1. We were able to walk, but were a bit unsteady at first. I involuntarily turned to the right, even though I was looking straight ahead and trying to walk straight. I also drove off the right shoulder of the road twice during my first week back. It was as if I were watching someone else drive—a weird and confusing sensation. One passenger suggested that NASA was putting something in our Tang. Another remarked that this wasn’t at all abnormal for a Goldwater man. I was a bit upset because I didn’t understand what was happening, and after I drove off the road the second time, I was very careful. This “right turn” tendency went away after the first week. I didn’t tell the doctors for fear that they might ground me or use me as a guinea pig for more medical tests. I haven’t had any further problems with this since the first week following the flight.
2. Almost all of the astronauts have dropped things during the first few days after return. In weightlessness, they had become used to releasing objects and having them float nearby until needed again. This was a great convenience in performing even simple tasks. I dropped the toothpaste tube and I almost dropped a glass of water on the bathroom floor the first morning after return. I felt it slipping in my fingers and gripped it again just in time. This tendency also goes away in a few days.
3. Another problem I noticed was a tendency to fall or roll out of bed. The NASA doctors got smart fast on this one. The beds we used on the aircraft carrier that picked us up were fitted with side rails. I thought this was ridiculous when I saw it. I was wrong. I tried to “float” out of bed that night, and the rail saved me from a fall.
4. Heaviness in bed was another post-mission sensation. It felt like I was collapsing the bed when I lay down—as if I weighed several hundred pounds. The pressure distributed on my body from my weight seemed excessive for about four or five nights.
5. On the third night after my return, I struggled out of bed to go to the bathroom and I got lost in the dark. I was turning to the right again.
161. How long does it take to get back to normal?
After our eighty-four day flight, it took about five weeks for our bodies to return to our normal pre-mission physical condition. The Russians have said it takes a cosmonaut about seven weeks to recover fully from a six-month flight.
162. How many engines are on the Shuttle?
Fifty-one engines are used by the Space Shuttle vehicle:
1. Two solid rocket booster (SRB) engines, with 2,600,000 pounds thrust each, used during the first two minutes of launch;
2. Three Orbiter main engines, with 470,000 pounds thrust each (vacuum), for launch only;
3. Two orbital maneuvering system (OMS) engines, with 6,000 pounds thrust each, for orbit insertion, orbital maneuvers, and deorbit;
4. Thirty-eight primary reaction control system (RCS) engines, with 900 pounds thrust each, to control the Shuttle attitude in orbit and make small translations;
5. Six vernier (fine control) RCS engines, with 25 pounds thrust each, to make small adjustments in attitude.
163. What is the most people the Shuttle can carry?
It can carry a maximum of ten for rescue missions. Seating can be provided for a crew of three (rescue crew) and seven passengers (the crew being rescued).
164. How much does the Shuttle weigh at liftoff?
The Space Shuttle vehicle weighs approximately 4,400,000 pounds at liftoff. The Space Shuttle Orbiter, the reusable spacecraft, weighs from 200,000 to 250,000 pounds, depending on payload carried.
165. How much can the Shuttle carry into space?
The Shuttle can carry as much as 65,000 pounds to equatorial circular orbits up to 230 miles. Smaller payloads can be delivered to circular orbits up to 690 miles. The higher the orbit, the less payload that can be carried—because the extra weight of fuel (propellant) needed to go higher must be subtracted from the payload weight. Also, if the launch is aimed to carry the Shuttle over or near the Earth’s polar regions, the payload capability will be reduced because the Earth’s rotation doesn’t contribute to the launch. (See Question 185.)
166. Why doesn’t the Shuttle use a heat shield like the older spacecraft?
The old heat shields actually burned away during reentry; thus, they could only be used once. Because the Shuttle is designed to make many flights into space and back again to Earth, it would be very expensive to put on a new shield for each flight; so they designed a new surface made up of tiles called the Thermal Protection System (TPS) or Reusable Surface Insulation (RSI). On a few of the early Shuttle flights some of the tiles were shaken loose from the upper surface during the launch and boost phase. In these problem areas the tiles have been replaced by Advanced Flexible Reusable Surface Insulation (AFRSI), a heat-resistant fabric.
167. What are the tiles made of?
They’re made of a silicon compound coated with a ceramic material that protects the tiles so they aren’t damaged by reentry heating. They are designed to last the life of the Shuttle spacecraft or for one hundred reentries through the Earth’s atmosphere. The AFRSI fabric is a quilted blanket of Nomex felt coated with a white silicon material.
168. How do the tiles work to dissipate or reject heat?
The tiles get rid of 95% of the reentry heat by radiation (rapidly emitting the heat generated by air friction). The remainder of the heat is slowly conducted into the tile, and some of this heat diffuses out to be re-radiated after landing. A very small amount, about one percent, actually reaches the metal skin of the Orbiter vehicle.
