Commercial Crew Development

From Wikipedia, the free encyclopedia

First group of nine astronauts selected for the NASA Commercial Crew Development program and the two selected spacecraft, the Boeing CST-100 Starliner (left) and SpaceX Crew Dragon

 

NASA Commercial Crew and Cargo
Initiative	Period
Development
Commercial Cargo Development	2006–2013
Commercial Space Transportation Capabilities	2007–2010
Commercial Crew Development (phase 1)	2010–2011
Commercial Crew Development (phase 2)	2011–2012
Commercial Crew integrated Capability (phase 3) (base period milestones)	2012–2014
Commercial Crew integrated Capability (phase 4) (optional period milestones)	2014–2017
Certification
Certification Products Contract (crew)	2012–2014
Commercial Crew Transportation Capability	2014–2017
Services
Commercial Resupply Services (cargo)	2011–2016
ISS Crew Transportation Services (crew)	2017–present
NASA's COTS program Private spaceflight companies

Commercial Crew Development (CCDev) is a multiphase, space technology development program that is funded by the U.S. government and administered by NASA. The program is intended to stimulate development of privately operated crew vehicles to be launched into low Earth orbit. The program is run by NASA's Commercial Crew and Cargo Program Office (C3PO).

In 2010, in the first phase of the program, NASA provided $50 million combined to five American companies; the money was intended for research and development into private-sector human spaceflight concepts and technologies. NASA solicited a second set of CCdev proposals for technology development projects lasting for a maximum of 14 months in October of that year. In April 2011, NASA announced they would award up to nearly $270 million to four companies as they met their CCDev 2 objectives. 

NASA awarded Space Act Agreements for the third phase, named CCiCap, in August 2012; this would last until 2014. CCiCap is followed by CCtCap with Federal Acquisition Regulation (FAR) Part 15 contracts, which formed the fourth and final phase of the program. Contracts were awarded to SpaceX and Boeing in September 2014. Test flights of both spacecraft are scheduled for late 2018. SpaceX and Boeing have contracts with NASA to each supply six flights to ISS between 2019 and 2024. The first group of astronauts assigned to fly on the two selected spacecraft were announced on August 3, 2018.

Requirements

The key, high-level requirements for the Commercial Crew vehicles include:

• Deliver and return four crew members and their equipment to International Space Station (ISS);
• Provide assured crew return in the event of an emergency;
• Serve as a 24-hour safe haven in the event of an emergency;
• Capable of remaining docked for 210 days—the Space Shuttle could only remain docked for a maximum of 12 days.

Program overview

Flag left aboard ISS by the crew of STS-135 is to be retrieved by the next crew launched on an American vehicle.

The NASA CCDev program followed Commercial Orbital Transportation Services (COTS), a program for developing commercial launch capability to send cargo into low Earth orbit. In December 2009, NASA provided the following description of the CCDev program:

The objectives of the Commercial Crew & Cargo Program are to implement U.S. Space Exploration policy with investments to stimulate the commercial space industry; facilitate U.S. private industry demonstration of cargo and crew space transportation capabilities with the goal of achieving safe, reliable, cost effective access to low-Earth orbit; and create a market environment in which commercial space transportation services are available to Government and private sector customers.

The Commercial Crew & Cargo Program is applying Recovery Act funds to stimulate efforts within the private sector to develop and demonstrate human spaceflight capabilities. NASA plans to use funds appropriated for "Exploration" under the American Recovery & Reinvestment Act of 2009 (ARRA) through its C3PO to support efforts within the private sector to develop system concepts and capabilities that could ultimately lead to the availability of commercial human spaceflight services. These efforts are intended to foster entrepreneurial activity leading to job growth in engineering, analysis, design, and research and to promote economic recovery as capabilities for new markets are created.

ARRA provided $400 million for space exploration related activities. Of this amount, $50 million is to be used for the development of commercial crew space transportation concepts and enabling capabilities. This effort is known as CCDev. The purpose of this activity is to provide funding to assist viable commercial entities in the development of system concepts, key technologies, and capabilities that could ultimately be used in commercial crew human space transportation systems. This development work must show, within the timeframe of the agreement, significant progress on long lead capabilities, technologies and commercial crew risk mitigation tasks in order to accelerate the development of their commercial crew space transportation concept.

Contract funding for the CCDev program is different from traditional space industry contractor funding used on the Space Shuttle, Apollo, Gemini, and Mercury programs. Contracts are explicitly designed to fund subsystem technology development objectives that NASA wants for NASA purposes; all other system technology development is funded by the commercial contractor. Contracts are issued for fixed-price, pay-for-performance milestones. "NASA's contribution is fixed".

Funding and effect on schedule

Requested vs appropriated funding by year

The first flight of the CCDev program was planned to occur in 2015, but insufficient funding caused delays. Administrator of NASA Charles Bolden attributed the delays to insufficient funding from Congress. Michael López-Alegría, President of the Commercial Spaceflight Federation, also attributed the delays in the program to funding problems.

For the fiscal year (FY) 2011 budget, US$500 million was requested for the CCDev program, but Congress granted only $270 million. For the FY 2012 budget, $850 million was requested but Congress approved a budget of $406 million, and as a result the first flight of CCDev was postponed from 2016 to 2017. For the 2013 budget, 830 million was requested but Congress approved $488 million. For the FY 2014 budget, $821 million was requested, Congress approved $696 million. In FY 2015, NASA received $805 million from Congress for the CCDev program; 95% of the $848 million requested by the Obama administration and the largest annual amount since the beginning of the program.

Spaceflight gap after STS

Saturn IB mounted on the "milkstool" platform. Its 1975 flight was the last manned U.S. mission until 1981

After the last flight of the STS in 2011 the clock began ticking on a U.S. spaceflight gap. The previous spaceflight gap was between 1975 (a Saturn IB launch) and the first STS flight in April 1981, about six years. Unlike the last human spaceflight gap, the U.S. has bought seats on the still-active Russian launcher as part of their continuing joint international project, the International Space Station. U.S. Congress was aware such a gap could occur and accelerated funding in 2008 and 2009 in preparation for the retirement of the Shuttle. At that time the first crewed flight of the planned Ares I launcher would not have occurred until 2015, and its first use at ISS until 2016. Steps were also taken to extend STS operation past 2010. However, in 2010 the Ares I was cancelled and focus shifted to the Space Launch System and the commercial crew program. As of 2016 the first manned flight of SLS is Exploration Mission 2, to launch in 2021 at the earliest. As of 2016 a manned commercial crew mission might occur as early as 2018. If NASA does get access to its own launcher it may be able to again trade seats rather than buy them, or the two countries may organize another sale. NASA has bought seats for 2018, and it may need to buy seats for 2019 also.

