The Commercial Future of Spaceflight

A SpaceX rocket will be the next U.S. vehicle to travel to the space station after the shuttlesretire.

The Obama administration recently announced its 2010 proposed budget, which includes $18.7 billion for NASA with a blueprint for retiring the space shuttles in 2010 and returning to the moon by the end of the next decade. But retiring the shuttles means that the United States is without a vehicle to travel to space until 2015, when NASA's next launch vehicle, the Ares rocket, is expected to make its debut.

In the interim, NASA must rely on the Russians' Soyuz spacecraft and the commercial sector to carry crew and cargo to the International Space Station (ISS), a $100 billion U.S. taxpayer asset.
Space Exploration Technologies (SpaceX) is a private company that won a $1.6 billion contract in December through NASA's Commercial Orbital Transportation Services (COTS) program to provide the agency with a launch vehicle capable of reaching ISS.

Technology Review spoke with Lawrence Williams, vice president of SpaceX, about the retirement of the shuttles, NASA's decision to partner with the private industry, and SpaceX's rocket design.

Technology Review: How does the retirement of the space shuttles, and more recently Russia's decision to stop taking paying passengers aboard the Soyuz spacecraft, affect the commercialization of space?

Lawrence Williams: People are so used to the U.S. having access to the space station that it has not really sunk in for most people that in 2010, under the current plan, the U.S. will no longer have its own vehicle, certainly [not] one with crew capability, to access space or the space station. We are going to be limited in the type of missions we can launch. The only option, without using companies like SpaceX, is to use the Russians, which is not a politically popular one.

Future rocket: The Falcon 9 (top) is a launch vehicle being developed by SpaceX to carry cargo and possibly crew to the space station. Lawrence Williams (bottom) is the vice president of SpaceX. Credit: SpaceX

NASA's plan therefore is to rely on the commercial sector to provide cargo capabilities to the station in the interim, until the successor system to the shuttle, the Ares-Orion program, is ready. So SpaceX and [a company called] Orbital Sciences have contracts to take cargo to ISS in that interim time period. We also have an option on our contract, which NASA has yet to exercise, that would allow us to also carry crew to space. In the absence of SpaceX taking crew, our only option, again, is the Russian Soyuz, which is how [the latest] space tourist, Charles Simonyi, is currently planning to travel to space. I think the Russians have decided to stop flying tourists because they are going to have to start flying a lot more U.S. astronauts.

TR: Can you expand on the terms of your contract with NASA?

LW: We have been awarded a contract to develop first the capability to just do cargo, and eventually demonstrations with crew, although NASA has yet to exercise that part of the contract. But we are developing our system with the plan in the future to evolve into carrying crew. The capsule that we have designed is a flexible system, so basically instead of carrying cargo to the space station you put in seats and a crew life-support system. We are currently the only company under contract with NASA to do crew, although again, that option has not been exercised.

The second part of the contract is for $1.6 billion for 12 flights of actual cargo. In other words, the first three flights are demonstration missions as part of the COTS program, and the 12 flights are actual cargo supply, and they start at the end of 2010.

TR: What's your schedule for the flight-demonstration missions?

LW: We are flying the booster later this summer without the cargo capsule on it. Then we will fly booster with the cargo capsule for our first demonstration flight the last quarter of this year [launching from] Cape Canaveral. We won't actually dock to the station, but we will be doing a demonstration flight of our capsule design and are scheduled to do the first docking with the station mid-2010. If we started doing crew development today, we think we could do the crew demonstration in 24 months.

TR: Is there a reason NASA has not started working with you for crew capabilities?

LW: Funding.

Payload volume: A quarter section of the 5.2-meter Falcon 9 fairing at SpaceX’s Hawthorne, CA, headquarters. Credit: SpaceX

TR: So does NASA need more government funding to exercise some of these capabilities?

LW: To a certain extent yes, but it is also a question of priorities: they have been spending a lot of money on the Ares-Orion, which is the next government system that should allow us to go back to the moon and Mars, and that system has been over budget. So it has been a question of spending money on that system or on commercial ventures. We are trying to develop a system that is mostly funded by the private sector--our founder and CEO put up the majority of the money to develop our capability--and we would like the government to be a big customer, but they are not our only customer. The government is not managing and running our program like they are with the space shuttle and the Ares-Orion. It is a different approach, but historically it has been a more efficient approach.
TR: How is your rocket designed, and how does it compare to Ares?

LW: What NASA is developing is really a completely different system. They are developing a system that is designed to support missions to the moon, Mars, and beyond. We have developed a system that will only have a small fraction of the capabilities of the Ares-Orion program. Therefore, the Ares-Orion is far overdesigned to go just to the space station, and we are far underdesigned to go to the moon.

