Monday, November 17, 2008

Bruce Moomaw on New Frontiers

Last time [the New Frontiers price cap] was $700 million in FY 05 dollars. The $650 million cost cap this time does not include the launch vehicle cost. Whatever flies is still going to have to be about the same cost as Juno.

And when it comes to Io or Ganymede missions: we won't know until February whether the Europa Flagship mission will fly to take a look at those worlds, and the New Frontiers mission proposals this time are due in May. Would any team really spend three months planning a mission to such a world with the serious odds that they would then discover (with only three months left to plan a replacement mission) that their mission was redundant?

[The following portions were written before Bruce realized that the cost cap does not include the launch vehicle, which will raise the overall NASA cost of the mission above the last selection's price target. It's not clear how the overall budget compares given inflation (which occurs at a different rate for aerospace than for consumers).]

Consider how comparatively simple Juno is -- spin-stabilized, and even its visible-light camera is optional. And yet there's a good chance it wouldn't have qualified for this round. (For that matter, consider the cost of MAVEN!) It will be a miracle, I think, if they can fit in anything under this cost cap that would be scientifically cost-effective for any of Jupiter's moons, and I would also tend to count out any comet-nucleus sample return and any Mars Network mission (consider the $1.2 billion cost estimate for even the minimum version of that as provided by the Mars Architecture Tiger Team.) A Mars Network mission focused solely on Mars meteorology, that would strew around a bunch of tiny lander capsules (like the Robert Haberle's "PASCAL" concept), might get in under the cost cap -- but would meteorology alone be enough, since planetary internal structure is the real primary goal of the suggested NF network mission, and something that focused just on Martian meteorology would be better described as a Mars Scout?

A solar-powered Trojan/Centaur flyby could also produce problems (especially given the need to shield its solar arrays from coma dust during the Centaur flyby -- maybe they could include an onboard battery capable of lasting long enough to relay back all the data from the Centaur?). An Aitken Basin sample return involving just one lander instead of the two included in the "Moonrise" concept might make it -- but there are uneasy doubts about the odds that one Aitken lander by itself could get the rather specific samples of mantle and impact-melt material that they need. All in all, I'd rate the favorites this time as being either a near-Earth asteroid sample return aimed at a really primitive asteroid of the sort that almost never turns up as meteorites (like the "OSIRIS REx" concept -- maybe aimed at Wilson-Harrington as a cross between an asteroid and a comet?) or a properly-scaled Venus mission (such as a significantly descoped version of Kevin Baines' "VALOR Plus").

[Van's comments: Bruce's comments nail what is likely to be the key focus of the next New Frontiers selection. I expect that the scientific community will display considerable ingenuity in proposing missions that address a portion of the goals for a target. Juno did that by proposing an orbiter that uses remote sensing to fulfill the goals for a mission that originally called for atmospheric entry probes. A descoped Valor Venus mission similarly fulfills the atmospheric goals for the in situ Venus mission. Unfortunately, we'll have to wait almost a year to the first down select to three missions to learn what has been proposed.]

1 comment:

  1. I think that at least one team will work a proposal for an Io mission. A proposal (using a Stirling RTG) is in the works and near completion for the Discovery program. I don't think it would take much to modify it for solar power (which may just show my ignorance!).

    The real work would come after the first down select, after which the Phase A study would be done. That comes many months after the selection of the next flagship target.