Spaceflight Insider

Is it or isn’t it? A review of statements about the EMDrive

A lot of claims have been made regarding NASA's EMDrive - but how accurate are claims that it could send crew to the Moon in four hours or to Mars in 70 days? (Image of Ion Drive being tested) Photo Credit: NASA

A lot of claims have been made regarding NASA’s EMDrive – but how accurate are claims that it could send a crew to the Moon in four hours or to Mars in 70 days? (Image of Ion Drive being tested) Photo Credit: NASA

For those not at NASA or with ties to a major aerospace or physics organization – it all must seem very confusing. The “it” being whether-or-not the EMDrive a number of groups have been working on. Reports appearing on one site or outlet states that it does – while reports on another say that it does not. Then you have statements a German researcher has confirmed that it works – only to have this statement dismissed by another outlet. So which is it? What is the truth about the EMDrive?

The “EMDrive” is an electromagnetic thruster that has been all the talk in space circles due to the fact that it does not use any reaction mass nor does it emit any type of directional radiation. This fact means little for those in the public.

What makes this system so exciting is that, for a mission to say, Mars, the flight time would drop from six months or more using conventional chemical-based systems to just a little more than two months. Although mass, volume, and speed are always discussed as being critical in terms of space exploration, perhaps the most important element of all in terms of human spaceflight is what we are all short of – time.

From a recent headline appearing on, one would think that a German physicist had closed the discussion on the matter: NASA’s ‘impossible’ EM Drive works: German researcher confirms and it can take us to the Moon in just 4 HOURS.

EMDrive image credit SPR Ltd. posted on SpaceFlight Insider

A model of the EMDrive. Photo Credit: SPR Ltd.

As they say, the devil is in the details and once one gets past the sensational headline, things within this report start to unravel fairly quickly. The author of the piece notes that the German physicist at the center of the controversy, Martin Tajmar, has produced a similar EM drive and that it functions as described – stating that it works but for reasons that “… he can’t clarify yet.”

Tajmar is the chairman of Space Systems at the Dresden University of Technology located in Germany and, therefore, should be taken at his word.

Less than a day later, however, i09 posted its own article with the headline: No, German Scientists Have Not Confirmed the “Impossible” EMDrive.

Whereas the Astronomy-Physics article had elements that cast doubt on the claims, i09’s report had Tajmar stating that the scientific method had been implemented and that all variables had been accounted for. Those two conflicting reports served only to make the situation even more confusing.

In an effort to better determine the current state of the EMDrive, SpaceFlight Insider contacted NASA’s Johnson Space Center, the site of the agency’s Eagleworks, one of the groups working to prove out the capabilities of new, advanced propulsion systems.

“It’s my understanding that this concept is pretty much in the theoretical stage of testing,” NASA’s Jay Bolden told SpaceFlight Insider. “This is a small project, one of the many propulsion-based projects that NASA is currently working on.”

NASA Warp Drive Sploid image posted on SpaceFlight Insider

Images of a proposed “warp-drive” spacecraft were part of a Sploid feature in 2014. Image Credit: Mark Rademaker

However, the statement from NASA that their system is theoretical runs contrary to what the website posts in its opening paragraph about the system:

Satellite Propulsion Research Ltd (SPR Ltd) a small UK based company, has demonstrated a remarkable new space propulsion technology. The company has successfully tested both an experimental thruster and a demonstrator engine which use patented microwave technology to convert electrical energy directly into thrust. No propellant is used in the conversion process. Thrust is produced by the amplification of the radiation pressure of an electromagnetic wave propagated through a resonant waveguide assembly.

In fact, there are two videos on the website that purport to show the system apparently being tested, moving an assembly around. In order to gain a better understanding of exactly what SPR Ltd. has demonstrated, SpaceFlight Insider reached out to the organization for clarification. As of this article’s publication, we have not received a response.

For NASA’s EMDrive, the process currently underway appears to be in its initial stages, with much more work still to be done before spacecraft can employ it on upcoming missions.

“They are obviously not able to create a whole lot of power behind the event that they are testing right now. It really is more of looking at the equations of the physics involved versus actual thrust vectoring and that type of thing,” Bolden stated.

In fact, NASA’s EMDrive and the one worked on by these private firms appear to be entirely different systems. With similarly-named propulsion systems being worked on by separate organizations, it is little wonder that there is so much confusion about what the status of NASA’s EMDrive versus the other EMDrives is. As for NASA, they have stated that their EMDrive is still in the earliest stages of development.

When asked if the claims about their EMDrive might be a little overstated, at least within the space agency, Bolden responded: “That’s probably an accurate way to describe what is going on at the moment. The math and the physics behind the description appear to work, but the actual, physical testing […] is still being evaluated.”

*This article was edited at 20:40 GMT on Aug. 8, 2015 to include information left out of the original article and to correct noted errors


Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

Reader Comments

The thing to remember is there are two seperate concepts here: 1 the massless microwave thrust drive, 2 the space-time compressing warp drive. Both therories are intheir infancy, but the microwave drive is at least possible now. Tring to decrease the mass-enrgy needed for the warp drive is still it’s main problem. Any use now would need a Jupiter sized mass to get any meaningful results.

love it, i’m 68 yrs old the things that have happened in my life time, love, i hope i live to see pro type fly in space with human controls, beem me up scotty;]

Tracy the Troll

What is your opinion of the validity of the EM Drive…Will we see it in 5years, 10 years or 20 years or never?

I do not know the answer to that question. I look to you for those kind of answers. Have a great day. Jim

Jason, the mobile web site is behaving really well today! Thanks to whoever sorted it out.

Hi Robert,
We’re just sorry you had problems! Have a great weekend.
Sincerely, Jason Rhian – Editor, SpaceFlight Insider

It’s very early days with this “technology”. Whether it amounts to anything or not, is anybody’s guess. As a supporter of HSF, I hope it does. Many issues still have to be addressed. For example, apparently a small thrust is measured when the device is operated within a vacuum, eliminating the possibility of heating “air” convection currents. But, is it (the thrust) caused by interacting with the Earth’s magnetic or gravitation field(s). The device will be needed to be testing, first in LEO (say at/near the ISS) and then further out (say at Earth/Moon L1).

With phased standing waves, a Warp Drive can be technologically proven possible.

Ya know what? I don’t even care anymore. Build it, fly to the goddamned moon and take a selfie on the top of Mons Huygens and then I’ll believe it. Until then, CUT THE CRAP!

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