What we have designed is similar to the Russian Soyuz and Progress spacecraft, and what [NASA] has developed is similar to the shuttle, but without the same amount of cargo capability in terms of mass, and without the winged design.

We developed a booster called the Falcon 9. On top of that booster, you can put large satellites, up to a five-meter fairing, or you can replace that fairing with a capsule called the Dragon. The Dragon is like a Gemini or Apollo capsule design, so it is a proven system, but we also have a unique trunk section that allows us to carry unpressurized cargo outside of the pressurized capsule.

TR: How does your approach stand out from those of other commercial space companies?

LW: The difference between our approach and what everyone else is trying to do is that we are so vertically integrated. We manufacture most of the vehicle, the booster as well as the dragon, in house. We don't have a large number of subcontracts, so we can do things much more efficiently, and we control the quality and cost of the manufacturing process.

TR: What is the next phase--more development?

LW: For the most part, that is the end of the development phase for the cargo version. We would like to be able to work on the crew development, which includes developing an escape tower, life-support systems, and all the additional capability needed. Like I said, it has been manufactured and designed from the beginning to evolve to crew, so it is not a whole new development. But we obviously need to develop some additional aspects of the system.

Monitoring Muscle

A handheld device could give doctors more precise data about muscle health--painlessly.

Measuring muscle: A new handheld device can quickly and painlessly assess the health of muscle tissue using a technology called electrical impedance myography. Credit: Brittany Sauser

MULTIMEDIA Watch a demo of the device.

Neuromuscular diseases like amyloid lateral sclerosis (ALS) and muscular dystrophy often involve a progressive loss of muscle function, but tracking the health of muscles over time is not always easy or precise. The best way to diagnose and evaluate muscle degeneration involves an uncomfortable needle test; both this test and other approaches like questionnaires are subjective and not easy to reproduce over multiple sessions.

A new device, under development by Seward Rutkove, a neurologist and scientist at Harvard Medical School, and his colleagues at MIT could provide a painless, noninvasive, and quantitative alternative. The prototype handheld probe, similar to an ultrasound probe, measures electrical impedance in the muscle, which changes depending on the health of the tissue.

The approach, also known as electric impedance myography (EIM), is a modification of the basic technology used in body composition devices to measure the percentage of fat or muscle in the body. A high-frequency electric current is applied to the skin through a set of noninvasive electrodes, while another set of skin electrodes records the resulting voltages from the tissue. The properties of the current change depend on the composition and microscopic structure of the underlying tissue.

Muscles are made of long bundled fibers oriented in the same direction. An electrical current passes more easily when it travels parallel to the fibers; when it passes across the fibers, it encounters more cell membranes, which cause a greater delay or phase shift in the current. Rutkove's group at Beth Israel Deaconess Medical Center has found that this phase shift varies depending on the health of the muscle, since diseased muscle has fewer cell membranes. In addition, energy is lost as the current flows through muscle, and more so when flowing across the fibers. Rutkove's group has found that looking at both phase shift and energy loss can provide unique information on the health of the muscle, since diseased muscles have fewer muscle fibers, smaller cell membranes, and abnormal amounts of fat and water in the muscle, all of which impact these measurements.

Rutkove's group initially made muscle measurements using off-the-shelf body composition devices modified to perform EIM. But the process required stick-on electrodes placed at several positions along a muscle, and a single body part might require multiple rounds placing the electrodes at various angles. The handheld probe, developed in collaboration with Joel Dawson's electrical-engineering lab at MIT, makes it possible to take the measurements quickly without a need for electrodes.

Dawson says that the main technical challenge in developing the device was to find a way to deliver electric currents at varying angles without requiring complex machinery. "We came up with the idea of having a lot of little pixel probes and connecting them together," he says. The head of the device contains two rings of small electrodes: one to send current, and one to measure voltage. These individual electrodes can be electrically connected in different combinations to act as single larger electrodes, or can be isolated individually to give a finer resolution. This allows the researchers to program the specific angles that they want to measure. The device is connected to a computer that calculates impedance measurements and displays the results graphically.

Rutkove is currently testing EIM in patients with ALS and in children with spinal muscular atrophy. He says that the biggest challenge for making EIM useful is knowing how to interpret the data. His work has shown that neuromuscular diseases can have unique EIM "signatures" that can be used to diagnose and treat the disease, but it's an ongoing research effort "to find the right signature or impedance profile that tells you it's one type of disease versus another." The technique must also be tested in enough patients to understand the normal range of individual variability.