NASA bought seats on the Russian launcher even while the Space Shuttle was active, and partners in the International Space Station project needed to cross-train on each-others launchers and equipment. When the STS program ended, this aspect of the involvement in ISS continued, and NASA has a contract for seats until at least 2017. The price has varied over time, and the batch of seats from 2016 to 2017 works out to 70.7 million per passenger per flight. The use of the Russian launcher Soyuz by NASA was a part of the ISS program which was orchestrated in the 1990s when that project was planned out: it is used as the emergency lifeboat for the station even before the Space Shuttle retired so anyone staying on the station had to train on this spacecraft regardless. The first Soyuz flight to ISS in 2000 included a U.S. astronaut (Soyuz TM-31 as part of Expedition 1). U.S. astronauts regularly flew on the Soyuz while the Shuttle program regularly visited the Station, even as it brought major components. Likewise Russian and other international partners also flew on the Space Shuttle and the Soyuz spacecraft, sometimes only on one direction of the journey.

The U.S. was working on an emergency escape vehicle called the HL-20 Personnel Launch System but was cancelled in 1993 in favor of using extra Soyuz spacecraft as lifeboats; not developing another spacecraft was seen as a way to save money in the aftermath of restructuring the Space Station Freedom project when the USSR dissolved in 1991. Regardless, CCDev "seats" have often been compared to Soyuz prices for comparison during its development. With no other launcher available NASA may have to buy seats until 2019 to access the international space station. The other main partners in ISS, the ESA, cancelled its own manned launch system, the Hermes mini-shuttle, in 1992. The ESA had previously traded Spacelab hardware for flights on Space Shuttles. There has been some interest from Europe in the CCDev contenders, especially with Dream Chaser, with one party saying it was, "..ideal vehicle for a broad range of space applications."

Phases

CCDev 1

Construction of the CST-100 pressure vessel was one of Boeing's CCDev 1 milestones

 

Under CCDev phase 1, NASA has entered into funded Space Act Agreements with several companies working on technologies and systems for human space flight. Funding was provided as part of the American Recovery and Reinvestment Act of 2009. A total of $50 million for 2010 was awarded to five American companies with the intention of fostering research and development into human spaceflight concepts and technologies in the private sector. The phase 1 amount was originally intended to be $150 million, most of which was diverted to the Constellation program by Senator Richard Shelby (R-AL). All 53 delivery milestones for the five companies were scheduled to be completed by the end of 2010.

Proposals selected

NASA awarded development funds to five companies under CCDev 1:

1. Blue Origin: $3.7M for an innovative 'pusher' Launch Abort System (LAS) and composite pressure vessels. As of February 2011, with the end of the second ground test, Blue Origin has completed all work for the pusher escape system planned under the contract. It has also "completed work on the other aspect of its award, risk reduction work on a composite pressure vessel" for its vehicle.
2. Boeing: $18M for development of the CST-100 capsule it demonstrated in October 2010. According to NASA's website all milestones were completed.
3. Paragon Space Development Corporation: $1.4M for a plug-and-play environmental control and life support system (ECLSS) Air Revitalization System (ARS) Engineering Development Unit. With "the completion of testing in mid-December [2010] of its 'Commercial Crew Transport Air Revitalization System', a life support system intended for use on [multiple different] commercial crew vehicles", Paragon has completed all work under the contract.
4. Sierra Nevada Corporation: $20M for development of the Dream Chaser, a reusable spaceplane vehicle that can transport cargo and up to eight people to low Earth orbit. Sierra Nevada completed its work under the contract in December 2010, with the structural testing of its engineering test article—its fourth and final milestone.
5. United Launch Alliance: $6.7M for an Emergency Detection System (EDS) for human-rating its Evolved Expendable Launch Vehicles (EELVs). In December 2010, ULA carried out a demonstration of its Emergency Detection System; according to NASA's website all milestones were completed.

Proposals received

During the evaluation phase of CCDev1 proposals were received from the following participants:

Ad Astra Rocket Company AlphaSpaces Andrews Space ARES Corporation Alliant Techsystems (ATK) Ball Aerospace Bigelow Aerospace Blue Origin Blue Smoke

Boeing Dii Aerospace Laboratories Exploration Partners Firestar Engineering Global Outpost HMX, Inc. IE Group KT Engineering Oceaneering Space Systems

Odyssey Space Research Orbital Outfitters Orbital Sciences Corporation Orbital Technologies Paragon Space Development Planetspace S.T.A.R. Systems Sierra Nevada Corporation SpaceED – UC Davis

SpaceX Stone Aerospace The Expanding Universe Thomas Lee Elifritz United Launch Alliance Universal Space Lines Universal Transport Systems Vivace XCOR Aerospace

CCDev 2

The construction of a Dragon crew mock-up was one of SpaceX's CCDev 2 milestones, it is seen here during an event

 

NASA sought a second set of Commercial Crew Development proposals in October 2010. These could be both new concepts and proposals that mature the design and development of system elements, such as launch vehicles and spacecraft. NASA originally planned to issue about $200 million of Space Act Agreements in March 2011. On April 18, 2011, NASA awarded nearly $270 million to four companies for developing U.S. vehicles that could fly astronauts after the Space Shuttle fleet's retirement.

In August the same year, NASA provided status on the progress milestones of the four companies developing crew vehicle technologies under CCDev 2. There are nine-to-eleven specific milestones, spread over the second quarter of 2011 through to the second quarter of 2012, that each company must meet to receive their performance-based funding for CCDev 2.

