From Orlando Sentinel
NASA outlines plans for moon and Mars
36 years after Apollo 11, the agency proposes new spacecraft and a lunar base to prepare for the next giant leap -- to the Red Planet.
By Michael Cabbage
Sentinel Space Editor
Posted July 31, 2005
NASA's new road map for the human exploration of space would land four astronauts on the moon by 2018 as the first step toward an eventual six-person voyage to Mars.
TO THE MOON
Pioneers would build a lunar outpost, most likely at the south pole, with living quarters, power plants and communication systems. Expeditions would scavenge the desolate landscape for precious supplies such as fuel and water.
Astronauts would roam the surface in high-tech dune buggies to search for answers to scientific riddles that continue to baffle researchers. The crews would blast off aboard rockets derived from the space-shuttle fleet and parachute back to Earth in capsules similar to those used during the Apollo program.
The assault on the moon would be a precursor to 500-day expeditions on Mars, an alien world more than 35 million miles away that some scientists suspect could hold evidence of extraterrestrial life.
Those and other specifics of NASA's ambitious plans for a new era of human space travel are outlined in a set of internal briefing charts on the agency's recent Exploration Systems Architecture Study. A copy of those briefings, parts of which are scheduled to be made public next month, was obtained by the Orlando Sentinel.
Some things are subject to change, and important decisions have yet to be made. But the study is the first detailed description of how NASA intends to accomplish the goals announced by President Bush in January 2004 of returning astronauts to the moon by 2020 to prepare for later missions to Mars.
J. SCOTT APPLEWHITE/THE ASSOCIATED PRESS
In a speech Jan. 14, 2004, at NASA's headquarters in Washington, President Bush announces his ambition to build a base on the moon and eventually send astronauts to Mars. A new study estimates the program will cost about $217 billion through 2025.
So far, the program has considerable support from the White House and Congress, but to become a reality, it will have to withstand the test of time. The study estimates the program will cost about $217 billion through 2025. NASA's exploration office is projected to receive about the same amount of money during that period.
To stay within the budget, NASA Administrator Michael Griffin has spent much of his first three months on the job refocusing the agency and its resources on preparing for a return to the moon.
"I hope that you will see as we bring it forward," Griffin told Congress on June 28, "a logical, clean, simple, straightforward approach."
Griffin's influence already has been felt. The current study is the result of a 60-day review of previous exploration plans. It contains a number of important changes. Among them:
A version of the same ship designed to carry astronauts to the moon first would ferry crews to the international space station. The gap between the initial manned launches of that vehicle in 2011 and the shuttle's planned retirement in 2010 was shortened from four years to one. And a new fleet of rockets to support human missions is expected to be cheaper and safer by building on existing parts of the shuttle.
NASA managers have declined to be interviewed about the plan until its public release. One, however, said privately that Griffin's involvement has made a huge difference.
"We [NASA] can no longer take a business-as-usual approach, and Mike Griffin clearly understands that," the manager said. "We have to be more financially and technically creative to do the things we need to do."
Doing the heavy lifting
All of the hardware needed for the Apollo moon landings from 1969 to 1972 reached orbit with a single launch of the giant Saturn 5 rocket. But because Saturn 5 production ended more than 30 years ago, NASA has been looking for new boosters powerful enough to lift the heavy loads required for lunar missions.
Engineers debated for months whether to develop a heavy-lift rocket from parts of the shuttle or rely on improved versions of the Atlas and Delta boosters used by the Air Force to launch satellites. According to the study, they chose the shuttle-derived option because of lower cost and superior lifting ability.
"[It's the] only viable solution given [the] time frame and current market," the study noted. The hardware and cargo required for lunar missions would lift off aboard a 40-story colossus built around the shuttle's external fuel tank. This unmanned booster would be developed between 2010 and 2018.
Five of the shuttle's main engines and larger versions of its twin booster rockets would power the launcher. Some versions would be capable of carrying a hefty 125 tons into Earth orbit, making it almost the equal of the Saturn 5. The projected price tag of $540 million per launch is comparable to the cost of a shuttle flight.
The giant booster would have a powerful new upper stage. This so-called Earth Departure Stage would be used to hurl spacecraft toward the moon. Also designed from the shuttle's fuel tank, it would be equipped with an upgraded pair of the same engines used on the Saturn 5's upper stages.
NASA has decided to launch future astronauts on moon and space-station missions aboard a separate rocket derived from another piece of shuttle hardware.
Starting in June 2011, astronauts would lift off to the station atop a modified version of the shuttle's pencil-shaped solid-rocket booster. The rocket's new second stage would be powered by one of the shuttle's main engines.
The $280 million missions would free NASA from having to depend solely on the Russians for station flights after the shuttle's retirement. The same rocket later would be used to launch crews into low Earth orbit to begin trips to the moon. NASA estimates the launcher would be nine times safer than the shuttle.
