Someone commented on my blog a few weeks ago (Tim Goff) saying why can't Voyager data be used to look for the Pioneer anomaly. I'd always ignored Voyager data before because the Voyager craft were not spin stabilised and so their trajectory was too jerky to see a smooth anomaly because of frequent course corrections. However, Tim's point was interesting because Voyager is now beyond Neptune so there should be fewer course corrections. Since then I've been pestering various NASA centres to try and get the raw position data and they keep directing me to modelled trajectory data which by definition won't show up anomalies.
Now finally I've received a reply from NASA JPL who look after the data and they say that they haven't done any two-way tracking of the Voyager spacecraft since the Neptune encounter and they've been relying on a model! (this says all you need to know about mainstream theoretical physics, it is not just at NASA). I hope this doesn't mean that no-one else has been doing any two-way tracking because the Voyager is unique now in sampling an ultra-low acceleration regime where dynamical anomalies are showing up in deep space (galaxy rotation, cosmic acceleration, the Pioneer and flyby anomalies) and where MiHsC predicts these deviations. If you're in a unique regime, you have to take the opportunity to measure it!
Needless to say I have just written several quick emails to some people I know at NASA in the hope that someone somewhere is measuring position/speed, or that some measurements can be started. I hope so!
PS: Someone has just implied online that since they think the Pioneer anomaly has been explained, why bother? But, the Pioneer anomaly has only been 'simulated' by a complex thermal model: this is not a proof, and is certainly not strong enough to throw away an opportunity to sample uniquely low accelerations, especially since the galaxy rotation anomaly & cosmic acceleration are of the same size and form..
PS: Someone has just implied online that since they think the Pioneer anomaly has been explained, why bother? But, the Pioneer anomaly has only been 'simulated' by a complex thermal model: this is not a proof, and is certainly not strong enough to throw away an opportunity to sample uniquely low accelerations, especially since the galaxy rotation anomaly & cosmic acceleration are of the same size and form..
3 comments:
Mike-
Down through the decades, NASA has shot a lot of stuff into space, including more than a few interplanetary craft. A few weeks ago, I was reading about a civilian group associated with NASA that makes it their business to keep tabs on these relics of the early space age:
'Skycorp Incorporated,' in San Jose California.
If anybody has the data on Voyager you are after, it's probably them. Failing that, they've been keeping tabs on quite a few other relics from the same era.
What I don't have for them is an email address.
Names: Dennis Wingo and Keith Cowing (owners)
Aha!
http://www.skycorpinc.com/lunar-orbiter-image-recovery.html
A new EM drive has been created over at the NSF forums. The old thread has been returned, albeit locked, with much of the personal stuff removed. NSF Admin warns about keeping the new thread on track.
Ran across this while working on Version 2. Thought I'd share, given your interest in wide binaries:
WDS: 21200+5259
DM +52 2916
A Mag = 7.7
B Mag = 7.9
Distance: 24 parsecs
Spectral type: K
DATE PA Sep
1828 115 6.1
1897 115 6.7
1991 115 6.7
2012 114 6.9
Somebody attempted an orbit on this one:
18,000 years, semi major axis of 12, and eccentricity of 0.54. Must be at closest approach now.
Works out to a separation of 147 au currently and 293 au at the semi-major axis (unless I miscopied something). Last time these two stars were in this position, we were keeping astronomical records on cave walls. Just about the longest binary orbit I have seen calculated (galactic orbits are a different matter)
Geneva Copenhagen distance estimate is close to mine (29 parsecs).
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