Proposals selected

Winners of funding in the second round of the CCDev were:

• Blue Origin, Kent, Washington: $22 million. Blue Origin proposed advancing technologies in support of a biconic nose cone design orbital vehicle, including launch abort systems and restartable, liquid oxygen/liquid hydrogen engines. Blue Origin has since completed all of its CCDev 2 milestones. In November 2014, NASA announced three additional unfunded milestones, which include further testing of Blue Origin's propellant tank, BE-3 engine and pusher escape system.
• Sierra Nevada Corporation, Louisville, Colorado: $80 million. Sierra Nevada proposed four phase 2 extensions of its Dream Chaser spaceplane technology. Like the Orbital Sciences proposal, the Dream Chaser was also a lifting body design. Sierra Nevada will use Virgin Galactic to market Dream Chaser commercial services and will use Virgin's WhiteKnightTwo carrier aircraft as a platform for drop trials of the Dream Chaser atmospheric test vehicle in 2012.
• Space Exploration Technologies (SpaceX), Hawthorne, California: $75 million. SpaceX proposed to develop an "integrated launch abort system design" for the Dragon spacecraft, with theoretical advantages over the more traditional tractor tower approaches used on earlier manned space capsules. The system would be part of SpaceX's Draco maneuvering system, which is currently used on the Dragon capsule for in-orbit maneuvering and de-orbit burns. SpaceX completed its CCDev 2 milestones by August 2012.
• The Boeing Company, Houston, Texas: $92.3 million. Boeing proposed additional development for the seven-person CST-100 spacecraft, beyond the objectives for the $18 million received from NASA in CCDev 1. The capsule will have personnel and cargo configurations, and is designed to be launched by multiple different rockets and be reusable up to 10 times.

Proposals selected without NASA funding

• United Launch Alliance proposed to extend development work on human-rating the Atlas V rocket. Although not selected for funding, NASA entered into an unfunded Space Act Agreement with ULA in July 2011 to share information with the goal of advancing the development of the rocket, which is the proposed launch vehicle for the Blue Origin, Boeing and Sierra Nevada Corporation proposals. ULA finished completing all of their CCDev 2 milestones by September 2012.
• Alliant Techsystems (ATK) and Astrium proposed development of the Liberty rocket derived from the Ares I and Ariane 5. On September 13, 2011, it was reported that NASA intended to form at agreement with ATK to further develop the Liberty rocket as a heavy launch vehicle capable of launching humans into space. Although no funding is to be provided by NASA, the agency will share expertise and technology. ATK finished completing all of its CCDev 2 milestones by August 2012.
• Excalibur Almaz Inc. is developing a crewed system incorporating modernized, Soviet-era space hardware designs intended for tourism flights to orbit. On October 26, 2011, NASA announced it had entered into an unfunded Space Act Agreement with EAI, establishing a framework to collaborate to further develop EAI's spacecraft concept for low Earth orbit crew transportation. EAI's concept for commercial crew to the ISS is to use the company's planned three-person space vehicle with an intermediate stage and fly the integrated vehicle on a commercially available launch vehicle. Excalibur Almaz finished completing all of their CCDev 2 milestones by June 2012.

Proposals not selected

Proposals that were not awarded funds in the second round of the CCDev program were:

• Orbital Sciences proposed the Prometheus lifting-body spaceplane vehicle, about one-quarter the size of the Space Shuttle. The Vertical Takeoff, Horizontal Landing (VTHL) vehicle would be launched on a human-rated Atlas V rocket but would land on a runway. The initial design would carry a crew of four, but it could carry up to six people or a combination of crew and cargo. In addition to Orbital Sciences, the consortium included Northrop Grumman that would have built the spaceplane and the United Launch Alliance that would have provided the launch vehicle. Virgin Galactic also confirmed it would be teaming with Orbital on the Orbital CCDev 2 project. After failing to be selected for a CCDev phase 2 award by NASA, Orbital announced in April 2011 it would likely wind down its efforts to develop a commercial crew vehicle.
• Paragon Space Development Corporation proposed additional development of the Commercial Crew Transport-Air Revitalization System (CCT-ARS) program in 2011, to permit the building-out of the other parts of the Environmental Control and Life Support Systems to provide the complete solution for its commercial crew transport customers.
• t/Space proposed a recoverable, reusable, eight-person crew or cargo transfer spacecraft that could launch on a variety of launch vehicles including the Atlas V, Falcon 9 and Taurus II rockets.
• United Space Alliance proposed under a plan called Commercial Space Transportation Service (CSTS) to fly commercially the two remaining Space Shuttle vehicles, Endeavour and Atlantis, twice a year from 2013 to 2017.

Commercial Crew integrated Capability

Flight testing of the Dream Chaser Engineering Test Article was one of Sierra Nevada's CCiCap milestones

 

The Commercial Crew integrated Capability (CCiCap) initiative is the third round of the CCdev program and was originally called CCDev 3. For this phase of the program, NASA wanted proposals to be complete, end-to-end designs including spacecraft, launch vehicles, launch services, ground and mission operations, and recovery. In September 2011, NASA released a draft request for proposals (RFP).

The U.S. government's was originally intended to use a new contracting mechanism for CCiCap that differed from the Space Act Agreement's fixed-price, milestone-based contracts of the previous phases. As of October 2011, NASA was planning to award competitive contracts under the more traditional Federal Acquisition Regulations (FAR) system instead of using Space Act Agreements. After some months of planning for the new-style contracting approach, NASA announced in mid-December 2011 it would resume use of Space Act Agreements because of Congressional funding reductions to the program for Fiscal Year 2012. NASA planned to use FAR contracts for the certification of Commercial Transportation Services to the ISS. The final RFP was released on February 7, 2012, with proposals due on March 23, 2012.

The funded Space Act Agreements were awarded on August 3, 2012, and amended on August 15, 2013. CCiCap contracts were planned to be completed by August 2014. NASA hoped facilitating development of this U.S. capability will provide safe, reliable and cost effective human transportation to low-Earth orbit (LEO).

Proposals selected

Winners of funding in the third round of the Commercial Crew Development program, announced on August 3, 2012, were:

• Sierra Nevada Corporation, Louisville, Colorado: $212.5 million. Sierra Nevada Corporation proposed further development of its Dream Chaser spaceplane/Atlas V system.
• Space Exploration Technologies (SpaceX), Hawthorne, California: $440 million. SpaceX proposed further development of the Dragon spacecraft / Falcon 9 system.
• The Boeing Company, Houston, Texas: $460 million. Boeing proposed further development for the CST-100 spacecraft/Atlas V system.

Proposals that passed acceptability screening

• ATK – Liberty

Proposals not selected

• Space Operations
• American Aerospace
• Spacedesign Corporation

Development achievements

NASA reported that as of November 2014, Boeing had completed its CCiCap milestones; Sierra Nevada had completed 10 of its 13 milestones; SpaceX had completed 13 of its 18 milestones. SpaceX received an extra milestone that is to be completed by March 2015. The milestones are listed in the appendixes to the Funded Space Act Agreements. In May 2014, Boeing, Sierra Nevada Corporation and SpaceX completed reviews detailing plans to meet NASA's certification requirements to transport crew members to and from the ISS.

