Daily Archives: April 14, 2017

Space Matter is a weekly column that delves into space science and the mechanics of spaceflight. From the latest discoveries in the universe around us to the fits and starts of rocket test flights, youll find analysis, discussion and an eternal optimism about space and launching ourselves into the cosmos.

Ive previously discussed the challenges of getting to Mars and landing on Mars; its not going to be easy to get humans to the surface of the red planet. And thats not even considering the discussion of what will happen to our bodies on the way. There have been studies documenting the psychological challenges of long-term spaceflight, and weve been studying the effects of zero-g on the human body for years on the International Space Station. But what about space radiation?

Radiation is a huge problem in space travel. The only reason its not a huge problem on Earth is because our planet is protected by a giant magnetic field that extends out into space; its what makes life on Earth possible. It protects our delicate planet from the ravages of space radiation.

There are two types of space radiation that anyone outside the Earths magnetic field has to worry about. The first are called galactic cosmic rays, or GCR radiation. These originate outside our solar system and travel through our galaxy at close to the speed of light. Its likely that these high-energy particles originate in the massive explosions of supernovae, though there is still some disagreement on this matter. These particles are composed of every element from hydrogen to uranium; their distinguishing feature is that theyre ionized, meaning their electrons have been stripped, so they hold a charge. That charge is what makes them interact with (and repelled by) Earths (charged) magnetic field.

This X-ray/UV image of our Sun shows the active weather regions as blue-white areas. Photo courtesy of NASA/JPL-Caltech/GSFC/JAXA

The second type of radiation comes from our Sun, and its much more common: solar particles. Our Sun, and all other stars, actually has its own weather. Sunspots are one form this weather takes. What we need to worry about, though, are solar proton events. These occur during solar weather activity (such as solar flaresbut they dont occur during every solar flare) and consist of charged particles (protons again!) that are unleashed into space by the suns magnetic field. Were protected from these particles by our planets magnetic field, but strong solar proton events can be associated with geomagnetic storms, which wreak havoc on the electrical grid.

Outside the protection of the Earths magnetic field, these two types of radiation can be a serious threat to astronauts. Whats more, our own magnetic field poses a threat in and of itself. The Earth is surrounded by radiation belts, called the Van Allen belts, which trap radiation particlestheyre part of how our planet is shielded from these particles. Galactic cosmic rays and charged solar particles fly through space straight into the Van Allen beltswhich means that there are basically giant belts of radioactive death circling our planet (too much?) These belts arent static, but there usually are two of them (sometimes three). The inner Van Allen belt begins about 600 miles above the surface of the Earth; the outer Van Allen belt extends to almost 40,000 miles out. For comparisons sake, the International Space Station, in low-Earth orbit, is 220 miles above the Earths surface, while the Moon is 238,900 miles from the Earth.

Astronaut Buzz Aldrin on the Moon during Apollo 11. Photo courtesy of NASA

But weve been to the Moon, you might be asking. Weve sent a total of nine manned missions around or onto the Moon (Apollo 8, 10, 11, 12, 13, 14, 15, 16, and 17), through the Van Allen radiation belts. This is actually a major factor in the conspiracy theory that the Moon landings were fakedastronauts would die after passing through the Van Allen belts.

Well, no, not quite. The Van Allen radiation belts are very dangerous, but there are ways around them. For one, theyre not a sphere encompassing the planet. Think of the belts surrounding the Earth as a giant donut, where Earth is the donut hole.

This image cutaway shows the Van Allen radiation belts surrounding the Earth. Photo courtesy of NASA

The team in charge of Apollos trajectory studied the Van Allen belts closely and charted a flight path that would allow the spacecrafts to bypass the thickest parts of the belt. In fact, Apollo missed the inner belt completely and sped quickly through very thin areas of the outer belt. The short duration of exposure to the belts meant that the spacecrafts aluminum shielding was enough to protect the astronauts. Presumably, NASA could chart a similar trajectory for a Mars mission.

The problem is what happens once astronauts travel through the radiation belts on are their way to their next destination. The Moon missions consisted of three days of travel each way, plus a few days on the surface or in orbit. Mars missions will consist of a minimum of nine months of travel one-way. A low dose of radiation might not have noticeable effects, but when these accumulate, astronauts may run into serious medium- and long-term health problems.

