Tag: engineering

Using its Space Launch System and Orion capsule, NASA is aiming for an unmanned test flight around the Moon in December 2017.

8:56 pm

Using its Space Launch System (SLS) and Orion capsule, NASA is aiming for an unmanned test flight around the Moon in December 2017.

Two important tidbits revealed by this article: First, the first test flight of Orion will use a Delta 4 Heavy rocket. Two, NASA hopes to have its heavy lift SLS rocket ready for the 2017 mission.

Forgive me for being cynical, but I will believe the second tidbit only when it happens.

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What is the International Space Station’s weakest link?

8:45 pm

What is the International Space Station’s weakest link?

Mark Mulqueen, ISS vehicle director for Boeing Co., said keeping the station’s environmental control and life support systems, or ECLSS, functioning over the next decade will likely be engineers’ toughest challenge. “I don’t think it’s sparing or the structure to get to 2020,” Mulqueen said. “It’s probably continued refinement of how we successfuly operate our ECLSS system on-orbit. There has been a lot of effort going into understanding that.”

The article outlines a number of other areas of concern, none of which appear to be serious, for now, but could be a problem as the years pass.

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ATK prepares for another test firing of its five-segment solid rocket motor.

9:31 am

ATK prepares for another test firing of its five-segment solid rocket motor.

The qualification campaign, led by rocket-builder ATK, will prove the solid-fueled motor is ready to help propel the Space Launch System from Earth on two test flights in 2017 and 2021.

Though obviously funded out of the Space Launch System program (SLS), there is no guarantee at this moment that ATK’s solid rocket will be used in these test flights. NASA has said that they are considering all options for picking the launch rocket.

In a sense, we are now seeing a side benefit produced by relying on independent and competing private companies to get into space. It has placed pressure on NASA and the companies building SLS to perform. Unlike in the past, when failure to produce a new rocket or spaceship meant that NASA would simply propose a new concept and start again, now failure will mean that someone else might get the work. The result: SLS might actually get built, for less money and faster.

Though I don’t see how NASA can possibly cut the costs down to compete with these private companies, their effort might succeed enough for Congress to keep the money spigots open until the rocket gets built.

Even as I say this I remain skeptical. Considering the federal budget situation, the politics of the upcoming election, and the strong possibility that private companies will successfully provide that launch capability at a tenth the cost, I expect that sometime in the next two or three years Congress will finally balk at SLS’s cost, and eliminate it.

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The first industrial railgun has begun firing tests at the Naval Surface Warfare Center in Virginia.

9:14 am

The first industrial railgun has begun firing tests at the Naval Surface Warfare Center in Virginia. With video.

Following a series of low-energy test shots, evaluation of the launcher is now underway and will see tests conducted at 20 megajoules to 32 megajoules – one megajoule is equivalent to a 1-ton object being thrust at 100 mph (161 km/h). Test projectiles similar to those previously fired from [the] laboratory’s launcher will be fired at speeds of 4,500 to 5,600 mph (7,242 to 9,012 km/h) using electricity instead of chemical propellants.

These speeds are a only little less than one third escape velocity. Pump this technology up a bit and you could have a cheap way to get simple supplies, such as fuel, water, oxygen, into orbit. In fact, one company is even trying to do it.

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The problems of making both wind and solar power practical sources of electrical power on the grid.

5:29 pm

The difficulties making both wind and solar power practical sources of electrical power on the grid.

According to the U.S. Department of Energy, when intermittent sources such as solar or wind reach about 20 percent of a region’s total energy production, balancing supply and demand becomes extremely challenging: rolling blackouts can sometimes become inevitable. The same problem exists elsewhere, notably in Germany, where a vast photovoltaic capacity has sprung up thanks to generous subsidies.

