The Advent of Genesis
NASA Gives Green Light to Sock a Comet
Artificial Intelligence to Command Mission
Apollo Vestiges Spotted on the Moon
Deep Space Network Upgraded for Crunch Time
Postcards from the
Pioneer 10 Keeps Going and Going . . .
The Advent of Genesis
The advent of NASAs next Discovery-class mission, Genesis, at the Kennedy Space Center has set the stage for the spacecrafts launch aboard a Boeing Delta II vehicle on 30 July. The genesis of the Genesis mission was a desire by researchers to capture a piece of the Sun ions and elements in the solar wind and bring samples back to Earth to study the exact composition of our star and probe the solar systems origin. If all goes as planned, Genesis will journey to the L-1 Libration point where the gravitational and centrifugal pull of the Sun and Earth are balanced and collect samples of charged solar particles. This will be the first mission since the days of Apollo to return extraterrestrial material for study, said Roger Wiens, a Genesis scientist from Los Alamos National Laboratory.
According to Genesis Principal Investigator, Donald Burnett, the sample of solar system matter will allow scientists to address fundamental questions about the solar and nebular compositions, and test theories about the origin of the Sun and the planets at the beginning of the solar system. Once Genesis enters its halo-like orbit, 1.5 million kilometers from Earth, the spacecraft will extend special Collector Arrays to trap isotopic samples of oxygen, nitrogen, the noble gases, and other elements, while an electrostatic mirror concentrates the solar wind particles. The $216 million probe also features ion and electron monitors to determine the ambient solar wind conditions. The concentrator addresses the missions primary scientific objectives [and] the monitors will be used to guide the missions operations, explained Dave McComas, a Genesis co-investigator from Los Alamos.
Exposed to the solar windstorm, the Collector Arrays will capture a few millionths of a gram of ions and particles, which will be carefully stowed in a contamination-proof canister within a sample, return capsule. The solar samples will return to Earth in a spectacular airborne capture over Utahs Air Force Testing and Training Range. The samples will then be analyzed to provide a solar matter Rosetta Stone, for comparing the solar nebulas composition to those of the planets and other solar system bodies.
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NASA Gives Green
Light to Sock a Comet
Taking a page from a science fiction movie script, the U.S. space agency has OKd a mission to KO a comet in an attempt to peer beneath its icy surface. The mission, appropriately dubbed Deep Impact, will intercept a comet in deep space and use a 350-kilogram copper cannonball, equipped with a camera, to blow a hole in the celestial body, some seven stories deep and about the size of a football field. Scheduled for launch in January 2004, the sharp-shooting spacecraft will take aim at its intended victim Comet Tempel 1 in July 2005.
The broadside loosed by Deep Impact as it flies by Comet Tempel 1 will slam into the cosmic snowball at 35,700 kilometers per hour and blast icy material into space with the force of its impact. With the comet still in its the crosshairs, a camera and infrared spectrometer onboard the flyby spacecraft, along with ground-based observatories, will study the icy debris and pristine interior material exposed by the spacecrafts salvo. Researchers hope the impact will allow them to measure freshly exposed material and study samples hidden deep below the surface of the comet, which could help determine whether comets exhaust their supply of gas and ice to space or seal it into their interiors.
Comet Tempel 1, discovered in 1867, makes an ideal target for Deep Impact since it orbits the sun every five and a half years, and frequently passes through the inner solar system, which causes evolutionary change in the mantle and upper crust. The $279 million mission to hit this cometary bulls eye is the latest lower-cost, highly focused Discovery mission to be approved by NASA. Three Discovery missions have completed their flight, one is operational Stardust and two others, in addition to Deep Impact, are under development, including the Genesis mission and The Comet Nucleus Tour (CONTOUR) mission.
