EM Drive

[KitemanSA]

There will still be points of issue even if there are no other thrusters. After all, there are flowing electrons in a magnetic field. EMF anyone?

[ladajo]

Tracking Satellites is not real time. You need multiple orbits through the Fences to get an accurate track. Optical tracking only works in short windows and if the weather cooperates during the observation windows. While Optical can be used to calculate orbits, it is more about getting a look at the object. The radar fences do the heavy lifting on establishing an accurate orbital track.

[GPecchia]

It's been a little hard to find updates for B1B2 or Barry-1. NSF forum recently locked the last discussion on the topic, https://forum.nasaspaceflight.com/index ... c=59047.25
I did find this: https://db.satnogs.org/satellite/QDDY-8 ... -1819-3935
I find this to be a fascinating experiment. IVO did extensive ground testing in third party vacuum chambers and got positive results. The next logical step was to put it in orbit and test it there.
I look forward to further updates.

[Carl White]

Can't locate the reference, but I remember the CEO stating that they wouldn't announce any results for two to six months after launch.

[pbelter]

Yesterday, I asked Mike McCulloch about test results coming from IVO. His response:

"Not started yet, afaik. They said they would tell me".

Mike is on twitter and he is pretty responsive if you follow him there.

[Giorgio]

According the latest news the 2 engines onboard will deliver one 0.25mN and the other 0.65mN at a power consumption of 1 watt.

This explain why they need such a long time to make a "baseline of orbital data", but at the same time i am worried that such a low power output might not give the inconfutable result that everyone is expecting.

Lets see how it will evolve......

[KitemanSA]

If the baseline data demonstrates ALL plausible external forcing functions, then mN level forces over time should be distinguishable, irrefutably.

[Carl White]

How much would they need just to maintain orbit? Taken from one of Mike McCulloch's tweets:



If it starts maintaining average altitude or rising, that's a pretty strong indication.

[RERT]

I think the chart shows it decelerating at about 10^-6 ms-2, though I'd very much welcome a second opinion.

If that's right a milli-newton should easily correct that acceleration.

[Giorgio]

If we consider only air drag, than at 500 Km height the air density can oscillate up to 2 orders of magnitude, from a minimum of 10^-13 to a maximum of 10^-11 Kg/m3 due to the sun flux oscillations and sun/earth geomagnetic activity that compress and expand the air bubble around the planet.

If we assume an orbital speed of 8 Km/sec and a drag coefficient of 1 (cube) and an area of 1/4 m2 (with solar panel expanded), we get a drag force that oscillates from a minimum of 0.00008 mN to a maximum of 0.008 mN

So in theory while even 0.25mN is enough to compensate the air drag alone, and if both engines work as predicted a 1 mN total thrust will be noticeable, but if they do not work at 100% of expected thrust than there is the risk to get an inconclusive result.

Additionally we need to consider also that we still need to add than all other source of influence on the spacecraft, magnetic drag, gravitational drag, solar wind drag, outgassing drag, and so on.

Anyhow, they put their money on the table to prove this technology, so I am keeping my finger crossed for them.

[RERT]

Calculating drag was my first thought as well, in fact I think I did it before probably elsewhere here.

Then I realised orbital mechanics should be able to translate height into speed, and we have the decay rate of height from the chart. Hence deceleration.

I started from v^2/r = g ~constant, and differentiate.

That will include all sources of drag.

If it is 10^-6, they have sized the thrusters appropriately.

[Carl White]

NORAD orbit data for Barry-1. Regularly updated.

https://celestrak.org/NORAD/elements/gr ... ATNR=58338

[Skipjack]

Either they have not turned it on yet, or it is not working...

[KitemanSA]

Either they have not turned it on yet, or it is not working...

Launched 11 Nov 23, needs 3 to 4 months (IIRC) of background data before “ignition”. So, not on yet.

[Skipjack]

Eh?
According to this "Jon Beam, Chief Operating Officer, praised the Mission Operations team for their exceptional work and agility, advancing ahead of schedule toward completing primary mission objectives by year's end."

https://forum.nasaspaceflight.com/index ... ic=60008.0