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Duncan Young

I'm just shocked that the cost of the thing ballooned up to half a billion dollars - for a comsat (that was becoming an science observatory and sample return technology experiment and laser comms trial etc etc.)

Yet another NASA mission becomes an overloaded lifeboat, and sinks without a trace...

Dwayne Day

This CBO report from last fall:


claims that NASA was projecting the cost of the "Mars Telesat" at $2.2 billion. (page 21)

I served as a reviewer for that report, and I remember being skeptical of an early draft that stated that the comsat would cost something like a billion dollars or more. As it was explained to me, NASA's internal cost estimates were pretty high. In addition, they wanted to convert radio signals (from Mars) into laser signals to send to earth. This involves some pretty heavy data processing that has not been done on an operational space system yet. So CBO thought that this program was going to be expensive and technologically challenging.

After that discussion, I began to doubt if MTO would happen at all. My worst fear was that NASA would start it, spend a few hundred million dollars, and then cancel it around 2008 or so. This would then force a major de-scope on the rover.

I would also point out that on the DoD side, they have been attempting to adapt lasers for comsat purposes for decades now and to little apparent progress. A lasercom experiment was slated for the Teal Ruby program in the early 1980s and was deleted. A lasercom system was scheduled for the DSP program in the 1980s and also canceled. The NRO recently canceled a planned data relay system relying upon lasers. And the USAF's T-Sat program has come under much criticism on Capitol Hill for its ambition.

So NASA's cancellation of MTO might be primarily a recognition of technical and budgetary challenges.

Bruce Moomaw

No, Dwayne, you've misread that sentence, which actually says: "As with the near-term lunar missions, CBO assumed that the Phoenix lander mission, planned for 2007; the Mars Science Laboratory mission, for 2009; and the Mars Telesat program, for around 2009, could be carried out within NASA’s projected funding level of about $2.2 billion." That is, the $2.2 billion figure is the total for all three missions.

As for MTO itself, there was a lot of unease at the first meeting of the Mars Strategic Roadmap group about adding that laser test to MTO -- but no skepticism about MTO itself (and, as Oliver says, some interest in the possibility of making sure it few before MSL-1). Since its cancellation, I've gotten in a webgroup fight with one engineer for MSL's camera who insists that it won't be as serious a loss as I thought, and specifically won't slow down MSL's transit acros the planet as much as I thought -- despite the fact that it would have allowed 6 to 9 contact periods per Sol with the rover, each lasting 30-90 minutes (as opposed to four 8-minute sessions per So, if Odyssey and MRO are both still working by then). I find this hard to believe, and intend to talk to Richard Cook -- currently MSL's project manager -- about it soon.

But in any case Michael Griffin probably had no choice. He was under orders to fund both the (very important reinstated "Glory" climate satellite mission and a $30 million preliminary study on the feaibility of a Shuttle flight to repair Hubble, without increasing NASA's total FY 06 science budget. Something had to go, and MTO was the most expendable thing (along with some of the early funding for Terrestrial Planet Finder, which I'm also not happy about). And that CBO paper -- which I had not previously read -- is one very useful document in general; it suggests that NASA is currently underestimating its costs by fully 23% (pg. 23), and that lots more trouble is therefore inevitably to come. (Sure enough, NASA Watch now quotes Griffin as saying that there is not enough money currently in NASA's budget to pay for Bush's Exploration Architecture:http://www.nasawatch.com/archives/2005/07/kicking_the_arc.html . In a sane world, they'd correct that by immediately cancelling Shuttle and Station, but then we aren't in a sane world.)

Oliver Morton

Thanks for the military comparisons, Dwayne. I seem to remember once seeing a model of a DSP satellite that had a little spar on it for a laser. Do we know if those lasers were for spacecraft to spacecraft links, or links to earth? Strikes me that aiming at earth and relying on a nice big telescope there to pick things up might be easier than sending a beam to another satellite.

That said, I too have been thinking that MTO might have been quite hard, mainly because high power lasers in space haven't been a great success of yet. IceSat's had its problems, and laser dificulties were one reason the vegetation monitoring lidar mission never got off the ground.

But I still think that without it we have something that looks a lot less like a coherent programme, and that with MSR being delayed things look likely to be a lot slower, to boot.

Dwayne Day

Yeah, I apparently misread that sentence from the CBO report.

As for Mr. Morton's question about the DSP, that little stubby thing on the front edge was indeed supposed to be a laser crosslink system (they called it the LCS). It was intended to allow DSP sensor data to be sent from one satellite to another without the requirement for a ground station. I believe that the goal was to eliminate the Austrailian ground station, although I cannot remember if the LCS was also supposed to handle telemetry in addition to sensor data. The pointing requirements for two GEO satellites were apparently prohibitive.

According to Jeff Richelson's book on the history of satellite missile warning, the LCS cost $400 million in late 1980s dollars before it was canceled. I don't know what they did instead, but I believe that the Australian ground site was closed in the latter 1990s. So they clearly developed some kind of alternative. Radio crosslinks have been used by DoD for at least 30 years and they can operate in frequencies that do not penetrate to the ground. But I imagine that lasers offered higher bandwidth and greater security.

I recently found information about a proposal as early as 1966 to NASA for a space lasercom experiment. This was a proposal for mounting a lasercom package on a modified Lunar Module ascent stage. That spacecraft would be launched along with an Apollo CSM. In one scenario, the astronaut would actually go outside the vehicle and manually aim the laser at earth.

So lasercom has been around as an idea for a long time, but has not really progressed very far. I don't know what the problem has been other than a general lack of technological maturity. Has DoD not made the right kinds of investments? Have they managed their experimental programs poorly? Or is it just too ambitious to get a high bandwidth system given the near-term state of the art? NRO did fly one experimental lasercom satellite in the 1990s, but the results are classified.

Rupert Goodwins

If space-based lasers aren't currently feasible, what does this mean for LISA?


I know those aren't high bandwidth links, but I don't think the modem side is the tricky bit.

Also, perhaps these people


could be persuaded to help out? They are sending a comsat to Mars, after all.


Jeffrey F. Bell

There may be some hidden factors in the cancellation of MTO:

1) The spacecraft is a failure point for the whole Mars program. If it dies, you lose a lot of data return. It's no accident that MTO's costs rose as a variety of faster/better/cheaper missions failed. They were probably plugging in redundant systems to insure it against failure. Once you adopt full "Class A" redundancy and component testing standards, you are looking at a billion-dollar mission.

2) Lasercom has a huge drawback: it doesn't work through clouds, and the current DSN sites are in low places where clouds are common in certain seasons. Any optical system would require constructing a whole new DSN network based on high mountains. Ask your local astronomer how long it takes to get approval for a new telescope on Mauna Kea or Tenerife.

Bruce Moomaw

There was a lot of unease in the Mars Strategic Roadmap group about that laser experiment, but their feelings about MTO itself wre entirely different -- they showed every sign of approving it strongly, although they've deemphasized this somewhat in their final report.

I've just sent Richard Cook (the new MSL project manager) an E-mail with the folowing questions:

(1) Since MTO was intended to return about five times as much data from MSL daily as Odyssey and MRO together can return, just how serious an impact will the MTO cancellation really have on MSL's science productivity -- and particularly on the rate at which it can drive across the Martian surface?

(2) Has the previous plan not to include a Direct-To-Earth capability in MSL been changed?

(3) In its August 22 editorial, "Space News" points out that a failure of MRO would now have a very serious impact on MSL. Is any possible consideration being given for this reason to selecting an orbiter as the next Mars Scout, equipping it with com relay equipment, and launching it simultaneously with (or before) the first MSL?

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