Preparation for the next phase

In June 2014, Boeing announced it intended to send out preliminary lay-off notices to 215 employees—approximately 170 in Houston and 45 in Florida—to prepare for the possibility that Boeing would not be selected to continue work into the next phase following the expected NASA shortlist in mid-2014. These advance notices are required under the Worker Adjustment and Retraining Notification Act (WARN) legislation under U.S. law, and must be issued 60 days before any large lay-off is expected to take effect. If Boeing was selected to continue, the lay-offs would not occur and Boeing would hire an additional 75 personnel. Sierra Nevada "is not preparing any WARN notices to its Dream Chaser workforce".

Certification Products Contract (CPC) phase 1

The first phase of the Certification Products Contract (CPC) involved the review of the integrated crew transportation systems through the creation of a certification plan that would result in the development of engineering standards, tests and analyses of the systems' designs. This phase of CPC was expected to run from January 22, 2013, to May 30, 2014.

Proposals selected

Winners of funding of phase 1 of the CPC, announced on December 10, 2012, were:

• Sierra Nevada Corporation, Louisville, Colorado: $10 million.
• Space Exploration Technologies (SpaceX), Hawthorne, California: $9.6 million.
• The Boeing Company, Houston, Texas: $9.9 million.

Certification Products Contract (CPC) phase 2

The second phase of the CPC was expected to begin in mid-2014; it would involve a full and open competition and would include the final development, testing and verifications to allow crewed demonstration flights to the ISS. Phase 2 is called Commercial Crew Transportation Capability (CCtCap). NASA proposed the second phase of the program would begin purchasing commercial astronaut transportation services with the CCtCap solicitation. Contract award and funding occurred in 2014; flights of NASA astronauts on CCtCap-provided vehicles would not occur before 2017. In a change from previous CCDev programs where commercial providers tested the developed technology to NASA contractual requirements, CCtCap will include Joint Test Teams (JTT) with NASA personnel operating in a traditional NASA acquisition approach in which NASA oversees some design choices and offers flexible-price cost-sharing to pay for the tests. NASA issued the draft CCtCap contract's Request For Proposals (RFP) on July 19, 2013; the response date was August 15, 2013.

According to the letter and Executive Summary:

• "The [CCtCap] contract is the second phase of a 2-phased procurement strategy to develop a U.S. commercial crew space transportation capability to achieve safe, reliable and cost effective access to and from the [ISS] with a goal of no later than 2017".
• Performance-based payments are to be used in this competitive, negotiated acquisition.
• Proposed deviation language to specific FAR and NFS clauses and proposed waiving of clauses were suggested.
• Under CCtCap the final Design, Development, Test, and Evaluation (DDTE) activities necessary to achieve NASA's certification of a Crew Transportation System (CTS) will be conducted. The contract will be issued under Federal Acquisition Regulations (FAR) Part 15 and will be Firm Fixed Price (FFP).

There are four separate Contract Line Items (CLINs) for CTS certification; ISS mission support, special studies and additional cargo capability if proposed. NASA was to supply four Docking System Block 1 Units on a no-charge-for-use basis. The first unit would be available in February 2016. NASA held a Commercial Crew Pre-proposal Conference at Kennedy Space Center on December 4, 2013, after formally requesting proposals for CCtCap in late November that year.

NASA's 2014 budget for CCtCap was US$696 million; it was reduced from an Obama Administration request of US$821 million. In May 2014, NASA announced each awardee was to perform at least one crewed test flight to verify the spacecraft could dock with the ISS and all its systems performed as expected. NASA intended to meet its station crew rotation requirements by including at least two, and at most six crewed, post-certification missions in the contracts. NASA also intended CCtCap would allow U.S. providers to supply other customers.

Awards

On September 16, 2014, NASA announced that Boeing and SpaceX had received contracts to provide crewed launch services to the ISS. For completing the same contract requirements, Boeing could receive up to US$4.2 billion, while SpaceX could receive up to US$2.6 billion. Both Boeing CST-100 flying on United Launch Alliance (ULA) Atlas V and SpaceX Dragon V2 flying on Falcon 9 were awarded for the same set of requirements: completing development and certification of their crew vehicle then flying a certification flight followed by up to six operational flights to the ISS. The contracts included at least two operational flights for each company.

The total program award of US$6.8 billion covers development costs through CCtCap program funding—$3.42 billion over the years 2015–2019 with $848 million in the commercial crew budget request for FY 2015—and $3.4 billion for operational crew resupply to the ISS—12 flights with four astronauts on each flight, where NASA assumed the same per-seat price of $70.7 million it would pay for each Soyuz seat in 2016. With the program awards in September, NASA did not release the number of proposals it received or any details about the selection process; it stated such information would be released "at an 'appropriate' but unspecified date".

On September 26, 2014, Sierra Nevada Corporation submitted a protest of the CCtCap awards, stating to have undercut Boeing by $900 million while scoring close to its competitors in the other criteria. The Government Accountability Office (GAO) had until January 5, 2015, to rule on the protest. By October 1, 2014, NASA had instructed Boeing and SpaceX to halt work on the CCtCap contracts. On October 8, 2014, NASA instructed the contractors to proceed with contract work during the GAO review. In January 2015, the GAO denied Sierra Nevada Corporation's protest.

In 2016 the firms scheduled additional testing and certification milestones. The auditors do not expect the first flights until late 2018.

CCtCap contract progress

As of December 2014, both SpaceX and Boeing had started work on their Commercial Crew Transportation Capability (CCtCap) contracts.

As of September 2016 although both companies are advancing they are running behind their previous schedule. Additional milestones have been agreed with NASA see Annex B (Boeing) and Annex C (SpaceX) of the September 2016 Audit of the Commercial Crew Program. Boeing increased its milestones from 23 to 34 and has achieved 15. SpaceX has increased its milestones from 18 to 21 and has achieved 8. SpaceX also has an uncompleted milestone left over from CCiCap.

Flights

As of January 2017 NASA has ordered twelve commercial post-certification missions to deliver astronauts to the International Space Station, six with each supplier. Astronaut selections for the first four missions were announced on August 2, 2018.

