Beam it up, Scotty: 3D Printing may have space applications

Tools and mechanical parts might be “beamed” up to a space station or a lunar or Mars base using technology that has in recent years become a central process in design prototyping known as 3D printing or SLS (selective laser sintering). In this technology, an object is scanned and a powdery substance is converted via a heating process into a duplicate solid form. A striking demonstration of this technology can be seen in this 4-minute video clip from the National Geographic Channel.

A variation of the technology might also be used for lunar materials production by fabricating items from lunar regolith. Markus Kayser has demonstrated a prototype “Solar Sinter” device that uses the power of the sun to produce glass-like objects made from desert sand. You can view a 6-minute video demonstration of the device as tested in the Sahara Desert.

ISDC 2011 – Flight System Development Forum

ISDC conference report by Dave Fischer

This is the first of two articles about the NASA Heavy Lift Vehicle program mandated by Congress.

Dan Dumbacher, Director of Engineering (NASA HQ)
Todd May, Associate Director, Technical (NASA MSFC)
Garry Lyles, Associate Director for Technical Management (NASA MSFC)

Dan Dumbacher introduced the panel by noting that NASA has been tasked with development of the next Heavy Lift Vehicle, and the folks at the Marshall Space Flight Center would like to get on with the job of building the next launch vehicle.

However, NASA’s budget is constrained by the current economy, and is likely to remain so for the foreseeable future. Indeed, it is likely to decrease somewhat over time.

The primary challenges in the confusing state of affairs revolve around the constituencies, as it always does in a political environment. The NASA Reauthorization Act of 2010, the 2011 budget from the administration, and the language of the compromise budget resolution for NASA in the summer of 2011 have all contributed to the muddled state of affairs.

The current manned programs include the International Space Station and Commercial Cargo and Crew. The new beyond-low-Earth-orbit program will require new infrastructure, a new launch vehicle, a new spacecraft (such as the Orion – Multi Purpose Crew Vehicle), and ground support.

Todd May comes from the International Space Station project, certainly the most ambitious and complex international project ever conducted. Todd reviewed the results of the 13 heavy lift proposals received from industry. There is no magic rocket. However, cost was heavily influenced by NASA management and oversight practices as well as flight rate.

Garry Lyles then gave a detailed description of the work done over the past year on the heavy lift vehicle. Interestingly, he noted that he had spent time at a conference of building architects. They taught him that design beauty grew out of the requirements of the building, and that operational simplicity grew out of internal complexity.

He chose to test the concept of machine beauty with the Requirements Analysis Cycle (RAC). Three teams were created. One was devoted to Lox/H2, the second to Lox/RP and the third could choose either combination, but would focus on a lean manufacturing philosophy. Their results would be folded into the first two teams within the first half of the cycle. The final instructions to the teams were to be innovative and have fun.

The teams conducted several thousand parametric studies. One result was that many combinations would satisfy the physical requirements. By the end of the studies, the primary drivers of affordability, however, turned out to be lean systems engineering, stable requirements and simple organization. Reduction in development time was critical. Private industry knew that first to market with reduced cycle time meant lower people costs, which are a major component of overall costs. The subject of how NASA’s program might relate to Falcon Heavy was not addressed.

Difficult changes will be required from the traditional risk-averse NASA culture in order to accomplish these goals. It is going to be hard for NASA to adapt and adopt the key practices:

1. The machine will be complex, but the operation must be simple
2. Adjust the design in order to simplify the manufacturing process
3. Requirements must be early and stable
4. There must be margin in performance
5. Cycle time must be as quick as possible, but no quicker
6. Streamline the oversight of contractors

Without these cultural changes, it will be impossible for NASA to accomplish the heavy lift task in front of it.

Constructing Cislunar Infrastructure – ISDC 2011

ISDC conference report by Dave Fischer

If those who think Mars is sufficiently hard to get to and remain to settle are correct, or those who think that it would be a terrible mistake to go to Mars and return leaving only flags and footprints are correct, then we are, in fact, not going to Mars anytime soon.  So where are we going?  And why are we going?

The current Flexible Path suggests that the manned exploration of an asteroid is a reasonable goal.  It avoids the problems of deep gravity wells, and does create launch vehicles and spacecraft.  However, as critics point out, this merely repeats the standard process of throwing away everything except the manned return capsule.  What might be done to create a permanent space faring infrastructure?

Why we are going is settlement.  That is the conclusion from reading policy statements, both formal and informal, from the past 10 years.  Beginning with the Vision for Space Exploration statement in 2004, up through the 2010 statement by the Obama administration, these policy statements all point toward the unspoken word, “settlement”.  Permanent occupation of space that exploits the economic resources available is the goal.  Now, what are the initial strategic steps, and what are the tactics to implement them.