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to Command Mission
New HAL-like software that thinks for itself and makes decisions without help from ground controllers will provide the brainpower for a constellation of NASA satellites in 2002. The so-called Continuous Activity Scheduling, Planning Execution and Replanning software shortened to the acronym CASPER will guide three identical miniature satellites, each weighing less than 15 kilograms, as part of the Three Corner Sat mission, which aims to demonstrate formation flying, and innovative operations and commanding. The new-fangled software and clever computers build on previous efforts to use artificial intelligence to control a spacecraft such as Deep Space 1 but this new software takes advantage of more advanced technology to continuously command a mission for about three months and respond quickly to events.
The onboard software performs the decision-making function for the spacecraft. Like a brain that uses inputs from the eyes and ears to make decisions, this software uses data from spacecraft sensors, such as cameras, to make decisions on how to carry out the mission, said Steve Chien, principal scientist and lead researcher in automated planning and scheduling technologies at NASAs Jet Propulsion Laboratory (JPL).
The specter of CASPER software controlling spacecraft for months at a time represents a dramatic shift in the way mission operations are conducted. Typically, all science data, good or bad, is sent back to Earth. The CASPER software will have the ability to make real-time decisions based on the images it acquires and send back only those that it deems important. Consequently, less time will be needed to transmit data, freeing up power and allowing the spacecraft to concentrate on other important tasks.
This capability represents a significant advance from traditional ground-based operations and [promises]...to dramatically increase mission science for this and future missions, said Colette Wilklow, Three Corner Sat mission operations team member. If smart software like CASPER proves successful, similar decision-making capabilities could be incorporated into a wide range of NASA applications including automated ground communications stations, autonomous planetary rovers and autonomous robot aircraft.
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Apollo Vestiges Spotted on the Moon
Evidence that long ago humans actually traveled to other worlds has been spotted on the lunar surface by researchers pouring over photos taken by Clementine, the former lunar-orbiting Defense Department probe. Misha Kreslavsky, a space scientist in the department of geological sciences at Brown University, found anomalies in the lunar surface in the vicinity of the Apollo 15 landing site near the Moons Apennine Mountains. It was in the shadow of those mountains that Moonwalkers David Scott and James Irwin scuffed up the lunar surface and left 25 kilometers of tire tracks from an electric-powered car during their three-day lunar stay in 1971.
Pouring over images from Clementine to locate fresh impacts or recent seismic activity on the Moon, Kreslavsky spotted smudges on the lunar surface precisely where the all-Air Force crew had landed in their lunar module Falcon. This is a result of my processing 52 images taken by the Clementine spacecraft through a red filter, Kreslavsky explained. Several anomalies can be seen on the processed images, including a diffuse dark spot at the landing site. All of them but one are related to small fresh impact craters. The only one not related to any crater, exactly coincides with the landing site, Kreslavsky added. The disruption in the lunar regolith, which measures a 50 to 150-meter radius around the landing site, was probably created by the lunar modules engine during touchdown. Unfortunately, the Clementine data do not allow similar studies for any other landing sites, Kreslavsky said.
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Deep Space Network
Upgraded for Crunch Time
Anticipating a population boom in interplanetary spacecraft, NASA is taking steps to prepare its globe-girdling net of giant radio ears the Deep Space Network (DSN) for an expected earful from the heavens. The network, which can communicate with spacecraft as far away as Pluto and beyond, uses clusters of antennas at three sites equally spaced round the Earth to cover spacecraft in any direction. Each station has one 70-meter diameter antenna, plus several smaller ones.
We are getting ready for a crunch period beginning in November 2003, said Rich Miller, head of DSN planning and commitments for JPL. In late 2003 and early 2004, the United States, Europe and Japan will each have missions arriving at Mars, two other spacecraft will be encountering comets, and a third comet mission will launch. Several other missions will also have continuing communication needs. [The new] missions all happen to lie in the same part of the sky, said Joseph Statman, Manager of the Deep Space Mission System Engineering Office at JPL, who described the area where the spacecraft will cluster as a slice of the sky with Mars in the middle. We need to track them but we dont have enough antennas.