169. What would happen if a lot of them came off?
It could cause the loss of the Shuttle during reentry. As noted in Question 166, above, on several of the early Shuttle flights some tiles were lost on the upper surface near the tail. These were not in a critical area and the missing tiles caused no serious problems during reentry.
170. How hot do the tiles get during reentry?
Although designed to tolerate a peak temperature of 2800°F, the highest temperature thus far experienced has been 2280°F.
171. How long a runway does the Shuttle need?
The Shuttle can land on a 10,000 foot runway, but it is better if the runway is 15,000 feet long. Many large civilian and military airfields have 10,000 foot runways. Because the Shuttle does not have engines it can use during landing, the longer runway makes it easier for the pilot to plan his landing.
172. Can it land on any airfield the right size?
Yes, but only a few airfields have all the special radio equipment to help guide the Shuttle toward the airfield. As the Shuttle pilots get more experience, they will probably become skilled enough to land on airfields without this special radio equipment. However, this would probably not be done except in an emergency.
173. On the Shuttle, how high up can they still eject?
Up to 100,000 feet.
NOTE: Ejection seats were active (capable of being used) on the two-man test flights of the Space Shuttle Columbia—the first four Shuttle flights. The Orbiters Challenger, Discovery and Atlantis are not designed to have ejection seats. The ejection seats in the Columbia were removed during retrofit (overhaul) in 1984.
174. Will it be possible to rescue Shuttle astronauts if they can’t get back from space? If there were an emergency, how soon could you send help?
At the present time (1985), rescue might be possible if circumstances were just right, i.e. if a Shuttle were in the late stages of preparation for launch when another Shuttle became stranded in space. Even then a rescue launch might take as long as a week. The crew in space can extend survival time while awaiting rescue by conserving oxygen and other consumables. Present estimates by NASA technicians are that the stranded crew can survive a week for each day’s worth of oxygen budgeted for average flight activity. Oxygen is used to generate electricity in the fuel cells in addition to replenishing the living compartment atmosphere.
175. How fast is the Shuttle going when it lands?
About 220 miles per hour.
176. How far does it roll after landing?
It depends on the speed at touchdown and the amount of braking used. Using maximum braking, the Shuttle can stop in about one mile. However, the tires and brakes would have to be replaced after a maximum braking roll-out.
177. How long does it take for the wheels to come down when the Shuttle is landing?
About six to eight seconds. The landing gear is lowered just before touchdown.
178. How long do the tires last?
They are designed for five normal landings.
179. When the Shuttle is reentering, when does it start to fly like an airplane again?
The aerodynamic control surfaces on the wings begin to be effective at about 250,000 feet altitude and a speed of 26,000 feet per second.
NOTE: The rudder does not become fully effective until the spacecraft has descended to 80,000 feet altitude. From 80,000 feet down to landing the Shuttle is controlled entirely by the control surfaces.
180. Why do the Shuttle astronauts have to wait so long to get out after landing?
They have to turn off all of the systems of the Shuttle, and they must wait for ground crews to make sure no harmful or toxic gases or fumes are still present in the air around the Shuttle. This takes about thirty minutes to one hour.
181. What causes the toxic gases? Where do the fumes come from?
The toxic gases or fumes are produced in two devices: (1) a gas turbine used to run hydraulic pumps for powering engine gimbals (steering controls), flight controls, and wheel brakes; and (2) an evaporator device used to cool equipment as the Shuttle descends below 80,000 feet.
The gas turbine is powered by gas pressure created by decomposing hydrazine, a caustic chemical. The evaporator–cooler uses a mixture of ammonia and water, because the ammonia evaporates more readily. An invisible cloud of these gases surrounds the Space Shuttle after landing and must be blown away by special fans used by the ground crews.
182. What kind of things would we want to build in space?
In addition to a multipurpose space station planned for the 1990s, some of the structures being considered are:
1. Large communication antennas: eventually most phone and television links will be through space relay units.
2. Solar power stations: solar energy collectors and transmitters.
3. Manned laboratories.
4. Space processing factories.
5. Storage warehouses.
6. Large spacecraft assembly facilities—for future space missions to the moon or Mars, for example.
7. Refueling and repair depots.
8. Medical research facilities.
183. Why spend so much money on space exploration when we still have sickness and hunger on Earth?
Most of the untreated sickness and hunger arising from inadequate domestic production occurs in areas that have not developed broad-based science and technology capabilities. These areas, often called underdeveloped countries, depend on the nations with advanced capabilities to help them. If we arbitrarily abandon human inquiry or exploration in a given area (astronomy, mathematics, genetic studies, or space), we may, unwittingly, deprive ourselves of advancements that would contribute to the solution of parts of these problems such as food production and distribution or medical care and treatment. This doesn’t mean that space exploration is going to provide answers to solve hunger and health problems, although many space program developments have already helped in both areas. It is essential to realize that if we ignore or curtail participation in a frontier discipline or arena, it has a stifling effect on research and development in many other areas. Incidentally, the amount spent on space exploration is probably less than popularly believed. The entire NASA budget is about 1½% of the Federal Budget, or a penny of each tax dollar. This is still a lot of money, about $6 billion, but less than the amount Americans spend on toys each year. I feel that it is money well spent. (See Question 184.)