At the International Space Development Conference (ISDC 2011), two proposals were made that result in permanent cislunar infrastructure: one by Dr. Paul Spudis and one by Stephen D. Covey.

Dr. Spudis advocated the conservative approach.  During Friday’s luncheon, Dr. Spudis presented “Can We Afford to Return to the Moon” (see the paper in the NSS Lunar Library by Spudis and Lavoie Mission and Implementation of an Affordable Lunar Return – pdf)

Spudis and Lavoie argue that over a period of roughly 16 years, employing a series of 31 missions, that a robotically built water mining operation at the South Pole of the moon, later employing humans living at the base to repair and maintain the equipment, would yield the following:

1.  Commercially valuable water for use as Lox/H2 fuel on the Moon and within cislunar space, sufficient to sustain the operation, with excess available for sale.

2.  Reusable Landers and Rovers.

3.  Permanent human occupation of the Moon.

4.  Routine access to all space assets within Cislunar space, including communications, GPS, weather, remote sensing and strategic monitoring satellites.

In essence, we create a “transcontinental railroad” with permanent settlements at various points between the Earth and the Moon.  The critical element is that this can be accomplished with the $7 Billion annual budget likely to be given NASA for the foreseeable future.  The projected cost of a Flexible Path mission to an asteroid has been estimated at $80 Billion, while the Cislunar project would cost $77 Billion.

The second proposal is far more radical: “Asteroid Capture for Space Solar Power”.  Here, Stephen D. Covey argued for a purely commercial venture to capture the asteroid 99942 Apophis, mine it for metals, silicon and oxygen, build Solar Power Satellites (SPS) and sell the power to utility companies on Earth.  An initial capital base of $30 Billion would be required.  But by the end of the sixth or seventh year of operation the enterprise would be at break even, and eventually generate $20 Billion per year in revenue.

At the end of eight years, 15 Solar Power Satellites would be in operation generating $20 Billion per year in revenue.  And only 10% of the asteroid would have been processed.  A total of 150 SPSs could be manufactured before another asteroid was needed.

The end result of this initial eight-year plan would be:

1.  A fully shielded (3 meters of slag from the mining operation) habitat for 8,000 people.

2.  Space based factory capable of producing 8 SPSs per year.

3.  Space infrastructure created by commercial space companies to support the operations.

4.  3-4% of Earth’s electrical needs supplied by Space based Solar Power

At the end of production, with 150 Satellites in operation, more than a third of Earth’s electrical needs would be supplied by Space Based Solar Power.

And who is to suggest that we cannot do both of these ventures at the same time?

CCDev2 – Blue Origin

Blue Origin
Blue Origin Spacecraft
Image Credit:
NASA / Blue Origin

Third in our series on the second round of funding in the Commercial Crew Development (CCDev) program is the secretive Blue Origin company. The award of $22 million has been announced by NASA.

Funding from this round will help with development through the requirements review stage including work on the thermal protection system and an analysis of the aerodynamics of its cone shaped body.

The spacecraft is designed to carry seven astronauts to low Earth orbit.

It will carry astronauts and cargo to and from the International Space Station and serve as an ISS emergency escape vehicle for up to 210 days. The vehicle is designed for launch on an Atlas V rocket.

Endeavour – Scrubbed

Endeavour at T-Minus 6 Hours
Image Credit: NASA TV

The launch of Endeavour was scrubbed today due to a failed heater in the APU (Auxiliary Power Unit) of the Shuttle. It looks like there are multiple failures on APU1. The Load Control Assembly appears to be the problem, although a short is possible. The next launch opportunity following repairs will be no earlier than Monday, and most likely Wednesday.

CCDev2 – Sierra Nevada

Image Credit: NASA

The second round of funding in the Commercial Crew Development (CCDev) program has been announced by NASA.

Sierra Nevada Corporation received $80 million in the second round to go with the $20 million it received in 2010. Sierra Nevada acquired the Dream Chaser project in December 2008, and won funding in round one of the CCDev program. This was the largest award in round one.

The project derives from the HL-20 program undertaken in 1990 by NASA’s Langley Research Center in Hampton, Virginia.

The Dream Chaser is designed to carry up to seven people to the International Space Station and back.

The vehicle is designed to launch vertically on an Atlas V rocket and land horizontally on conventional runways.

CCDev2 – Boeing

Boeing CST-100
Image Credit: Boeing

NASA announced the second round of funding in the Commercial Crew Development (CCDev) program.