Projections for demands on the network from November 2003 to February 2004 indicate the greatest need for increased communications capacity will be at the station located in Madrid, Spain. To prepare for the rain of radio signals on the plain in Spain, NASA will build a 34-meter wide advanced dish antenna to add about 70 hours of spacecraft-tracking time per week when Mars is in view. The new antenna should be completed at the Madrid complex by November 2003, and will accompany other improvements in the capabilities of existing antennas at all three of the networks tracking complexes. As part of the upgrade, older hardware and software systems will be phased out and replaced with ones that are more reliable and, in some cases, automated. Also, the DSN complexes in Spain and Australia will receive processing equipment that will allow operators to combine signals from multiple on-site antennas, increasing their sensitivity to distant transmissions.
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Pioneer 10 Keeps Going and Going . . .
All but given up for lost, the famed Pioneer 10 spacecraft answered a call from Earth, ending speculation that the plucky probe launched 29 years ago had finally fallen silent. In a test of communication technologies for future interstellar missions, scientists operating a radio telescope antenna established contact with the small spacecraft in April, the first time the spacecraft had been heard from since August of 2000. Pioneer 10 lives on, declared Pioneer 10 Project Manager Larry Lasher of NASA Ames Research Center. The fact that we can still stay connected with the spacecraft is fantastic. We are overjoyed, Lasher added.
Now orbiting more than 11 billion kilometers from Earth, well beyond the orbit of Pluto and approaching the vasty deep of interstellar space, signals from Pioneer 10 take almost 22 hours to make the round trip between Earth. Although Pioneer 10s feeble signal had been tracked by the Deep Space Network as it headed toward the constellation Taurus, the dogged spacecraft stopped broadcasting last summer. We [had] been listening for the Pioneer 10 signal in a one-way downlink non-coherent transmission mode since last summer with no success, Lasher said. We therefore concluded that in order for Pioneer 10 to talk to us, we need[ed] to talk to it. A signal was sent to the spacecraft, which locked onto it and finally radioed a faint reply
Launched on 2 March 1972, Pioneer 10 was the first spacecraft to pass through the asteroid belt and the first to obtain close-up images of Jupiter. Following its encounter with the Jovian giant, Pioneer 10 explored the outer regions of the solar system, studying energetic particles from the sun, and cosmic rays entering our portion of the Milky Way. In 1983, it became the first man-made object to leave the solar system when it passed the orbit of distant Pluto. The spacecraft continued to make valuable scientific investigations in the outer regions of our solar system until its mission officially ended in March 1997. In addition to these feats, Pioneer 10 carries the now-famous gold-anodized greeting card from Earth complete with an image of a man and woman au naturel.
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7 March Russian space officials set 19 March as the date for dumping the Mir space station. They want to wait until the craft drifts closer to Earth before giving it the final shove toward a fiery plunge into the Pacific Ocean.
8 March The Space Shuttle Discovery launched from the Kennedy Space Center towards the International Space Station (ISS), hauling a new resident crew into orbit along with fresh supplies, critical construction equipment and the outposts first science research rack.
EUROBIRD and BSAT-2A successfully launched into orbit atop an Ariane 5 rocket from Kourou, French Guiana. The two new communications satellites will serve customers on the islands of Great Britain and Japan.
11 March A giant research balloon intended to circle the globe at the edge of space was forced down by shifting high-altitude winds less than 24 hours after its launch. NASA hoped the Ultra Long Duration Balloon would circumnavigate the Earth at a height of 20 miles, scraping along the edge of the atmosphere to study outer space.
18 March The XM-2 Rock satellite aboard a Boeing Sea Launch Zenit-3SL launched from the Odyssey floating launch platform in the Pacific. The XM Radio satellite will provide digital radio entertainment broadcasting to the U.S.
19 March The Russian Space Station Mir was sent into a gradual deorbit. Launched in Feb 1986, Mir was visited by 111 spacecraft. Astronauts occupied it for 4591 days and performed 79 space walks.
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7 April The improved 3-stage Proton launch vehicle, with a new digital flight control system and enhanced first stage engines launched the Ekran-M No. 18, a UHF television broadcasting satellite, from the Baikonur Cosmodrome.