Spacecraft	Mission	Description	Crew	Date
Dragon 2	SpX-DM1	Uncrewed test flight	None	January 2019
CST-100	Boe-OFT	Uncrewed test flight	None	March 2019
Dragon 2		In-flight abort test at max Q	None	May 2019
Dragon 2	SpX-DM2	Crewed test flight	Robert Behnken, Douglas Hurley	June 2019
CST-100	Boe-CFT	Crewed test flight	Eric Boe, Christopher Ferguson, Nicole Aunapu Mann	August 2019
Dragon 2	Crew-1	First Dragon mission to ISS	Victor J. Glover, Michael S. Hopkins	September 2019
CST-100	CTS-1	First Starliner mission to ISS	Josh Cassada, Sunita Williams	February 2020

Funding summary

The funding of all commercial crew contractors for each phase of the CCP program is as follows—CCtCap values are maxima and include post-development operational flights.

Funding Summary (millions of US$)

Round (years)	CCDev1 (2010–2011)	CCDev2(2011–2012)	CCiCap (2012–2014)	CPC1 (2013–2014)	CCtCap	Total (2010–2017)
Manufacturers of spacecraft
The Boeing Company	18.0	92.3 + 20.61	460.0 + 203	9.9	4,200.0	4,820.9
Blue Origin	3.7	22.0	–	–	–	25.7
Sierra Nevada Corporation	20.0	80.0 + 25.61	212.5 + 153	10.0	–	362.1
SpaceX	–	75.0	440.0 + 203	9.6	2,600.0	3,144.6
Excalibur Almaz	–	02	–	–	–	0
Manufacturers of launch vehicles
United Launch Alliance	6.7	0	–	–	–	6.7
Alliant Techsystems (ATK)	–	0	–	–	–	0
Others
Paragon Space Development Corporation	1.4	–	–	–	–	1.4
Total:	49.8	315.5	1,167.5	29.6	6,800.0	8,362.4
1 Additional amount awarded in 2011. 2 Space Act Agreement signed in 2011 in the frame of CCDev2. 3 Additional amount awarded in 2013.

Variable Specific Impulse Magnetoplasma Rocket (VASIMR -- updated, with Zubrin's Comments)

From Wikipedia, the free encyclopedia

Artist's impression of multi-megawatt VASIMR spacecraft

The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) is an electromagnetic thruster under development for possible use in spacecraft propulsion. It uses radio waves to ionize and heat a propellant. Then a magnetic field accelerates the resulting plasma to generate thrust (plasma propulsion engine). It is one of several types of spacecraft electric propulsion systems. 

The VASIMR method for heating plasma was originally developed from nuclear fusion research. It is intended to bridge the gap between high-thrust, low-specific impulse and low-thrust, high-specific impulse systems, and is capable of functioning in either mode. Former NASA astronaut Franklin Chang Díaz created the VASIMR concept and has been developing it since 1977.

VASIMRs units for development and test are assembled by Ad Astra Rocket Company in Costa Rica.

Design and operation

VASIMR schematic

 

VASIMR, sometimes referred to as the Electro-thermal Plasma Thruster or Electro-thermal Magnetoplasma Rocket, uses radio waves to ionize and heat the propellant, which is then accelerated with magnetic fields to generate thrust. This engine is electrodeless, of the same propulsion family as the electrodeless plasma thruster, the microwave arcjet, or the pulsed inductive thruster class. It can be thought of as an electrodeless version of an arcjet rocket that can reach higher propellant temperature by limiting the heat flux from the plasma to the structure. Neither type of engine uses electrodes; this eliminates the electrode erosion that shortens the life of other ion thruster designs. Since every part of a VASIMR engine is magnetically shielded and does not directly contact plasma, the durability of this engine is predicted to be greater than many other ion/plasma engines.

VASIMR has been described as a convergent-divergent nozzle for ions and electrons. The propellant (a neutral gas such as argon or xenon) is injected into a hollow cylinder surfaced with electromagnets. On entering the engine, the gas is first heated to a “cold plasma” by a helicon RF antenna (also known as a “coupler”) that bombards the gas with electromagnetic waves, stripping electrons off the propellant atoms and producing a plasma of ions and loose electrons that flow down the engine compartment. By varying the amount of energy dedicated to RF heating and the amount of propellant delivered for plasma generation, VASIMR is capable of generating either low-thrust, high–specific impulse exhaust or relatively high-thrust, low–specific impulse exhaust. The second phase of the engine is a strong electromagnet positioned to compress the ionized plasma in a similar fashion to a convergent-divergent nozzle that compresses gas in traditional rocket engines.

A second coupler, known as the Ion Cyclotron Heating (ICH) section, emits electromagnetic waves in resonance with the orbits of ions and electrons as they travel through the engine. Resonance is achieved through a reduction of the magnetic field in this portion of the engine that slows the orbital motion of the plasma particles. This section further heats the plasma to greater than 1,000,000 K (1,000,000 °C; 1,800,000 °F) —about 173 times the temperature of the Sun's surface.

The path of ions and electrons through the engine approximates lines parallel to the engine walls; however, the particles actually orbit those lines while traveling linearly through the engine. The final, diverging, section of the engine contains an expanding magnetic field that drives the ions and electrons in steadily expanding spirals and ejects them from the engine, parallel and opposite to the direction of motion at velocities as great as 50,000 m/s (110,000 mph).

Advantages and drawbacks

In contrast to the typical cyclotron resonance heating processes, VASIMR ions are immediately ejected from the magnetic nozzle before they achieve thermalized distribution. Based on novel theoretical work in 2004 by Alexey V. Arefiev and Boris N. Breizman of University of Texas at Austin, virtually all of the energy in the ion cyclotron wave is uniformly transferred to ionized plasma in a single-pass cyclotron absorption process. This allows for ions to leave the magnetic nozzle with a very narrow energy distribution, and for significantly simplified and compact magnet arrangement in the engine.

VASIMR does not use electrodes; instead, it magnetically shields plasma from most hardware parts, thus eliminating electrode erosion, a major source of wear in ion engines. Compared to traditional rocket engines with very complex plumbing, high performance valves, actuators and turbopumps, VASIMR has almost no moving parts (apart from minor ones, like gas valves), maximizing long term durability.

However, new problems emerge, such as interaction with strong magnetic fields and thermal management. The relatively large power at which VASIMR operates generates substantial waste heat that needs to be channeled away without creating thermal overload and thermal stress. Powerful superconducting electromagnets, necessary to contain hot plasma, generate tesla-range magnetic fields that can cause problems with other onboard devices and produce unwanted torque by interaction with the magnetosphere. To counter this latter effect, the VF-200 consists of two 100 kW thruster units packaged with magnetic fields oriented in opposite directions, making a net zero-torque magnetic quadrupole.

