NASA Just Cancelled Its Advanced Spacecraft Power Program. This is the title of a blog post by Casey Dreier, Advocacy and Outreach Coordinator for the Planetary Society. He quoted an announcement from Jim Green, director of NASA’s Planetary Science Division.
With an adequate supply of Plutonium-238, and considering the current budget-constrained environment, NASA has decided to discontinue procurement of ASRG flight hardware. We have given direction to the Department of Energy, which manages the flight procurement, to end work on the flight units. The hardware procured under this activity will be transferred to the Glenn Research Center to continue development and testing of the Stirling technology.
Generators, power from Pu-238
The ASRG is the Advanced Stirling Radioisotope Generator. It was to improve the efficiency of energy conversion from isotope decay to electricity by a factor of 4. The existing system, the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), powers the Curiosity rover, providing about 125 watts of electrical power from 4.8 kg of Pu-238. [Curiosity specifications] The ASRG would provide about 140 watts from 0.8 kg. [ASRG Specifications] RTGs in space have been in use since the 1960s. The Stirling engine dates back to the early 1800s.
While the power output level is similar, the ASRG is also lighter (~20 kg) than the MMRTG (45 kg). But the ASRG is still in development; it would be a few years before it is ready for flight.
However, the overriding constraint on future outer planets missions (Jupiter and beyond) and heavy rovers like Curiosity is the amount of Plutonium-238 available. The Department of Energy will produce about 1.5-2.0 kg per year, paid for from the NASA Planetary Science budget. (This is a new cost item in the NASA budget, which gets no increase to cover it.) It would take 2-3 years to have enough for another Mars rover like Curiosity. In the meantime, no missions to the outer planets could be flown. By reducing the Pu-238 requirement to 0.8 kg, you could launch 1-2 outer planets explorers per year.
So the ASRG cancellation announcement got me upset.
The Planetary Society provided a standard form letter regarding the precarious state of funding for planetary science. (Follow Casey’s blogpost. The link is at the bottom.) I embellished it with my specific concerns about the ASRG program cancellation, but left the requested actions (“I strongly urge…”) the same as what the Planetary Society formulated to avoid mixed messages on action. The Planetary Society site is able to find your elected officials based on your zip code.
This letter was sent to my congressman (Mike Honda), two senators (Barbara Boxer, Dianne Feinstein), and the president (Barack Obama). (Some representatives, like Rep. Honda, require entry on a separate form their office provides. This requires a copy-n-paste, but an easy step. It is probably a decent first-level spam filter.)
Below is my letter, modified from the Planetary Society original, and sent off to my elected officials.
I am extremely concerned about the cancellation just announced of NASA’s Advanced Stirling Radioisotope Generator (ASRG) program. This program was going to vastly improve the capabilities of spacecraft exploring the outer planets when compared to current radioisotope thermoelectric generators (RTGs).
NASA’s Planetary Science Division (PSD), responsible for popular missions such as the Curiosity rover on Mars and the Cassini orbiter at Saturn, has suffered continuous budgetary attacks by the Office of Management and Budget for the past two years. As a result, we’ve seen missions delayed and cancelled, international partnerships broken, and an immeasurable loss of science.
In order to ensure any viability of any future outer planets missions, NASA PSD had to eat the cost to restart miniscule Pu-238 production WITH NO INCREASE in overall budget. This strikes me as both unfair and foolish.
I urge you to restore funding for NASA PSD to $1.5 billion per year, its recent historical average and the minimum required to maintain our edge in solar system exploration. Both the Senate and the House have recommended this level in their 2013 NASA Authorization bills.
I strongly urge the following:
* Restore funding for NASA’s Planetary Science Division to its historical average of $1.5 billion per year for the next five years.
* Ensure that NASA pursues a balanced program of planetary exploration as defined in the National Research Council’s “Decadal Survey” report, including storage of a sample to return from Mars and a mission to Europa.
* Maintain operations of existing spacecraft to ensure taxpayers get the highest science return on their fiscal investment.
I thank Congress for their efforts to restore funding to NASA’s Planetary Science Division in 2013. Before sequestration, Congress rejected the 20% cut proposed by the Office of Management and Budget in fiscal year 2013. Despite this, the OMB proposed further cuts in 2014.
Planetary science is one of the most successful parts of NASA.. These missions have consistently proven to be popular with the public, return an enormous amount of science, spur creative technological solutions within NASA and private industry, and foster strong international relationships. NASA’s planetary science program is one of the best investments the government can make.
There is bipartisan support for Planetary Science and exploration in both houses of Congress and across party lines. I strongly encourage you to join with your colleagues in government to restore funding to a minimum of $1.5 billion a year to maintain NASA’s leadership in space exploration.