The 2001 Mars Odyssey launched from Cape Canaveral by a Boeing Delta 7925. The first spacecraft in the revamped NASA Mars Exploration Program, Mars Odyssey carries a 6-meter boom with a gamma ray spectrometer for remote sensing of Martian surface mineralogy, as well as an infrared imager and a radiation environment monitor. Mars Odyssey will reach Mars orbit in October.
11 April Russian officials gave the green light to California millionaire Dennis Tito to become the first tourist in space despite reservations from NASA. Tito took his final exam by practicing maneuvers in a Russian Soyuz capsule simulator outside Moscow. Launch is set for 28 April on a mission to the International Space Station. Tito will reportedly pay $20 million for the flight and will spend about a week on the station. Tito will be accompanied into orbit by Soyuz commander Talgat Musabayev and flight engineer Yuri Baturin. Their mission is to dock their fresh Soyuz vehicle to the station and then fly a used one back to Earth.
18 April India successfully fired its biggest satellite rocket, the Geo-synchronous Satellite Launch Vehicle (GSLV-D1), into orbit after the maiden test launch was aborted last month due to technical trouble. The rocket blasted off from the spaceport in Sriharikota on Indias southeastern coast near the Bay of Bengal. Taking 10 years to build, the launch propelled India into the ranks of a select club of countries able to fire big satellites deep into space and could also give the nuclear-capable nation the ability to test a range of military technologies.
19 April The Space Shuttle Endeavour launched from the Kennedy Space Center for the ISS, sending up the SSRMS robot arm, also called Canadarm-2, used on the Orbiter itself. Despite the need to replace a bad electronics box in the cockpit, NASA remained on track for launch.
28 April A Soyuz rocket carrying two Russian astronauts and the first space tourist, Dennis Tito, blasted off from Baikonur for the ISS. The rocket delivered supplies and a new Soyuz lifeboat to be used as an escape pod for the stations crew. Because the rocket propellant stored inside the lifeboat degrades over time, Russian flight rules call for Soyuz lifeboats to be replaced every six months.
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Basics of Space Medicine & Physiology: Space Motion Sickness
By Eleanor A. ORangers, Pharm.D.
Space motion sickness (SMS) is one of the most common medical complaints occurring during spaceflight. The first case of SMS was reported by Soviet cosmonaut Gherman Titov, who reported feeling as if he were flying upside-down shortly after entering earth orbit on Vostok II. Thereafter, he described dizziness exacerbated by head movement, and later, he became motion sick. In the U.S., SMS was not observed until the Apollo program, presumably because astronauts were restrained in their flight couches, had limited head mobility with in-flight helmet use, and limited cabin space for free-floating activity.
The incidence of SMS, based upon data from the Apollo, Skylab and Space Shuttle programs, approaches 70% (this incidence is similar to the Russian cosmonaut experience). Repeat spaceflight does not appear to reduce susceptibility to SMS. Symptoms are usually experienced within one hour of entering weightlessness, and generally resolve within 3 to 4 days. Symptoms include flushing, malaise, loss of appetite, nausea, vomiting, headache, impaired concentration, lack of initiative and irritability. Because SMS is so common, Space Shuttle crew workload is typically light during the first 24 hours of a flight, and EVAs are restricted. It is also noteworthy that SMS can occur with transition from different gravity environments. Approximately 90% of cosmonauts returning from missions lasting several months have reported SMS upon return to earth. SMS is a serious operational issue that could impact mission success. Emergency egress could be difficult for those with SMS (vomiting in an EVA suit could suffocate an astronaut). Moreover, with the potential for SMS recurrence when transitioning into another gravitational environment (not to mention balance problems!), imagine how this could impact a landing on Mars (a transition from 0-G to 0.38-G?) Protracted SMS on the Martian surface could also exacerbate interpersonal conflict, and may affect nutritional status of an astronaut as well.