Research and development

The testing vacuum chamber, containing the 50 kW VASIMR, operated in ASPL in 2005–2006

The first VASIMR experiment was conducted at Massachusetts Institute of Technology in 1983 on the magnetic mirror plasma device. Important refinements were introduced to the rocket concept in the 1990s, including the use of the "helicon" plasma source, which replaced the plasma gun originally envisioned and made the rocket completely "electrodeless"—adding to durability and long life. A new patent was granted in 2002. 

In 1995, the Advanced Space Propulsion Laboratory (ASPL) was founded at NASA Lyndon B. Johnson Space Center, in the Sonny Carter Training Facility. The magnetic mirror device was brought from MIT. The first plasma experiment in Houston was conducted with a microwave plasma source. Collaboration was established with University of Houston, UT-Austin, Rice University and other academic institutions. 

In 1998, the first helicon plasma experiment was performed at the ASPL. VASIMR experiment (VX) 10 in 1998 achieved a helicon RF plasma discharge as great as 10 kW, VX-25 in 2002 as great as 25 kW, and VX-50 as great as 50 kW. In March 2000, the VASIMR group was given a Rotary National Award for Space Achievement/Stellar Award. By 2005 breakthroughs were obtained at ASPL including full/efficient plasma production and acceleration of the plasma ions. VX-50 proved capable of 0.5 newtons (0.1 lbf) of thrust. Published data on VX-50, capable of 50 kW of total radio frequency power, showed ICRF (second stage) efficiency to be 59% calculated by 90% N_A coupling efficiency × 65% N_B ion speed boosting efficiency.

Ad Astra Rocket Company (AARC) was incorporated on January 14, 2005. On June 23, 2005, Ad Astra and NASA signed the first Space Act Agreement to privatize VASIMR Technology. On July 8, 2005, Díaz retired from NASA after 25 years. Ad Astra’s Board of Directors was formed and Díaz became chairman and CEO on July 15, 2005. In July 2006, AARC opened its Costa Rica subsidiary in Liberia on the campus of Earth University. In December 2006, AARC-Costa Rica performed its first plasma experiment on the VX-CR device, using helicon ionization of argon.

The 100 kilowatt VASIMR experiment was successfully running by 2007 and demonstrated efficient plasma production with an ionization cost below 100 eV. VX-100 plasma output tripled the prior record of the VX-50.

Model VX-100 was expected to have N_B ion speed boosting efficiency of 80%. Instead, efficiency losses emerged from the conversion of DC electric current to radio frequency power and the energy consumption of the auxiliary equipment for the superconducting magnet. By comparison, 2009 state-of-the-art, proven ion engine designs such as NASA's High Power Electric Propulsion (HiPEP) operated at 80% total thruster/PPU energy efficiency.

200 kW engine

On October 24, 2008 the company announced that the plasma generation component of the VX-200 engine—helicon first stage or solid-state high frequency power transmitter—had reached operational status. The key enabling technology, solid-state DC-RF power-processing, reached 98% efficiency. The helicon discharge used 30 kW of radio waves to turn argon gas into plasma. The remaining 170 kW of power was allocated for acceleration of plasma in the second part of the engine, via ion cyclotron resonance heating.

Based on data from VX-100 testing, it was expected that the VX-200 engine would have a system efficiency of 60–65% and thrust level of 5 N. Optimal specific impulse appeared to be around 5,000 s using low cost argon propellant. One of the remaining untested issues was potential vs actual thrust—whether the hot plasma actually detached from the rocket. Another issue was waste heat management. About 60% of input energy became useful kinetic energy. Much of the remaining 40% is secondary ionizations from plasma crossing magnetic field lines and exhaust divergence. A significant portion of that 40% was waste heat. Managing and rejecting that waste heat is critical.

VX-200 plasma engine at full power, employing both stages with full magnetic field

 

Between April and September 2009, tests were performed on the VX-200 prototype with integrated 2-tesla superconducting magnets. They expanded the power range of the VASIMR to its operational capability of 200 kW.

During November 2010, long duration, full power firing tests were performed, reaching steady state operation for 25 seconds and validating basic design characteristics.

Results presented in January 2011 confirmed that the design point for optimal efficiency on the VX-200 is 50 km/s exhaust velocity, or an I_sp of 5000 s. Based on these data, thruster efficiency of 72% was achieved, yielding overall system efficiency (DC electricity to thruster power) of 60% (since the DC to RF power conversion efficiency exceeds 95%) with argon propellant. VX-200 generates a thrust of around 5.4 N at 200 kW total RF power, and 3.2 N at 100 kW RF power.

The 200 kW VX-200 had executed more than 10,000 engine firings by 2013, while demonstrating greater than 70% thruster efficiency—relative to RF power input—with argon propellant at full power.

VF-200

The VF-200 flight-rated thruster consists of two 100 kW VASIMR units with opposite magnetic dipoles so that no net torque is applied to the space station when the thruster magnets are working. The VF-200-1 is the first flight unit and was slated to be tested in space attached to the ISS.

NASA partnership

In June 2005, Ad Astra signed its first Space Act Agreement with NASA, which led to the development of the VASIMR engine. In December 10, 2007, AARC and NASA signed an Umbrella Space Act Agreement relating to the space agency's potential interest in the engine . In December 8, 2008, NASA and AARC entered into a Space Act Agreement that could lead to conducting a space flight test of the engine on the ISS.

From 2008 Ad Astra was working on placing and testing a flight version of the VASIMR thruster for the International Space Station (ISS). The first related agreement with NASA was signed on December 8, 2008, and a formal preliminary design review took plaace on 26 June 2013.

In March 2, 2011, Ad Astra and NASA Johnson Space Center signed a Support Agreement to collaborate on research, analysis and development on space-based cryogenic magnet operations and electric propulsion systems currently under development by Ad Astra. By February 2011, NASA had assigned 100 people to the project to work with Ad Astra to integrate the VF-200 onto the International Space Station. On December 16, 2013, AARC and NASA signed another five-year Umbrella Space Act Agreement.

However, in 2015 NASA ended plans for flying the VF-200 to the ISS. A NASA spokesperson stated that the ISS "was not an ideal demonstration platform for the desired performance level of the engines". Ad Astra stated that tests of a VASIMR thruster on the ISS would remain an option after a future in-space demonstration. Work with NASA continued in 2015 under NASA's NextSTEP program with planning for a 100-hour vacuum chamber test of the VX-200SSTM thruster.