You can bet that NASA and other private spaceflight companies are working hard to mitigate this risk, from nutritional supplements to counteract the effects of radiation to improving spacecraft shielding to better protect astronauts from radiation. Its important to note, though, that while were well on our way, we havent solved the space radiation problem yet.

Top photo courtesy of NASA/JPL-Caltech/GSFC/JAXA

Swapna Krishna is a freelance writer, editor and giant space/sci-fi geek.

Continued here:

Space Matter: Human Bodies and Space Travel :: Science ... - Paste Magazine

Printed headline:Work in Progress

When British entrepreneur Richard Branson established Virgin Galactic in 2004, he envisioned a company that would pioneer and develop a space tourism operation, allowing passengers to experience flight in a suborbital environment 100 km (62mi.) above the Earth. This required the development and certification of a totally new type of aircraft systema suborbital spaceplaneultimately dubbed SpaceShipTwocapable of carrying two pilots and up to six passengers and launched from a specially designed, four-engine, twin-hull mother shipWhiteKnightTwoat an altitude of about 15,000 km (50,000,000 ft). Seconds after release from the mother ship, the spaceplane would then ignite its single hybrid rocket motor, ascending at up to 2,600 mph to reach its suborbital altitude. The spaceplane would shortly thereafter return to the spaceport, a specially built terminal, airfield and maintenance complex from which it was ferried by the mother ship, at a slow reentry speed, in both a powered and glide mode.

The spaceport, officially called Spaceport America, is under development in New Mexico. Upon commencement of commercial service, Virgin Galactic will relocate its headquarters and operations center there from its current location at Mojave, California.

To date, flight testing of SpaceShipTwo and WhiteKnightTwo continues, as two additional SpaceShipTwos are in the early stages of production. The first production SpaceShipTwo, which was officially unveiled and rolled out on Dec. 7, 2009, was lost in a fatal accident in October 2014. A second WhiteKnightTwo is in the early design stages.

Virgin Galactic is also in the process of establishing the technical support infrastructure for the exotic aircraft. Virgin Galactics Spaceline Technical Operations Director Pedro Caballer discussed with Inside MRO contributing writer Paul Seidenman supply chain and maintenance support challenges, whichas with the flight testscontinue to be a work in progress.

Virgin Galactics MRO Support Evolving

MRO infrastructure developed from scratch

Supply chain still a work in progress

Most MRO to be done in-house

Continuous inflight monitoring planned

Virgin Galactic is breaking new ground with respect to commercial space travel and has built a radically different spacecraft system. What were some of the maintenance support challenges?

Caballer: For maintenance support, the biggest challenge we faced was that the majority of our technical needs for supporting our spaceflight systems did not exist when the program began. That included all of the flight and technical manuals, technical training, maintenance programs, management tools, spare parts strategy and suppliers, and repair service suppliers for maintaining those spare parts.

Are the parts and components for SpaceShipTwo and the WhiteKnightTwo launch vehicle generally available off the shelf todayor is everything essentially custom-built for this operation?

Each vehicle has a slight degree of difference in its parts makeup between off-the-shelf product and custom product. For example, SpaceShipTwo is mostly custom-builtwith a ratio of about 70% that needed to be custom-built and 30% available off the shelf. For WhiteKnightTwo, about 60% of the parts are custom-built and 40% are off the shelf.

At the start of the program, what assurance did you have that the supply base could provide adequate materials support at the level you would need as your operation evolved?

Pedro Caballer, Virgin Galactics spaceline technical operations director. Credit: Virgin Galactic

To answer that question, you have to understand that The Spaceship Co., a Virgin Galactic sister organization, is our primary OEM. It is the builder of SpaceShipTwo and WhiteKnightTwo and therefore had an established supply chain in place for production. However, the operational supply chain solutions for Virgin Galactic can be strategically different and were not readily in place. That was one of our challenges, and our supply chain team is tasked with developing those solutions.

Over the past several years, we have been working diligently to establish a stable supply base, although that is not complete yet. We have established a strong supplier base, mostly in areas of consumables and expendables, such as seals and filters. We are working on strengthening the rotable and repairable parts supply chain right now, and that is the final element to our supplier solution we need to put in place.

Has the supply base, in fact, expanded to the point where materials support will be readily available as needed?

Yes. We believe that the supply base will expand, especially for consumable and expendable parts. We have solutions in place for some repairables for the flight-testing phase, but we want to build a comprehensive and deep supply base solution for all repairables right at the start of our commercial operations.

