WASHINGTON- NASA is set to begin rolling out the results of a landmark space explorationarchitecture study that calls for building an Apollo-like astronaut capsule andconducting up to six lunar sorties per year using rocket hardware derived fromthe space shuttle.
Sixty daysin the making, the Exploration Systems Architecture Study will go a long waytoward defining the approach and the hardware NASA will use to returnastronauts to the Moon by 2020, and eventually go on to Mars.
That hardwareincludes the so-called Crew Exploration Vehicle (CEV) and the rockets that willbe needed to loft both the CEV and huge amounts of cargo that will be needed toestablish a sustainable astronaut presence on the lunar surface.
Long beforebeing named NASA administrator this spring, Mike Griffin was on the recordsaying that he thought the United States ought to take maximum advantage ofexisting space shuttle hardware and infrastructure in building the newlaunchers.
In publicspeeches, congressional testimony and interviews since being sworn in, Griffinhas made clear that he still believes shuttle-derived launchers are the way togo, not just for the really big Moon-bound cargo payloads but also for the CEV,whose destinations are to include lunar orbit and the international spacestation.
And nothingdiscovered in the course of the Exploration Systems Architecture Study seems tohave dampened that belief.
"We havestudied this as carefully and ecumenically as we know how to do," Griffin toldSpace News in a June 27 interview at NASA Headquarters here. "For the purposesof launching the CEV, while we could probably make anything work, clearly thesafest, most cost-effective, highest-reliability path that we see isshuttle-derived."
Chicago-basedBoeing and Bethesda, Md.-based Lockheed Martin have been pushing variants oftheir respective Delta 4 and Atlas 5 rockets as the solution to all of NASA'sexploration needs. Both rockets were developed under the U.S. Air Force EvolvedExpendable Launch Vehicle (EELV) program for launching military satellites andwould require upgrades to handle the 25-ton CEV and major redesigns to meetNASA's heavy-lift cargo needs. To return to the Moon in a meaningful way, NASAsays it needs a vehicle capable of placing 100 metric tons of cargo into Earthorbit, far beyond the capability of the Delta 4 or Atlas 5.
Griffinsaid that all things considered, shuttle-derived hardware looks like the bestchoice for the heavy-lift cargo missions and for the CEV.
"[T]herewould be a bunch of changes that would have to be put into the EELV to humanrate it, and I don't know that that's the most fiscally sound path for NASA togo down. And frankly, I don't know that the EELV community would welcome usgetting into their production lines in order to make those kinds ofmodifications," Griffin said. "So all that would have to be thought throughvery carefully. Right now the path we think is the most favorable is theshuttle-derived, in part because that gives us the best work force transitionissues."
Griffinsaid using shuttle-derived launchers would help NASA retain the work force itneeds to keep flying the space shuttle safely until the last orbiter in thefleet is retired at the end of the decade.
Griffinsaid in the interview that NASA likely would be ready to go public with itsexploration plans around mid-July after coordinating with other parts of theU.S. government and with industry. Initial coordination briefings were set tobegin the week of July 4.
"In thepast we've often been accused of bringing in the solution with no other optionsand I am trying hard to get away from that," Griffin said. "There are numerousstakeholders and I want to play fair with all of them. I'm not going to go outwith an uncoordinated NASA position."
Nevertheless,NASA gave a small group of outside experts an update on the Exploration SystemsArchitecture Study the week of June 27 and, according to a Washington-basedsource who had been briefed in turn, laid out a lunar exploration architecturethat includes as many as six flights a year to the Moon.
Accordingto this source, key elements of the lunar exploration architecture are cominginto focus. For example:
- The CEV would be a reusable capsule capable of carrying four passengers to the Moon.
- NASA would use a three-person version of the CEV capsule to ferry astronauts to and from the international space station three times a year.
- An unmanned version of the CEV would be used as a cargo carrier, conducting three space station resupply missions a year.
- Both the CEV launcher and the heavy-lifter would be shuttle-derived and cost about $3 billion a year once in service.