Since the available power from the ISS is less than 200 kW, the ISS VASIMR would have included a trickle-charged battery system, allowing for 15-minute pulses of thrust. Testing of the engine on the ISS would have been valuable, because it orbits at a relatively low altitude and experiences fairly high levels of atmospheric drag, making periodic boosts of altitude necessary. Currently, altitude reboosting by chemical rockets fulfills this requirement. The VASIMR test on the ISS might lead to a capability of maintaining the ISS, or a similar space station, in a stable orbit at 1/20th of the approximately $210 million/year present estimated cost.

VX-200SS

In March 2015, Ad Astra announced a $10 million award from NASA to advance the technology readiness of the next version of the VASIMR engine, the VX-200SS (SS stands for steady state) to meet the needs of deep space missions.

In August 2016, Ad Astra announced completion of the milestones for the first year of its 3-year contract with NASA. This allowed for first high-power plasma firings of the engines, with a stated goal to reach 100 hr and 100 kW by mid-2018. In August 2017, the company reported completing its Year 2 milestones for the VASIMR electric plasma rocket engine. NASA gave approval for Ad Astra to proceed with Year 3 after reviewing completion of a 10-hour cumulative test of the 200SS™ rocket at 100 kW.

Potential applications

VASIMR is not suitable to launch payloads from the Earth's surface because it has a low thrust-to-weight ratio and requires an ambient vacuum. Instead, the engine would function as an upper stage for cargo, reducing fuel requirements for in-space transport. The engine is anticipated to perform the following functions at a fraction of the cost of chemical technologies: drag compensation for space stations, lunar cargo delivery, satellite repositioning, satellite refueling, maintenance and repair, in space resource recovery, and deep space robotic missions. 

Other applications for VASIMR such as the rapid transportation of people to Mars would require a very high power, low mass energy source, such as a nuclear reactor. In 2010 NASA Administrator Charles Bolden said that VASIMR technology could be the breakthrough technology that would reduce the travel time on a Mars mission from 2.5 years to 5 months.

In August 2008, Tim Glover, Ad Astra director of development, publicly stated that the first expected application of VASIMR engine is "hauling things [non-human cargo] from low-Earth orbit to low-lunar orbit" supporting NASA's return to Moon efforts.

Space tug/orbital transfer vehicle

The most important near-term application of VASIMR-powered spacecraft is cargo transport. Studies have shown that, despite longer transit times, VASIMR-powered spacecraft will be much more efficient than traditional integrated chemical rockets when moving goods through space. An orbital transfer vehicle (OTV)—essentially a "space tug"—powered by a single VF-200 engine would be capable of transporting about 7 metric tons of cargo from low Earth orbit (LEO) to low Lunar orbit (LLO) with about a six-month transit time. 

NASA envisions delivering about 34 metric tons of useful cargo to LLO in a single flight with a chemically propelled vehicle. To make that trip, about 60 metric tons of LOX-LH2 propellant would be expended. A comparable OTV would employ 5 VF-200 engines powered by a 1 MW solar array. To do the same job, a VASIMR-powered OTV would need to expend only about 8 metric tons of argon propellant. The total mass of such an electric OTV would be in the range of 49 t (outbound & return fuel: 9 t, hardware: 6 t, cargo 34 t). 

OTV transit times can be reduced by carrying lighter loads and/or expending more argon propellant with VASIMR throttled up to higher thrust at less efficient (lower I_sp) operating conditions. For instance, an empty OTV on the return trip to Earth covers the distance in about 23 days at optimal specific impulse of 5,000 s (50 kN·s/kg) or in about 14 days at I_sp of 3,000 s (30 kN·s/kg). The total mass of the NASA specifications' OTV (including structure, solar array, fuel tank, avionics, propellant and cargo) was assumed to be 100 metric tons (98.4 long tons; 110 short tons) allowing almost double the cargo capacity compared to chemically propelled vehicles but requiring even bigger solar arrays (or other source of power) capable of providing 2 MW. 

As of October 2010, Ad Astra Rocket Company was targeting space tug missions to help "clean up the ever-growing problem of space trash". As of 2016 no such commercial product had reached the market.

Mars in 39 days

In order to conduct a crewed trip to Mars in just 39 days, the VASIMR would require an electrical power level available only by nuclear propulsion (specifically the nuclear electric type) by way of nuclear power in space. This kind of nuclear fission reactor might use a traditional Rankine/Brayton/Stirling conversion engine such as that used by the SAFE-400 reactor (Brayton cycle) or the DUFF Kilopower reactor (Stirling cycle) to convert heat to electricity. However, the vehicle might be better served with non-moving parts and non-steam based power conversion using a thermocell technology of the thermoelectric (including graphene-based thermal power conversion), pyroelectric, thermophotovoltaic, or thermionic magnetohydrodynamic type. Thermoelectric materials are also an option for converting heat energy (being both black-body radiation and the kinetic thermal vibration of molecules and other particles) to electric current energy (electrons flowing through a circuit). Avoiding the need for "football-field sized radiators" (Zubrin quote) for a "200,000 kilowatt (200 megawatt) reactor with a power-to-mass density of 1,000 watts per kilogram" (Díaz quote) this reactor would require efficient waste heat capturing technology. For comparison, a Seawolf-class nuclear-powered fast attack submarine uses a 34 megawatt reactor, and the Gerald R. Ford-class aircraft carrier uses a 300 megawatt A1B reactor.

Zubrin criticisms

The crewed Mars mission advocate Robert Zubrin has called VASIMR a hoax, claiming that it is less efficient than other electric thrusters that are now operational. He also believes that electric propulsion is not necessary to get to Mars; therefore, budgets should not be assigned to develop it. His second critique concentrates on the lack of a suitable power source. Ad Astra responded in a press release:

In the near term, using solar-electric power at levels of 100 kW to 1 MW, VASIMR propulsion could transfer heavy payloads to Mars using only one to four first-generation thrusters in relatively simple engine architectures.[...] It is abundantly clear that the nuclear reactor technology required for such missions [fast manned Mars transport] is not available today and major advances in reactor design and power conversion are needed.