"We have ways to construct such vehicles using shuttle solid-rocket motors and external tanks and shuttle main engines," Griffin said of the new boosters Friday. "We think the existing components offer us huge cost advantages as opposed to starting from a clean sheet of paper, and that's what I've proposed doing."
New spacecraft are being designed to ride atop the new rockets. Engineers already are developing a cone-shaped Crew Exploration Vehicle, or CEV. Initial versions of the CEV would launch aboard the modified shuttle booster rocket and carry three-person crews to the space station a couple of times per year.
The ships also could be used to transport cargo to the outpost. Larger, future versions of the capsule would take four people to the moon and six-person crews to Mars.
Last month, NASA awarded a pair of $28 million contracts to Lockheed Martin and a Northrop Grumman-Boeing team to come up with designs for the new ship. The agency will select one of the two proposals in March.
NASA managers plan to review the CEV's engineering design in July 2006 with the goal of having the spacecraft ready for a manned launch to the station in 2011. Having the CEV available as soon as possible could become critical if the White House rethinks the shuttle's 2010 retirement date because of continuing problems with hazardous launch debris during shuttle Discovery's liftoff Tuesday. The CEV will be strikingly similar to the Apollo command module but larger. Astronauts on future lunar flights will have more than twice the room. In another throwback to Apollo, the 12-ton capsule would be mated to a service module that provides power and propulsion during the journey to and from the moon. Crews returning home in the CEV would jettison the service module before making a fiery plunge through Earth's atmosphere and parachuting to the ground.
The capsule then would thump down on land as Russian missions did instead of splashing down in the Pacific Ocean as Apollo flights did.
NASA already has identified three possible landing sites in the Western United States: Edwards Air Force Base in Southern California's Mojave Desert, the Carson Flats area of Nevada and near Moses Lake in eastern Washington.
The ship's flight path would carry it over the Pacific Ocean, minimizing the risk to people below if something went wrong. If necessary, the capsule would be capable of making a water landing. The CEV will have an expendable heat shield, and versions that go to the space station could be reused for up to 10 missions.
In addition to the CEV, engineers have begun looking at designs for the lander that will carry astronauts from lunar orbit to the moon's surface and back. Development is scheduled to accelerate in 2010, with a spacecraft ready for flight by 2018. The lander's design follows the same general concept as Apollo's. It has two basic parts.
The bottom descent stage is a four-legged platform with rocket engines that lower the craft to the moon's surface. A detachable upper ascent stage serves as a crew compartment and launches the astronauts back to lunar orbit when their mission is complete.
The ascent stage's engines are designed to burn liquid-methane propellant. Small amounts of methane are thought to be present in Mars' atmosphere, creating the possibility that astronauts might be able to produce their own rocket fuel instead of carrying it with them
The lander would remain on the lunar surface for about a week. An airlock would allow a crew of four astronauts to leave the ship for moonwalks. The lander held only two astronauts during the Apollo missions.
The craft is designed to carry up to 23 tons of cargo and could be used to rotate crews living at a lunar base.
"We can gain quite a bit of science," said David Black, an astrophysicist and head of a research association that oversees the Lunar and Planetary Institute in Houston. "One of the things we can get is a better handle on the origin of the moon and how it relates to Earth."
Getting to the moon
One of the great technical challenges of the early 1960s was how to design the Apollo moon landings. Engineers debated a number of ideas.
Some suggested a direct approach in which parts of a massive Saturn 8 or Nova rocket would launch from Earth, fly to the moon, land there, blast off again and return to Earth. The size of the rocket needed and the fuel required made the idea impractical.
Another approach, initially favored by rocket visionary Wernher von Braun, was called Earth Orbit Rendezvous. This method proposed launching several smaller rockets carrying the hardware needed for a lunar mission.
The pieces would be assembled in Earth orbit, and then the larger spacecraft would travel to the moon and back. This plan was abandoned in 1962 largely because of unknowns about putting together a rocket in space.
Apollo engineers ultimately decided on a third approach known as Lunar Orbit Rendezvous. A single Saturn 5 booster launched all of the spacecraft needed for the mission. After the systems were checked out in Earth orbit, the rocket's third stage restarted to propel the mission to the moon.
Next, the Apollo command module and service module separated and docked with a lunar lander housed inside the third stage. Once in orbit around the moon, two astronauts piloted the lander to the surface. An ascent stage atop the lander launched back to lunar orbit, where it mated with the command module for the astronauts' return to Earth.
In recent months, NASA engineers have been debating some of the same issues their predecessors faced four decades ago. The result is a new blueprint similar to Apollo's but with features of von Braun's early Earth Orbit Rendezvous approach. Future lunar missions would launch aboard two separate rockets. The giant new 40-story booster would carry the lunar lander into space atop the fuel-filled Earth Departure Stage. Next, the CEV and service module would lift off aboard the smaller, modified shuttle booster.
