WASHINGTON – NASA has agreed to give the Mars Phoenix lander team the extra $31 million it needs to get the spacecraft ready to launch by August, but the U.S. space agency has yet to sign off on a new total estimate for the mission.


Mars Exploration Program Director Doug McCuistion told Space News Jan. 31 that he approved going forward with
despite the overrun because he believes the mission is finally on a sound technical footing. But he said he has asked the team to revisit what it needs to spend on the post-launch operations phase of the mission, which includes a 10-month cruise to the red planet followed by five months of surface operations.


McCuistion said the overrun would be covered from within the Mars Exploration Program’s budget. He declined, however, to provide specifics on the programmatic impacts of the overrun until after NASA rolls out its 2008 budget request on Feb. 5.


NASA ordered a formal cancellation review for the Phoenix lander last fall after learning the project had overrun its $386 million budget trying to overcome a number of setbacks, including problems with a commercially purchased radar altimeter and unexpected difficulties finding a suitable landing site.


lander, NASA’s next mission to Mars, was picked in 2003 as the first of a planned series of low-cost, competitively selected Mars Scout missions. If successful,
would be the first Mars spacecraft since NASA’s Viking missions of the 1970s to settle down on the planets surface using onboard rocket thrusters instead of airbags.


A critical component of
‘s landing system is a radar altimeter brought over from the commercial aviation field. Drop tests last year, however, revealed that the radar altimeter needed more software and firmware modifications for use as a spacecraft landing radar than previously assumed.


Barry Goldstein,
project manager at NASA’s Jet Propulsion Laboratory in
, told reporters Feb. 1 that the spacecraft was on track for its August launch from
Cape Canaveral
, aboard a United Launch Alliance Delta 2 rocket.


“The vehicle is behaving very nicely. Things are looking good technically as well as with the schedule and where we are headed. We have no threats to [delay the] launch at this point,” he said.


Goldstein and other
project officials spoke to reporters about the spacecraft’s status and upcoming mission during a press briefing held at Lockheed Martin Space Systems near
, the site where the Mars lander is being built and readied for flight.


Lockheed Martin is due to ship
in early May where it will undergo final pre-launch checkout. Edward Sedivy,
program manager at Lockheed Martin, said the lander is “very strong and very robust from the test perspective.”


Meanwhile, the
lander team has not yet finalized exactly where it plans to touch down once the spacecraft reaches Mars in May 2008.


The team thought at one point that they had selected a safe landing spot for
but high-resolution imagery taken by NASA’s Mars Reconnaissance Orbiter last year showed that site to be littered with enormous boulders. Peter Smith, the
principal investigator at the
, said three candidate sites are now being intensely mapped by MRO and the Mars Odyssey orbiter to ensure a high probability of a safe touch down. In plotting out landing areas, “we paint the parts green that we think are the safest places … and we have a place we call ‘Green Valley’ now that’s so green that it looks very secure for us,” Smith told reporters in Denver.


A final landing site selection is expected in early March, Smith said. “We want to select both a safe site and a scientifically interesting site … with safety being No. 1 of course … or else we don’t get anything.”


The stationary lander is equipped with a robotic scoop to dig and scratch into the martian surface for answers regarding the history of water on Mars and the planet’s potential as an extraterrestrial address for life. After a 10-month cruise to Mars, the lander is expected to spend five months on the planet’s surface gathering science.