GPS on Mars?

Roland Piquepaille writes "SPACE.com published two days ago an article named "Red Planet Wayfinder: A GPS System for Mars." You'll read that NASA researchers are studying a 'global positioning satellite (GPS) system around Mars that could also function as a communications network.' This would imply 'a constellation of microsatellites, or Microsats, and one or more relatively large Mars Aerostationary Relay Satellites, or MARSats,' according to the Mars Network website at NASA's Jet Propulsion Laboratory (JPL). This sounds like a neat idea, but there are several issues here. First, the JPL site mentioned above has not been updated since 1999. Then, there is no mention of such a mission at NASA's Mars exploration program website. So, here is my question: is this a recycled 4-year old article? In this overview, you'll find some spectacular images and more indications leading to think that the article was written in 2000. And please note that a Slashdot reader asked last December 'Whatever Happened To The Mars Network?' without receiving an adequate answer."

Comments

Robinson called it "APS" (mildly OT)

[Embedded Geek]

I seem to recall in Kim Stanley Robinson's Red Mars, he refers to an Ares Positioning System (APS).

Just thought we should get our TLAs (Three Letter Acronyms) straight.

Re:Robinson called it "APS" (mildly OT)

[peragrin]

Actually i thought it was Red Planet with Val Kilmer, and trinity(matrix) they had MPS or Mars Postioning System. Of coure they also used the 1997 mars pathfinder rover, which after 50 years in the desert was still working.

Re:Robinson called it "APS" (mildly OT)

[Anonymous Coward]

Acronyms really should make a "word" and not just an abbreviation. NATO is an acronym but FBI is not. Unfortunately dictionary.com agrees but m-w.com doesn't. I think it is another example of the English language changing.

Re:First things first

[another_henry]

We can't put GPS satellites (or any other permanent satellite) around the Moon. Its mass is too unevenly distributed, and the gravitational field too warped, to have any permanent stable orbits. Anything put into orbit will crash after a few hundred orbits, without manual correction with rockets.

What about the GPS Ground Segment?

[bostonkarl]

What folks fail to recognize is that there is a huge (read costly) Earth-based infrastucture to VERY ACCURATELY measure and predict GPS satellite orbits. This information is beamed up to the individual GPS sattelites, which in turn is broadcasted to GPS users in "ephemeris messages". These messages change anywhere from 2 to 6 hours. Seems like it would be quite a bit of work to perform this for the proposed Martian GPS system. Accurately measuring the orbital parameters of man-made sattelites Pparked around Mars from Earth-based sensors isn't a walk in the park. One certainly wouldn't obtain the accuracy of the Earth GPS, nor would I expect the reliability.

Nitpick: That's "Areostationary"

[Urban Garlic]

Satellites which are stationary relative to an observer on Mars should oughta be called "Areostationary", not "Aerostationary".

This is because the Greek name for Mars is Ares, and conventionally, greek names are used for the roots of these sorts of things.

See, e.g., here

I know, I know, English is a living language and the spelling error didn't change the meaning, so I should shut up. Pendants like me are domed to definately loose this rediculus fite.

Re:Unix geeks and their self-referencing acronyms.

[julesh]

Aerostationary? Not moving in air??

Perhaps they mean areostationary (not moving with relation to Mars; the martian equivalent of geostationary).

Re:If I accidentally get lost on Mars

[JollyGreenLlama]

Actually, accourding to their website, OnStar is currently available on certain models of Acuras, Audi, Buicks, Cadillacs, Chevrolets, GMCs, Hummers, Isuzus, Oldsmobiles, Pontiacs, Saabs, Saturns, Subarus, and Volkswagons.

So, unless some deal gets done with Ford before an implementation of the Mars GPS, you'd be absolutely correct. A bit off-topic, but correct.

SPACE.com response to allegation of recycling news

[tariq_malik]

Dear Roland, While I do appreciate your interest in SPACE.com, I do feel it necessary to respond to the allegations that I have merely recycled a story and mission from 2000. This, in fact, is not the case as I will mention following. Your focus on previous Mars Network (Marsats and Microsats) constitutes one paragraph of a story targeted at future NASA missions and efforts. It was included - the images as well - to serve as a reference for the work that is going on today. The passage you refer follows: Previous network designs called for a constellation of small microsatellites called Marsnet to serve Mars explorers while a larger spacecraft, Marsat, would relay data between the planet and Earth. That is the only mention of such a system. Note the following: But current studies expect the system to grow gradually from piggybacked services aboard future science spacecraft to a dedicated platform, such as the anticipated Mars Telecommunications Orbiter set for 2009 - the first satellite specifically designed to facilitate communications with another world. You'll find that the bulk of this article highlights current efforts for Mars navigation and communication, and their usefulness for future exploration. You're allegation that Michael Mendillo has listed no research is absolutely false. His latest paper - cited in my article - was published in Radio Science in April of this year. Ionospheric effects upon a satellite navigation system at Mars Michael Mendillo Center for Space Physics, Boston University, Boston, Massachusetts, USA RADIO SCIENCE, VOL. 39, RS2028, doi:10.1029/2003RS002933, 2004 You can find an abstract of the research here: http://www.agu.org/pubs/crossref/2004/2003RS002933 .shtml While I appreciate your interest in both Mars and SPACE.com, I am disappointed that you did not contact me directly to air your concerns, instead posting your theories on a web journal with inaccurate depictions of my journalistic intent. My e-mail address is attached to every story that I write. I am open to discuss this matter at length with you should you have additional questions. Sincerely, Tariq Malik SPACE.com tmalik@hq.space.com