Once in low Earth orbit, the CEV would dock with the lunar lander. From there, the mission would be virtually identical to Apollo's. The Earth Departure Stage would rocket the spacecraft toward lunar orbit. Four astronauts would descend to the surface aboard the lander. A week or so later, they would lift off from the moon and dock with the CEV, which would carry them back to Earth.
"You have to take the long view and not get yourself into a situation like before where we go to the moon and aren't positioned to build on it," astrophysicist Black said. "This approach makes a lot of sense if you are going on to Mars."
Current plans call for a minimum of two lunar missions per year beginning in 2018.
Astronauts would conduct long-term research in several scientific disciplines, including astrobiology, geology, astronomy and physics. Some of the studies will gauge how the human body responds over time to weaker gravity, increased solar radiation and other conditions found away from Earth.
Crews also would try to take advantage of any available resources on the moon and live off the land. The goal is to eventually develop a lunar base.
A likely location for an outpost is near Shackleton Crater at the moon's south pole, where scientists suspect there are relatively high levels of hydrogen, a potential fuel source, and the possibility of water ice. Missions would gradually build power, communication and navigation systems, and a place to live. Rovers more advanced than those during Apollo would be used to explore the surface.
Other high-priority sites for exploration include the north pole, three locations on the dark side of the moon and the Sea of Tranquillity, where Apollo 11 made the first manned lunar landing in 1969.
One of NASA's main reasons for returning astronauts to the moon and living there is to master the technologies and gain the experience needed for future human voyages to Mars. Detailed development of those expeditions is expected to begin about 2020, but the broad outlines already are starting to take shape.
Four or five launches with the giant heavy-lift boosters would carry into orbit the mission's spacecraft and hardware. Before the six-person crew lifts off, however, an outpost with living quarters, power, communications and a return ship would land on the Martian surface by remote control.
The astronauts' trip would take about six months each way. Once on Mars, the crew would spend 500 days exploring large areas of the surface and doing research, including the search for evidence of past or present life. Astronauts would attempt to tap the Martian environment for oxygen and water, two essential supplies, and liquid oxygen and methane, the two propellants that will power the landing craft.
Risks and challenges await
NASA's ambitious plan faces several major technical and political challenges.
One is keeping astronauts healthy. For years, scientists have been concerned about exposure to harmful solar radiation in space, where Earth's atmosphere no longer provides a shield.
According to the study, astronauts who spend long periods of time in low Earth orbit have a 3 percent additional risk of contracting lethal cancer during their lifetime. Currently, there are no radiation guidelines for missions beyond Earth's orbit, although the National Council on Radiation Protection is developing some.
A massive solar storm in August 1972 was the largest radiation event ever recorded. Engineers are trying to develop CEV shielding to offer protection from a storm four times that strong. NASA estimates that an aluminum vehicle with moderate shielding would limit the chance of an astronaut getting sick from such an event to 2.9 percent, with a tiny 0.02 percent chance of death. The space agency assesses the lunar missions' overall risks as relatively small, mainly because of the use of proven systems and technology.
NASA estimates the chance of a failure derailing a mission is less than 6.3 percent, with the chance of the crew dying at 1.3 percent. In contrast, a May 1962 risk analysis before the Apollo program concluded the chance of losing astronauts during the first attempt to land on the moon was 22 percent.
Political challenges here on Earth pose a threat of a different sort. The program's cost already has stirred debate. The estimated $217 billion price tag is only $7 billion more than the projected budget for NASA's exploration office during the next 20 years
. That estimate also includes developing new engines for the Earth Departure Stage. NASA now plans a cheaper approach that would modify engines used during Apollo.
The money crunch will be greatest during the next five years while the shuttle is still flying. But over time, adequate funding for the plan appears likely, at least on paper, if the projects can manage to stay within their budgets.
NASA's overall budget is expected to reach about $17 billion in 2006. If the agency averages only $20 billion annually during the next 20 years, it will receive a total of $400 billion. The estimated $217 billion exploration cost through 2025 represents 54 percent of that total. NASA already spends about half of its budget on human-spaceflight programs.
The challenge will be to keep the projects on schedule and within budget. The plan also must survive three presidential elections and five new Congresses before astronauts again can walk on the moon.
"It's going to take a long, persistent, patient effort," said Rep. Vernon Ehlers, R-Mich., a member of the House Science Committee. "The question is: 'Will political leaders and the public continue that support for that length of time?' "
U.S. Sen. Bill Nelson, D-Fla., who flew aboard the shuttle as a congressman, is optimistic.
"I think with a visionary president, you can ignite the imagination of people and kindle that yearning for exploration," Nelson said. "I think this is very doable in Congress because Congress is a reflection of the American people."