[meteorite-list] Discovery Mission Finalists Could Be Given Second Shot (Titan Mare Explorer, Comet Hopper)

[Ron Baalke]

http://www.spacenews.com/article/civil-space/36485discovery-mission-finalists-could-be-given-second-shot

Discovery Mission Finalists Could Be Given Second Shot
By Brian Berger 
Space news
July 26, 2013

WASHINGTON - U.S. Senate appropriators are attempting to breath new life 
into one of two deep-space mission proposals that were passed over in 
the most recent competition under NASA's Discovery-series of cost-capped 
planetary probes.

In a proposed spending bill for 2014, the Senate Appropriations Committee 
directed NASA to resume design work on one of the Discovery finalists: 
a lander that would hop on and off a comet racing toward the sun; and 
a probe that would splash down in one of the large methane-ethane seas 
on Saturn's largest moon, Titan.

In 2010, a total of 28 teams sent NASA proposals for a slew of robotic 
solar system exploration missions that could be ready to launch by the 
end of 2016 for no more than $425 million, not including the cost of an 
Atlas 5 rocket or comparable vehicle. The following year, NASA selected 
three finalists: the Jet Propulsion Laboratory's Mars-bound Geophysical 
Monitoring Station, the Johns Hopkins University Applied Physics Laboratory's 
Titan Mare Explorer (TiME) and the University of Maryland's Comet Hopper. 

Each team was awarded $3 million to refine their concepts over the next 
12 months. 

Last August, NASA chose the Mars mission proposal - an instrument-laden 
lander renamed InSight to avoid confusion with the since-canceled Gravity 
and Extreme Magnetism Small Explorer mission - to proceed toward a 2016 
launch.

The two runners-up have strong Maryland pedigrees, a point almost certainly 
not lost on Sen. Barbara Mikulski (D-Md.), who chairs the appropriations 
panel and led the drafting of the 2014 Commerce, Justice, Science and 
Related Agencies Appropriations Act (S. 1329), which includes NASA. A 
report accompanying the bill, approved by the committee July 18, "directs 
NASA to provide additional funding in Discovery to initiate Phase B study 
activities on an additional Discovery mission from the most recent 2012 
announcement of opportunity with the highest scientific value that meets 
the program's cost cap."

University of Maryland researcher Jessica Sunshine, the principal investigator 
behind the Comet Hopper proposal, quipped that she "had a heart attack" 
when she learned that Senate appropriators want to give Comet Hopper and 
TiME a second shot at becoming full-fledged missions.

"It was a surprise to me," Sunshine said July 25. "Being as objective 
as I can be - and I realize I don't have a lot of credibility here - I 
think it's a great idea."

Sunshine said Phase B funding, which typically amounts to 10-15 percent 
of total mission costs, would allow her team "to make sure everything 
you think will work is actually going to work."

"Phase B is the time when you sit down and really define your technical 
specifications for everything," she said. "No metal is bent; it's still 
a study," but "there are some long lead items that if you don't procure 
them in Phase B you won't make it."

Comet Hopper, which would orbit and land multiple times on Comet Wirtanen 
as it approaches the sun, would be built by Lockheed Martin Corp. of Bethesda, 
Md., under the management of NASA's Goddard Space Flight Center in Greenbelt, 
Md. 

TiME, a floating lander that would be dropped onto the surface of one 
of the largest lakes on Titan, was proposed by Ellen Stofan of Gaithersburg, 
Md.-based Proxemy Research and would be built by the Applied Physics Laboratory 
in Laurel, Md. 

TiME's deputy principal investigator, Jonathan Lunine of Cornell University's 
Center for Radiophysics and Space Research, told SpaceNews he and Stofan 
"are very much encouraged by the language in the Senate bill."

TiME is ready to go if and when the Senate language becomes law," he wrote 
in a July 26 email. "Of course, it is all up to the political process, 
but the seas of Titan await us!"