The article proposes several reasonable solutions for storing power for use when there are lulls in wind or sunlight. All, however, appear costly, and all appear to end up making fossil fuels themselves more cost effective. For example,

A pumped-hydro facility consists of two reservoirs with a substantial drop in height between them. When there is excess electricity to go around, electric pumps move water from the lower reservoir into the upper one, thereby storing energy in the form of gravitational potential energy. When wind and solar wane or simply cannot keep up with demand, operators let water flow down and through turbines, generating electricity. In compressed-air facilities, excess electricity pumps air into underground caverns, and it is later released at high pressure to turn turbines.

Pumped hydro has been used for decades to balance the load on large U.S. grids. About 2.5 percent of the electricity used by U.S. consumers has cycled through one of these plants. In Europe the amount is 4 percent and in Japan 10 percent.

Reading this, I immediately asked, why not use this technology now to help reduce the amount of fossil fuels you need to burn? Japan seems to have figured this out. Why not us?

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The 3D printer that can build a house

4:54 pm

The 3D printer that can build a house.

The D-Shape is potentially capable of printing a two story building – complete with stairs, partition walls, columns, domes, and piping cavities – using only ordinary sand and an inorganic binder. The resulting material is said to be indistinguishable from marble, and exhibits the same physical properties, with durability highly superior to that of masonry and reinforced concrete.

The building process is very close to what we’d expect of a huge 3D printer. A nozzle moves along a pre-programmed path, extruding a liquid adhesive compound on a bed of sand with a solid catalyst mixed in. The binding agent reacts with the catalyst, and the solidifying process begins. Meanwhile, the remaining sand serves to support the structure. Then, another layer of sand is added and the whole process is repeated. Since it’s computer assisted, no specialist knowledge is required to use the printer. All that’s needed is a CAD design file.

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The fundamental design flaw of all of Tesla Motors’ electric cars.

3:35 pm

The fundamental design flaw of all of Tesla Motors’ electric cars.

A Tesla Roadster that is simply parked without being plugged in will eventually become a “brick”. The parasitic load from the car’s always-on subsystems continually drains the battery and if the battery’s charge is ever totally depleted, it is essentially destroyed. Complete discharge can happen even when the car is plugged in if it isn’t receiving sufficient current to charge, which can be caused by something as simple as using an extension cord. After battery death, the car is completely inoperable. At least in the case of the Tesla Roadster, it’s not even possible to enable tow mode, meaning the wheels will not turn and the vehicle cannot be pushed nor transported to a repair facility by traditional means.

This problem could destroy the company, which, believe it or not, might actually have a negative effect on the American space program! Elon Musk, the man behind SpaceX and the Falcon 9 rocket and the Dragon capsule is also the CEO of Tesla. If Tesla goes down, one wonders if that could have an impact on SpaceX’s effort to get Americans into space.

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John Glenn – the first American in orbit

6:02 pm

An evening pause: On the fiftieth anniversary of John Glenn’s orbital flight.

After putting a chimpanzee into orbit in November, NASA finally felt ready to send a man into orbit to answer the Soviets and their two manned orbital missions of Gagarin and Titov the previous year.

After Glenn’s mission and for the next few months, it looked like the U.S. was catching up with the Soviets in space. That would change before the year was summer was over.

The video below gives a nice summary of key moments in Glenn’s flight, though the special effects of the “fireflies” is poorly done. And we now know that the “fireflies” were nothing more than frozen particles of condensation coming off the capsule.

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ISS to finally get an experimental centrifuge

6:22 pm

At last! The ISS is to finally going to get an experimental centrifuge.

I have studied at length all the research done on all the space station ever launched, from Skylab, all the Russian Salyut stations, Mir, and now ISS, and from I could tell, only once was a centrifuge experiment put in space, by the Russians. Though the centrifuge was small and the results inconclusive, they suggested that even the addition of a truly miniscule amount of force could significantly mitigate the effects of weightlessness on plants and materials.

To finally get an experimental centrifuge on ISS is wonderful news. In order to build an interplanetary spaceship as cheaply and as efficiently as possible using centrifugal force to create artificial gravity we need to know the minimum amount of centrifugal force we need. Less energy will probably require less complex engineering, which should also require less launch weight to orbit, lowering the cost in all ways.

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