As with Titov, head movements appear to provoke and/or exacerbate SMS. Astronauts and cosmonauts have also reported that changes in their perception of body orientation can also elicit SMS (e.g. Titovs report of flying upside-down). The most widely accepted explanation for SMS is the sensory-conflict theory. The middle ear, which assists in balance, body orientation and the perception of movement, senses that down is the pull of gravity towards the ground. The eyes provide visual cues that the brain interprets as normal on earth: the ceiling is up; the ground is down. Moreover, the sense of touch also contributes to the perception of up and down: the ground is felt beneath the feet. During spaceflight, however, the body is freed from the 1-G orientation of earth. The senses must adapt to a new, weightless environment. The middle ear no longer senses down and perception of motion may be disrupted. The eyes, on the other hand, still recognize up as the ceiling and down as the floor of the spacecraft cabin . . . but the feet no longer feel the floor. Other crew members floating upside-down relative to the cabin ceiling and floor are also initially disconcerting. The brain is believed to be temporarily confused with the conflicting sensory information it is receiving (relative to the normal earth environment) and responds by triggering SMS. It is believed that the brain and sensory adaptation to weightlessness occurs rapidly, which may be correlated with the subsequent improvement in SMS over the first few days of spaceflight. The actual physiology of these adaptive changes is being actively investigated but as yet is incompletely understood. The headward redistribution of body fluids in weightlessness may also play a role in eliciting SMS.
SMS is treated with medications once it occurs. Unfortunately, the identification of those prone to SMS has been mostly unsuccessful, so prophylaxis is not encouraged. It appears that medications used on earth to treat motion sickness have had success in treating SMS. In the past, scopolamine, with or without dextroamphetamine (scope-dex), was the treatment-of-choice for SMS in the U.S. manned spaceflight program. However, these medications are not without problems. Scopolamine is associated with side effects such as dry mouth, blurry vision, dizziness and sedation, which could impact crew performance. Moreover, there is some evidence that scopolamine may delay brain and sensory adaptation to weightlessness; some astronauts discontinuing scopolamine during spaceflight had SMS recur despite being several days into a mission. Dextroamphetamine, on the other hand, is only available as a tablet (which may be a problem to administer if an astronaut is vomiting) and has the potential for abuse. Therefore, the identification of alternate treatments including non-oral routes of administration for SMS was desirable. Beginning on STS-26, intramuscular injections of promethazine (Phenergan®) were administered to counteract SMS, with apparent success in many astronauts. Intramuscular injections and/or suppositories of promethazine are now the treatment-of-choice for SMS in the U.S. manned spaceflight program. Nevertheless, promethazine does not alleviate SMS in all astronauts, and identification of additional medications may be advisable. With regards to non-medication treatments, biofeedback control has been examined as a means of preventing and controlling SMS, but has been unsuccessful. Preflight adaptation training devices, which are intended to acclimate astronauts to the weightless environment, may offer promise in enhancing treatment of SMS. Nevertheless, additional research on understanding the physiology of SMS and brain and sensory adaptation to weightlessness and transition from differing gravitational environments must be accomplished before complete prevention of SMS can be realized.
1. Graybiel A, Miller EF, Homick JL. Experiment M131. Human Vestibular Function in Biomedical results of Skylab (http://lsda.jsc.nasa.gov/books/skylab/Ch11.htm.)
2. Sensorimotor Integration in A Strategy for Research In Space Biology and Medicine In the New Century, Space Studies Board, National Research Council, Washington, D.C.: National Academy Press, 1998, pp. 63-79.
3. Lathan CE, Clement G. Response of the neurovestibular system to spaceflight in Churchill SE (ed.) Fundamentals of Space Life Sciences Malabar, FL: Kreiger Publishing Co., 1997, pp. 65-82.
4. Reschke MF, Harm D, Parker DE et al. Neurophysiologic Aspects: Space Motion Sickness in Nicogossian A, Huntoon C, Pool S (eds.) Space Physiology and Medicine, 3rd edition Philadelphia: Lea & Febiger, 1994, pp.228-260.
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