— Ad Astra Rocket Company, Facts About the VASIMR Engine and its Development

As a response to VASIMR being labeled as a hoax by Zubrin, Ad Astra added a section to their FAQ:

It [the hoax claim] was made by an individual who never visited the MIT or NASA facilities where the research originated or the Ad Astra Rocket Company laboratories where the development continues and, despite an open invitation, has never bothered to see any of the prototypes being fired in the vacuum chamber and reviewed the copious amounts of calibrated and validated data available. It is unclear whether this person has read or understood the numerous peer-reviewed and published articles regarding this work.

— Ad Astra Rocket Company, Is VASIMR Propulsion a Hoax?

Zubrin Comments Regarding VASIMIR 

Original link:  https://spacenews.com/vasimr-hoax/
Date:  July 13, 2011

“[C]ritical to deep space exploration will be the development of breakthrough propulsion systems.” — U.S. President Barack Obama, Kennedy Space Center, April 15, 2010 The Obama administration claims that it is developing a new breakthrough propulsion system, known as VASIMR, which uniquely will make it possible for astronauts to travel safely and quickly to Mars. We can’t go to Mars until we have the revolutionary VASIMR, they say, but just wait; it’s on the way, and once it arrives, all things will be possible. Washington is a city known for its smoke and mirrors, but rarely has such total falsehood been touted as a basis for science policy. VASIMR, or the Variable Specific Impulse Magnetoplasma Rocket, is not new. Rather, it has been researched at considerable government expense by its inventor, Franklin Chang Diaz, for three decades. More importantly, it is neither revolutionary nor particularly promising. Rather, it is just another addition to the family of electric thrusters, which convert electric power to jet thrust, but are markedly inferior to the ones we already have. Existing ion thrusters routinely achieve 70 percent efficiency and have operated successfully both on the test stand and in space for thousands of hours. In contrast, after 30 years of research, the VASIMR has only obtained about 50 percent efficiency in test stand burns of a few seconds’ duration, and that is only at high specific impulse. When the specific impulse is reduced, the efficiency drops in direct proportion. This means that the VASIMR’s much chanted (but always doubtful) claim that it could offer significant mission benefit by trading specific impulse for thrust is simply false. In contrast, this capability has been demonstrated by the ion-drive that propelled Dawn spacecraft on its way to an asteroid. Finally, if it is to be used in space, VASIMR will require practical high temperature superconducting magnets, which do not exist. But wait, there’s more. To achieve his much-repeated claim that VASIMR could enable a 39-day one-way transit to Mars, Chang Diaz posits a nuclear reactor system with a power of 200,000 kilowatts and a power-to-mass ratio of 1,000 watts per kilogram. In fact, the largest space nuclear reactor ever built, the Soviet Topaz, had a power of 10 kilowatts and a power-to-mass ratio of 10 watts per kilogram. There is thus no basis whatsoever for believing in the feasibility of Chang Diaz’s fantasy power system. Space nuclear reactors with power in the range of 50 to 100 kilowatts, and power-to-mass ratios of 20 to 30 watts per kilogram, are feasible, and would be of considerable value in enabling ion-propelled high-data-rate probes to the outer solar system, as well as serving as a reliable source of surface power for a Mars base. However, rather than spend its research dollars on such an actually useful technology, the administration has chosen to fund VASIMR. No electric propulsion system — neither the inferior VASIMR nor its superior ion-drive competitors — can achieve a quick transit to Mars, because the thrust-to-weight ratio of any realistic power system (even without a payload) is much too low. If generous but potentially realistic numbers are assumed (50 watts per kilogram), Chang Diaz’s hypothetical 200,000-kilowatt nuclear electric spaceship would have a launch mass of 7,700 metric tons, including 4,000 tons of very expensive and very radioactive high-technology reactor system hardware requiring maintenance support from a virtual parallel universe of futuristic orbital infrastructure. Yet it would still get to Mars no quicker than the 6-month transit executed by the Mars Odyssey spacecraft using chemical propulsion in 2001, and which could be readily accomplished by a human crew launched directly to Mars by a heavy-lift booster no more advanced than the (140-ton-to-orbit) Saturn 5 employed to send astronauts to the Moon in the 1960s. That said, the fact that the administration is not making an effort to develop a space nuclear reactor of any kind, let alone the gigantic super-advanced one needed for the VASIMR hyper drive, demonstrates that the program is being conducted on false premises. Far from enabling a human mission to Mars, VASIMR is primarily useful as a smokescreen for those who wish to avoid embracing such a program. Yet their entire case is disingenuous, because in reality, there is no need to develop any faster propulsion system before humans venture to the red planet. As noted, the current one-way transit time is six months, exactly the same as a standard crew rotation on the space station. The six-month transit trajectory is actually the best one to use for a human crew because it provides for a free return orbit, an important safety feature which a faster trajectory would lack. Thus even if we had a truly superior and practical propulsion technology, such as nuclear thermal rockets (which the Obama administration is also not developing), we would use its capability to increase the mission payload, rather than shorten the transit. The argument that we must go much faster to avoid cosmic rays is demonstrably false, as proven not only by standard radiation risk analysis — which estimates about a 1 percent cancer risk for the 50 rem dose that astronauts would receive on a Mars round trip — but by the fact that about a dozen astronauts and cosmonauts have already received such a cumulative cosmic ray dose during repeated flights on the international space station or Mir, and, as expected, none of them have evidenced any radiological health effects. (Cosmic ray dose rates on the space station are fully half of those in interplanetary space — half because the Earth blocks out half the sky. The Earth’s magnetic field does not shield effectively against cosmic rays. As a result, over the next 10 years, space station crews will receive the same number of person-rems of cosmic radiation as would have been received by five crews of equal size flying to Mars and back over the same period.) As for avoiding zero-gravity deconditioning, the practical answer is to simply prevent it entirely by rotating the spacecraft to provide artificial gravity rather than waste decades and vast sums in a futile effort to develop warp drive. NASA has spent a lot on VASIMR, but its real cost is not the tens of millions spent on the thruster but the tens of billions that will be wasted as the human spaceflight program is kept mired in Earth orbit for the indefinite future, accomplishing nothing while waiting for the false vision to materialize. That is why, as unpleasant as it might be, this illusion needs to be exposed. The Mars Society is holding its next international convention in Dallas, Aug. 4-7, 2011. Currently, we have a panel scheduled, titled: “VASIMR: Silver Bullet or Hoax.” I invite Chang Diaz and a colleague to come and take two of the four spots on it and defend the practical value of their concept in formal public debate. Let the truth prevail.