- The CEV would launch atop a single solid-rocket booster whose design is virtually the same as those that help lift the space shuttle off the launch pad.
- The heavy-lift vehicle initially would be sized to lift 100 metric tons into orbit for Moon missions but could evolve to loft 120 metric tons for Mars missions.
The U.S.Space Transportation Policy released by the White House in January requiresNASA and the Pentagon to reach a joint recommendation on the nation's nextheavy-lift launcher and leaves it to the president to decide. The policy alsodirects NASA to give preference to a solution based on EELV hardware to helpthe Air Force defray the costs of supporting the program.
Griffinsaid June 27 that he had yet to meet with U.S. Defense Secretary DonaldRumsfeld but did meet recently with Air Force Gen. Lance Lord, commander of AirForce Space Command, to discuss NASA's case for building shuttle-derivedlaunchers. Griffin said Lord agreed that a shuttle-derived vehicle "was theobvious path" for NASA's exploration needs.
But thatdoes not necessarily mean the Air Force won't be getting any NASA help inshouldering the EELV burden: Griffin said he told Lord that NASA would bewilling to switch to the medium-lift variants of the EELVs to loft its sciencespacecraft "provided that there is not an undue financial penalty for NASA."
That mightspell the end of Boeing's smaller but highly reliable Delta 2 rocket, which hasserved as NASA's primary workhorse for the past decade or more. That vehicle isno longer in the Air Force's plans.
Griffin calleda switch to EELV "the most nascent of plans" noting that NASA still has about adozen Delta 2 launches under contract.
Air ForceSpace Command spokeswoman Maj. Angie Blair said June 28 that Lord was on traveland not immediately available to comment on his meeting with Griffin. A DefenseDepartment official, who asked not to be identified by name, confirmed thatGriffin and Lord had reached a tentative agreement on Delta 2 and said that theAir Force is not likely to stand in the way of NASA developing shuttle-derivedlaunchers.
"We want tohelp them do what works best for them," the Defense Department official said."Ultimately it is their call, not ours."
SingleStick and In-Line Heavy
Griffin likesto point out in interviews and public talks that the space shuttle isessentially a heavy-lift launcher with a very heavy payload shroud -- theshroud, of course, being the space shuttle orbiter itself. And NASA has foryears been studying options for a heavy-lift vehicle based on the shuttle'smain engines, external tank and solid rocket motors.
Forlaunching the CEV, Griffin said he favors using a modified shuttle solid-rocketbooster equipped with a new upper stage. Industry officials say options forpowering the upper stage include a modified space shuttle main engine or theJ-2 engine that was used on both the second and third stages of the giantSaturn 5 rocket of Apollo fame.
There aretwo basic designs for a shuttle-derived heavy lifter. The so-calledside-mounted vehicle, which closely resembles today's space shuttle launchconfiguration except that the orbiter would be replaced with a cargo carrier,could lift 75-90 metric tons. The so-called in-line heavy-lifter has the cargocarrier mounted above the core-stage tank. Utilizing four to five space shuttlemain engines, two solid rocket boosters and a modified external tank, it wouldbe about the size of a Saturn 5 and could loft up to 120 metric tons.
ATKThiokol, the Magna, Utah-based company that builds the solid-rocket boosters,has been touting shuttle-derived solutions for NASA's exploration needs.
"It's safe,it's simple and it's soon," said former NASA astronaut Scott Horowitz, ATKThiokol's director of exploration space transportation. "That has been themantra since the astronaut office first looked at this problem after theColumbia accident."
Horowitzhas been making the rounds in Washington in recent weeks briefing congressionalstaffers and news media on shuttle-derived launcher designs. In an interviewwith Space News, he estimated development costs for a human-rated CEV launchvehicle based on the shuttle solid rocket booster at $1 billion to $1.5billion, a figure that does not include the CEV itself.
"ProbablyNASA could spend $200 [million] to $300 million a year and this thing could besitting on the pad by 2010 and ready to put people on top," Horowitz said.