Boeing was the big winner in CCDev-2, getting $92.3 million, on top of the $18 million it won last year.

The initial $18 million allowed Boeing to complete several risk reduction demonstrations and a System Definition Review (SDR) in October, 2010. The CST-100’s system characteristics and configuration were base-lined. Boeing designed, built and tested a pressurized structure of the crew module. It also developed an avionics systems integration facility to support rapid prototyping and full-scale development.

Boeing notes that the CST-100 spacecraft relies on proven materials and subsystem technologies that are safe and affordable.

Plans include ferrying astronauts and supplies to the International Space Station (ISS), as well as crew and passengers to the Space Station being proposed by Bigelow Aerospace. The CST-100 is designed to carry up to seven passengers and is designed to be launched by a number of different expendable launch vehicles. These include United Launch Alliance’s Delta 4 and Atlas 5, Space Exploration Technologies’ Falcon 9, and the European Ariane 5.

NASA’s new 14-month CCDev-2 Space Act Agreement will enable Boeing to further mature its system to a Preliminary Design Review (PDR), a critical step that ensures the system design meets all requirements.

ATV-2 Johannes Kepler

Keeping the International Space Station (ISS) supplied will become an increasing challenge with the retirement of the US Space Shuttle in 2011. This is the first in a series to look at how the ISS will be serviced for the next five or six years.

The Japanese were schedule to launch their second H-II Transfer Vehicle (HTV-2) resupply mission today, 20 January, but weather has caused the mission to be rescheduled for a possible launch on Saturday.

The Russians fly their Progress spacecraft on resupply missions, and the next one is scheduled for 28 January.

Johannes Kepler ATV-2
ATV-2 Johannes Kepler
Image Credit:
European Space Agency (ESA)

The European Space Agency (ESA) has flown their Automated Transfer Vehicle (ATV-1 or Jules Verne) to the ISS once before on 9 March 2008, and their next launch is coming up on 15 February 2011.

On the commercial side, Space X has successfully orbited their Dragon spacecraft and returned to Earth. Their next test flight is penciled in for July and the first resupply mission is penciled in for December.

And Orbital Sciences Corporation has their first cargo delivery test of its Cygnus spacecraft scheduled for December 2011.

That summarizes the partners working to support the International Space Station.

Here is a more detailed look at the European Space Agency’s ATV system.

The 20 ton Johannes Kepler ATV has a cargo capacity of up to 7 metric tons. The composition of this load can vary depending on the mission:

  • 1.5 to 5.5 metric tons of freight and supplies (food, research instruments, tools, etc.)
  • up to 840 kilograms of drinking water
  • up to 100 kilograms of gases (air, oxygen and nitrogen)
  • up to four metric tons of fuel for orbit correction and up to 860 kilograms of propellant to refuel the space station.

The spacecraft is compose of two main sections. The first is the ATV Service Module (below, left), which is not pressurized, includes propulsion systems, electrical power, computers, communications and most of the avionics. The ATV uses four main engines and 28 small thrusters to control the navigation of the spacecraft. Four solar panels are deployed after launch and supply 4800 Watts of power to the batteries and the electrical systems.

The second component is the Integrated Cargo Carrier (below, right). The large section in the front is pressurized and comprises about 90% of the cargo volume. It handles all the dry cargo, including the racks on each side. The inhabitants of the International Space Station access this area through the hatch in the Russian docking system.

Service Module
ATV Service Module & Four Main Engines
Image Credit: ESA

Service Module
Cutaway of ATV Cargo Carrier
Image Credit: ESA

The Equipped External Bay of the Integrated Cargo Carrier (ICC) holds 22 spherical tanks of different sizes and colors (below, left). These tanks are used to re-supply the Station with propellant for the International Space Station propulsion system, various gases (air, oxygen, and nitrogen) and water for the crew.

The contents of these tanks are delivered to the Station through dedicated connections, or through manually operated hoses.

Service Module
ATV Liquid Resupply Tanks
Image Credit: ESA

Docking Module
Russian Docking Module
Image Credit: ESA

The ATV uses the Russian-made docking equipment sensors to perform the approach and docking sequence (above, right). The procedure is the same as with the Soyuz manned capsules and the Progress resupply spacecraft.

The Russian docking system enables physical, electrical and propellant connections with the Station. Access to the ICC is through the Russian hatch.

Once the ATV is securely docked, the crew can enter the cargo section and remove the payload, which usually includes maintenance supplies, science hardware, parcels of fresh food, mail and family tapes or DVDs.