"The idea of having a tool that is noninvasive and painless to assess muscle function is very attractive," says Michael Benatar, a neurologist at Emory University, who is testing the device in patients. Currently, the best test for muscle function is electromyography (EMG), which involves placing a needle into the muscle and having the patient contract the muscle. Benatar has been testing the EIM method in patients with ALS to see if the technique could be used for early detection of disease. "We're hoping we might be able to detect abnormalities with EIM that aren't apparent clinically or with conventional techniques," he says. But he adds that EIM is not ready to be used more widely in the clinic until it's clear how to interpret the results.

Rutkove hopes that in the meantime, EIM will prove useful as a research tool. His group is also conducting studies on animals with neuromuscular diseases to understand in more detail how EIM readings relate to the underlying tissue changes with disease.

Why Chrysler Chose A123 Batteries

The automaker wanted U.S.-based manufacturing and a flexible battery design.

Power block: A new battery module serves as a basic building block that can be used to make battery packs of different shapes that fit different vehicles. Credit: A123 Systems

MULTIMEDIA Take a look inside the new battery pack.

This week, Chrysler announced that it will use batteries from A123 Systems in its planned electric vehicles and plug-in hybrids, the first of which will be available in small demonstration fleets by the end of the year. The automaker will use a modular battery system that the two companies developed together over the past three years.

Chrysler chose A123 in part because the company was looking for a supplier based in the United States, says Lou Rhodes, the vice president of advanced vehicle engineering at Chrysler. A123 is based in Watertown, MA, and is building factories in Michigan. The company's battery cells--the basic components of a battery pack--met Chrysler's performance and safety specifications, and the company was developing battery modules that could be easily adapted to fit different vehicles. This was important, Rhodes says, because the automaker plans to start selling several different electric vehicles at around the same time.

A123 and Chrysler developed battery systems that use the same battery cell--one with a flat shape known as a prismatic cell--rather than tailoring the cells' chemistries for each different vehicle. Rhodes expects that this will lead to larger volume production for the battery cell, which could drive down costs. The companies also developed battery modules--units that consist of a collection of cells with safety systems and electronic controls. The modules are designed so that the number of cells in each, as well as the voltage, can be varied according to the application. Finally, the companies developed battery packs for each vehicle. These comprise a varying number of modules arranged in different ways, depending on the configuration of the vehicle.

A123's technology also lent itself to relatively simple battery packs, Rhodes says. The cells use a lithium iron phosphate electrode that is chemically much more stable than the lithium cobalt oxide used in most laptops and in some electric vehicles. Cobalt oxide batteries have been known, in very rare cases, to catch fire in laptops. To prevent this in the much larger and potentially more dangerous battery packs in electric vehicles, companies such as Tesla Motors have designed elaborate cooling systems that carry coolant past each of the thousands of cells in the pack. Because iron phosphate cells are less prone to overheating, the coolant system can be far simpler. The battery modules sit on a heat sink--flat metal sheet--which is cooled by a coolant loop.

Power block: The components of a new battery module. Credit: A123 Systems

A123's battery chemistry does have a disadvantage compared with some other types of lithium ion batteries, including cobalt oxide. It stores less energy, which would limit the range of a car. But Chrysler is making up for this in part by taking advantage of the battery's stability. Cobalt oxide deteriorates quickly if a battery is completely discharged and recharged; to make such batteries last longer and keep them more stable, they're typically electronically limited to using only half of their energy. But A123 says that its iron phosphate batteries can be discharged almost completely without degrading; the result is that more of the energy in the battery can be used. In Chrysler's electric vehicle, the battery pack can be discharged to 10 percent charge to provide a range of up to 200 miles--comparable to the range in similarly sized batteries with chemistries that store more energy.

At a press conference at the New York Auto Show earlier this week, Chrysler's president,James Press, emphasized that the cars will be produced domestically. "In our tradition of being the quintessential American company," he said, "we're partnering with A123 Systems, which is Massachusetts based, and we're going to build a factory in Michigan, and build all-American batteries for our cars."

The decision could help promote an advanced battery industry in the United States, assuming the foundering automaker can stay afloat. A123 Systems is building factories in Michigan to manufacture battery cells and modules and assemble these together to make battery packs, and Chrysler hopes to provide a market for those batteries.

Right now, almost all advanced battery makers build their batteries overseas, including A123, although it has a pack assembly facility in Massachusetts. The company has started construction on the first factory, with help from the state of Michigan, but David Vieau, A123's CEO, says that further help in the form of loans or grants from the federal government could help the company scale up its operations. A123 has applied for $1.8 billion under a loan program that was funded late last year. The company may also apply for grants made available under the stimulus package passed in February.