AO-40 experiment leads successful acquiring of GPS signals on Moon

Lots of reports in the mainstream news about this accomplishment, see official NASA link below. But none of them tell of the origination of the idea.

It came from the inspiration of a radio amateur, Frank KA3HDO, who proceeded to get NASA to sponsor the first experiment on the AO-40 mission. There is documentation of those results searchable online.

For this he was awarded at the 2017 Hamvention.

Amateur of the Year

Amateur Radio on the International Space Station International Chair Frank Bauer, KA3HDO, is Hamvention’s 2017 Amateur of the Year. Bauer has been a driving force behind the program since its inception. He also serves as AMSAT-NA Vice President for Human Spaceflight.

In the mid-1990s, Bauer proposed an experiment to have the high-Earth orbit (HEO) AMSAT Phase 3D satellite (AO-40) measure the signal strength of the GPS satellite constellation. The AO-40 experiment subsequently has been cited often in aerospace literature, as it remained the most comprehensive above-the-constellation data source for nearly a decade and led to changes in the system’s specifications and applications. The results of the AO-40 experiment jump started a game-changing transformation in navigation at HEO/GEO altitudes, enabling new and exciting missions in these orbits.

Frank KA3HDO is also named as a consultant on the international team that developed the current Moon lander package named LuGRE. And I believe Kevin KD4RTP is named in the NASA release below. I have little doubt other radio amateurs were involved as well.

All civilized radio amateurs ought to show pride in being a member of the licensed service and technical fellowship that makes such leading positive contributions.

73, John, WØPV

NASA Successfully Acquires GPS Signals on Moon



“On Earth we can use GNSS signals to navigate in everything from smartphones to airplanes,” said Kevin Coggins (KD4RTP) deputy associate administrator for NASA’s SCaN (Space Communications and Navigation) Program. “Now, LuGRE shows us that we can successfully acquire and track GNSS signals at the Moon. This is a very exciting discovery for lunar navigation, and we hope to leverage this capability for future missions.”

(click link above to read & see more)


The joint NASA, Italian Space Agency, Qascom, and PoliTO LuGRE team at NASA’s Goddard Space Flight Center.

 

Outstanding that the hobby reaches now the world beyond.

 

AO-40 failed.

What's the hype?

Kraus/KC4ZGP

 

Nice work Frank!

 

Rockets and space missions fail. Often. But coming up with a methodology that proves useful and applies far beyond one mission is a clever and vital piece of space technology.

 

Cynical silliness.

While AO-40 was operationally challenged and did not achieve all its intended objectives, it did not completely lose function nor all planned capabilities for several years. So in the manner that Apollo 13 was before, at very least it easily can be considered a "successful failure".

While AO-40 not being enabled to achieve Phase 3-D status was disappointing, too much fuss has been made of that. This was a secondary point of the OP as well

After the initial malfunction of the kick-motor, explosion & losses, the AMSAT AO-40 team persevered and made a significant recovery, one aspect being the successful first ever GPS in space experiment.

The radio amateurs involved back then exhibited the will and ability to improvise, adapt and overcome (traits also promoted in the USMC) as described here, which mentions Ian @ZL1AOX as being a prime contributor.

According to that recount, ironically the troubles with propulsion led to an unplanned increase in apogee altitude, "considerably higher", which actually would have enhanced & amplified the GPS in space experimental results!

Which repeating the cited statement from the ARRL, "jump started a game-changing transformation", like todays LuGRE Moon mission.

A cause for celebration of radio amateurs.

 

I'm proud to hear this good news, as I actually helped build a few parts that flew on AO-40. and... a few that didn't that I got to take home and now reside in the shack here.

btw, is AO-40 still in orbit? I don't see an element set anywhere for our old bird. Pardon the pun.

73,
K5PK

 

Frank KA3HDO, congratulations!
73 !

 

Every partial success is a success in this pioneer issues.

 

Yes, it is. With about 604mi perigee it will never deorbit in foreseen, dozen thousands of years, future.

 

Thanks for this interesting post! I was unaware of the science behind use of GPS on the Moon.

 

This would only work for locating yourself on the Earth facing side of the Moon though!

Neat stuff and great work.

 

Well I don't know about "civilized radio amateurs"... Are there radio amateurs who are 'savages'?

Interesting experiment.
What makes GPS work on earth is the known geostationary fix of the stats, and the time it takes for each signal to reach the RX.
The fixed points are far enough apart to allow triangulation of one's position and accuracy is determined by the number of individual TX heard.

It would seem to me that because the geostationary positions of the Sats are now much closer together relative to the RX that their time differences would become so minute as to become impractical for NAV. Other things with would reduce reliability/ accuracy would be the inherent time delay between the earth sats and the moon, and that unlike terrestrial nav, everything is in relative motion.

Expanding that idea to a Mars mission would seem extreme, but I can see them being useful as a VOR station like setup for return to/from earth.

 

Just listen to any pileup.....

 

Where might I find the orbital element set for AO-40? I'd like to track it?

73 de Steve
K5PK