Both Comet Hopper and TiME were designed to carry a government-furnished 
power source known as the Advanced Stirling Radioisotope Generator (ASRG). 
The plutonium-fueled device, still in development, is expected to be four 
times more efficient than the current-generation nuclear battery that 
powers the Mars Curiosity rover, for example. 

InSight, which was selected at a time when NASA was taking flak for scaling 
back its contribution to Europe's ExoMars missions, will rely on solar 
power when it lands near the martian equator in September 2016 to begin 
a two-year mission to study the red planet's geological evolution.

While neither the Comet Hopper nor TiME team would have had to pay for 
the ASRG itself, NASA required them to set aside $20 million of their 
$425 million notional mission budgets to pay for environmental compliance, 
nuclear launch safety approval and related launch services. "This $20 
million cost was not of course carried by the non-ASRG InSight team and 
$20 million greatly exceeds what missions typically pay for a power system," 
Sunshine said. "Thus there really was a disincentive to use this technology 
that NASA needs tested for its future."

Lockheed Martin Space Systems of Denver remains under contract to deliver 
two ASRGs in 2016. What NASA will do with the unfueled flight units is 
unclear. Len Dudzinski, NASA program executive for radioisotope power 
systems, told the NASA-chartered Outer Planets Assessment Group July 15 
that a planned ground-based mock mission known internally as M1 is off 
the table for now. 

Sunshine thinks that is for the best. "We have two groups of people that 
spent more than $3 million each to get up to speed and understand what 
needs to be done" to integrate an ASRG, she said. "To say you are going 
to go off and start a new study is throwing out a heck of a lot of expertise 
that you already paid for twice."

Sunshine said her team was barred by Discovery program rules from working 
with the ASRG's government-industry development team during the competition 
because the system was being offered to all comers as government-furnished 
equipment.

If NASA ultimately funds a Phase B effort for Comet Hopper or TiME, Sunshine 
said, the agency's ASRG efforts would benefit. "Either one of us or both 
of us could accomplish a lot" in terms of working through the details 
of integrating an ASRG - which, unlike the radioisotope thermoelectric 
generators it would replace, has moving parts - with a science spacecraft. 

Lunine agreed. "We did not see - nor do we now see - a need for a mock 
mission."

There were questions about whether Lockheed could deliver a flight-ready 
ASRG in time for a 2016 liftoff, according to Sunshine. A Department of 
Energy-led design review held in June 2012  - just weeks before Discovery's 
final down-select - raised "a lot of schedule concerns," she said. 

Those schedule concerns were rendered all but moot when NASA passed over 
the two ASRG-powered Discovery finalists. The ASRG team is still working 
toward a 2016 delivery, Sunshine said, but with no spacecraft headed to 
the launch pad that year, the team no longer needs to worry about delivering 
a fueled flight unit or leaving enough time for installation.

And given that the Phase B effort Senate appropriators want NASA to fund 
would not begin until 2014 and would run at least a year, a flight-ready 
ASRG should be available in plenty of time for a reinstated  Comet Hopper 
or TiME mission, the launch of which would likewise slip. 

With the Republican-controlled House and Democrat-led Senate billions 
of dollars apart on spending and the Oct. 1 start of the 2014 budget year 
looming, the odds of Congress enacting full-year appropriations in the 
weeks ahead are considered slim. But if either Comet Hopper or TiME eventually 
makes it to the launch pad, it would not be the first NASA mission Mikulski 
has raised from the dead, with or without sending an appropriations bill 
to the president's desk.

After NASA canceled the Pluto-Kuiper Express mission in 2000 because of 
budgetary reasons, Mikulski stepped in with the funding and political 
pressure NASA needed to launch the Applied Physics Laboratory-built New 
Horizons mission in 2006. That same year, after months of cajoling from 
Mikulski, NASA finally reinstated the Hubble servicing mission it had 
canceled in the wake of the 2003 Space Shuttle Columbia accident.