NSS Director Stan Rosen on The Space Show

You can hear NSS Director Dr. Stan Rosen as a guest on The Space Show (Internet radio program December 26, 2010) speaking about using space to improve life on Earth, and revolutionary space applications:

Galactic Cosmic Rays (GCR) – The 800 Pound Gorilla

The most recent issue of Science News (18 December 2010) has the following notes from 17 December 1960:

HEAVY SHIELD UNNECESSARY — Heavy shielding as protection for an astronaut against space radiations may not be necessary, at least for trips of less than 50 hours and at distances not greater than 618 miles from earth…. [B]iological specimens were encased in different types of metal to test their effectiveness as shielding materials. Some specimens were shielded only by the thin aluminum covering of the specimen capsule and the comparatively thin shell of the recovery capsule. Radiation dosimeters showed that aluminum provided better shielding properties than lead and that any heavy metal such as gold or lead becomes a hazard during a solar flare as high energy protons interact with these heavy metals to create damaging X-rays.

However, if you want to travel to the Moon or journey anywhere within the Solar System, Galactic Cosmic Radiation will require that the human crew is protected. Let’s take a look at the problem and the research required to test and implement solutions.


The GCR problem arises from interstellar atomic nuclei traveling near the speed of light striking the structure of a spacecraft. The resulting shower of secondary particles cause radiation damage. The Earth is protected by the Van Allen belts and a deep atmosphere. Brief journeys such as an Apollo mission does not expose the astronaut to dangerous dosages. However, astronauts on such a journey are at risk from Solar flares (Solar Particle Events – SPE). SPEs can be mitigated with layers of hydrogen rich materials such as polyethylene or water. GCRs, however, require spaceships on long journeys of more than 100 days, or habitats on the Lunar or Martian surface, to be surrounded by tens of meters of water for passive protection, or magnetic shields for active protection. Either solution is extremely heavy and makes space flight prohibitive in terms of propellant requirements.

The following sections discuss each aspect and provide references for further reading about the problem

The Source of GCR

Galactic Cosmic Rays come from outside our Solar System, but from within our galaxy, the Milky Way. They are comprised of atomic nuclei that have been stripped of their electrons. These nuclei can be any element. Common elements are carbon, oxygen, magnesium, silicon, and iron with similar abundances as the Solar System. Lithium, Berylium and Boron are overabundant relative to the Solar System ratios.

The Shielding Problem

Early on, it was suggested that cosmic rays could penetrate the Apollo spacecraft. From “Biomedical Results of Apollo” section IV, chapter 2, Apollo Light Flash Investigations we have the following account:

Crewmembers of the Apollo 11 mission were the first astronauts to describe an unusual visual phenomenon associated with space flight. During transearth coast, both the Commander and the Lunar Module Pilot reported seeing faint spots or flashes of light when the cabin was dark and they had become dark-adapted. It is believed that these light flashes result from high energy, heavy cosmic rays penetrating the Command Module structure and the crew members’ eyes. These particles are thought to be capable of producing, visual sensations through interaction with the retina, either by direct deposition of ionization energy in the retina or through creation of visible light via the Cerenkov effect.

When Galactic Cosmic Rays collide with another atom, such as those contained in the Aluminum, Stainless Steel or Titanium structures of a spacecraft, they can create a shower of secondary particles, These secondary particles cause radiation damage in living organisms (humans).

The problem is creating sufficiently powerful barriers to these extremely energetic nuclei.

Researching Solutions

  • Passive Shielding – At least for solar flares (SPE), some solutions are easier than the GCR problem.
  • Active Shielding
  • Fast Passage to avoid exposure (VASIMR propelled craft). A proposal for vapor core reactors integrated with VASIMR engines.
  • A proposal for studying radiation and other factors associated with long term human occupation of space.
  • NASA’s Space Radiation Program in association with the Brookhaven National Laboratories.
  • In 2008, the National Academies of Science published Managing Space Radiation Risk in the New Era of Space Exploration, which included chapter 6: Findings and Recommendations
  • From the Summary in Radiation Shielding Simulation For Interplanetary Manned Missions
      Inflatable Habitat + shielding

    • Hadronic interactions are significant, systematics is under control
    • The shielding capabilities of an inflatable habitat are comparable to a conventional rigid structure – Water / polyethylene are equivalent
    • Shielding thickness optimisation involves complex physics effects
    • An additional shielding layer, enclosing a special shelter zone, is effective against SPE
      Moon Habitat

    • Regolith shielding limits GCR and SPE exposure effectively
    • Its shielding capabilities against GCR can be better than conventional Al structures as in the ISS

See also the recent article in New Scientist about radiation hazards. A tip of the hat to ParabolicArc.