WASHINGTON — Despite a painful budget squeeze, the United States will undertake a jampacked array of new astronomy missions over the next 12 months.
The goals range from counting tiny specks of carbon in Earth's atmosphere to surveying the outer boundary of the solar system and studying the farthest corners of the universe.
NASA asked for $4.44 billion to pay for these and more than 40 existing and future science projects in the next fiscal year. But astronomers complain that the budget is still too tight.
NASA has ``too few resources to accomplish the many tasks that the nation has placed on the agency,'' Lennard Fisk, chairman of the National Academy of Sciences' prestigious Space Studies Board, told Congress.
The pressure led Alan Stern, NASA's deputy administrator for science, to quit in frustration last month.
The first event in this astronomical parade (on the 400th anniversary of Galileo's invention of the telescope) will be the landing of NASA's Phoenix spacecraft near the north pole of Mars on May 25. The lander is equipped with a robotic arm that'll scoop up some icy soil to see if it contains the ingredients for microbial life.
If it lands safely _always a question — Phoenix will join the Spirit and Opportunity rovers, which have been exploring the equatorial regions of the planet since 2004. In addition, three satellites now orbiting Mars — two American and one European — will adjust their flight paths to handle communications with Phoenix as it parachutes onto the northern ice cap.
Next in line is the launch of a large space telescope named GLAST (for Gamma-ray Large Area Space Telescope), which will study extremely high-energy gamma rays streaking from massive black holes and colliding stars. Celestial gamma rays are the most powerful form of electromagnetic radiation known to science. The rays are lethal to human cells, but fortunately are blocked by Earth's atmosphere.
By studying gamma rays, scientists can test theories about the birth and early evolution of the universe that would be impossible in earth-bound laboratories. GLAST was supposed to be launched on May 16, but a rocket problem forced a delay to early June.
Aiming closer to home, NASA will launch a satellite on June 15 to measure changes as small as one inch in the sea level. The Ocean Surface Topography Mission will cover 95 percent of the ice-free seas every 10 days. Average sea levels have risen about six inches over the last century as global warming melts glaciers and heats ocean waters.
Then on Aug. 7, if all goes well, the space shuttle Atlantis will boost a crew of seven to the 18-year-old Hubble space telescope, which badly needs repairs to extend its life another five years. In five spacewalks, the astronauts will fix two broken scientific instruments and install three new ones, giving Hubble far greater capabilities to explore the nature and origin of the universe.
``Hubble is a national treasure, and all of NASA is looking forward to seeing it receive this tune-up and upgrade,'' Stern told the American Astronomical Society in January.
Later in August or September, a satellite called IBEX, for Interstellar Boundary Explorer, will be launched to explore the outer border of the solar system. This is the region where the solar wind — a blast of particles streaming a million miles an hour from the sun — slows down and stops when it hits contrary winds coming from the stars.
Two 1970s-era spacecraft have already crossed that frontier — Voyager I in 2004 and Voyager II last August. The Voyagers revealed what was happening at only two specific points in the boundary region.
In contrast, IBEX will be ``making all-sky observations of the sun's interstellar interaction,'' said David McComas, the mission's chief scientist at the Southwest Research Institute in San Antonio, Texas. IBEX may confirm a suspected ``hydrogen wall'' built of hydrogen atoms guarding the border of our sun's realm.
December will be a busy month, with three missions planned for launch.
The biggest is the Lunar Reconnaissance Orbiter (LRO), the first step in President Bush's plan to return humans to the moon. The orbiter will scout potential sites for robots and humans to land — robots starting in 2013 and humans in 2020.
Piggy-backing on the LRO will be the Lunar Crater Observation Sensing Satellite, which will send a rocket crashing into a huge crater at the moon's south pole. The impact will kick up material that may contain water useful for future human colonists.
Also coming in December is an Orbiting Carbon Observatory, which will provide precise measurements of carbon dioxide in the atmosphere. The rise in CO2, a major greenhouse gas, is believed responsible for much of the global warming that is changing Earth's climate.
The third December mission is a Solar Dynamics Observatory, which will study the varying activity of the sun. Of special interest is the sun's role in ``space weather'' — the winds, magnetic fields and radiation that affect life on Earth and in space.
Next February will bring a launch of intense interest to astronomers_ the Kepler mission. This is an orbiting telescope that'll try to detect Earth-sized planets in regions around other stars where liquid water exists and life might be possible. Kepler will measure the brightness of 100,000 stars every 30 minutes, watching for a tiny dip in the starlight, which indicates that a planet is passing in front of it.
NASA will round out the year next March when it launches the Glory satellite to measure changes in soot and dust-like particles in the atmosphere. These particles dim the sun's light, reducing the amount of solar energy — the prime regulator of our planet's temperature — that reaches the Earth's surface. Glory's data could help determine how much climate change is a byproduct of natural events or of manmade sources.
MISSIONS AT A GLANCE
Here's the lineup of coming astronomy missions:
(Dates are approximate or subject to change)
_ May 25: Phoenix lands near Mars' north pole
_ Early June: Launch GLAST high-energy gamma ray telescope
_ June 15: Begin OSTM mission to measure ocean surface
_ Aug. 7: Hubble Space Telescope servicing mission begins
_ August-September: Launch IBEX mission to determine edge of solar system
_ December: Lunar Reconnaissance Orbiter heads to the moon.
_ December: Launch Orbiting Carbon Observatory to count carbon in atmosphere
_ December: Solar Dynamics Observatory launched to observe space weather
_ February: Kepler Mission begins hunt for Earth-like planets
_ March: Launch Glory satellite to measure sun-dimming aerosols in atmosphere