"Mission to the Fires of Hell" looks to larger launcher

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http://www.spacenews.com/article/civil-space/41380solar-probe-plus-nasa%E2%80%99s-%E2%80%98mission-to-the-fires-of-hell%E2%80%99-trading-atlas-5-for

Solar Probe Plus, NASAs Mission to the Fires of Hell, Trading Atlas 5 for Bigger Launch Vehicle

Solar Probe Plus, a flagship heliophysics mission NASA expects to cost some $1.5 billion to build and launch around July 2018, needs a bigger rocket than United Launch Alliances Atlas 5, according to a senior official at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, where the solar observatory is being built.

The plan we had was to go on an Atlas 5, but the problem is that required us to develop a new, high-performance custom upper stage, and that represented a fairly significant risk for the project, Michael Ryschkewitsch, head of APLs Space Sector, said in a July 22 interview here. Our team made the case to NASA headquarters that the overall risk to the mission would be lowered if we went to a heavy class launch vehicle. The obvious players right now are Delta 4 Heavy and Falcon Heavy.

Trading up to a Delta 4 Heavy or Falcon Heavy means the money paid to ATK Missile Products of Beltsville, Maryland, for work on the customized kick-stage motor, known as STAR 48GXV, was a wasted effort for Solar Probe Plus. APL spokesman Michael Buckley said July 23 that ATK was paid $15.7 million for the work, which culminated with a December test firing of the solid-fueled STAR motor.

The Delta 4 Heavy is Denver-based ULAs most powerful launcher, typically used for the largest classified national security satellites. Falcon Heavy is a concept from upstart launch services provider and spacecraft maker Space Exploration Technologies Corp. of Hawthorne, California.

SpaceX plans to launch the first Falcon Heavy in 2015 from Cape Canaveral Air Force Station and advertises that the 27-engine rocket will be able to lift 53 metric tons to low Earth orbit: More than twice the payload of ... the Delta IV Heavy, at one-third the cost, according to SpaceXs website.

The Delta 4 Heavy, which has flown seven times including its 2004 debut, is capable of lifting roughly 26,000 kilograms to low Earth orbit. NASA is paying $375 million for the Delta 4 Heavy it ordered in 2011 for this Decembers unmanned test launch of the Orion crew capsule.

Although Falcon Heavy has yet to fly, NASAs Launch Services Program left the door open for SpaceX to compete for Solar Probe Plus launch services in a draft request for proposals released July 10. While NASA will consider only rockets certified to loft Category 3 payloads the internal designation reserved for the most important and risk-averse missions agency rules allow for Category 3 certification with as few as three launches, NASA spokesman Joshua Buck wrote in a July 24 email.

SpaceX, has three Falcon Heavy launches on its manifest between now and 2017: an inaugural demonstration launch planned for 2015 followed in short order by the shared launch of the National Oceanic and Atmospheric Administrations Deep Space Climate Observatory and the U.S. Air Forces Space Test Program-2 experimental spacecraft, and a 2017 launch of a commercial communications satellite for Intelsat of Washington and Luxembourg. SpaceX spokesman John Taylor declined to comment about whether SpaceX would seek certification to launch Solar Probe Plus.

The ATK-built stage scrapped along with plans to launch Solar Probe Plus on ULAs most-powerful Atlas 5 the so-called 551 variant that features five solid-rocket boosters and a 5.4-meter payload fairing was based on a similar solid-fuel upper stage ATK made for the Atlas 5 that launched the roughly 480-kilogram New Horizons probe toward Pluto in 2006. APL thought Solar Probe Plus could use a similar setup, but the amount of energy required to fly so close to the sun without getting sucked in, coupled with Solar Probe Plus heftier 658-kilogram launch mass, was more than the New Horizons launch rig could handle, Ryschkewitsch said July 22.

ATK spokesman Michael DiMauro confirmed July 24 that ATK has halted STAR 48 GXV development.

NASAs Science Mission Directorate approved Solar Probe Plus to proceed into development in March. The orbiter is bound for a nearly seven-year primary mission to the fires of hell, Nicky Fox, APL-based Solar Probe Plus project scientist, told SpaceNews here after a Maryland Space Business Roundtable Luncheon attended by employees of APL, NASA Goddard, and many local NASA contractors.

At its closest, Solar Probe Plus and its 10 instruments will fly about 6 million kilometersfrom the suns surface. The mission will measure blasts of charged particles, or solar winds, emanating from the stars corona. Solar winds can disrupt sensitive electronic equipment in space and on Earths surface. Sending a dedicated probe to the sun was identified as the top priority in a 10-year heliophysics roadmap, The Sun to the Earth and Beyond, published in 2003 by the National Research Council.