4,500kN) gas-gas (full flow) liquid methane and oxygen engine, with an ISP of 321s at sea level 363s at vacuum.
Mr. Mueller confirmed nine of these engines would power each 10 meter diameter core of the notional MCT (Mars Colonization Transport). The 9 million pounds of thrust would be more than the first stage of the Saturn V (7.68 million pounds). Tom Mueller has revealed the company is deep into the development of the first “full flow methane-liquid oxygen” rocket engine
Nextbigfuture – NASA scientists have blueprinted a low-cost Mars sample-return mission that would use a souped-up Dragon capsule from SpaceX and the firm’s planned Falcon Heavy rocket to get to the Red Planet by the early 2020s.
The new study demonstrates the viability of the entry, descent and landing of the unmanned Dragon space capsule at Mars. Moreover, the spacecraft’s descent technique would help set the stage for future human missions to the Red Planet, researchers said.
It was an internal study at NASA’s Ames Research Center.
The study group spent a couple of years reviewing the engineering problem. They concluded that a minimally modified Dragon capsule — dubbed “”Red Dragon”” — could indeed successfully perform an all-propulsive entry, descent and landing on Mars “”without violating the laws of physics,”” Lemke said.
Nextbigfuture – John Cramer a physicist from the University of Washington, well-known to SF fans via his “Alternate View” columns in the “Analog” science fiction magazine, as well as several novels. John focused on the use of wormholes to allow rapid transit to other star systems. Simply put, wormholes are “tunnels” between two regions in space-time, compatible with Einstein’s equations of General Relativity as one possible mathematical solution. Outside a wormhole itself, observers would see two “ends” of the one space-time structure. Whether wormholes exist or not is a matter for astronomical observation, as larger wormholes should produce distinctive gravitational lensing patterns that astronomers might be lucky enough to see. If the connection formed between the two ends of a wormhole is shorter than the distance through regular space-time, then passing through the wormhole allows apparently faster-than-light travel, though nothing ever exceeds lightspeed locally. Thanks to time-dilation — the slowing of time experienced when approaching lightspeed — a time-lag can be developed between the two ends if one end is sent to a distant star. For example, if a one end is accelerated to a time-dilation of 7,000 (0.99999999c), then only 75 minutes is required for the traveling end to appear to travel 1 light-year from the stationary end’s point-of-view. John Cramer discussed how this might allow a network of rapid-transit wormholes to be set-up throughout the Galaxy – with the caveat that the network can’t be allowed to form a “Closed Time-like Circuit,” else this might destroy the wormholes via amplifying quantum fields.