Have the maintenance manuals been completed and approved yet?

The maintenance manuals for the spaceflight system are progressing well through their development. We work with multiple types of technical data sets to maintain our vehicles, much like newly designed and manufactured aircraft run through in a flight-test program.

SpaceShipTwo launches from the four-engine, twin-hull mother ship, WhiteKnightTwo.Credit: Virgin Galactic

Who is supplying the propulsion systems for SpaceShipTwo and WhiteKnightTwo? Were the engines off the shelf, with some modifications, or was a totally new design required?

The Spaceship Co. has developed the rocket propulsion solution for SpaceShipTwo, and it will be our supplier and repair source for these all-new motors and propulsion components, respectively. As for WhiteKnightTwo, Pratt & Whitney Canada is supplying the engine, which is an experimental variant of the PW308A commercial turbofan.

Who supplies the avionics? As with the engines, were they off the shelf or one-offs?

We have several avionics suppliers and solution architects. The Spaceship Co. is one of them, and as they have grown a world-class avionics team, they develop and integrate quite a bit in-house, with some industry-leading avionics suppliers. Im not at liberty to disclose the names of the others, but I can tell you that they are providing off-the-shelf equipment for our vehicles currently in flight test, and those are the systems we will use in commercial operations.

Is The Spaceship Co. the entity in charge of overseeing logistics and material support?

In addition to being the OEM for our vehicles, The Spaceship Co. also is considered the component supplier to Virgin Galactic for items they have designed and manufactured as well as the provider of continual component service repair solutions.

Virgin Galactic, itself, has responsibility for supply chain oversight and support for the remainder of the components that are not manufactured by The Spaceship Co. Much like the airlines, those components will be managed within the framework of the established vehicle delivery configuration.

All maintenance for Virgin Galactics spaceflight system is done in-house at its Mojave base.Credit: Virgin Galactic

Are the spaceships and the launch vehicle equipped with state-of-the-art diagnostics that will monitor system maintenance status and provide real-time performance information?

We have established an extensive network of data acquisition and measurement across the entire spaceflight system. It involves a combination of real-time and recorded data that is analyzed with every flight. That data will provide the information needed to support our aircraft health and reliability management framework.

Our operation, we believe, is unique in that it involves a mix of real-time monitoring of systems inflightsimilar to a NASA control roomalong with the capability to perform post-flight data analysis to ensure that system health is appropriate. The system monitoring, in real time, is done using a telemetry architecture similar to ACARS.

When you tested the major components, what were some of the lessons learned with respect to predicted life limits? In some cases, were they better than expected?

To date, we have had positive results concerning life-limited component testing. That testing, which is carried out in-house as well as contracted to outside laboratoriesand conducted under conditions that we would see in spacehas shown us that several components already have exceeded expectations. In fact, so far no component has failed before its anticipated life limits have occurred.

Virgin Galactic is planning to relocate its base at Mojave, California, to Spaceport America in New Mexico.Credit: Virgin Galactic

How will most maintenance support be carried out? In-house? By the system OEMs?

All maintenance execution for the spaceflight system will be done in-house at Mojave, until we move to our new Spaceport America complex in New Mexico, at the start of commercial operations. This will be the base of operations for Virgin Galactic once the flight-test program is completed and we begin commercial operations. We have grown a team at Virgin Galactic that will provide technical services and execution to all our spaceline operational assets to meet schedule demands and requirements.

Will component support be under some type of time-and-material contracts with the OEMs?

Component services and repairs are being supported by the OEMs and approved third-party suppliers as we continue to evolve the support framework for the spaceflight system components. For each maintenance support solution, we are developing agreements that are tailored to ensure the success of our spaceline operation.

What further issues regarding materials support have yet to be worked out prior to the first commercial flights?

Right now, there are no major issues; but keep in mind, we are still a work in progress to establish the final supply-chain solution. Once we do that, we will successfully meet our commercial operations needs.

Has Virgin Galactic established a launch date for its first commercial flight?

No date has been advertised as to when commercial operations will begin because the current focus is on completing the flight-test program and operational readiness checks before the aircraft will be launched into service. This will include a series of verifications to assure that all work done on the project, which is driven by safety considerations, has been completed in a satisfactory manner. Any announcements of the first flight will be driven by safety considerations, not by schedule.

More here:

Exclusive: Virgin Galactic Preps For Space Travel Technical Support - MRO Network