184. Are our current goals in space different from the Russians? Are we working on different things than they are?
Yes. The Russians appear to have as their major immediate goal the achievement of permanent manned presence in space, first in Earth orbit and later near the moon. Their space stations will become progressively larger, with the capability to accommodate larger crews and longer stays in space. They appear to be thinking of permanent stations on the moon, and some Russian spokesmen have predicted a Soviet mission to Mars before the end of this century. The Russians are now launching five satellites for each U.S. satellite and have resumed the lead in the manned exploration of space. Their goal is to achieve preeminence in space and, in the process, to demonstrate the superiority of their political system.
Official American goals are less ambitious and are becoming restricted to work in Earth orbit. We are primarily working on improving the quality of instruments used to observe the Earth and to decrease the cost of carrying equipment into space. Scientific satellite programs, planned to continue studies of the solar system, have been largely abandoned because money is not available. It is sad, but true, that political leadership in the U.S. has never grasped the philosophical and historical importance of space exploration. The Apollo lunar landing program clearly demonstrated American superiority in manned space exploration—this lead was surrendered to the Russians in the 1970s. The American lead in planetary exploration is about to suffer a similar fate. Throughout history, the most successful societies have explored new worlds and their progress has been stimulated by new discoveries. Space exploration will continue. If we in America don’t do it, then other nations will.
185. Why is the launch center located in Florida?
The Air Force selected Cape Canaveral for missile testing in the 1950s, and when NASA was formed in 1958, it relied on Air Force experience and facilities to assist in the launches of the early spacecraft. Mercury and Gemini orbital space missions were launched by Air Force boosters (rockets) originally designed for missiles. During the 1960s, NASA developed its own launch facilities on Cape Canaveral at the Kennedy Space Center. These facilities have evolved into a highly reliable launch base for manned and unmanned spacecraft.
The Air Force chose the Florida location because of several favorable features of the site:
1. The secluded location simplified security.
2. The site faced the Atlantic Ocean; rockets could be launched eastward over the ocean without risk to the general population.
3. Rail, highway, air, and water transportation were reasonably accessible.
4. The mild subtropical climate provided moderate weather for year-round operations.
5. A southerly location in the United States makes the best use of the “sling-shot” effect caused by the Earth’s rotation. The eastward motion of the Earth’s surface due to its rotation adds over 1,000 mph to the speed of a rocket launched in an easterly direction at the equator. This advantage decreases progressively as the launch site is moved north or south of the equator. Thus, a launch site in the southern part of the continental United States would be best. At Cape Canaveral, the eastward surface velocity is almost 900 mph, a distinct asset for orbital launches.
186. What are the medical spin-offs from the space program?
I don’t know all of them. One of NASA’s responsibilities is to see to it that discoveries made in space program research and operations are offered to others who might possibly have a need for it. For example, image processing techniques developed to clarify pictures of planets can also be used to improve the quality of X-ray photographs to make it easier for doctors to detect tiny hairline fractures that might have gone undetected before. A system used to heat the faceplate of helmets has also been used to keep burn victims warm, as they can’t tolerate blankets, and to provide uniform warmth for premature babies in incubators. It would probably take a good book to explain them all.
187. What benefits have we gotten from the space program?
That’s a bit like asking, “What benefits have we gotten from our schools, colleges, and universities?”
There have been many practical benefits from the space programs. Computer design, electronic miniaturization, medical equipment, management techniques, weather observation, and international communications have all benefited from developments made in space exploration. However, I believe the most important are the subtle and intangible benefits that have occurred within the minds and spirits of people. Among these benefits are aroused curiosity, the intellectual stimulation that attends exploration, an appreciation of the importance of goals, the virtue of dedication, the necessity of commitment, and belief in one’s ability to accomplish. The overall attitudes of people influence their aspirations and ability to attain. Awareness of the achievability of difficult goals has a strong influence on the objectives we set for ourselves. I believe the most beneficial legacy of the space program has been to elevate our expectation of ourselves.
APPENDIX A
SUMMARY OF PHYSIOLOGICAL EFFECTS
1. WEIGHTLESSNESS: FLUID SHIFT—An abnormally high volume of blood and tissue fluid tends to concentrate in the upper part of the body.
EFFECT OR SYMPTOM
1.1
Giddy, light-headed feeling
1.2
Bug-eyed sensation
1.3
“Flush” feeling in face
1.4
Awareness of neck pulse; throbbing in head
1.5
Distended veins in forehead and neck
1.6
Hypersensitivity to head movements; excessive or exaggerated sensation of rotation caused by head movements (Note 1)
1.7
Moderate to severe headache
1.8
How Do You Go to the Bathroom In Space? Page 7